A material handling apparatus for use in lifting and transporting relatively large items, particularly rolled hay bales, is provided. The apparatus includes a grapple-like lifting component having a frame, an upper fork set and a bottom fork set. Both sets of forks are movable relative to the frame and to each other, their movement actuated by a single, floating, double-acting hydraulic piston and cylinder arrangement. The lifting component is designed to be connected to a typical 3-point hitch of a farm machine (a tractor or the like) and includes another integral hitch structure attached to the frame for connecting a carriage component. The carriage component consists of a generally U-shaped bale receiving basket pivotally attached to a wheeled trailer-like frame. The basket is held in a bale receiving position by latches spaced along the length of the frame. When the latches are released, basket tips and the bales roll from the carriage.

A recent development in farming has been the increased use of relatively large rolled bales of forage crops such as hay. The bales are typically five to eight feet in diameter and weigh approximately 1,000 to 3,000 pounds.
Material handling fork lift vehicles are well known, and there are numerous patents disclosing devices designed for manipulating and transporting the large round bales of forage crops. For example, U.S. Pat. No. 3,934,726 (to Martin) discloses a bale carrier for connection to the three point hitch of a tractor. The Martin carrier includes a pair of concentric pipes, an inner second pipe rotatably mounted in an outer first pipe, and a support frame. A tine is secured to each end of the second pipe for piercing engagement with a hay bale. The frame extends upwardly from the first pipe and a hydraulic cylinder is mounted on the frame to operate a single hook arm for engaging the upper portion of a bale.
Unlike the present invention, the hydraulic cylinder associated with the Martin carrier operates only the single, short upper arm; the lower tines must be moved into their bale-piercing position by hand. Additionally, the Martin carrier requires a bale to be pierced by the tines and, thus, there is no way simply to dump a bale into a carriage or transport vehicle. Rather, the Martin device requires that the bottom of a bale be brought into contact with a trailer surface or the ground to create enough friction to slide it off the tines. This piercing and removal process is hard on all the equipment involved.
Another bale retrieving and transporting apparatus is disclosed in U.S. Pat. No. 3,985,246 (Seymour). The Seymour retrieving and transporting apparatus includes a lower supporting structure consisting of tines adapted to be inserted under bale, a rear supporting structure, basically a frame, and a bale discharging means comprising a hydraulically operated arm for pushing a bale from the tines. The tines are fixedly mounted on the frame, and the Seymour apparatus does not include any means for contacting the upper portion of a bale to securely hold it while it is being transported.
Other rolled bale transportion devices are disclosed in U.S. Pat. Nos. 3,974,926 (Kopaska) and 4,459,075 (Eichenberger). The transporter disclosed by Kopaska, like that disclosed by Martin, relies upon frictional contact with the ground to remove a bale. The Eichenberger loading device is a trailer to which is attached a long, articulated, hydraulically operated pivoting arm for gripping and lifting the bales onto the trailer.
U.S. Pat. Nos. 4,092,050 (Sobeck), 4,580,843 (Lund) and 5,123,800 (Druse, Sr.) disclose bale carriers or rack assemblies, basically modified trailers, for transporting rolled bales. None of the latter three patents discloses means for picking up bales and loading them onto the carriers, nor is there any suggestion that such carriers or rack assemblies can be connected directly to bale lifters.
Despite the advancements and improvements in the art concerning the lifting and moving of relatively large rolled bales of material or other items, there still are some significant problems. For example, solid items can not be pierced, and if a bale is pierced as suggested in the Martin patent, there is no way simply to dump the bale from the lifter. Another problem is that the bales or material to be lifted may vary in size and, even in those patented devices with an arm or clamp for contacting the upper portion of a bale, e.g., the Martin or Kopaska devices, respectively, the arm or clamp is very short and has only a limited range of motion.
While the patent to Martin suggests that lower tines may be foldable to a storage position, the tines must be moved by hand. The Martin patent suggests that the Martin carrier does not interfere with the normal towing use of the tractor when the lower tines and the upper arm are positioned in nonworking positions, but there is no suggestion about how to couple a carriage of the general type disclosed in the Sobeck, Lund or Druse, Sr. patents to a bale manipulator so that two devices can be used in combination conveniently and safely.


Apparatus for franking mail items is disclosed. The apparatus includes a display constructed for co-operation with a photocopier in which the display is controlled to display a franking pattern to be printed, the display being located as an original image in the photocopier, and the photocopier is operated to copy the displayed pattern and to print the pattern as a franking impression on a mail item. A sensor detects scanning of the display by the photocopier and the output of the sensor is utilised to control the display to ensure that only a number of mails items are franked with postage which has been accounted for.

This invention to relates to franking of mail items with postage charge.
Known postage meters for franking mail items include accounting means to carry out accounting functions in respect of postage charges dispensed by the meter and a printer to print a franking impression on the each mail item to indicate that a postage charge has been applied to the mail item and has been levied against the user of the postage meter. Earlier postage meters incorporated a drum printer to print the franking impression. The drum printer comprises a rotatable print drum carrying a fixed printing die to print invariable parts of the impression and sets of print wheels which are set to print a required value of postage charge and the date on which the printing is effected. In more recent developments of postage meters the rotatable print drum has been replaced by electronic digital printing devices. These digital printing devices comprise means to print dots selectively in a plurality of positions in a column and the franking impression is printed in a succession of print cycles in each of which cycles the printing device prints dots in positions such as to build up the impression in a column-by-column manner. Digital printing devices proposed for this purpose include thermal printers and ink jet.


A single cell for a solid oxide fuel cell and a solid oxide fuel cell using the same practicable and excellent in generation performance and durability, wherein a fuel electrode including a cermet of a catalyst and a second solid electrolyte with oxide ion conductivity at 1000° C. of 0.20 S/cm or more is bonded to one side of a solid electrolyte plate with the conductivity of 0.07 S/cm or more and bending strength of 700 MPa or more, and an air electrode including a compound of perovskite type transition metal oxide with a third solid electrolyte is bonded to the other side. A surface of the fuel electrode is coated with a layer, and an air electrode surface is coated with a layer, and an aqueous solution where a noble metal compound is dissolved in water is impregnated into the air electrode.

1. Field of the Invention
The present invention relates to a single cell for a solid oxide fuel cell and a solid oxide fuel cell using the same, more particularly to a single cell for a solid oxide fuel cell and a solid oxide fuel cell using the same which are preferably used for a distributed power source, a cogeneration system or the like in urban areas.
2. Description of Related Art
A solid oxide fuel cell (hereinafter referred to as an "SOFC") is a fuel cell in which a solid electrolyte showing oxide ion conductivity is used as an electrolyte. In the SOFC, since the electrolyte is solid, there is no problem of dissipation of the electrolyte, and long life can be expected. Further, as an operating temperature is as high as about 1000° C., the utility value of waste heat is also high. Furthermore, as an output power density is high, the SOFC can be expected to be compact and of high efficiency.
In general, cell structures of the SOFC are broadly divided into those of planar type, tubular type and integral type. Among them, the planar type SOFC has advantages of high power density as internal resistance is comparatively low, and of high output power density per unit area because thin cells are laminated.
The planar type SOFC is further broadly divided into those of a self-supporting electrolyte film type and of a supported electrolyte film type. The former one has a structure in which a plurality of single cells are laminated via a separator, wherein both sides of a plate solid electrolyte are bonded to a fuel electrode brought into contact with a fuel gas such as hydrogen and city gas, and to an air electrode brought into contact with an oxidant gas such as air and oxygen.
On the other hand, the latter one has a structure in which a plurality of single cells are laminated via a separator, wherein a very thin solid electrolyte film is supported by a thick fuel electrode, and a thin air electrode is bonded to the other side of the thin solid electrolyte film.
In the SOFC with such a constitution, if the fuel electrode and the air electrode are provided with the fuel gas and the oxidant gas, respectively, since there exists a difference between oxygen partial pressure on the air electrode side and that on the fuel electrode side, the oxygen ionizes at the air electrode and is carried through the solid electrolyte to the fuel electrode, then the oxide ion at the fuel electrode reacts with the fuel gas to emit an electron. Therefore, if a load is connected to the fuel and air electrodes, it becomes possible to directly take out free energy change of the cell reaction as electrical energy for power generation.
Incidentally, for the solid electrolyte used in the above-mentioned SOFC, yttria-stabilized zirconia (hereinafter referred to as "YSZ") is conventionally used. However, YSZ is of high internal resistance and shows low oxide ion conductivity. Therefore, recently, in view of improving the output power density, lowering the operating temperature or the like of SOFC, attention has been directed at scandia-stabilized zirconia (hereinafter referred to as "ScSZ"), and a variety of researches are conducted.
For example, Japanese Patent Application Unexamined Publication No. Hei6-107462 discloses a technique relating to a single cell for an SOFC, and an SOFC in which a solid electrolyte is scandia and alumina-stabilized zirconia prepared by substituting a part of Sc in ScSZ which contains Sc as a main dopant with Al with stable tervalence for maintaining the oxide ion conductivity higher than that of YSZ and for suppressing phasetransition.
In addition, generally, for the fuel electrode, a cermet of Ni and YSZ containing 8 mol % of Y2O3 (hereinafter referred to as "Ni-8YSZ") or the like is used. For the air electrode, (La, Sr) MnO3 being perovskite type transition metal oxide or the like is used. For the separator, LaCrO3 or the like is used.
However, even if a single cell for an SOFC and an SOFC are constituted by using the above-mentioned materials as a solid electrolyte, a fuel electrode, an air electrode and a separator (in the case of the SOFC), it cannot be necessarily said that a single cell for an SOFC and an SOFC having practicable generating performance and durability are directly obtained.
That is because, since the single cell and the SOFC are used while being bonded to or in contact with different types of constituting materials at the times of manufacture, fabrication and operation, the cell performance is greatly influenced not only by material properties exhibited by each constituting material such as the oxide ion conductivity of the solid electrolyte or mechanical characteristics such as strength and toughness, or electrode activity of the fuel electrode and the air electrode or the like, but also by an interaction between the different types of constituting materials such as a bonding state of the solid electrolyte to both of the electrodes or a contact state of each electrode with the separator. Therefore, unless a comprehensive development is performed in view of those characteristics, it can be said that a single cell for an SOFC and an SOFC capable of developing excellent generating performance and durability as a cell are not obtained.
Consequently, in the case of putting the single cell and the SOFC into practical use at an early stage, it is specifically important to improve the cell performance of the single cell itself being a fundamental unit structure, and not to degrade the cell performance in the case of stacking the single cells. That is because, depending on the constitution of the single cell, the generating performance and the durability developed by the single cell becomes entirely alien, and as a result, the generating performance and the durability of the SOFC when a plurality of the single cells are stacked are greatly influenced.


