A tennis racket comprising a head formed as a closed loop at the upper end, a handle for being gripped by a player at the lower end and coupling beams therebetween, the head being formed with varied inertial cross-sectional configurations around its periphery with a nearly circular cross-sectional configuration at the upper edge of the head and the lower edge of the head and with an oval wide-beam cross-sectional configurations at the sides of the head between the 2 and 5 o'clock positions and the 7 and 10 o'clock positions for generating a stiffness that is about 70% of the other sections which have nearly circular cross-sectional configuration and strings in a plane secured in the head.

1. Field of the Invention
This invention relates to a varied inertia head racket and, more particularly, to a tennis racket having a frame fabricated of a composite material with a cross-sectional configuration forming an air foil mid-head and essentially circular above and below whereby the frame will create minimum shock and vibration when striking a ball.
2. Description of the Background Art
In tennis, players use rackets to strike a resilient ball across a net. The racket is constructed of a frame having a handle portion gripped by the player, and having a looped head portion with crossed strings for striking the ball, and having an intermediate portion therebetween with beams and a yoke or throat piece coupling the handle and the head.
Tennis racket frames have been traditionally constructed of a large number of materials. Originally they were constructed of wood. Subsequently, metal rackets were utilized to a great extent. More recently, racket frames of composite materials have become popular since they decrease weight and improve playability features in terms of increased strength and stiffness. Composite rackets, however, are expensive. This is because of more complex fabrication techniques. Composite rackets, however, tend to create an excessively large shock or vibration when striking the ball. This is uncomfortable and physically detrimental to the player. Consequently, there is an ever increasing search for superior materials and designs for tennis racket frames in order to maximize playability in terms of strength and reduced weight while minimizing shocks and vibrations when striking a ball. All this is done against a background of minimizing costs.
As illustrated by a great number of patents as well as commercial rackets, efforts are continuing to improve tennis rackets. None of the previous rackets, however, provides the benefits attained with the present invention. Additionally, the prior patents and commercial devices do not suggest the present inventive combination of component elements and materials arranged and configured as disclosed and claimed herein. The present invention achieves its intended purposes, objects and advantages through a new, useful and unobvious combination of component elements, with a use of the minimum number of functioning parts, at a reasonable cost to manufacture, and by employing only readily available material.
Therefore, it is an object of the present invention to provide a tennis racket comprising a head formed as a closed loop at the upper end, a handle for being gripped by a player at the lower end and coupling beams therebetween, the head being formed with varied inertial cross-sectional configurations around its periphery with a nearly circular cross-sectional configuration at the upper edge of the head and the lower edge of the head and with an oval wide-beam cross-sectional configurations at the sides of the head between the 2 and 5 o'clock positions and the 7 and 10 o'clock positions for generating a stiffness that is about 70% of the other sections which have nearly circular cross-sectional configuration and strings in a plane secured in the head.
It is a further object of the present invention to improve tennis rackets by enhancing playability and comfort with a viable combination of power and control.
It is a further object of the present invention to form the head of a tennis racket with a nearly circular cross-sectional configuration at its upper and lower extents and a wide-body oval cross-sectional configuration at its lateral extents.
It is a further object of the present invention to vary the inertia of the head of a tennis racket frame around the periphery of its head.
It is a further object of the present invention to configure the cross-sectional configuration of a racket frame with an air-foil mid-head and essentially circular above and below to effect a wrap-around when striking a ball.
It is a further object of the present invention to configure the frames of tennis rackets to effect varied inertia.
It is a further object of the present invention to improve composite tennis racket frames.
It is a further object of the present invention to minimize shock and vibration of a tennis racket when striking a ball.
It is a further object of the present invention to make hitting tennis balls more comfortable for players.
The foregoing has outlined some of the more pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or by modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.


Zwitterionic compounds, photovoltaic cell charge carrier layers containing such compounds, photovoltaic cells including such charge carrier layers, and related methods are disclosed.

Photovoltaic cells, sometimes called solar cells, can convert light, such as sunlight, into electrical energy. One type of photovoltaic cell is a dye-sensitized solar cell (DSSC).
Referring to FIG. 1, is a DSSC 100 includes a charge carrier layer 140 (e.g., including an electrolyte, such as an iodide/iodine solution) and a photosensitized layer 145 (e.g., including a semiconductor material, such as TiO2 particles) disposed between an electrode 101 and a counter electrode 111. Photosensitized layer 145 also includes a photosensitizing agent, such as a dye. In general, the photosensitizing agent is capable of absorbing photons within a wavelength range of operation (e.g., within the solar spectrum). Electrode 101 includes a substrate 160 (e.g., a glass or polymer substrate) and an electrically conductive layer 150 (e.g., an ITO layer or tin oxide layer) disposed on substrate 160. Counter electrode 111 includes a substrate 110, an electrically conductive layer 120 (e.g., ITO layer or tin oxide layer), and a layer 130 formed of a material (e.g., platinum) that catalyzes a redox reaction in charge carrier layer 140. Electrode 101 and counter electrode 111 are electrically connected across an external electrical load 170.
During operation, in response to illumination by radiation in the solar spectrum, DSSC 100 undergoes cycles of excitation, oxidation, and reduction that produce a flow of electrons across load 170. Incident light excites photosensitizing agent molecules in photosensitized layer 145. The photoexcited photosensitizing agent molecules then inject electrons into the conduction band of the semiconductor in layer 145, which leaves the photosensitizing agent molecules oxidized. The injected electrons flow through the semiconductor material, to electrically conductive layer 150, then to external load 170. After flowing through external load 170, the electrons flow to layer 120, then to layer 130 and subsequently to layer 140, where the electrons reduce the electrolyte material in charge carrier layer 140 at catalyst layer 130. The reduced electrolyte can then reduce the oxidized photosensitizing agent molecules back to their neutral state. The electrolyte in layer 140 can act as a redox mediator to control the flow of electrons from counter electrode 111 to working electrode 101. This cycle of excitation, oxidation, and reduction is repeated to provide continuous electrical energy to external load 170.

