A plug-in unit-mounting structure which makes it possible to efficiently accommodate plug-in units without being dependent on the structure of a shelf. The plug-in unit-mounting structure comprises a shelf that has connectors disposed on a back wiring board, for being fitted to the plug-in units, and at least one mounting frame that is mounted in the shelf, for each accommodating an associated one of the plug-in units, and enabling the plug-in unit to be inserted in and removed from an associated one of the connectors, the mounting frame being provided with a guide rail which enables a position of disposition of the plug-in unit to be changed according to a size of the plug-in unit. This makes it possible to efficiently accommodate plug-in units without being dependent on the structure of a shelf.

1. Field of the Invention
This invention relates to a plug-in unit-mounting structure and an electronic apparatus, and more particularly to a plug-in unit-mounting structure for mounting plug-in units having various circuit packages mounted on printed circuit boards thereof, and an electronic apparatus.
2. Description of the Related Art
Electronic apparatuses for communication, such as transmitters and switchboards, use a bookshelf-type electronic apparatus in which a plurality of printed circuit board units (hereinafter referred to as "plug-in units (PIUS) each having electronic circuit packages are vertically mounted on a back wiring board (BWB) mounted on the rear face of a metal shelf thereof. The PIU comprises a printed circuit board and a plurality of electronic circuit packages each formed with electronic circuits, such as LSIs (Large-Scale Integrated circuits), mounted on the printed circuit board. There have been already proposed several plug-in unit-mounting techniques for mounting PIUs on the BWB.
FIG. 13 is a front view of an example of a plug-in unit-mounting structure.
In a metal shelf 100, respective sets of substantially C-shaped upper and lower guide rails 103a and 103b are secured to upper and lower sides 101 and 102 thereof in a manner opposed to each other at equally-spaced intervals. Box-shaped full-size PIUs 104 can be vertically mounted in the metal shelf 100 using the upper guide rails 103a and the lower guide rails 103b as guides. Further, center rails 105 are provided between associated ones of the upper and lower guide rail 103a and 103b of the metal shelf 100 as intermediate guide members. With this arrangement, half-size box-shaped PIUs 106 can be vertically mounted at respective upper shelves of the metal shelf 100 using the upper guide rails 103a and the center rails 105 as guides. Similarly, half-size box-shaped PIUs 107 can be mounted at respective lower shelves using the center rails 105 and the lower guide rails 103b as guides (see e.g. the pamphlet of International Publication WO 00/074454 (Section of [Brief Description of the Construction of Telecommunications Apparatus 10] in PREFERRED EMBODIMENTS FOR WORKING THE INVENTION, and FIG. 1)).
Thus, PIUs 104, 106 and 107 having different sizes can be mounted on the BWB (not shown) of the metal shelf 100 shown in FIG. 13, and hence it is possible to simplify the design of e.g. a package-type communication apparatus, which improves not only economy but also the convenience of maintenance.
FIG. 14 is a front view of another example of the plug-in unit-mounting structure.
In a metal shelf 200, guide rails 202 are not mounted on the upper and lower sides, but are mounted on a BWB 201 in a cantilever manner such that they protrude forward and are inwardly opposed to each other. Box-shaped PIUs 203 and 204 having bar-shaped guides (not shown) mounted along two opposed sides which are orthogonal to a side where connectors are mounted can be vertically mounted in the metal shelf 200 using the guide rails 202 as guides. The vertical distances between locations where the guide rails 202 are mounted are determined in a manner adapted to the sizes of the PIUs to be mounted (see e.g. Japanese Unexamined Patent Publication No. H04-113693 (fourth and fifth pages, and FIGS. 1 and 3).
Thus, the metal shelf 200 shown in FIG. 14 is configured such that the guide rails 202 are mounted on the BWB 201 in a manner adapted to the sizes of the PIUs 203 and 204 having different sizes. Therefore, the PIUs 203 and 204 can be mounted on the metal shelf 200 in high density without the waste of space.