Systems, apparatuses, and methods are described for wireless communications. A wireless device may have different capabilities for downlink preemption and uplink preemption. A base station may assign a first radio network temporary identifier (RNTI) for downlink preemption and a second RNTI for uplink preemption. The wireless device may receive downlink control information indicating, based on the first RNTI or the second RNTI, a downlink preemption or an uplink preemption.

A base station may communicate with a wireless device via uplink and downlink channels. Wireless communications may be associated with various services, such as for ultra reliable low latency communications (URLLC), enhanced mobile broadband (eMBB) communications, and/or other communications. Some wireless communications may be preempted over other wireless communications, for example, based on service type(s) and/or other information. Preemption may comprise uplink preemption and/or downlink preemption. It is desired to improve wireless communications using uplink preemption and/or downlink preemption without adversely increasing signaling overhead and/or decreasing spectral efficiency.

Wireless communications for uplink preemption and downlink preemption


An integrated sorbent injection, heat recovery, and flue gas desulfurization system is disclosed. A dry sorbent is injected into the flue gas upstream of the air heater. This reduces the acid dew point temperature, permitting additional heat energy to be captured when the flue gas passes through the air heater. The flue gas then passes through a desulfurization unit and through a baghouse, where solids are captured. The capture of additional heat energy permits the overall boiler efficiency to be increased while safely operating at a lower flue gas temperature. The integrated system consumes no greater quantity of sorbent than conventional methods but provides the benefit of improved plant heat rate.

The present disclosure relates to a flue gas desulfurization (FGD) system which is used to remove particulates, gases, and other contaminants from flue gas produced during combustion of medium- to high-sulfur fuels. In particular, sulfur dioxide (SO2), sulfur trioxide (SO3), HCl, and other acid gases can be captured; the acid dew point temperature of the flue gas can be reduced, and associated equipment corrosion can be lessened. Sorbents are used more effectively in the present system. This, among other things, increases boiler efficiency, enhances system corrosion resistance, improves material usage, reduces capital costs and operating costs, and improves capture of particulates and/or other contaminants.
During combustion in a boiler, the chemical energy in a fuel is converted to thermal heat, which can be used in various forms for different applications. The fuels used in the combustion process can include a wide range of solid, liquid, and gaseous substances, including coal (with low, medium, or high sulfur content), oil (diesel, No. 2, Bunker C or No. 6), natural gas, wood, tires, biomass, etc.
Combustion in the boiler transforms the fuel into a large number of chemical compounds. Water (H2O) and carbon dioxide (CO2) are the primary products of complete combustion. However, other combustion reactions with chemical components in the fuel result in undesirable byproducts. Depending on the fuel used, such byproducts may include particulates (e.g. fly ash), acid gases such as sulfur oxides (SOx) or halides (HCl, HF) or nitric oxides (NOx), metals such as mercury or arsenic, carbon monoxide (CO), and hydrocarbons (HC). The emissions levels of many of these byproducts will vary depending on the constituents found in the fuel, but can also be altered by the application of emissions control technologies.
The acid dew point temperature (ADP) is the temperature at which the acid gases in the flue gas are expected to begin condensing on the internal portions of the various system components in contact with the flue gas. Such acidic condensation results in corrosion of the system components, and is desirably avoided.
One means of avoiding this corrosion is by designing the heat recovery components so that the lowest expected temperature of the flue gas exceeds the ADP by a suitable margin. By doing so, however, some of the energy that is leaving the boiler envelope (as heat in the flue gas) is not captured. Unrecovered energy directly reduces the efficiency of the boiler, which has an unfavorable impact on the plant heat rate; the increased heat rate is equivalent to reduced plant efficiency. Reduced boiler efficiency also degrades the plant heat rate by requiring additional fan power to handle increased air and gas flows, as well as additional power in fuel and ash handling systems.
It would be desirable to provide systems and methods to remove particulates, gases, and other contaminants from the flue gas while also lessening equipment corrosion and/or improving the boiler efficiency and overall plant efficiency.

Integrated sorbent injection and flue gas desulfurization system


A transmission casing embodying the concepts of the present invention has a one-piece body portion with front and rear faces. The first of two major openings penetrates the front face, and the second of the two major openings penetrates the rear face. A pair of axially spaced front and rear drive gear bearing supports are provided in the transmission casing, and the drive gear bearing supports are axially accessible through the first major opening. A pair of axially spaced front and rear idler gear bearing supports are laterally displaced from the respective drive gear bearing supports and the idler gear bearing supports are also axially accessible through the first opening. A final drive bearing retainer is demountably secured within the second major opening. A final drive rear bearing support is carried by the final drive bearing retainer. An aperture for receiving the final drive front bearing support penetrates the first face and is aligned with the final drive rear bearing support.

It is common practice to provide either a split or a multiple piece casing within which to house the transmission mechanism. This approach has heretofore been employed in order to provide access to the interior of the casing. Such access is deemed necessary to insert and assemble not only the components of the transmission but also the bearings to support the rotatable members of the transmission mechanism. When one employs either split or multiple piece casings, gaskets and a plurality of fasteners are required to secure the casing in its assembled condition.
When one or more gaskets are employed to seal the casing, several factors must be taken into consideration. Most importantly, the casing must have sufficient rigidity to assure that the surfaces that engage the sealing gaskets will maintain their structural integrity in order to maintain the requisite seal. This generally requires the use of additional material to make the casing, and even then, special considerations may need to be given to the particular structural configuration necessary to impart the desired rigidity to the casing.
Each accommodation required to assure that either a split or a multiple piece casing will provide the desired results increases the costs of providing such a transmission. As such, the benefits to be achieved by the adoption and use of a one-piece casing are apparent but have remained elusive inasmuch as the designs heretofore available do not obviate all the deficiencies experienced with the historic split or multiple piece casings.

One-piece power transmission casing and a method of assembling a transmission mechanism therein


A system and method to establish the lock point of a digital synchronous circuit (e.g., a DLL) at the center of or close to the center of its delay line is disclosed. The synchronous circuit is configured to selectively use either a reference clock or its inverted version as the clock signal input to the delay line based on a relationship among the phases of the reference clock, the inverted reference clock, and a feedback clock (generated at the output of the delay line). A delayed version of the feedback clock may be used during determination of the phase relationship. The selective use of the opposite phase of the reference clock for the input of the delay line results in centralization of the lock point for most cases as well as improvement in the tuning range and the time to establish the initial lock, without requiring an additional delay line.