Zwitterionic compounds and photovoltaic cells containing same


A switching control circuit is coupled to a switching device and an auxiliary winding of a transformer, wherein a primary winding of the transformer is coupled to the switching device. The switching control circuit includes a voltage receiver, a comparing unit and a propagation delay circuit, wherein the voltage receiver is coupled to the auxiliary winding of the transformer for receiving a reflected voltage signal and transforming the reflected voltage signal into a peak voltage signal, while the switching device is turned off. The comparing unit is coupled to the voltage receiver for receiving the peak voltage signal and a first threshold voltage, and outputting a comparison result. The propagation delay circuit is coupled to the comparing unit for receiving the comparison result, and outputting a PWM signal to turn on the switching device after a delay time.

1. Field of the Invention
The present invention relates generally to a switching control circuit, and more specifically to a switching control circuit used for a switching power converter.
2. Description of Related Art
A power converter is used to convert an unregulated power source to a regulated voltage or current source. The power converter normally includes a transformer or a magnetic device having a primary winding and a secondary winding to provide isolation. A switching device connected in the primary winding to control energy transfer from the primary winding to the secondary winding. The power converter operates at a high frequency for allowing size and weight reduction.
However, the switching operation of the switching device will generate switching losses and electric-magnetic-interference (EMI). FIG. 1 shows a fly-back power converter and the waveforms are shown in FIG. 2. The switching device Q1 is applied to switch a transformer T1 and control the power delivered from the primary winding NP to the secondary winding NS of the transformer T1. Energy is stored in the transformer T1 when the switching device Q1 is turned on. As the switching device Q1 is switched off, the energy of the transformer T1 is discharged to the output of the fly-back power converter through a rectifier DS. In the meantime, a reflected voltage signal VR is generated in the primary winding NP of the transformer T1 in accordance with the output voltage VO and the turn-ratio of the transformer T1. Therefore, the voltage VD across the switching device Q1 is equal to the input voltage VIN plus the reflected voltage signal VR once the switching device Q1 is turned off. The energy from the voltage VD is stored in the imaginary parasitic capacitor CQ, corresponding to the parasitic capacitance of the switching device Q1. After a discharge period TDS, the energy of the transformer T1 is fully discharged, the energy stored in the parasitic capacitor CQ flows back to the input voltage VIN through the primary winding NP of the transformer T1. The parasitic capacitor CQ and the primary winding inductor (not shown) of the transformer T1 develop a resonant tank, wherein its resonant frequency fR can be shown as equation (1),
                              f          R                =                  1                      2                        π                                                                        L                  p                                ×                                  C                  j                                                                                (        1        )
Wherein, Cj is the capacitance of the parasitic capacitor CQ; LP is the inductance of the primary winding inductor of the transformer T1.
During the resonant period, the energy of the parasitic capacitor CQ is delivered to the primary inductor of the transformer T1 back and forth. There is a delay time Tq corresponding to the time the parasitic capacitor CQ takes to discharge until the voltage VD reaches a minimum value. The delay time Tq is the period of the quasi-resonance and it can be expressed as equation (2).
                              T          q                =                  1                      4            ×                          f              R                                                          (        2        )
Sum up, if the switching device Q1 is turned on during the valley voltage across the switching device Q1, which can achieve the soft switching so as to minimize the switching loss and EMI of the power converter.

Switching control circuit for a switching power converter


A method and apparatus for combining raw fibrous and binding materials in a single mixing step (Step S3), followed by consolidation (Step S5) so as to greatly shorten the overall cycle time to a finished fiber-reinforced composite part. Chopped fibrous materials and binder materials are deposited sequentially onto a belt conveyor (Step S2) so that the materials are successively layered, one on top of each other in a predetermined ratio, and subsequently mixed (Step S3) to achieve uniform dispersion throughout. The mixed materials are then deposited into a rotating mold (Step S4) to further ensure uniform dispersion of fibrous and binder materials. Impregnation of the fibrous materials with the binder material occur in-situ as the uniformly mixed materials are heated and subsequently compacted in the mold (Step S5) to obtain the desired shape of the fiber-reinforced composite part.