FIG. 15 is a front view of still another example of the plug-in unit-mounting structure.
Respective sets of substantially C-shaped guide rails 303a and 303b are secured to an upper side 301 and a lower side 302 of a metal shelf 300 in a manner opposed to each other. Printed circuit board-type full-size PIUs 304 can be vertically mounted on the metal shelf 300 using the guide rails 303a and 303b as guides. Further, some of the guide rails 303a and 303b secured to the metal shelf 300 hold mounting frames 305 for the PIUs 306 and 307. Each mounting frame 305 has center rails 305a and 305b integrally formed therewith, and grooves 305c formed in the top and bottom thereof, for engagement with the guide rails 303a and 303b (see e.g. Japanese Unexamined Patent Publication No. 2005-277281 (Paragraph Numbers [0010] to [0024] and FIG. 1)).
As described above, in the metal shelf 300 shown in FIG. 15, by using the mounting frame 305, half-size PIUs 306 of printed circuit board type can be mounted at upper shelves by each being guided between the guide rail 303a and the center rail 305a of the mounting frame 305. Similarly, half-size PIUs 307 of printed circuit board type other than those 306 can be also mounted on lower shelves by each being guided between the guide rail 303b and the center rail 305b of the mounting frame 305.
In the illustrated example, only by fixing the guide rails 303a and 303b to opposed sides of the metal shelf 300, it is possible to cope with PIUs having different sizes. Therefore, as distinct from the case of the metal shelf 100 shown in FIG. 13, it is not necessary to provide the center rails 105 thereto as the intermediate guide members, which makes it possible to perform high-density mounting using a smaller number of components. Further, as distinct from the metal shelf 200 shown in FIG. 14, it is not required to mount each guide rail 202 on the BWB 201 in a manner adapted to the size of a PIU 203. Therefore, even when the PIUs 304, 306 and 307 already mounted in the metal shelf 300 are replaced by PIUs having different sizes, it is possible to easily mount PIUs having desired widths at predetermined locations.
However, in both of the above-described plug-in unit structure shown in FIGS. 13 and 15, the guide rails for guiding the PIUs to the BWB are mounted on the metal shelves themselves. In general, the number of layers of a printed circuit board increases or decreases depending on the amount of wiring, and hence as the amount of wiring becomes larger, the size of the printed circuit board in the direction of the thickness thereof inevitably tends to increase. Therefore, in the cases of the metal shelves 100 and 300, there is a problem that existing guide rails are not suitable for the mounting of a PIU on which is mounted a different printed circuit board increased in size in the direction of thickness thereof and having a larger amount of wiring.
Further, in the case of the metal shelf 300 shown in FIG. 15, if a PIU has a different thickness, as in the case of a PIU in which a heat sink provided with a radiation fin is arranged on a printed circuit board, it is not easy to mount the PIU on the metal shelf 300. What is more, when mounting a box-shaped PIU without containing a printed circuit board to begin with, it is required to provide guide rails for guiding the box-shaped PIU in place of the fixed guide rails 303a and 303b.
On the other hand, the FIG. 14 metal shelf 200 for mounting the box-shaped PIUs 203 and 204 is adapted only to the box-shaped PIUs 203 and 204, and hence it is impossible to mount PIUs having a printed circuit board exposed without being covered with a box-shaped covering. Further, since the opposed guide rails 202 are separately fixed to the BWB 201, and hence, the distance between the opposed guide rails is sometimes not uniform due to variations of parts thereof.
As described above, the above-described electronic apparatuses suffer from the problem that it is not easy to replace PIUs mounted on a shelf or increase or reduce the number of mounting frames e.g. when changing the design of the apparatuses.