1. Field of the Disclosure
The present disclosure generally relates to synchronous circuits and, more particularly, to a system and method to centralize the lock point of a synchronous circuit.
2. Brief Description of Related Art
Most digital logic implemented on integrated circuits is clocked synchronous sequential logic. In electronic devices such as synchronous dynamic random access memory circuits (SDRAMs), microprocessors, digital signal processors, etc., the processing, storage, and retrieval of information is coordinated or synchronized with a clock signal. The speed and stability of the clock signal determines to a large extent the data rate at which a circuit can function. Many high speed integrated circuit devices, such as SDRAMs, microprocessors, etc., rely upon clock signals to control the flow of commands, data, addresses, etc., into, through and out of the devices.
In SDRAMs or other memory devices, it is desirable to have the data output from the memory synchronized with the system clock that also serves the microprocessor. Delay-locked loops (DLLs) are synchronous circuits used in SDRAMs to synchronize an external clock (e.g., the system clock serving a microprocessor) and an internal clock (e.g., the clock used internally within the SDRAM to perform data read/write operations on various memory cells) with each other. Typically, a DLL is a feedback circuit that operates to feed back a phase difference-related signal to control a delay line, until the timing of one clock signal (e.g., the system clock) is advanced or delayed until its rising edge is coincident (or "locked") with the rising edge of a second clock signal (e.g., the memory internal clock).
FIG. 1 depicts a simplified block diagram of a prior art delay-locked loop (DLL) 10 that can be internal to an SDRAM (not shown). The DLL 10 receives a reference clock 12 as an input and generates an output clock or the CLKOut signal 13 at its output. A Tree_CLK signal 13* is, in turn, fed back as a feedback clock 14 as discussed later. The reference clock 12 is interchangeably referred to herein as "Ref" or "Ref clock signal" or "Ref clock"; whereas the feedback clock 14 is interchangeably referred to herein as "FB" or "FB clock signal" or "FB clock." The reference clock 12 is typically the external system clock serving the microprocessor or a delayed/buffered version of it. In the embodiment of FIG. 1, the system clock CLK 24 and its inverted version CLK_25 are fed into a clock receiver 23 and appear at the receiver's outputs 26 and 27, respectively. The system clocks are then buffered through a clock buffer 28. One output of the clock buffer 28—i.e., the Ref clock 12—thus is a buffered version of the system clock CLK 24. The other output 30 of the clock buffer 28 is a buffered version of the inverted system clock CLK_25 or the inverted version of the Ref clock 12. This output 30 of the clock buffer 28 is interchangeably referred to herein as the "inverted reference clock" or "Ref* clock" or "Ref* clock signal." In traditional synchronous circuits with a single delay line (e.g., the DLL circuit 10 with a delay line 16), only the Ref clock 12 is input into the delay line as shown in FIG. 1.
The Ref clock 12 may be fed into the delay line 16 via a buffer 15. The output of the buffer 15 is a CLKIn signal 17, which is a buffered version of the reference clock 12. The clock output of the delay line 16—the CLKOut signal 13—is used to provide the internal clock (not shown) used by the SDRAM to perform data read/write operations on memory cells and to transfer the data out of the SDRAM to the data requesting device (e.g., a microprocessor). Thus, as shown in FIG. 1, the CLKOut 13 is sent to a clock distribution network or clock tree circuit 20 whose output 21 may be coupled to SDRAM clock driver and data output stages to clock the data retrieval and transfer operations. As can be seen from FIG. 1, the CLKOut signal 13 (and, hence, the FB clock 14) is generated using a delay line 16, which introduces a specific delay into the input Ref clock 12 (or CLKIn 17) to obtain the "lock" condition.
A phase detector (PD) 18 compares the relative timing of the edges of the system clock CLK 24 and the memory's internal clock (not shown) by comparing the relative timing of their respective representative signals—the input clock signal (the Ref clock 12) which relates to the system clock 24, and the FB clock signal 14 which relates to the memory's internal clock—so as to establish the lock condition. As shown in FIG. 1, an I/O model circuit 22 may be a part of the DLL 10 to function as a buffer or dummy delay circuit for the Tree_CLK signal 13* before the Tree_CLK signal 13* is fed into the phase detector 18 as the FB clock 14. The Tree_CLK signal 13* may be obtained from the clock tree circuit 20 in such a manner as to make the FB clock 14 effectively represent the memory's internal clock, which may be present through the clock driver and data output stages. The I/O model 22 may be a replica of the system clock receiver 23, the external clock buffer 28, and the clock and data output path (including the clock driver coupled to the output 21) so as to match respective delays imparted by these stages to the system clock 24 and the CLKOut signal 13, thereby making the Ref clock 12 and the FB clock 14 resemble, respectively, the system clock CLK 24 and the internal clock of the memory as closely as possible. Thus, the I/O model 22 attempts to maintain the phase relationship between the Ref clock 12 and the FB clock 14 as close as possible to the phase relationship that exists between the system clock CLK 24 and the memory's internal clock. The Ref clock 12 and the FB clock 14 are fed as inputs into the phase detector 18 for phase comparison. The output of the PD 18—a delay adjustment signal or indication 19—controls the amount of delay imparted to the CLKIn signal 17 by the delay line 16.
The delay adjustment signal 19 may determine whether the Ref clock 12 should be shifted left (SL) or shifted right (SR) through the appropriate delay in the delay line 16 so as to match the phases of the Ref clock 12 and the FB clock 14 to establish the lock condition. The delay imparted to the Ref clock 12 by the delay line 16 operates to adjust the time difference between the output clock (i.e., the FB clock 14) and the input Ref clock 12 until they are aligned. The phase detector 18 generates the shift left and shift right signals depending on the detected phase difference or timing difference between the Ref clock 12 and the FB clock 14.
FIG. 2 illustrates exemplary timing relationships among various clock signals operated on by the phase detector 18 in the DLL 10 in FIG. 1. The Ref clock 12 and the FB clock 14 are input to the phase detector 18, which generates the shift left or shift right signals depending on whether the rising edge of the Ref clock 12 appears before or after the rising edge of the FB clock 14. In practice, the DLL 10 is considered "locked" (i.e., the Ref clock 12 and the FB clock 14 are "synchronized") when the rising edges of the Ref clock 12 and the FB clock 14 are substantially aligned. As shown in part (a) in FIG. 2, when the Ref clock 12 is "leading" or "faster" than the FB clock 14 (i.e., when the rising edge of the Ref clock 12 appears before the rising edge of the FB clock 14) by a time amount equal to "tPE", the PD 18 may generate a shift right (SR) indication to instruct the delay line 16 to right shift the Ref clock 12 by "tpE" to achieve the lock condition. Similarly, as shown in part (b) in FIG. 2, when the Ref clock 12 is "slower" than or "lagging" the FB clock 14 (i.e., when the rising edge of the Ref clock 12 appears after the rising edge of the FB clock 14) by the time amount "tPE", the PD 18 may generate a shift left (SL) signal to instruct the delay line 16 to left shift the Ref clock 12 by "tPE" to establish the lock. The parameter "tPE" (tPE>0) may indicate a small phase error between the FB clock 14 and the Ref clock 12, especially when the FB clock 14 is almost in phase with the Ref clock 12. As discussed below with reference to FIG. 3, in such a situation, the DLL 10 may lock to the either end of the delay line 16.
FIG. 3 depicts delay line lock point locations for the clock signals in FIG. 2 using a traditional DLL locking mechanism (e.g., the DLL 10 in FIG. 1). In conventional DLL locking mechanisms, when the feedback signal (the FB clock 14) is almost in phase with the reference signal (the Ref clock 12), as illustrated in parts (a) and (b) in FIG. 2, the DLL may lock to either end of the delay line 16. FIG. 3 symbolically designates the right end of the delay line 16 as its initial signal entry point 31. In case (b) in FIG. 2, upon entry into the delay line 16 at the initial entry point 31, the Ref clock 12 may be shifted left to establish the lock point 33 that represents a delay of "tPE" from the initial entry point 31. Thus, the lock point 33 remains close to the right end of the delay line 16. On the other end, for case (a) in FIG. 2, because the initial entry point 31 is fixed at the right end of the delay line 16, the Ref clock 12 may not be further shifted right by "tPE", but, instead, may have to be shifted left by an amount of delay equal to "tCK−tPE" so as to establish the lock point 32 close to the other (left) end of the delay line 16. The clock period of the Ref clock 12 (or the Ref* 30) is designated as "tCK." As is observed with reference to the traditional lock point establishment mechanism illustrated in FIG. 3, there may not be enough room for additional tuning or locking range after the initial lock is established or a longer lock time may be required because of the locking performed towards either end of the delay line 16, instead of towards the center of the delay line. For example, in case of the lock point (b) in FIG. 3, an additional spare delay 34 may be required as part of the delay line 16 for better tuning range (e.g., to accommodate voltage, temperature and frequency fluctuations) after the initial lock 33. The spare delay 34 may increase circuit power consumption and may represent additional hardware. On the other hand, in case of the lock point (a) in FIG. 3, a force-shift-left logic may be required to left shift the Ref clock 12 from the initial entry point 31. Also, in case of lock point (a), longer lock time (from "tPE" to "tCK−tPE") and, hence, longer delay line 16 may be required.
Therefore, it is desirable to lock a digital synchronous circuit (e.g., a DLL) at the center of or close to the center of the delay line to reduce initial lock time and provide extra tuning range in the event of voltage, temperature and frequency changes after the initial lock is established, but without increasing the size or changing the configuration of the delay line or without requiring a spare delay. When the synchronous circuit is tuned at the center or close to the center of its delay line, more room is available to accommodate voltage, temperature and frequency fluctuations that may affect the initially-established lock.

Centralizing the lock point of a synchronous circuit


A stent having a hollow, cylindrical body made with a plurality of rings. The rings each extend circumferentially around the cylindrical body and include an undulating series of angulated peaks and valleys. The rings are joined together by a series of links, the rings and links being shaped and arranged to promote a very low compressed profile and longitudinal flexibility during stent delivery on the catheter and effective scaffolding after deployment. The rings are provided with inflection points on some portions of the rings which extend in a generally circumferential direction for a short distance.