1. Field of the Invention
The present invention relates to a method and apparatus for forming fiber reinforced composite parts.
2. Description of the Related Art
Fiber-reinforced composite structures, such as carbon-carbon composites for example, are widely used as friction materials for heavy-duty brakes in automobiles, trucks, and aircraft. This is because they exhibit high thermal conductivity, large heat capacity, and excellent friction and wear characteristics and thus can provide excellent performance.
However, past manufacturing processes for producing these fiber-reinforced composite structures were often lengthy undertakings, requiring months to fabricate a single part. In one example, a typical fiber-reinforced composite part was prepared by a non-woven process that involved needle-punching layers of carbon fibers to form a preform, a slow, time-consuming process. When two or more layers of fibers are needle punched together by metal needles having barbs on one end, the barbs commingle fibers from a particular layer into successive layers. The commingled fibers essentially stitch the layers of fiber together. This non-woven technology achieved preform densities on the order of about 0.5 g/cc. To obtain a final composite part, the preform was subsequently infiltrated with a matrix binder material via a chemical vapor deposition ("CVD") or chemical vapor infiltration ("CVI") process, for example. CVD and CVI are used interchangeably for the purposes of the present application.
In another process, a preform was prepared by building up successive layers of pre-impregnated carbon fiber fabric. Tows (the term "tow" is used hereinafter to refer to a strand of continuous filaments) of carbon fiber were woven into a two-dimensional fabric, and thereupon dipped into a liquid bath to impregnate the fabric with a liquid resin. The resin-impregnated fabric was then pulled between rollers to form a sheet of pre-impregnated carbon-fiber fabric. After impregnation, the fabric was dried and b-staged under low heat. A plurality of desired shapes were then cut out of the sheet material and stacked within a mold, and subsequently cured using heat and pressure to obtain the desired composite part. In order to produce a carbon-carbon component, the composite part is carbonized which creates internal porosity. Multiple infiltration cycles using CVD or resin were required to achieve final density of the composite part. For this reason, it often took a term of several months to obtain a final product, causing the product to be extremely expensive. Further, much material was wasted in order to obtain the final product.
Several processes have been developed in order to reduce overall processing time needed to manufacture a fiber reinforced composite part. One process, a "random-fiber process", uses entirely tow material. Somewhat similar to the pre-impregnating method described above, in the random-fiber process a continuous tow of fiber is dipped through a resin bath, dried, and then chopped to a desired length. The resin coated chopped fibers are then placed into a mold and cured using heat and pressure. However, the steps of impregnating the continuous tow are performed separately from the molding and curing required to create the composite part, thereby extending the "process cycle" of manufacturing the composite part.
Another method involves a molding compound process whereby chopped fibrous material are mixed with a resin so as to form a continuous sheet of mixed material. A plurality of desired shapes are then cut out of the sheet material and stacked within a mold, and subsequently cured using heat and pressure to obtain the desired composite part. Again, this process requires extensive time and wastes material in order to obtain the final product.
A further process developed to shorten the manufacturing time involves using a liquid slurry to mix the fibrous material with a resin powder, as illustrated in U.S. Pat. No. 5,744,075 to Klett et al. However, the fibrous material needs to be chopped into small pieces (on the order of ¼ to ½ inch (about 0.6–1.3 cm)) so as to attain a uniform mix with the resin powder in the slurry. Thus, longer chopped fibers (1–1½ inches (about 2.5–3.8 cm)) do not work well in this liquid slurry method, since a uniform dispersion of fibrous material and resin powder in the slurry cannot be attained with the longer chopped fiber lengths. The longer fibers tended to "ball-up" during mixing with the powdered resin and during deposition into the mold, making it difficult to obtain a uniform end product. Moreover, this "balling effect" directly contributed to the "loftiness" of the preform, a disadvantageous result of the water slurry method since a lofty preform was difficult to control within the mold. Additionally, an excess step of drying the preform was required (i.e., removing the water from the preform in the heating step is required before pressing the materials into a composite part).
Recent developments have introduced a method and apparatus that combines chopped fibers and a powdered resin utilizing a dry-blending process. Such a dry-blending process and apparatus 100 is illustrated in the rough schematic diagram of FIG. 1. Apparatus 100 includes a first lower enclosure 101 connected to a second upper enclosure 102 via a neck portion 119. First enclosure 101 has an adjuster 120 connected thereto which houses compressed air lines 121 and 124 for feeding air jets 122. Second enclosure 102 houses a screen 126, and has a funnel 132 and vacuum line 135 connected thereto.
In FIG. 1, chopped tow 115 is loaded into first enclosure 101, where air jets 122 feed compressed air into the chopped tow 115 within first enclosure 101. The compressed air fed via compressed air lines 121 and air jets 122 enters below the level of chopped tow in first enclosure 101. This compressed air forces the chopped tow 115 into upper portion 117 of first enclosure 101 such that the individual fibers of the chopped tow 115 are entrained in air and further broken-up (defibrillated) into smaller strands or filaments 118. Adjuster 120 maintains the compressed air jets 122 at a level equal to or below the chopped tow 115 within first enclosure 101.
The broken-up fibers 118 entrained in air in the upper section 117 are then forced through neck portion 119 into a second enclosure 102, whereby they are mixed with a powdered resin 130 fed through at funnel 132 of second enclosure 102. The powder resin 130 mixes with the broken-up fibers in a powder and fiber mixing region 140, whereupon the "mixed materials" settle at the bottom of second enclosure 102 to form a layer which constitutes the building-up of a preform 125. The mixed materials fall due to a vacuum 135 being applied to the bottom of second enclosure 102 which removes the bulk of the air volume in second enclosure 102, thereby allowing the mixed materials to fall and condense at the bottom of second enclosure 102 on top of screen 126.
The "dry-blending" apparatus of FIG. 1 provides a medium for mixing the powder 130 with the fibrous material (chopped tow 115) to attain a uniform mixture of the binder material with the fibrous material. However, in the apparatus 100 of FIG. 1, the proportions of chopped fiber and binder material have to be first individually weighed out to obtain the proper proportions, before being loaded in enclosures 101 and 102 to be mixed in mixing region 140. Further, apparatus 100 of FIG. 1 is limited to a single-batch process, i.e., to make one final fiber-reinforced composite part, the individual proportions for each fibrous material and binder material have to be weighed and added individually for each preform made.
Yet a further process to shorten the manufacturing cycle time of a composite part is illustrated in U.S. Pat. No. 5,236,639 to Sakagami et al. The objective of this process is to provide excess carbon material to fill pores in the matrix material during subsequent curing and carbonization steps, thus producing a carbon-carbon composite material that requires no repetition of production steps including any further densification of the composite material. This involves mechanically mixing a matrix carbon material and carbon fibers in proportions that are determined on the basis of the carbonization ratio of the matrix material and on the basis of the desired ratio of fibers to be contained in a resultant end product. However, such a process requires the use of excess carbon matrix material, a curing step under pressure after formation of an intermediate-formed part such as a preform or mold, and also requires subsequent carbonization and graphitization of the cured intermediate part, both under pressure, to obtain the final fully-densified composite part. Of course, no further production steps are required or repeated, including densification of the composite material. However, it is costly and time consuming to perform the curing, carbonization and graphitization all under pressure.
Therefore, what is desired is a method and apparatus which would feed, blend, and deposit various lengths of chopped fibrous and binder materials into a mold of a desired final shape, wherein the raw fibrous materials and binder materials are combined in a single step, followed by consolidation of the materials. The resultant preform would not require any curing or carbonization under pressure during the follow-on heating processes to manufacture the final composite part. Such a method and apparatus would provide fiber-reinforced composite parts with densities that are higher than achieved with current technologies, and would decrease overall cycle time to a finished composite part. The method can be used to provide an intermediate preform product that is subsequently stabilized, carbonized, optionally heat treated, densified, and final heat treated to provide a carbon-carbon composite material.