Plug-in unit-mounting structure and electronic apparatus


An electric junction box having a simple configuration that can prevent a terminal from being pulled down. In an upper connector attached to a fuse box, terminal holders are provided so as to support relay portions of bus bar terminals from the front. Such a structure provides a simple configuration that can prevent the bus bar terminals from being pulled down when being received into and removed from an opposite connector. The relay portions are clamped between rear end edges of the terminal holders and rear walls of connectors. Such a configuration completely controls movement of the relay portions along the fitting direction to the opposite connector, thus reliably preventing displacement of the bus bar terminals.

1. Field of the Invention
The present invention relates to an electric junction box and more particularly to an electric junction box including a terminal holder configured to provide support to a bus bar terminal of the electric junction box.
2. Description of Related Art
The prior art, such as Japanese Patent Laid Open Publication 2001-25137, discloses an electric junction box used for distributing electric power from a vehicle power source to various electrical components. In the electric junction box of the prior art, the electric junction box has control elements and switching elements mounted on one surface of a circuit board and a circuit component mounted on the other surface of the circuit board within a water-proof case. The bus bar is adhered to the circuit component through an insulating layer. The bus bar board is electrically connected to the switching elements forming an electrical circuit.
Some prior art electric junction boxes include a case having a hood shaped connector that accommodates a bus bar terminal inside. In the aforementioned prior art electric junction boxes, the bus bar terminal is provided at an end of the bus bar. Further, an opposite connector is received into the connector and provided on an end of an electric wire connected to a power source, an alternator or similar device. An opposite terminal received by the opposite connector is configured to be electrically connected to an end of the bus bar terminal.
In cases where the height of a bus bar board differs from the height of a connector, or the bus bar terminal extends in a direction from the bus bar board that differs from a receiving direction of the bus bar terminal to an opposite connector; the bus bar terminal is required to be cranked or folded by bending in order to be received by the connector. When the bus bar terminal is repeatedly received by and removed from the opposite connector an end of the bus bar terminal is pulled due to frictional engagement with the opposite connector. As a result, a bending portion of the bus bar terminal may be deformed near its end.
The bus bar terminal can be prevented from being pulled down and deformed by fixing a locking piece to the bus bar terminal. In the aforementioned configuration the locking piece is configured to elastically fix the bus bar terminal from an inner peripheral surface of the connector.
The construction of the prior art described above, however, has the disadvantage of requiring the additional labor of configuring the locking piece to engage the bus bar terminal in an assembling process and also complicates the housing structure, resulting in increased costs.


The apparatus for metering the state of charge of a battery has a battery current sensor providing a voltage signal dependent on a current flowing into or out of the battery, an integrator for integrating the voltage signal, a window detector circuit providing an output signal each time an output of the integrator reaches an upper or lower threshold voltage level, a digital processing device utilizing the output signals of the window detector circuit to construct a digital battery charge state model, and a switch arrangement for reversing connection of the battery current sensor to the integrator periodically so as to cancel effect of any voltage offset in the output of the integrator.

1. Field of the Invention
This invention relates to apparatus and method for the coulometric metering of the state of charge of a battery, for use, for instance, in a handheld telecommunications device.
2. Description of the Prior Art
Conventionally, battery state of charge meters depend on either measuring the voltage across the battery, or measuring the battery current and charging or discharging a battery modeling device. Judging battery state of charge purely on the basis of the battery voltage is difficult because of variations of battery voltage with load and temperature. Battery history is also relevant. Furthermore, a high level of accuracy of voltage measurement is required as the voltage fluctuates little.
In so-called coulometric metering using a battery modeling device, the modeling device is charged and discharged in accordance with the current flowing into and out of the battery. The modeling device has traditionally been an analog device, but a digital model is more appropriate for use in handheld telecommunications devices. Periodically sampling the battery current and converting the current samples to digital format for digital processing involves various problems. To keep the power consumed by the metering process as low as possible, the sampling frequency should kept be low, but this can give rise to inaccuracies caused by short current pulses between samples. The accuracy of conversion also needs to be high and, because very low current levels are involved, small errors introduced by the analog components of the sampling circuitry can become significant.

Apparatus and method for coulometric metering of battery state of charge


A method for performing trans-anal resection is achieved by applying a first stitch about the rectum, wherein deep bites of the first stitch capture and fold a rectum wall, creating a longitudinal staple line in the rectal wall at a position adjacent the first stitch, positioning a curved surgical stapler instrument in the rectum for capturing the rectal wall held by the first stitch, firing the surgical stapler instrument creating a circumferential first staple line approximately along the arc defined by the first stitch, and repeating the procedure about the circumference of the rectum until a predetermined portion of the rectum is fully resected.