The invention relates to intraluminal endovascular stenting, and in particular, to a low profile stent.
Endovascular stenting is particularly useful for arteries which are blocked or narrowed and is an alternative to surgical procedures that intend to bypass the occlusion. The procedure involves inserting a prosthesis into a body lumen and expanding it to prevent collapse of a vessel wall. While stenting has most commonly been used adjunctively, following an intervention such as angioplasty or atherectomy, there is increasing interest in primary, or direct stent placement.
Percutaneous transluminal angioplasty (PTCA) is used to open coronary arteries which have been occluded by a build-up of cholesterol fats or atherosclerotic plaque. Typically, a guide catheter is inserted into a major artery in the groin and is passed to the heart, providing a conduit to the ostia of the coronary arteries from outside the body. A balloon catheter and guidewire are advanced through the guiding catheter and steered through the coronary vasculature to the site of therapy. The balloon at the distal end of the catheter is inflated, causing the site of the stenosis to widen. The dilatation of the occlusion, however, can form flaps, fissures and dissections which threaten re-closure of the dilated vessel or even perforations in the vessel wall. Implantation of a stent can provide support for such flaps and dissections and thereby prevent reclosure of the vessel or provide a patch repair for a perforated vessel wall until corrective surgery can be performed. Reducing the possibility of restenosis after angioplasty reduces the likelihood that a secondary angioplasty procedure or a surgical bypass operation will be necessary.
A stent is typically a cylindrically shaped device formed from wire(s) or a tube and is intended to act as a permanent prosthesis. A stent is deployed in a body lumen from a radially compressed configuration into a radially expanded configuration which allows it to contact and support a body lumen. The stent can be made to be radially self-expanding or expandable by the use of an expansion device. The self-expanding stent is made from a resilient springy material while the expandable stent is made from a material which is plastically deformable. A plastically deformable stent can be implanted during an angioplasty procedure by using a balloon catheter bearing a crimped, or compressed stent which has been loaded onto the balloon. The stent radially expands as the balloon is inflated, forcing the stent into contact with the body lumen, thereby forming a supporting relationship with the vessel wall. Deployment is effected after the stent has been introduced percutaneously, transported transluminally and positioned at a desired location by means of the balloon catheter.
A balloon of appropriate size and pressure is first used to open the lesion. The process can be repeated with a stent loaded onto a balloon. Direct stenting involves simultaneously performing angioplasty and stent implantation using a stent mounted on a dilatation balloon. The stent remains as a permanent scaffold after the balloon is withdrawn. A balloon capable of withstanding relatively high inflation pressures may be preferable for stent deployment because the stent must be forced against the artery""s interior wall so that it will fully expand, thereby precluding the ends of the stent from hanging down into the channel, encouraging the formation of thrombus.
In adjunctive stenting, a stent delivery system with a small diameter profile is not required because the narrowing has already been enlarged by the preceding device. However, in direct stenting, the stent and delivery balloon catheter need to be inserted into a stenosis that has not been previously dilated. Thus, for direct stenting to be applicable to many patients, the stent and delivery system must have a very low profile. The primary advantage of direct stenting is the procedural efficiency gained by eliminating a primary angioplasty step. The resulting procedure can be shorter and less expensive.
Primary angioplasty followed by stent placement typically requires a catheter exchange, which is usually performed over a guidewire. Given the prevalence of this staged procedure, the most commonly used balloon catheters have been over-the-wire types, having either a full length guidewire lumen or a short, distal guidewire lumen as found in rapid exchange catheters. Fixed wire, or xe2x80x9cballoon-on-a-wirexe2x80x9d type balloon catheters have been seldom used for primary angioplasty in stenting procedures, and these catheters have not been used to deliver stents at all. With their small size and wire-like trackability, fixed wire catheters are able to provide relatively quick and simple balloon placement and access to lesions that cannot be reached with other types of catheters. The small size of fixed wire catheters also permits their use through very small guiding catheters. However, these balloon catheters lack the ability to maintain guidewire position across a lesion for exchange purposes and they may encounter problems re-crossing a dilated area. Another reason that fixed wire balloon catheters have not been used for stent delivery is that the very small deflated profile of the balloon on such a catheter may be too small to securely carry a compressed stent of conventional design.
Previous structures used as stents or intraluminal vascular grafts have included coiled stainless steel springs, helically wound spring coils made from a shape memory alloy, expanding metal stents formed in a zig-zag pattern, and diamond shaped, rectangular shaped, and other mesh and non-mesh designs. Exemplary stent devices are disclosed in U.S. Pat. No. 5,776,161 issued to Globerman, U.S. Pat. No. 5,449,373 issued to Pinchasik et al, U.S. Pat. No. 5,643,312 issued to Fischell et al and U.S. Pat. No. 5,421,955 issued to Lau et al.
Problems to be overcome in stent design include inadequate radial force to maintain stent expansion, inadequate scaffolding of tissue against the wall, predilatation longitudinal rigidity that negatively impacts on stent delivery, and shortening of the stent as a consequence of radial expansion. Predilatation longitudinal rigidity is a significant stent shortcoming that prevents the threading of the stent through long tortuous vessels and lesions. Shortening of the stent is also a problem, as it is important that the stent cover the entire lesion to minimize the risk of post-operative complications. Many of these problems result from the often conflicting goals of stent design. For example, to provide uniform support to the vessel wall, it is desirable to have a high degree of scaffolding in the stent when it is expanded to its nominal radial size. However, it is also desirable to have a small, relatively smooth delivered profile when the stent is mounted on the catheter to permit the stent and catheter to traverse small diameter lesions. The person skilled in the art will appreciate that, as a stent with a very small delivered profile expands radially, its structural elements become farther apart and create openings which reduce the amount of scaffolding available to support the vessel. A similar situation exists with respect to the conflicting goals of improved scaffolding and flexibility during catheter delivery since proper scaffolding will not be accomplished if there are too few supporting structural elements. However, a stent with too many structural elements may be difficult to crimp small enough to fit onto the balloon catheter such that the structural elements do not abut or interfere with each other during delivery through tortuous vessels. Also, in some stents, during plastic deformation of the stent (i.e. balloon expansion), the strain is concentrated at small zones. This limits the properties of the material that can be used as well as the radial force and the expansion rate.
Co-pending U.S. patent application Ser. No. 09/292,991, entitled Medical Device for Intraluminal Endovascular Stenting, addresses a number of these issues. The ""991 application discloses an expandable stent having a small initial diameter, flexibility along its longitudinal axis prior to expansion and minimization of rigid local strain on the stent material by the presence of rotation joints which have minimal strain during stent expansion. The stent of the ""991 application has substantially the same length before and after expansion and it is easy to deliver, being longitudinally flexible when constrained. However, the delivery of such a stent on very low profile, fixed wire delivery catheters requires additional improvements in the size of the minimal crimped diameter.
The stent of the present invention has a hollow, cylindrical body made with a plurality of rings. It is manufactured from tubing having a diameter between a minimal crimped diameter of the stent and a nominal size that is closely matched to the size of the vessel to be treated. In the manufactured form of the stent, each ring extends circumferentially around the cylindrical body and includes an undulating series of peaks and valleys. The undulating peaks and valleys of each ring are formed by opposing angled segments, which are joined to each other by substantially straight struts. Adjacent rings are joined together by a circumferentially disposed series of links, which are shaped and arranged to promote longitudinal flexibility as the stent is delivered by the catheter. The links also promote effective scaffolding after stent deployment and prevent shortening of the stent as it is expanded.
Each ring is provided with inflection points, which may be substantially centered on the struts that extend between adjacent peaks and valleys of the ring. At each inflection point, a portion of the ring extends in a generally circumferential direction for a short distance, producing an offset in the otherwise straight strut. A link is joined at one end to an inflection point on one ring and the link is also joined at a second end to a second inflection point on an adjacent ring. Preferably, when the stent device is unexpanded, each link includes at least two angled segments that are capable of deflecting to promote longitudinal flexing of the stent when it is subjected to bending forces, such as those encountered during delivery of the stent and catheter through a tortuous vascular anatomy. Also preferably, each inflection point has a length, measured circumferentially, which is at least as great as the width of the link to which it is attached. Preferably, the circumferential length of the inflection point is no more than about twice the width of the link to which it is attached. When the stent is crimped on the balloon catheter, the links can fit closely together in a nested arrangement with the undulations of the rings. When the stent is expanded, vessel scaffolding is promoted by this nested arrangement, which allows a large number of connecting links. The terms xe2x80x9cnestxe2x80x9d, xe2x80x9cnestedxe2x80x9d or nestingxe2x80x9d are used herein to mean that the elements are conformally arranged such they can be in very close proximity when the stent is crimped and loaded onto a catheter but without substantial contact that would affect the ability of the various elements to move in relation to each other as the stent and catheter are advanced through a tortuous body vessel. In some embodiments of the invention, only one link is connected to an inflection point. This makes the inflection point a xe2x80x9cdead endxe2x80x9d and permits some of the flexing forces which are not absorbed by the link itself to be absorbed by the rings to which it is attached. The links are arranged to provide flexibility, and the peaks and valleys of the rings are paired with each other in an in-phase relationship. Preferably, the rings are joined by multiple links, most preferably three or more links, and each ring has the same number of inflection points as the number of attached links. When a large number of connecting links are employed, the angles in the links are preferably of a complimentary shape to each other such that they will nest together when the stent is crimped for mounting onto the catheter.
Another aspect of the invention is the conformal nesting of ring and link components such that the stent can be readily crimped for loading onto a balloon or other expansion device on the catheter. A stent made according to the present invention may be made from a tube which is cut with lasers or other techniques that are well known to those skilled in the art. The initial pattern cut into the tube includes sufficient spacing between link and ring components such that the stent can be crimped onto a catheter without causing general abutment of the ring and link components with each other. During deployment of the stent catheter through tortuous coronary arteries, the pattern also permits longitudinal movement of the link components without disturbing the crimp of the ring components. The need for spacing between the components in the crimped condition must be balanced with the need to provide improved scaffolding of the vessel being treated. That is, a relatively abundant number of links provides improved scaffolding of the vessel but potentially interferes with the ability to crimp the stent onto the catheter.
In another aspect of the invention, the stent configuration has undulating peaks and valleys of adjacent rings paired with each other in an in-phase relationship. Such a configuration can allow interconnecting links to nest within the peaks and valleys of the rings by providing at least two angled segments in a central portion of the link.
The compressed stent of the present invention can be securely mounted onto a very low profile, fixed wire catheter by incorporating relatively sharp angled bends instead of gentle curves and by placing adjacent portions of links and rings close together to provide the spacing needed for more compact nesting of the ring and link components. A further aid in reducing the minimal crimp diameter of the stent is to make the rings and links as narrow as possibly permitted by other design constraints. Thus, in the present invention, large numbers of connecting links can be included within a stent design having a very low minimal crimp diameter.


A superconducting machine is disclosed, in particular for use as a generator in a stand-alone power system. In at least one embodiment, the superconducting machine includes a stator and a rotor capable of rotating with respect to the stator. At least one superconducting coil for generating at least two magnetic poles is provided on at least one component part, in particular the rotor, which superconducting coil is cooled via a cooling device; and at least two parallel winding elements are provided on the respective other component part, in particular the stator, in the armature winding for each phase, which winding elements can be connected either in series or in parallel via at least one switching device.