Process and apparatus for operating a machine of the tobacco processing industry. The process includes guiding at least one wrapper strip along a conveyor path from a wrapping strip supply to a garniture device, and fixing the at least one wrapper strip in at least one preset position along the conveyor path The instant abstract is neither intended to define the invention disclosed in this specification nor intended to limit the scope of the invention in any way.

1. Field of the Invention
The invention relates to a process for operating a machine of the tobacco processing industry.
The invention also relates to a device for feeding at least one wrapper strip to a feed element that feeds the at least one wrapper snip to a rod of smokeable material or filter maternal of the tobacco processing industry, whereby the device comprises at least one cutting element severing the at least one wrapper strip.
The invention further relates to a process for returning to service a rod machine, whereby at least one wrapper strip is fed to at least one rod of smokeable material or filter material of the tobacco processing industry. The rod is conveyed by a rod conveyor and fed to at least one conveyor element carrying the at least one wrapper strip, whereby rod and wrapper strip are conveyed to a garniture for the continuous wrapping of the rod with the wrapper strip. The invention further relates to a process for emptying a rod machine, in particular a cigarette rod machine or a filter rod machine, such that a wrapper strip for wrapping a rod of smokeable material or filter material of the tobacco processing industry, located in a corresponding device or feed device, is at least partially removed,
2. Discussion of Background Information
A paper web feed device for a machine for producing cigarettes is known from DE 36 00 321 C2, which corresponds to U.S. Pat. No. 4,649,409. A suction roller is hereby provided for conveying at least one paper web to a garniture belt. Using an actuator device, on which a Wife is provided, it is possible to sever the paper web at the point where, after a start up of the cigarette production machine, the pressure applied to the cigarette paper is no longer defective. With this device a so-called startup wastage or spoilage is therefore eliminated during return to service. On the return to service or restarting of the cigarette production machine a manual action is necessary to thread the paper web after a machine stoppage.
With cigarette rod production or filter rod production, the problem can nevertheless occur that wrapping paper remains in the machine at the end of tho production of cigarette rods or filter rods, so that this has to be removed afterwards before start up or return to service. Furthermore, in the event of a tear of the wrapper strip and in the case of an initial start up of the rod machine it is necessary to manually feed the wrapper strip to a feed element, so that the wrapper strip is conveyed to a garniture belt and ultimately to a garniture. After an interruption in operation a manual feed is also necessary in the cited DE 36 00 321 C2.
This takes a relatively long time and is disruptive, in particular with two-rod machines, and also leads to faulty cigarettes rods or filter rods. In particular operational stoppages must be considered here, after which the wrapper strips regularly have to be threaded in corresponding elements. Furthermore, it is disadvantageous that in the event of an unintended tear in the wrapper strip, an undefined wrapper strip length can remain in the machine in the event of a stoppage.

Process and device for conveying a wrapper strip in a machine of the tobacco processing industry


In cameras and methods, a plurality of image pairs are captured. Each image pair has an archival image of a scene and an electronic image of the same scene. The electronic images are stored in camera memory. Photofinishing metadata and image metadata is generated for the image pairs. One or more of the electronic images are downloaded to provide downloaded files. Photofinishing metadata is excluded from the downloaded files.