1. Field of the Invention
The present invention relates to a surgical stapling and cutting instrument adapted for use in trans-anal resection and an associated method for performing trans-anal resection. More particularly, the present invention relates to a surgical stapling and cutting instrument having a curvature particularly adapted to fit within the rectum adjacent the anal canal for the performance of the trans-anal resection as well as the method for using the surgical stapling and cutting instrument.
2. Description of the Prior Art
Surgical stapling and cutting instruments are commonly utilized in the diagnosis and treatment of pathologies treated by staple resection. Surgical stapling instruments provide a mechanism to extend the transluminal exploitation of mechanical suturing devices introduced via the anal canal, mouth, stomach and service accesses. Although surgical stapling and cutting instruments are most commonly utilized with rectal pathologies, surgical stapling and cutting instruments may be used in a variety of environments.
Surgical stapling and cutting instruments generally include a support frame, an anvil attached to the support frame and a cartridge module carrying a plurality of staples. The instruments also include a driver within the cartridge module which pushes all of the staples out simultaneously into the anvil to form the staples into a generally B-shape, suturing tissue together. In addition, these instruments include approximation mechanisms for moving the cartridge module from a spaced position relative to the anvil to accept tissue therebetween to a closed position where the tissue is clamped between the anvil and the cartridge module. Finally, the instruments include a firing means for moving the staple driver forward to form the staples against the anvil.
In addition to other procedures, surgical stapling and cutting instruments have been utilized in conjunction with trans-anal resections. Trans-anal resection is a surgical procedure utilized to remove tissue, for example, tumorous tissue, within the rectum by operating through the anus. This procedure is commonly performed to treat early stage rectal cancer or rectal tumors close to the anus. In accordance with this procedure, a section of the rectum is removed and the remaining opposed edges are coupled to complete the linking of the anus with the remainder of the rectum.
With the foregoing in mind, those skilled in the art will appreciate the need for more advanced procedures relating to trans-anal resection, as well as the need for advanced instruments specifically designed to facilitate the advanced surgical procedures. The present invention addresses this need through the provision of a technique for trans-anal resection and an associated curved cutter stapler adapted for assisting in the performance of the procedure.

Method for performing trans-anal resection with a curved cutter stapler


An antifuse based PROM cell design allows large currents to be sinked during cell programming to ensure low programmed resistance of the cell while using minimum-geometry select devices. This is achieved by utilizing a pseudo SCR latchup effect during programming. The regions in the semiconductor substrate forming lower antifuse electrodes for the antifuses in the PROM cells are doped at low levels with phosphorus. An antifuse layer formed from an oxide, oxide-nitride, or oxide-nitride-oxide antifuse layer, is formed over the lower antifuse electrode, and an upper antifuse electrode is formed from polysilicon. A minimum-geometry N-Channel select transistor is formed in series with the antifuse to complete the PROM cell. The drain and source diffusions of the select transistor are arsenic doped and the drain diffusion is contiguous with the lower antifuse electrode. A bit line is contacted to the upper antifuse electrode and the select transistor gate is part of a polysilicon word line. The source diffusion of the select transistor is grounded.

1. Field of the Invention
The present invention relates to antifuse technology. More particularly, the present invention relates to a novel programmable read only memory cell fabricated using antifuse technology.
2. The Prior Art
In applications employing normal ONO antifuses having their lower electrodes disposed in the silicon substrate, substrate regions comprising lower antifuse electrodes have typically been doped to very high levels (i.e., 1e20) with arsenic, usually in the same masking step used to form source/drain diffusions for active devices in the substrate.
Programming antifuses often takes a large amount of current, in excess of 4 mA and as much as 15 mA if an output impedance of 250 ohms or less is desired in the programmed antifuse. This means that a rather large MOS transistor is required, as much as 20 .mu..
This large transistor size is rather prohibitive for programmable read only memory (PROM) cells. The tradeoff between on resistances of programmed antifuse PROM cells higher than 250 ohms and the need for such large select transistors has been unacceptable in the prior art.


An agitation apparatus which is suitable for use in a cleaning head of a vacuum cleaner includes first and second flow paths. Each of these flow paths has a resonant cavity and an inlet/outlet port which joins the cavity to a space within the cleaning head. A generator, such as a loudspeaker with a diaphragm, generates an alternating pressure wave between the ports. Pressure waves are emitted from one of the ports in an anti-phase relationship with the pressure waves from the other of the ports, thus reducing operating noise. Due to both sides of the generator or diaphragm being exposed to an equal static pressure, the generator operates more reliably. A plurality of these arrangements can be provided across the cleaning head, and a part of the agitation apparatus, such as the driver, can be mounted on the main body of the vacuum cleaner.