Superconducting machines comprising superconducting coils, residing in particular of a high-temperature superconductor material, as excitation windings for generating the magnetic fields in the poles are already known from the prior art. In electric machines of this kind, the superconducting coil must be actively cooled via a cooling device, in particular having at least one cold head. If the temperature of the superconducting coil rises above its operating temperature, the rated excitation current for operating the superconducting machine can no longer be achieved.
When operated in generator mode, such superconducting machines, particularly high-temperature superconductor synchronous machines, are also used as energy sources in a stand-alone power system, e.g. on a ship. Here the problem arises as to how, after a malfunction, e.g. a cooling failure, operation of the power system can basically be maintained to a limited extent or restored, as, particularly after a failure of the cooling of the superconducting coil, heating of the excitation winding occurs, with the result that operation at rated current is no longer possible.
To solve this problem, it has been proposed to provide an emergency power supply, e.g. an additional diesel set, which, prior to the actual desired operation being restored, also provides power over a comparatively long period for auxiliary equipment for cooling the superconducting coil as an excitation winding. Here, however, an additional generator device is required, which is expensive and makes superconducting machines, particularly high-temperature superconductor synchronous machines, a less attractive proposition for generating energy in a stand-alone power system.

Superconducting machine and method for the operation thereof


A method and apparatus for remote maintenance and error recovery for plural stations interconnected in a distributed network. A monitor application is established within selected stations within the network in a terminate and stay resident mode. The monitor application is then automatically invoked in response to error message, reconfiguration messages, or network status messages received at that station by listing the monitor application address within user appendages associated with such error messages or reconfiguration messages within the network interface of the station. An error message may be displayed and any selected application or procedure may then be invoked by the monitor application in an application independent manner. In one embodiment of the present invention, a station may be reset remotely in response to an error message or reconfiguration message by utilizing the monitor application and the station may then be directed to establish communication with a server device in order to update system software. This may be simply accomplished within a computer station utilizing a DOS operating system by merely altering the automatic execution batch file.

1. Technical Field
The present invention relates in general to the field of distributed computer networks and in particular to a method and apparatus for remote maintenance and error recovery within distributed data processing networks. Still more particularly, the present invention relates to a method and apparatus which permits network stations to automatically invoke a selected application or procedure in response to an error message or reconfiguration message from the network.
2. Description of the Related Art
Distributed data processing networks are well known in the art. In fact, in selected applications, networks of terminals or so-called "personal" computers are rapidly supplanting large concentrated data processing systems due to the ease of updating, modifying and relocating such systems. Examples of various types of networks in use today include: bus topologies; ring topologies; star topologies; and, tree topologies. Each topology utilizes a distinctive manner to interconnect all stations within the network.
Additionally, many different protocols exist for formatting data which is exchanged between stations within a network. For example, token ring networks allow unidirectional data transmission between data stations by a token passing procedure over one transmission medium so that transmitted data returns to the transmitting station. IEEE Standard 802.5 was approved for token ring networks in December of 1984.
Many other network protocols exist including: Advanced Peer-to-Peer Networks (APPN); Ethernet Networks (as set forth in IEEE Standard 802.3); Token Bus Network (IEEE Standard 802.4); and others. Many of these networks are so-called "self-healing" networks in that the network system possess the ability to reconfigure the network in response to an error condition. For example, within token ring networks, one station, referred to as the "active monitor" provides token monitoring and other functions. The active monitor station resolves lost tokens, frames which circle the ring more than once, clocking, and the presence of other active monitors on the ring. A timer within the active monitor station is typically utilized to detect a lost token by timing the period of time required for the largest possible frame of data to circle the ring. If this time is exceeded, the active monitor assumes the token was lost, purges the ring and initiates a new token.
Certain errors within such networks are often referred to as "hard" errors. Hard errors are permanent faults, usually in equipment, which cause a ring to cease operation within normal architecture protocols. A ring station which is downstream from a hard error will recognize such an error at its receiver input and begin transmitting beacon frames, paced at predetermined intervals, with an all station address. This continues until the fault is restored. Fault restoration generally occurs by having each station perform a test in response to an error signal and then reattach itself to the ring only if the test is successful.
Thus, an error signal may be utilized to automatically reconfigure a ring network by removing a station which has caused the fault condition. Additionally, a station may be removed by utilizing an explicit command, such as "Auto Removal" which is utilized in an IBM Token-Ring Network to remove a device, such as an attached personal computer, from the data passing activity without human intervention by means of a token-ring adapter card. This technique, as well as other low level commands, is accomplished utilizing the so-called "Logical Link Control" (LLC) standard which is defined by IEEE Standard 802.2.
While these methods described above permit such networks to practice "self-healing" the end result may not be acceptable. For example, certain errors may result in the reconfiguration of a network which deletes a "bridge" or "gateway" station which may be necessary for connectivity within the larger network. In such situations a bridge or gateway station must then be manually reset to reestablish communication between the two rings or a ring in a host system. Additionally, certain network management facilities may suspend a station, requiring that station to undergo a manual Initial Program Load (IPL) to return the station to full communication.
Thus, it should be apparent that a need exists for a method and system which will permit remote maintenance and error recovery in distributed data processing networks.

Method and apparatus for remote maintenance and error recovery in distributed data processing networks

International Business Machines Corporation


A ball valve for refrigerating system includes a valve body, a valve seat that fits into the valve body by a screw thread, a valve ball accommodated within the valve body, two plastic sealing elements on both sides of the valve ball, a valve rod connected to the valve ball, and a valve cap on said valve rod. One of the two sealing elements is a first sealing element which is provided with a suitable spring assembly on its periphery. The spring assembly includes at least two springs with ladder-shaped longitudinal sections that are reverse-superimposed. The inside of first sealing element fits well with the surface of said valve ball, while its outside functions as a supporting surface and an acting surface for said spring assembly. The resulting configuration provides a ball valve with a desirable sealing effect.

1. Field of Invention
This invention relates to a ball valve for refrigerating system.
2. Description of the Related Art
It is known to use ball valves for connecting, intercepting or regulating a cold medium in split refrigerating systems. Generally ball valves (see FIG. 1) have PTFE plastic sealing gaskets on both sides of the valve ball. By screwing in the valve seat along the thread on one side of the valve body, under certain compression, the interactive valve ball and sealing gaskets within the valve body cling to each other closely, and thus function as seal. A valve rod with an "O" ring is connected to the valve ball, so as to open or close the ball valve conveniently by turning the valve rod which drives the valve ball turn. However, due to obvious compression creep of the PTFE plastic sealing gaskets, this kind of ball valve suffers from great permanent compression deformation under high temperature and pressure, thus causing the decreasing of sealing impacting force between the interactive valve ball and PTFE plastic sealing gaskets. The sealing effect is not ideal.


An endogenous oil extracted from Brassica seeds is disclosed that contains, after crushing and extraction, greater than 86% oleic acid and less than 2.5% α-linolenic acid. The oil also contains less than 7% linoleic acid. The Brassica seeds are produced by plants that contain seed-specific inhibition of microsomal oleate desaturase and microsomal linoleate desaturase gene expression. Such inhibition can be created by cosuppression or antisense technology. Such an oil has a very high oxidative stability in the absence of added antioxidants.

Diets high in saturated fats increase low density lipoproteins (LDL) which mediate the deposition of cholesterol on blood vessels. High plasma levels of serum cholesterol are closely correlated with atherosclerosis and coronary heart disease (Conner et al., Coronary Heart Disease: Prevention, Complications, and Treatment, pp. 43-64, 1985). By producing oilseed Brassica varieties with reduced levels of individual and total saturated fats in the seed oil, oil-based food products which contain less saturated fats can be produced. Such products will benefit public health by reducing the incidence of atherosclerosis and coronary heart disease.
The dietary effects of monounsaturated fats have also been shown to have dramatic effects on health. Oleic acid, the only monounsaturated fat in most edible vegetable oils, lowers LDL as effectively as linoleic acid, but does not affect high density lipoproteins (HDL) levels (Mattson, F. H., J. Am. Diet. Assoc., 89:387-391, 1989; Mensink et al., New England J. Med., 321:436-441, 1989). Oleic acid is at least as effective in lowering plasma cholesterol as a diet low in fat and high in carbohydrates (Grundy, S. M., New England J. Med., 314:745-748, 1986; Mensink et al., New England J. Med., 321:436-441, 1989). In fact, a high oleic acid diet is preferable to low fat, high carbohydrate diets for diabetics (Garg et al., New England J. Med., 319:829-834, 1988). Diets high in monounsaturated fats are also correlated with reduced systolic blood pressure (Williams et al., J. Am. Med. Assoc., 257:3251-3256, 1987). Epidemiological studies have demonstrated that the "Mediterranean" diet, which is high in fat and monounsaturates, is not associated with coronary heart disease.
Intensive breeding has produced Brassica plants whose seed oil contains less than 2% erucic acid. The same varieties have also been bred so that the defatted meal contains less than 30 μmol glucosinolates/gram. Brassica seeds, or oils extracted from Brassica seeds, that contain less than 2% erucic acid (C22:1), and produce a meal with less than 30 μmol glucosinolates/gram are referred to as canola seeds or canola oils. Plant lines producing such seeds are also referred to as canola lines or varieties.
Many breeding studies have been directed to alteration of the fatty acid composition in seeds of Brassica varieties. For example, Pleines and Freidt, Fat Sci. Technol., 90(5), 167-171 (1988) describe plant lines with reduced C18:3 levels (2.5-5.8%) combined with high oleic content (73-79%). Roy and Tarr, Z. Pflanzenzuchtg, 95(3), 201-209 (1985) teaches transfer of genes through an interspecific cross from Brassica juncea into Brassica napus resulting in a reconstituted line combining high linoleic with low linolenic acid content. Roy and Tarr, Plant Breeding, 98, 89-96 (1987) discuss prospects for development of B. napus L. having improved linolenic and linolenic acid content. Canvin, Can. J. Botany, 43, 63-69 (1965) discusses the effect of temperature on the fatty acid composition of oils from several seed crops including rapeseed.
Mutations can be induced with extremely high doses of radiation and/or chemical mutagens (Gaul, H. Radiation Botany (1964) 4:155-232). High dose levels which exceed LD50, and typically reach LD90, led to maximum achievable mutation rates. In mutation breeding of Brassica varieties, high levels of chemical mutagens alone or combined with radiation have induced a limited number of fatty acid mutations (Rakow, G. Z. Pflanzenzuchtg (1973) 69:62-82).
Rakow and McGregor, J. Amer. Oil Chem. Soc., 50, 400-403 (October 1973) discuss problems associated with selecting mutants affecting seed linoleic and linolenic acid levels. The low α-linolenic acid mutation derived from the Rakow mutation breeding program did not have direct commercial application because of low seed yield. The first commercial cultivar using the low α-linolenic acid mutation derived in 1973 was released in 1988 as the variety Stellar (Scarth, R. et al., Can. J. Plant Sci. (1988) 68:509-511). The α-linolenic acid content of Stellar seeds was greater than 3% and the linoleic acid content was about 28%.
Chemical and/or radiation mutagenesis has been used in an attempt to develop an endogenous canola oil having an oleic acid content of greater than 79% and an α-linolenic acid content of less than 5%. Wong, et at., EP 0 323 753 B1. However, the lowest α-linolenic acid level achieved was about 2.7%. PCT US91/05910 discloses mutagenesis of a starting Brassica napus line in order to increase the oleic acid content in the seed oil. However, the oleic acid content in canola oil extracted from seeds of such mutant lines did not exceed 80%.
The quality of canola oil and its suitability for different end uses is in large measure determined by the relative proportion of the various fatty acids present in the seed triacylglycerides. As an example, the oxidative stability of canola oil, especially at high temperatures, decreases as the proportion of tri-unsaturated acids increases. Oxidative stability decreases to a lesser extent as the proportion of di-unsaturated acids increases. However, it has not been possible to alter the fatty acid composition in Brassica seeds beyond certain limits. Thus, an endogenous canola oil having altered fatty acid compositions in seeds is not available for certain specialty uses. Instead, such specialty oils typically are prepared from canola oil by further processing, such as hydrogenation and/or fractionation.