The invention relates to photography and photographic equipment and more particularly relates to hybrid cameras and methods in which electronic images are downloaded with reduced metadata.
A continuing problem in the manipulation of digital images has been the size of the images relative to the capacity of the infrastructure required to manipulate those images. This particularly relates to bandwidth of network connections, but also relates to such things as the speed of connected communication ports of cameras and computers. This problem has led to digital camera users physically transferring removable memory elements to obtain photofinishing. This has the inconveniences of transferring film and, unlike photographic film, in many cases also risks damage or loss to an expensive memory element. This risk is resolved by some hybrid cameras which allow for the transfer of archival images in a film unit and at the same time provide immediate image review and electronic image downloading. In hybrid cameras, electronic images can be limited to a lower resolution than corresponding archival images so as to increase the speed of downloading. This is helpful, but further reductions in the time required for downloading are desirable.
Hybrid electronic-film cameras allow photographers to capture scene images (the light images of particular scenes) as latent images on photographic film and as electronic images that are digitized and stored in memory. Metadata corresponding to the images is also written to the memory and film. Some or all of the metadata can relate to photofinishing of the film. The electronic images are retained in the memory until being overwritten or being removed, such as by withdrawal of a removable memory unit. The electronic images are made available for use by downloading into a computer or other device. The photographer is generally allowed to view electronic images in the memory of the camera. It is currently impractical to supply so much memory in a hybrid camera that all electronic images that a photographer is likely to have an interest in reviewing indefinitely remain available for the photographer to review. Thus, some electronic images in the memory must be overwritten when later images are captured. It is desirable to delay the overwriting of earlier images so that the user will have as long as possible to review those images. Photofinishing metadata recorded in a film unit is used in the photofinishing of that film unit.
The C, H, and P print formats of APS film can be recorded on a respective APS film unit as magnetically recorded metadata on a layer of the filmstrip. APS cameras are available that allow some magnetically recorded metadata for an image to be changed after capture of that image. For example, the number of prints wanted can be changed or set to zero.
It would thus be desirable to provide improved cameras and methods in which photofinishing metadata can be changed after image capture and downloaded images are reduced in size.
The invention is defined by the claims. The invention, in its broader aspects, provides cameras and methods, in which a plurality of image pairs are captured. Each image pair has an archival image of a scene and an electronic image of the same scene. The electronic images are stored in camera memory. Photofinishing metadata and image metadata is generated for the image pairs. One or more of the electronic images are downloaded to provide downloaded files. Photofinishing metadata is excluded from the downloaded files.
It is an advantageous effect of the invention that improved cameras and methods are provided in which photofinishing metadata is stored in memory and can be changed after image capture, but photofinishing metadata is removed from downloaded images.

Hybrid cameras that download electronic images with reduced metadata and methods


A method includes generating multiple delayed versions of a first signal using at least one first delay line, selecting at least one version of the first signal, and generating a second signal based on the first signal and the at least one selected version of the first signal. The method also includes generating multiple delayed versions of the second signal using at least one second delay line, and selecting at least one version of the second signal. In addition, the method includes modifying selection of the at least one version of the first signal and the at least one version of the second signal to achieve a desired output signal based on the at least one selected version of the second signal. This method could be used in various circuits, such as duty cycle correction circuits, frequency multiplier circuits, and digital multiphase oscillator circuits.

Many types of circuits often need to delay digital signals in order to operate properly. For example, duty cycle correction circuits often delay one or more digital signals in order to produce a clock signal having a duty cycle of approximately fifty percent. This may be useful in various applications, such as in synchronous dynamic random access memories (SDRAMs) and delay locked loops (DLLs), where both rising and falling edges of a clock signal are used.
Conventional circuits that delay digital signals often suffer from various problems. For example, the accuracy of conventional duty cycle correction circuits is often proportional to the "lock time" needed to reach the appropriate duty cycle. Higher accuracy typically requires longer lock times, and shorter lock times typically require lower accuracy. Also, conventional circuits that delay digital signals often suffer from process, voltage, and temperature (PVT) variations. Because of this, the behaviour of the conventional circuits typically varies based on changes or variations in manufacturing processes, operating voltages, and operating temperatures.

Circuit and method for digital delay and circuits incorporating the same


A tubular housing includes at least one fixed helical vane formed onto the inner surfaces of the tubular housing in a spiral and adapted to direct fluid into a spiraled flow and focus fluid onto a fan blade assembly associated with an alternator system and located within the tubular housing before a system exhaust. A generator cone can be mounted near the center and front of the fan blade assembly facing fluid passing through the tubular housing. As fluid passes over the generator cone it experiences compression between the generator cone and housing resulting in increased pressure and velocity of the fluid, thereby increasing rotational speed of the generator blades and generator as the compressed, spiraled fluid passes through the blades and exits the tubular housing. The system can be used for fixed or mobile applications in water, wind and manually induced air flow.

Wind and stream or oceanographic water are forces of nature in the form of fluid that surround us and as a whole is barely being tapped for its energy generating potential. Wind is harnessed to sail ships, pump water, and create electricity, just to name a few. Hydroelectric power has also contributed largely to the production of electricity. Hydroelectric systems have also typically deployed as large industrial system and have not found wide use in the private sector. Yet untapped potential exists with streams and shorelines near residential and commercial developments.
Recent events in the world have highlighted the need for alternative, cleaner methods of power production, whether it is from the wind, the sun, water, or organic matter. Changes in battery storage capacity and life and generator efficiency have made it so that individuals desiring to supplement their energy requirements may do so at a much more affordable cost over 15 years ago. These so-called "Green" technologies continue to be improved as energy shortages and high costs of energy plague society.
In general, electric power generation systems can be classified into hydroelectric power generation, thermal power generation, nuclear power generation, solar power generation, bio-fuel power generation and wind power generation using wind energy. Wind energy is limitless, purely domestic renewable energy that is freely available in the world. The wind power generation system faces some difficulty in its stability due to fluctuation in direction and speed of air. Wind energy has been used as a source of power for sailing ships for several thousands of years, and until recently, we have been using it in water pumping and operating flour mills. Recently, many new ideas and theories for windmill and wind power generation have surfaced, like propeller shaped blades as part of large, scaled power generators that rotate based on aerodynamics of the blade designs.
Wind generated power has been used as a source of electricity that can be used directly by buildings and other fixed infrastructure, or has been fed directly into public utility system grids for distribution and use by public utility customers. Wind generated electrical power will continue to find uses as its need increases at all levels and types of consumption and as an alternative energy to fossil fuels.
It is known in the art that the propeller of a wind power generator should ideally be positioned in the path of the flowing air. In most systems currently being deployed internationally, propellers and generators can reach height greater than 100 feet and rotational diameters greater than 50 ft. Propellers currently used with wind power generators are designed in such a way to produce power output as various wind speed conditions press against propeller blades. It is unfortunate that such system must be so large, which is a main point of contention by many communities.
Systems for the generation of electrical power from natural sources are clearly needed that are smaller than is currently available and in wide use. There is also more specifically a need for smaller, less visually intrusive fluid powered electric generation systems for fixed residential, commercial and mobile applications. With the current invention a system is presented that can less expensively generate electrical energy from fluid flow, be it air or water. Power generated by the present invention can be utilized in fixed as well as mobile applications and can generate electrical power from wind, vehicle-induced airflow, flowing water in a stream or river, flowing water through water utility lines, and ocean flow near coastlines.