Vacuum cleaners generally remove dirt, dust and other debris from a surface by a combination of a suction force, generated by a motor-driven fan, and some form of mechanical agitation of the floor surface. The mechanical agitation often takes the form of a rotating brush bar which is driven by a motor or by an air turbine. The rotating brush bar 'beats' the carpet pile while the suction force 'sucks' dirt and dust from the surface.
Agitation of a carpet by a brush bar inevitably causes some damage to the carpet and also causes wear on the brush bar and the drive system for the brush bar.
There have been various proposals for tools which make use of a vibrating airstream to promote the release of dirt from a carpet. U.S. Pat. No. 5,400,466 shows a cleaning head with a loudspeaker supported and sealed within the cleaning head which directs airwaves towards the surface in the frequency range of 10-200 Hz or 200-500 Hz.
However, tools of this kind have a disadvantage in that they can be noisy in use. Also, the use of a loudspeaker near to a source of suction causes problems with operation of the loudspeaker since there is a tendency for the loudspeaker cone to be sucked towards the source of suction.


Provided is an image processing apparatus including: a cutout frame setting section configured to set a cutout frame for partially cutting out an editing target image as an editing target; an image editing section configured to edit, in response to an instruction from a user, an image in the cutout frame superimposed on the editing target image; and a cutout image generation section configured to cut out the image in the cutout frame from the editing target image and generate a cutout image.

The present disclosure relates to an image processing apparatus, an image processing method, and a program, more particularly, to an image processing apparatus, an image processing method, and a program with which operability in an image cutout operation can be improved.
In recent years, along with a prevalence of digital still cameras, editing processing is generally performed on a photographed image as digital data after photographing. As such image editing processing, there is image cutout processing that involves partially cutting out a photographed image in a rectangle and removing unnecessary parts (see, for example, Japanese Patent Application Laid-open No. 2007-281650).
As shown in FIG. 1, for example, in a case where an image editing application program is activated and an image editing is to be performed by a mouse operation in a personal computer, an editing target image is first selected to be displayed from photographed images, and a corner of an area to be cut out from the editing target image is clicked to determine a reference position. Then, a drag operation is performed diagonally from the reference position so as to set an arbitrary cutout frame and enable the image in the frame to be cut out.

Apparatus, method and program for cutting out a part of an image


An engine control computer estimates the cumulative NO.sub.x storage in a NO.sub.x trap based on engine operating conditions and enters a NO.sub.x purge mode of operation when a maximum storage capacity limit, based on trap temperature, is exceeded. The purge mode is terminated when NO.sub.x storage level decreases below a minimum storage capacity limit. The rate of NO.sub.x dissipation is also based on trap temperature.

Conventional lean burn engine control systems include an air/fuel controller that delivers fuel to the engine intake proportional to measured air mass to maintain a desired air/fuel, lean of stoichiometric. The typical three-way catalytic converter provided in the engine exhaust passage does not convert the NO.sub.x produced while running lean and in order to reduce NO.sub.x emission to the atmosphere, it has been proposed to locate a NO.sub.x trap downstream of the three-way catalyst.
A typical NO.sub.x trap utilizes alkali metal or alkaline earth materials in combination with platinum in order to store or occlude NO.sub.x under lean operating conditions. The mechanisms for NO.sub.x storage involves the oxidation of NO to NO.sub.2 over the platinum followed by the subsequent formation of a nitrate complex with the alkaline metal or alkaline earth. Under stoichiometric operation or operation rich of stoichiometric, the nitrate complexes are thermodynamically unstable, and the stored NO.sub.x is released and catalytically reduced by the excess of CO, H.sub.2, and hydrocarbons (HCs) in the exhaust.
Accordingly, in the prior art, the amount of NO.sub.x introduced to the trap since the last purge is estimated and when the trap is estimated to be full the engine is switched to a relatively rich air/fuel to purge the NO.sub.x trap. After a predetermined purge time interval, the engine is returned to lean operation. The prior art relies on engine speed to determine NO.sub.x accumulation, see for example U.S. Pat. No. 5,473,887. However, engine speed alone does not provide an accurate estimation of NO.sub.x accumulation since several other variables that affect NO.sub.x accumulation are different at the same engine speed depending on other engine operating condition, thereby causing wide swings in the rate of NO.sub.x accumulation. It is important to obtain as accurate an estimate of NO.sub.x accumulation as possible since underestimation will permit lean operation to continue after the trap is full and tailpipe NO.sub.x emission will result. On the other hand overestimation of the accumulated NO.sub.x will cause purging at a rich A/F at a higher frequency than required, reducing fuel economy.