This patent is subject to a terminal disclaimer.

Canola oil having increased oleic acid and decreased linolenic acid content


The combination of a photoconductive switch coupled to an energy storage ice wherein the switch is comprised of photoconductive semiconductor switch while the energy storage device comprises a tapered radio transmission line. A photoconductive semiconductor gallium arsenide switch is embedded in a circular disc of dielectric material having a thickness dimension which reduces linearly outward from the center, with upper and lower layers of continuous radial metallization configured in a circular pattern located thereon. The upper layer of metallization includes an apertured grid adjacent one surface of the switch, while the outer conductor of a coaxial output signal line is connected to the metallization layer on the opposite side with the inner conductor thereof passing through the dielectric layer to the undersurface of the semiconductor switch.

1. Field of the Invention
This invention relates generally to electrical pulse signal generators and more particularly to a sub-nanosecond, kilovolt pulse generator for use in impulse radar apparatus, active electromagnetic signal jammers, and relatively high power microwave weapon systems.
2. Description of the Prior Art
Recently there has been much research activity into the generation of nanosecond type pulses utilizing a high power photoconductive solid state semiconductor switch coupled to a storage device. In the above cross referenced related application, there is disclosed a sub-nanosecond pulse generator using a radial transmission line comprised of a photoconductive bulk GaAs switch embedded in a circular dielectric disc of constant thickness with radial type layers of metallization formed on top and bottom surfaces thereof. In one embodiment, the layers of metallization are generally circular in configuration with continuous surface areas. In another embodiment, the continuous surface areas of metallization are replaced by a plurality of outwardly extending stripline segments which converge to a region of common metallization at the middle.
Since the characteristic impedance of such a device is inversely proportional to the width of the dielectric separating the top and bottom layers of metallization, the radial transmission line creates a non-uniform characteristic impedance primarily due to its geometrical configuration. Therefore, at a location outward from the center of the radial transmission line, the impedance is smaller compared to that at a location closer in. When the radial transmission line is charged and the photoconductive switch is optically activated, traveling waves begin to flow from the low impedance region to the high impedance region and in the process,, voltage transformation occurs. The variation of this characteristic impedance between the inner edge and outer edge of the radial transmission line acts like a built in voltage step-up transformer. Accordingly, the degree of impedance variation in the radial line will determine the magnitude of voltage gain at a load connected to the device.
For practical system applications, an optically activated hybrid pulser should produce high peak power pulses with subnanosecond risetime. In addition, the pulser should operate reliably for a long period of time.

Tapered radial transmission line for an optically activated hybrid pulser

The United States of America as represented by the Secretary of the Army


In a dynamic flow rate adjusting method, a press-fitting degree of an adjusting pipe is adjusted to regulate a load applied to a needle by a spring in a direction for closing an injection hole. Thus, a dynamic injection quantity of an injector is adjusted. An injection command signal having one-minute long pulse width is applied to the injector to measure a static flow rate, from which the press-fitting degree is calculated. Thus, the press-fitting degree, in which variation in the static flow rate is taken into consideration, can be calculated. Therefore, variation in the dynamic flow rate of each injector, which is calculated from the press-fitting degree, includes only a dynamic flow rate error, while a static flow rate error is eliminated from the variation in the dynamic flow rate.

1. Field of the Invention
The present invention relates to a dynamic flow rate adjusting method for an injector.
2. Description of Related Art
An adjusting system shown in FIG. 1 adjusts a dynamic flow rate of an injector 1. The dynamic flow rate of fluid injected by the injector 1 is adjusted by regulating biasing force of a spring 21. The biasing force of the spring 21 is regulated by adjusting a press-fitting position of an adjusting pipe 23. The dynamic flow rate is quantity of fluid injected during a stroke (opening and closing motion) of a needle 30. The injector 1 injects experimental fluid through injection holes 25 when the needle 30 as a valve member separates from a valve seat 27. As the experimental fluid, incombustible fluid having substantially the same viscosity as the fuel is used in order to prevent ignition and the like. The spring 21 as a biasing member biases the needle 30 in a direction for seating the needle 30 on the valve seat 27, or a direction for closing the injection holes 25. The adjusting pipe 23 is driven to an inside of a housing 10 of the injector 1 when press-fitted. When the press-fitting position of the adjusting pipe 23 is determined and the target dynamic flow rate is achieved, the adjusting pipe 23 is fixed to the housing 10 by crimping and the like. If current is supplied to a coil 50 as an electric driving member, magnetic force is generated for attracting the needle 30 toward a fixed core 22 (upward in FIG. 1) against the biasing force of the spring 21. Thus, the needle 30 separates from the valve seat 27. A maximum lifting distance of the needle 30 is defined by the position of the fixed core 22.
A pump 100 draws the experimental fluid from a tank 101 to the injector 1. A pressure gauge 102 measures pressure of the fluid supplied to the injector 1. A flowmeter 103 as measuring means measures the flow rate of the fluid flowing through the injector 1. For instance, the flowmeter 103 outputs a pulse number of pulse signals generated per unit time in accordance with the flow rate, as a flow rate signal. The pulse number outputted by the flowmeter 13 increases as the flow rate increases. A back pressure valve 104 regulates the pressure of the fluid supplied to the injector 1 to a predetermined pressure. A pressure reducing valve may be employed instead of the back pressure valve 104. A motor gear 111 rotating with a motor 110 as an adjusting amount changing means is meshed with a screw gear 112. The screw gear 112 is connected with a driving screw 113 in thread engagement. If the screw gear 112 rotates, the driving screw 113 moves upward or downward in FIG. 1. If the driving screw 113 moves downward, the adjusting pipe 23 is driven to the inside of the housing 10. A personal computer (PC) 120 as calculating means receives the flow rate signal outputted by the flowmeter 103 and calculates the dynamic flow rate corresponding to the present press-fitting position of the adjusting pipe 23. The PC 120 controls a driving circuit 121 based on a difference between the calculated dynamic flow rate and the target dynamic flow rate. Thus, the PC 120 regulates controlling current supplied to the motor 110 from the driving circuit 121. The PC 120 calculates the press-fitting position of the adjusting pipe 23 for the next time.
If the adjusting pipe 23 is driven into the housing 10, the biasing force of the spring 21 is increased. If the adjusting pipe 23 is press-fitted, a valve opening period To of the injector 1 is lengthened, and a valve closing period Tc is contracted as shown in FIG. 9 in the case where the coil 50 is applied with the controlling pulse current having an identical frequency, an identical pulse width and an identical amplitude. Therefore, a time length of one injection performed by the injector 1 is contracted and the injection quantity is reduced. Accordingly, the dynamic flow rate calculated by the PC 120 based on the flow rate signal outputted by the flowmeter 103 is reduced. The valve opening period To is a time length from the time when an injection pulse signal for commanding the injection is turned on to the time when the needle 30 separates from the valve seat 27 and the needle 30 is stopped by the fixed core 22, so a lifting distance of the needle 30 is maximized. The valve closing period Tc is a time length from the time when the injection pulse signal is turned off to the time when the needle 30 is seated on the valve seat 27 and the injection is stopped. In FIG. 9, an axis qb represents the flow rate before the adjusting pipe 23 is press-fitted, and an axis qa is the flow rate after the adjusting pipe 23 is press-fitted.
A conventional adjusting method of the dynamic flow rate performed with the adjusting pipe 23 will be explained based on FIGS. 10 and 11. In FIG. 10, an axis of abscissas represents the press-fitting degree L of the adjusting pipe 23 and an axis of ordinates represents the dynamic flow rate q. A symbol qt on the axis q represents the target dynamic flow rate. The press-fitting degree L as an adjusting amount of the adjusting pipe 23 represents displacement of the adjusting pipe 23 from an initial position to the position where the adjusting pipe 23 is press-fitted. In the case where a plurality of injectors 1 having identical structure are adjusted, an average value of a rate of change (a change rate Kq) of the dynamic flow rate q with respect to the press-fitting degree L of the adjusting pipe 23 is calculated in advance from measurements of the injectors 1. Then, the press-fitting degree L of the adjusting pipe 23 for achieving the target dynamic flow rate qt is calculated based on the change rate Kq.
However, the dynamic flow rate q includes a dynamic flow rate error Ed and a static flow rate error Es of a static flow rate as shown in FIG. 10. Therefore, if the press-fitting degree L of the adjusting pipe 23 for the present adjustment is calculated from the above change rate Kq, there is a possibility that the press-fitting degree L may become too large. The static flow rate represents a flow rate of fluid injected by the injector 1 when the injector 1 injects the fluid continuously for a predetermined period. The static flow rate error Es is an error in the flow rate caused by errors generated in processing steps of parts constituting the injector 1. For instance, the static flow rate error Es is caused by variation in an opening area of the fluid passage at the time when the needle 30 is lifted or by variation in the maximum lifting distance of the needle 30. The dynamic flow rate error Ed represents an error in the flow rate caused by the error in electromagnetic characteristics of the coil 50 and elastic characteristics of the spring 21. Thus, in the conventional adjusting method for achieving the target dynamic flow rate qt based on the change rate Kq of the dynamic flow rate q with respect to the press-fitting degree L of the adjusting pipe 23, the change rate Kq includes the dynamic flow rate error Ed and the static flow rate error Es.
If the press-fitting degree L of the adjusting pipe 23 is too large, there is a possibility that the dynamic flow rate q may become smaller than the target dynamic flow rate qt. The position of the adjusting pipe 23 is fixed by press-fitting. Therefore, if the press-fitting degree L is too large, the adjusting pipe 23 cannot be brought back.
Therefore, in the case where the press-fitting degree L of the adjusting pipe 23 is calculated based on the change rate Kq of the dynamic flow rate q with respect to the press-fitting degree L, a rate of change in the press-fitting degree L per press-fitting process has to be reduced in order not to drive the adjusting pipe 23 excessively during the adjustment of the dynamic flow rate q. Therefore, as shown in FIG. 11, the number of times to drive the adjusting pipe 23 is increased until the dynamic flow rate 1 reaches a standard area Rqt corresponding to the target dynamic flow rate qt and a time length for the adjustment is lengthened. Heavy lines "CHECK" in FIG. 11 represent periods in which the dynamic flow rate q is measured and the press-fitting degree L of the adjusting pipe 23 is calculated.