This patent is subject to a terminal disclaimer.

Fluid driven electric power generation system


In one aspect, it is disclosed a system for inspection of a load, comprising: a detection device configured to detect, after transmission through the load, successive radiation pulses emitted at a predetermined frequency by a source, the load being in movement in an inspection direction, at an inspection speed with respect to the system, the detection device comprising a matrix of a plurality of arrays of detectors, wherein the matrix has a width associated with the inspection direction, the width of the matrix being based on the inspection speed of the load and the predetermined frequency of the successive radiation pulses.

Inspection systems use inspection radiation transmitted through a load (such as a vehicle) for inspecting cargo of the load, for example to detect hidden objects (such as weapons or dangerous material).
In some examples, the load is moving with respect to the inspection system. A final image of the load and/or cargo is constructed by grouping thin images of the load generated during the movement of the load with respect to the inspection system.
When the speed of the load with respect to the inspection system increases, a distance between two successive thin images increases, and parts of the load may not be viewed in the final image. This may result in hidden objects not being detected.
Aspects of the present invention address some of the above issues.

Inspection system with a matrix and method


An improved clocked data converter with a vibrating microelectromechanical systems (MEMS) resonator. The MEMS resonator is used as part of the clock circuitry of an analog to digital converter or a digital to analog converter. The MEMS resonator may be used as the frequency determining element of an on-chip oscillator, or as a bandpass filter used to clean up an external clock signal.

Analog to digital converters (ADCs) and digital to analog converters (DACs) are used in a wide variety of electronic systems, bridging the analog and digital worlds. They are widely used as modular components as well as key components in system-on-chip (SOC) integrated circuits. ADCs and DACs are clocked components, performing conversions according to a clock signal. The performance of both analog to digital converters and digital to analog to digital converters is adversely affected by the effects of clock jitter. Jitter is the result of imperfect clock sources, and of clock signal propagation problems including signal reflections and noise contamination. Some data converter topologies, e.g. sigma-delta types, are especially sensitive to clock jitter. In spite of advances in phased lock loop (PLL) technology, clock jitter remains a key obstacle to improving data converter performance.

Data converter with integrated MEMS resonator clock


An equipment rack panel system using one or more rack extension panels with optional raceway to interconnect equipment cables to service cables through connectors within the rack extension panel. The rack extension panel is either fastened to or integral with one of the posts of the equipment rack or otherwise adjacent to the equipment rack and extends away from the equipment rack so as not to occupy space within the equipment rack normally reserved for equipment.

1. Field of the Invention
The present invention is directed generally to equipment racks for data equipment.
2. Description of the Related Art
A conventional equipment rack, frame, cabinet and the like (referred to generally herein as a "rack") can hold conventional data equipment, sized typically in a rack unit format, such as communication, computer or other equipment, to generally provide structural support to position the data equipment in a vertically stacked arrangement within the equipment rack. Conventional patch panels, also typically sized in a rack unit format, can also be positioned in or attached to the equipment rack to receive equipment cables coupled to the data equipment for interconnecting the equipment cables with service cables via connectors carried by the patch panels.
Unfortunately, as these conventional patch panels share the vertically stacked arrangement with the data equipment within the conventional equipment rack, the equipment cables, wires, and the like (referred to generally herein as "cables") may be of undesirable length to span the distances between the data equipment and the patch panels. Furthermore, since the patch panels and data equipment may be arranged in inconvenient elevations in the equipment rack, management of the equipment cables may pose a challenge.


The invention relates to an electromechanical actuating drive for a valve, in particular of a steam turbine. It has a push rod for setting an opening position of the valve and also an electric motor for driving the push rod. The push rod is connected to the electric motor via a transmission device which generates a changing torque, depending on the axial displacement of the push rod. The invention relates, furthermore, to a steam turbine.