Method and apparatus for maintaining catalyst efficiency of a NO.sub.x trap


A multi-wavelength optical imaging system and method. In one example, an optical imaging system includes an integrated dewar assembly housing a staring detector that includes a plurality of focal plane array sensors spatially distributed over a common focal plane and aligned relative to one another, each of the plurality of focal plane array sensors being configured for a different waveband. The optical imaging system further includes foreoptics, such as a telescope, optically coupled to the integrated dewar assembly and configured to direct and focus light from an entrance pupil of the optical imaging system into an optical beam incident on at least one of the plurality of focal plane array sensors.

Various applications use multi-wavelength sensors. Currently there are two solutions generally employed for multiple wavelength staring sensors, namely the use of single multi-wavelength focal plane array sensors, or the use of multiple co-aligned single wavelength focal plane array sensors.
Using multiple separate co-aligned single wavelength focal plane array sensors entails independently aligning the individual sensors with high precision, typically using a beamsplitter and alignment targets. As a result, this approach generally uses highly sophisticated mounting systems which will accommodate alignment correction while holding the focal plane array sensors accurately in their relative positions during operation of the system and over the operating temperature range. A further complication with this approach is that the sensors are generally aligned at ambient temperature; however, they will often be cryogenically cooled during operation, which can lead to alignment errors. Using multi-wavelength focal plane array sensors simplifies the alignment of the wavelength bands since the alignment is done during manufacturing of the sensor array itself. For example, the different wavelength detectors may be grown on top of each other on a semiconductor wafer. However, this process increases the cost of the sensor and risk of defects that result from the additional processing and handling steps during manufacture, and reduces the array's performance. For example, defective pixels in one wavelength band are typically correlated with defective pixels in another wavelength band since the band-detectors are grown on top of one another.

Imaging system with multiple focal plane array sensors


The present invention relates to a method for enhancing the use of a computer network which is accessed by use of a wireless device. Specifically, one embodiment of the present invention pertains to a method of using server-resident software assistants, programs to assist the wireless device user, to perform a significant amount of the tedious input tasks required when wireless devices such as PDAs attempt to exploit the services available on the Internet. The method provides a mechanism by which software assistants can be programmed to a users' own specific information and ways of performing tasks that exploit Internet services such as purchasing, information searches, event planning and complex scheduling. The task can be organized in structural task lists that interface with a user's stored preferences and PIM information on the portable electronic device.

As the components required to build a computer system have reduced in size, new categories of computer systems have emerged. One of the more recent categories of computer systems is the portable or "palmtop" computer system, or personal digital assistant (PDA). A palmtop computer system is a computer that is small enough to be held in the hand of a user and is thus "palm-sized." By virtue of their size, palmtop computer systems are also lightweight and so are exceptionally portable and convenient. As a result, palmtops are readily carried about in a briefcase or purse, and some palmtops are compact enough to fit into a person's pocket. Further development of PDAs has enabled their use for portable, and now wireless, access to computer networks and the World Wide Web. The portability and convenience makes such devices ideal for such wireless access when the user is away from a wired workstation.
On the other hand, because they are relatively small, the displays on PDAs or palmtops are necessarily limited in their ability to present information from many websites and the speed of entering information into an interactive window is necessarily slow. Most limiting, however, is the narrow communication band-width currently available to these convenient devices.
The area in which PDAs and palmtops excel is in the area of personal information management (PIM). Most operating systems in palmtops are extremely well adapted, incorporating personal information managers (PIMs) in the basic collection of permanent applications.
On wireless PDAs, the integration of PIM data with the world-wide-web is tightly concentrated in a few areas, such as synchronization of a personal calendar with a web-based calendar or in placing a phone call. Current web browsing mechanisms on wireless PDAs also burden the user with deciding what kind of information is needed, where to retrieve information, how to aggregate information from multiple websites, and how to utilize the information to aid in a given task. These limitations are further aggravated by limited bandwidth and lack of adequate input methods.
What is required, then, is a mechanism for providing a better Internet experience for a user that relieves user input demands and increases output effectiveness. Such a mechanism should efficiently use the limited bandwidth available between wireless devices and their web portals, whether implemented as proprietary cellular networks or other, non-proprietary, portals.