Dynamic flow rate adjusting method for injector


In the structure of register files composed of a master register file and a working register file, when data is read, the working register file is accessed. When data is written, the both the master register file and the working register file are accessed. In the working register file, data of the current window, and data preceded thereby, and data followed thereby are stored. Thus, even if the SAVE instruction or the RESTORE instruction are successively executed, instructions can be processed out of order. As a result, the efficiency of the process is improved.

1. Field of the Invention
The present invention relates to a register access processing method for use with an information processing apparatus having an architecture of a register window and using an out-of-order instruction execution system, the method allowing the order of instructions to be changed so that an instruction goes ahead of a register window switching instruction.
2. Description of the Related Art
Some information processing apparatus having an architecture using a reduced instruction set has a plurality of register sets (hereinafter referred to as register windows). Thus, in the apparatus, it is not necessary to save or restore to a memory stack a register that takes place when a subroutine is called or returned.
The register windows are connected in a ring shape and managed by register window numbers (hereinafter referred to as window numbers). For example, eight register windows are assigned window numbers 0 to 7 and used in the order of 0, 1, 2, . . . , and 7. The window number of a register window that is being used is stored by a register (hereinafter, this register is referred to as current window pointer (CWP)).
FIG. 1 shows the structure of a ring-shaped register file.
Each register window file composed of for example 32 64-bit registers. Among these registers, eight registers are common in all the register windows. As shown in FIG. 1, other eight registers are in common with the immediately preceding register window. Further eight registers are in common with the immediately following register window.
These registers are referred to as overlap register window. There are two types of register window switching instructions that are a SAVE instruction and a RESTORE instruction. The SAVE instruction increments CWP. The RESTORE instruction decrements CWP. Thus, in the following description, the register window switching instructions are referred to as SAVE instruction and RESTORE instruction.
FIG. 1 shows the case that the number n of windows is eight and a total of 136 registers of which eight "local" registers×eight windows=64 registers, eight overlapped in/out registers×eight windows=64 registers, and eight global registers (not shown). It is necessary to allow data to be written and read to and from all the registers.
In the related art, there are problem with respect to speed and scale of a circuit that reads data from such a large register file.
FIG. 2 is a schematic diagram showing the structure of a register file composed of a master register file and a working register file.
As the number of register windows becomes large, a very large register file is required (when the number of register windows is eight, 136 registers are required). As a result, it becomes difficult to supply an operand to an arithmetic unit at high speed. Thus, as shown in FIG. 2, in addition to a register file (portion (51) shown in FIG. 2) that stores all windows as shown in FIG. 2 (the register file is referred to as master register file (MRF)), a subset (portion (52) shown in FIG. 2 (52)) of the MRF is disposed. The subset stores a copy of one window pointed by CWP in the MRF (hereinafter, the subset is referred to as working register file (WRF)). The WRF supplies an operand to the arithmetic unit. Since the WRF stores only a window pointed by CWP, the capacity of the WRF is 32 entries that is smaller than that of the MRF. Thus, data can be read from the WRF at high speed.
However, in such a structure, since the WRF stores only registers for one window, when the SAVE instruction or the RESTORE instruction is executed, an operand that is required after an instruction that will be executed after the SAVE instruction or the RESTORE instruction cannot be supplied from the WRF.
Thus, when the SAVE instruction or the RESTORE instruction is executed, since the window of the WRF is replaced with a new window, since a window transferring process takes place from the MRF to the WRF, while the process is taking place, the execution of instructions that follow is stalled.
In addition, the information processing apparatus that changes the processing order of instructions corresponding to an out-of-order instruction executes the instructions that can be processed regardless of the execution order of the program. However, the apparatus cannot execute an instruction preceded by the SAVE instruction or the RESTORE instruction even if the apparatus can process the instruction, until a window is transferred to the WRF after the SAVE instruction or the RESTORE instruction is executed.
Such a restriction causes the performance of the information processing apparatus corresponding to the out-of-order instruction execution system that generates a large number of instructions at a time to largely deteriorate. The information processing apparatus corresponding to the out-of-order instruction execution system pre-reads many instructions and pre-stores them to buffers. Instructions that are stored and that are executable are executed in the changed order different from that designated by the program so that the throughput of the execution of the instructions is improved. Thus, when the SAVE instruction or the RESTORE instruction is executed, if the execution order of instructions cannot be changed, whenever the SAVE instruction or the RESTORE instruction is executed, the out-of-order processing mechanism does not work. As a result, the performance of the apparatus remarkably deteriorates.

Register file in the register window system and controlling method thereof


A data processing system for efficiently manipulating a graphic object displayed within a graphic user interface in the data processing system. The graphic object is defined by interrelated variables. Under the present invention, interrelated variables defining the graphic object are associated with at least one data structure, wherein the each data structure includes a value for at least one of the interrelated variables. An editing object is displayed within the graphic user interface in response to a selection of the graphic object by a user. The user is permitted to alter a value for one of the interrelated variables utilizing the editing object. A value for at least one other variable is automatically altered in response to the user altering the value for one of the interrelated variables utilizing the editing object. A display of the graphic object automatically altered in response to an alteration of the value for the at least one other variable, wherein the graphic object is efficiently manipulated.

1. Technical Field
The present invention relates in general to an improved data processing system and in particular to an improved method and system for manipulating graphic objects. Still more particularly, the present invention relates to an improved method and system for manipulating graphic objects and updating data structures.
2. Description of the Related Art
Data may be manipulated in many ways in a modern state-of-the-art data processing system including: data accessing, data encoding, data communications, data compression, data conversion, data entry, data exchange, data filing, data linking, data locking, data manipulation, data mapping, data modeling, etc. The large amounts of data that are available to the user of a modern state-of-the-art data processing system often become overwhelming in magnitude and complexity. These situations often may arise in the creation and execution of documents in a graphic user interface (GUI) employing windows.
Data processing systems are capable of communicating information to users in many formats, such as text, graphics, and sounds. Many times a user will create a graph to present information from various sources, such as spread sheets, word processing documents, and data bases to provide a coherent and comprehensive presentation to the user. A graph may be represented by a number of different components. For example, a bar in a bar graph may be represented by a single value or by an equation defined by two or more variables. In some cases, a user may desire to edit or alter the graph to determine how changes in different components of the graph will affect other components. Presently, a user must change or alter values for the various variables at the data structure containing the values for the variable the user desires to change by utilizing another program such as a spread sheet program or a database manages to change the values. As a result, a user often has to perform a number of complicated manipulations in order to change the graph. Such manipulations may become cumbersome and confusing when a large number of variables make up a graph.
Therefore it would be advantageous to have a method and system for providing a user an efficient way to manipulate a graph that is defined by a number of different variables.