The invention relates to an electromechanical actuating drive for a valve, in particular of a turbine, with a push rod for setting an opening position of the valve and with an electric motor for driving the push rod. The invention relates, furthermore, to a steam turbine with a valve and with an associated actuating drive.
A turbine, in particular a steam turbine, usually has a considerable number of valves which may be used, for example, as fresh-steam, intercepting or bypass valves and also as scram valves. In such cases, the opening position of each of these valves serves for setting a respective material or steam stream and is capable of being set, for example, via a push rod assigned to the respective valve. Such a push rod is an integral part of an actuating drive assigned to the valve. In this context, the actuating drive may have to satisfy stringent requirements, particularly as regards actuating force and actuating speed. For the valve to have a high degree of reliability, it may be necessary, for example, that the actuating drive have an actuating force of about 200 kN and an actuating time of about 100 ms.
EP 0 040 732 A1 specifies an actuating drive for steam turbine valves which has a decentral hydraulic system. The hydraulic system of such an actuating drive is integrated to form a compact drive block arranged on the valve housing, so that only a cable system is still necessary for supplying energy to the actuating drive. If oil is used as hydraulic fluid, this may lead, under extremely unfavorable circumstances, to an ignition of the oil and therefore to a fire in the steam turbine.
DE 44 46 605 A1 specifies a valve for a steam turbine which has a valve spindle with a valve cone arranged thereon. The valve spindle is driven via an electric motor which is connected to the valve spindle via an electromagnetically actuated coupling. For automatic selfclosing of the valve, the latter comprises a cup spring system. The electromagnetic coupling is connected to a threaded bush which cooperates with the valve spindle guided fixedly in terms of rotation and which thus moves the latter axially. The threaded bush is designed as a spherical threaded bush, so that it acts upon the valve spindle with low play and low friction. Since the valve spindle is guided fixedly in terms of rotation, that is to say the latter can be moved up and down only axially when the threaded bush rotates, there is no need for a drive having a translational effect. Instead, an electric motor rotating in two different directions is sufficient for this purpose. However, the electric motor must have a torque safety device, in order thereby to prevent the situation where, for example during the closing of the valve, the valve cone adjoining the valve spindle at one end does not, when coming to bear against the sealing seat assigned to it, suffers damage or damages said sealing seat.
DE 36 18 479 A1 discloses a fitting for shutting off a flow, with a housing, in which a closing piece is movable between the open and shut end positions with the aid of a thread, with a rotary drive (drive motor) which is switched off with a time delay. A gear with two concentrically arranged ballscrew spindles is arranged between the rotary drive and the closing piece. A purely mechanical setting of a torque is achieved by means of this double-spindle system, the setting being carried out at a correspondingly high rotational speed without much effort.
An object on which the invention is based is, therefore, to specify an actuating drive for a valve, in particular of a turbine, in which, along with a particularly low risk of fire, fault-free operation of the valve is ensured. A further object of the invention is to specify a steam turbine with a low risk of operation being disrupted by a fire.
This and other objects are achieved by means of an electromechanical actuating drive with a push rod for setting an opening position of the valve, and with an electric motor for driving the push rod, the push rod and the electric motor being connected to one another via a transmission device, by means of which a changing torque can be generated, depending on the axial displacement of the push rod.
An electromechanical actuating drive with a transmission device, by means of which a changing torque can be generated, depending on the stroke of the push rod, is particularly advantageous in those valves in which the force to be exerted on the push rod during the closing or the opening of the valve changes as a function of the stroke of the push rod. This may occur in valves, for example in a steam turbine, in which a prevailing steam pressure is present on the valve cone and supports the latter during the closing operation or keeps the valve cone closed. In such a valve, initially a high force (steam pressurexc3x97effective valve cone surface) has to be overcome in order to open the valves to some extent. As soon as a particular opening cross section is afforded, pressure relief takes place, so that, during the further opening operation, in each case a lower force is necessary in order to displace the push rod. The transmission device may be designed appropriately, depending on the size, load and requirement of the valve, in particular the opening and closing operation (closing speed, etc.). Moreover, using an electric motor markedly reduces a risk of fire, as compared with actuating drives with oil hydraulics.
The electric motor is preferably designed as a variable-speed synchronous motor. A synchronous motor of this type makes it possible, particularly in conjunction with a power amplifier, to have highly accurate position regulation with a control accuracy of about 0.1 mm, along with a motor power up to about 30 kW. The power amplifier acts, in this case, as a frequency converter and allows a general or position-dependent reduction in the motor current and in the motor rotational speed. At the same time, all the drive powers and drive actuating speeds which are required in practice can be afforded by an appropriate adaption of the operating parameters.
In order to convert the rotational movement of the electric motor into a linear movement provided for driving the push rod, the transmission device is designed preferably as a crank mechanism, a planetary gear or the like.
Feed-dependent torque/force transmission is possible by means of a crank mechanism. Moreover, in the case of a quick closing of the valve, such as occurs, for example, during a quick-action closure of a valve in a turbine, necessary limit damping may already be achieved by means of the crank mechanism. Additional devices for speed reduction during the last stroke of the valve cone (sealing piece) into the valve seat may therefore be dispensed with, as required. In this case, a crank mechanism has a crank element, in particular a crank disk, which rotates about an axis of rotation and on which the push rod acts at a connection point, the connection point being at a distance from the axis of rotation of the crank element (crank disk). During a rotational movement of the crank disk, the push rod connected to it executes a linear movement along the main axis of the push rod between two maximum end positions. A very high torque can be generated in these end positions via the crank disk, since, during a rotation of the crank disk, only a very short linear distance is covered in the direction of the push axis in the respective end position.