Web-based task assistants for wireless personal devices


A fuel spacer for a fuel assembly comprises a plurality of tubular ferrules each forming a fuel rod insertion passage, a belt-like support member for supporting the tubular ferrules bundled in a lattice arrangement and a spring member for axially supporting the fuel rods disposed in the ferrules. The adjoining ferrules are joined together horizontally, each of the ferrules has at least one end to which a plurality of cutout portions are formed circumferentially of the end portion and at least one flat portion is formed between adjoining petal portions at which the adjoining ferrules are spot welded. Each of the cutout portions and petal portions of the tubular ferrule has various shapes such as trapezoidal, rectangular, triangular, V or M shape. The cutout portions and petal portions may be formed at both axial ends of the tubular ferrule. The adjoining ferrules are joined together such that an end portion of one ferrule to which the cutout portions are formed is spot welded to an end portion of another ferrule to which any cutout portion is not formed. The petal portions formed on a downstream side with respect to a coolant flow in a fuel assembly is twisted outward to provide revolutional flow and an opened end of the ferrule.

The present invention relates to a fuel spacer for a fuel assembly and, more particularly, an independent cell type fuel spacer for the fuel assembly.
A known fuel spacer for a fuel assembly incorporated in a boiling water type reactor has a structure, as for example, is disclosed in the Japanese Patent Laid-open (KOKAI) No. 59-65287 (65287/1984) and shown in FIG. 15. Referring to FIG. 15, the fuel spacer is composed of a plurality of tubular ferrules 41 in each of which a fuel rod is charged and these tubular ferrules 41 are arranged in a lattice structure, in which the adjoining ones are joined together by welding means, for example. A water rod is also charged in the tubular ferrule 41. As shown in FIG. 15, the ferrule 41 has inward projections 13b formed to its cylindrical wall, and a cutout 15 is formed to the ferrule wall and a pawl portion 16 is also formed so as to project in the cutout 15.
Also known are cylindrical ferrules 42 each having an octagonal cross section as shown in FIG. 16, in which each ferrule 42 has inward projections 43 formed to the cylindrical wall thereof and reference numeral 44 denotes a continuous loop spring.
Furthermore, there has been also studied a fuel spacer to be utilized for a fuel assembly in which a water rod has an outer diameter larger than an inner diameter of a cylindrical ferrule, such as that disclosed in the Japanese Patent Laid-open (KOKAI) No. 61-198096 (198096/1986).
Recently, there has been developed an analysis of a mechanism between a transition boiling generation and a shape of a fuel spacer of a fuel assembly. Namely, it has been found out that transition boiling is likely to be generated at a portion near the lower ends of a first or second fuel spacer from the upper side of the fuel assembly in an installed state at a time when a power of the fuel assembly approaches its critical power output (at present, seven or eight fuel spacers are disposed axially along the fuel assembly). The fuel spacer acts to deposit liquid drops of a coolant to a surface of a fuel rod on a downstream side of the fuel spacer by agitating two phase flows of steam and liquid, thereby making the thickness of a liquid film thicker. As a result, the critical power output increases, contributing in the increasing of thermal margin of the fuel, increasing the power density of a reactor and increasing the power generation capacity. Accordingly, it has been considered to increase the number of the fuel spacers to be arranged.
However, increasing of the number of the fuel spacers results in the increasing of fuel axial pressure loss. Because fuel spacers each have a relatively large local pressure loss due to rapid constriction or expansion of flow sectional area, and fuel spacer local pressure loss occupys a large portion of axial pressure loss. It provides a problem in stability of the fuel assembly and increasing the necessary lift of a pump for circulating a coolant in a core, which also results in an economical disadvantage.