Method and system for manipulating graphical objects


A funnel having a hose with positionable rigidity, wherein the structural configuration of the hose may be selectively positionably manipulated for facilitating the introduction, guidance and maneuverability of same through, between and/or around the parameters, boundaries and/or obstacles presented within a spatially-constrained work space, and wherein the funnel and communicating hose of the present invention may be configurationally manipulated to prevent or minimize undesirable drainage or leakage of residual liquid therefrom following a fluid transfer process. Also disclosed is a method of use of the apparatus of the present invention.

Funnels are commonly utilized to catch and direct the downward or gravitational flow of fluid from one container into another—such as in the instance of transferring motor oil from an oil container into the oil reservoir of a vehicle. Although in many circumstances the fluid receiving aperture of a selected reservoir or container is readily accessible, and therefore, enables the direct engagement of the funnel therewith, in various other applications, the fluid-receiving containers or reservoirs may be deeply recessed within and/or reside behind structural obstacles (i.e., such as within spatially-constrained engine compartments, large machinery, and the like) that prevent the direct engagement of a funnel to the fluid receiving apertures thereof.
Accordingly, conventional practice typically dictates the employ of an elongated flexible tube, wherein the proximal end of the tube is securely engaged to the spout of the funnel, and wherein the length of tubing is fed through or worked around the structural obstacles in an attempt to insert the distal end of the tube into the fluid receiving aperture of a deeply-recessed or obscured container; thus, permitting the conveyance or funneling of fluid therethrough. To facilitate such fluid transfer practices, many applicable flexible tubes are often manufactured from corrugated or pleated and expandable plastic tubing, simple rubber tubing, and/or flexible metal conduit. Unfortunately, however, each such type of tubing share inherent disadvantages that render application of same highly impractical, messy, and ineffective.
For instance, although corrugated and expandable plastic tubing possesses the requisite flexibility for facilitating the positionable manipulation of same, such tubing, and the thin plastic material from which such tubing is typically manufactured, characteristically comprises an inherently high degree of resiliency or memory. As a result, such resilient tubing will not hold or maintain a desired positionably manipulated configuration absent a continuous manual force applied or exerted thereover. That is, such tubing does not provide the user with precise positionable rigidity, but instead, attempts to resume a substantially, and naturally, colinear or columnar configuration. Accordingly, when such tubing is being utilized to gain access and funnel liquids into deeply recessed and/or obscured containers, attempting to successfully feed or work the positionably manipulated length of tubing through and/or around structural obstacles within a work space can be largely difficult, as the users hands and arms will likely not fit in or through an already spatially-constrained work space. As such, without a continuous manual force applied or exerted over the tube to maintain a desired positionably manipulated configuration of same, the tube will resiliently return to its original columnar configuration, thereby retarding, hindering or preventing access to the recessed/obscured container. Unfortunately, tubing manufactured from rubber and/or metal conduit share similar disadvantages.
Metal conduit is further notorious for long-term or latent disadvantages that surface through frequent use of same. Specifically, although metal conduit provides a certain degree of resiliency or memory, regular and repeated shaping, bending and overall positional manipulation of the conduit results in structural degradation about the stress points (i.e., areas repeatedly bent or shaped) of the tubing. Consequently, a plurality of fissures or cracks develop through the length of the metal conduit, thus subjecting the conduit to potential breakage, and further resulting in leakage of fluid through the fissures during use and application of the conduit.
Yet another disadvantage commonly associated with fluid transfer assemblies incorporating such flexible and resilient tubing is that during and/or upon resilient return of the tube into a naturally columnar configuration, or during sag of the tube, residual liquid within the tubing tends to drain or leak from the distal end thereof, thereby soiling surrounding surface areas. Additionally, following completion of the fluid transfer process, the funnel engaged to the proximal end of the tube is often laid down or rested on its side and, as such, residual liquid from within the funnel and/or tube tends to leak or spill therefrom; thus, similarly soiling surrounding surface areas. Unfortunately, available funnel-based fluid transferring assemblies do not provide a means for preventing such undesirable drainage or leakage of residual liquid therefrom.
Therefore, it is readily apparent that there is a need for a funnel having a hose with positionable rigidity, wherein the hose may be regularly and repeatedly shaped, bent, twisted, or otherwise structurally configured or arranged to maintain a hands-free positionably manipulated configuration for facilitating the introduction, guidance and maneuverability of same through, between and/or around the parameters, boundaries and/or obstacles presented within a spatially-constrained work space. There is a further need for such a fluid transfer assembly that provides a flexible hose that may be regularly and repeatedly configurationally manipulated without risk of structural degradation about the stress points thereof. There is still a further need for such a fluid transfer assembly that may be configurationally manipulated to prevent undesirable drainage or leakage of residual liquid from the funnel and/or communicating hose prior to and/or following completion of the fluid transfer process.

Funnel having a hose with positionable rigidity


A tool for clamping using end surfaces of box workpieces, comprises a soleplate and an upper template. A tightening cylinder has a piston rod connected with a top plate, and the top plate and the piston rods are in swinging connection. Three protrusions are arranged on the upper surface of the top plate and distributed in a triangle shape. A rotating shaft is arranged beside a position of the upper template, the upper end of the rotating shaft is provided with a hand wheel capable of driving the rotating shaft to rotate, the rotating shaft is sleeved with a compression spring on the portion between the hand wheel and the upper surface of the upper template, and the lower end of the rotating shaft is fixed with one end of a transverse support rod which is linked with the rotating shaft.

When machining fitting surfaces of box workpieces, the box workpieces need to be clamped and fixed using the end faces of the box workpieces. As the end surfaces of the box workpieces are often uneven, it is difficult in using the existing tools to clamp and fix the box workpieces by using the end surfaces of the box workpieces, thus making the machining of the fitting surfaces of the box workpieces difficult.

Tool for clamping using end faces of workpieces

Hengdian Electronic Industry Zone, Dongyang, Zhejiang


A system and method for actuating a shut-off valve in a wellbore wherein the shut-off valve element can be positively closed before the pump is removed from the well. A hydraulic actuator component is operably associated with the shut-off valve to provide for selective isolation of the well by positive closing of the valve prior to removal of the pump and opening of the valve after replacement of a pump within the wellbore. The hydraulic actuator component has a balanced hydraulic design wherein the valve closure element may be moved toward an open or closed position by flow of hydraulic fluid through first and second hydraulic lines. When a repaired pump or replacement pump is placed into the well, the actuator is stabbed into a packer element to seat it. The hydraulic actuator assembly is then operated to open the shut-off valve, thereby reestablishing well operation.

1. Field of the Invention
The invention relates generally to systems and methods for shutting in and isolating a production reservoir in association with the operation of pulling a failed artificial-lift pump from a well.
2. Description of the Related Art
During the later stages of production of hydrocarbons from a wellbore, downhole artificial lift pumps are often used to help assist hydrocarbons from the well. Unfortunately, these pumps occasionally suffer breakdowns or malfunction and tend to have a lifespan of only 2–3 years, in any case. When a pump become non-operational, the pump is pulled from the wellbore and either repaired or replaced with a new pump during a workover of the well. In order to remove the pump from the wellbore, it is necessary to close off, or isolate, the well below the pump against fluid flow. If the well remains live while the pump is being removed, pressurized fluid could be forced to the surface very quickly, resulting in a dangerous situation at the wellhead and potentially reducing the ability of the well to produce further.
One technique for isolating a well is to "kill" the well by introducing fluids, such as seawater, at the surface of the well to increase the hydrostatic pressure within the well to a point where it is higher than the formation pressure. The problem with this technique is that it is usually undesirable to introduce fluids into the formation below, as such may reduce the quality and quantity of production fluid that may be obtained from the well later.
A second method for isolating the well is to provide a shut-off valve below the pump that is being removed and then to close the shut-off valve as the pump is removed from the well. A conventional shut-off valve arrangement is a sliding sleeve valve having lateral fluid openings with an internal sleeve that is axially moveable between positions that open and close against fluid communication. A sliding sleeve cut-off valve of this type is described in, for example, U.S. Pat. No. 5,156,220 issued to Forehand et al. and U.S. Pat. No. 5,316,084 issued to Murray et al. Each of these patents are owned by the assignee of the present invention and are hereby incorporated by reference. A shut-off valve assembly of this type is also available commercially from the Baker Oil Tools division of Baker Hughes Incorporated as the Model "CMQ-22" Sliding Sleeve.
Typically, the valve element of the sliding sleeve valve is closed solely by the action of removing the pump. The pump has a stinger extending downwardly therefrom with a shifting collet on the lower end. The shifting collet is formed to engage the sleeve element of the sliding sleeve valve. When the pump is pulled from the wellbore, a tubing hanger pressure seal at the surface of the well is breached. The shifting collet is then pulled upwardly and moves the sleeve member of the sliding sleeve valve upwardly as well. When the repaired pump or replacement pump is to be disposed into the well, the stinger with shifting collet is secured to the lower end of the repaired/replaced pump. As the pump is run into the wellbore, the shifting collet once more engages the sleeve element of the sliding sleeve valve and, this time, moves the sleeve element axially downwardly within the valve to open the lateral fluid ports to fluid communication.
This procedure for opening and closing the shut-off valve, while simple, presents practical problems. Because the well is live, there is typically a significant pressure differential across the shut-off valve. The inventors have recognized that, if the valve is not positively closed at the time the pump is removed, pressure may escape from the well below the pump. With the procedure where the sleeve element is closed by pulling the pump from the well, the valve is not fully closed until the pump is raised some distance within the wellbore, thereby permitting such an escape of pressure.
The present invention addresses the problems of the prior art.

Method and apparatus to isolate a wellbore during pump workover