The actuating drive is preferably designed in such a way that, when a closing position of the valve is reached, an angle in the range of between 5xc2x0 and 20xc2x0, preferably about 10xc2x0, is formed between the main axis of the push rod and a connecting line between the connection point, at which the push rod acts on the crank disk, and the axis of rotation. Thus, when the valve is in the closing position, the connection point is located in the vicinity of a maximum end position, so that, during a rotation of the crank disk, a high torque and therefore a high force can be transmitted to the push rod. Thus, it becomes possible for the valve to be opened particularly easily by means of the actuating drive, without a particularly high-power and/or variable-torque electric motor having to be provided. The push rod is connected preferably to a connecting rod which acts at the connection point, in particular a crank pin connected fixedly to the crank disk. The connecting rod is connected rotationally movably to the push rod and to the crank pin in a plane in which the main axis of the push rod lies.
By means of the transmission device, in particular the crank mechanism, feed-dependent torque/force conversion can be implemented in a simple way, even in applications where a high feed force of, for example, approximately 200 kN is necessary in order to open a valve. By a variation in the crank radius (in the distance between the connection point and the axis of rotation) or by a displacement of the operating point, that is to say the position which the connection point assumes when the valve is in the closing position, the characteristic curve (torque characteristic curve) of the crank mechanism can be adapted to different requirements. For example, for a scram valve of a steam turbine, the choice of the geometry of the crank disk may be made with a view to providing a very high force for opening the valve and to the return force, acting in the event of a quick-action closure, of a storage spring assembly, in such a way that as high an acceleration force as possible is exerted on the crank mechanism.
An actuating drive with such a transmission device also affords the advantage that limit damping can be assumed even by the rotating crank disk. This is particularly important in the event of a quick-action closure, since, on the one hand, the valve must close with an average speed of, for example, 2 m/s and, on the other hand, the valve cone should come to rest on the valve seat only at a speed of, for example, 0.07 m/s. To be precise, without such limit damping, the valve cone would move, approximately unbacked, into the valve seat and could be damaged itself or could damage the valve seat.
As a result of a storage spring assembly (return spring system) which generates a uniform closing speed of the push rod in the event of a quick-action closure, there is a greater crank angle in the region of the end position, so that the crank disk is further accelerated in this region. The greater crank angle and the acceleration on the crank disk may therefore be utilized pre-eminently for limit damping in the region of the end position.
The actuating drive preferably has an electromagnetic denture clutch which ensures the transmission of force from the electric motor to the push rod, in particular to the transmission device. The electromagnetic clutch is preferably a positive clutch, in which two clutch parts engage positively one in the other and force and torque transmission thereby takes place without any appreciable contact pressure between these two clutch parts. By contrast, in a nonpositive clutch, the two clutch parts are pressed against one another with high pressure, so that force and torque transmission takes place for the substantial part as a result of this.
What is achieved by the electromagnetic clutch is that, in the event of a quick-action closure, the masses to be accelerated are extremely low and a minimal closing time is thereby achieved. Consequently, when the clutch is opened, there is a separation of the crank mechanism from the electric motor and from a rotary system assigned to the electric motor and comprising, for example, a gear and a drive shaft to the crank mechanism.
The electromagnetic clutch preferably has at least three coil systems (exciting coils) independent of one another, and, even if one coil system fails, it is ensured that the denture clutch is opened and also is kept closed. This system of coil systems operated independent of one another, in which the clutch continues to be operational if one coil system fails, is designated as the nxe2x88x921 of n safety technique. Preferably, the clutch has three coil systems independent of one another and is therefore designed according to a 2-of-3 safety technique. In order to keep the clutch closed, the force of two coils is sufficient in this case. It is still possible to open the clutch even when one coil continues to draw the clutch together and the two remaining coils are switched for release of the clutch. The clutch preferably has a spacer element, in particular a spring, which, when the clutch is in the opened state, prevents the clutch parts from engaging one into the other. The coil systems have to act counter to this spacer element during the closing of the clutch. Preferably, at the same time, the clutch is designed in such a way that all three coil systems (all n coil systems) must function in order to close the clutch.
The denture clutch preferably has a clutch disk which is rotatable about a clutch axis and which can be brought along the clutch axis into engagement with a drive shaft connected to the electric motor. In this case, the clutch axis preferably coincides with the axis of rotation of the transmission device, that is to say of the crank mechanism. The clutch has, furthermore, a clutch hub, and, in one embodiment, the clutch hub is directly connected positively to the clutch disk and the clutch hub is spaced from the transmission device via the spacer means, in particular a spring. In another embodiment, the clutch disk is connected to the clutch hub via a spacer means, in particular a spring, and can be brought along the clutch axis into engagement with the clutch hub. In both instances, in each case only a low mass has to be moved during the opening and closing of the clutch, in order to achieve a separation of the electric motor from the transmission device.
The actuating drive preferably has a return spring system which is connected to the push rod and which exerts a force on the push rod in the direction of the closing position of the valve. Particularly in the event of a quick-action closure, closing of the valve is achieved via the return spring system by a corresponding force being exerted on the push rod.
Preferably, the denture clutch is mounted by means of a clutch bearing in such a way that at most a slight force has to be applied in order to disengage the denture clutch. Preferably, too, the clutch bearing at the same time comprises a ball joint. In a particularly preferred embodiment, the clutch disk is held by at least one holding rod mounted in the ball joint. By virtue of this embodiment of the denture clutch, the latter can be disengaged by means of even only a slight force. In particular, there is not catching of the denture clutch due to high static friction, which could prevent the denture clutch from being disengaged.
The object aimed at a steam turbine is achieved by means of a steam turbine such as has an actuating valve for setting a steam stream, in which case the actuating valve can be opened and closed via an actuating drive described in more detail above.
The advantages achieved by means of the invention are, in particular, that, by virtue of the electric motor provided for driving the push rod, it becomes possible for the actuating drive to be operated without pressure oil. Consequently, particularly in use in a steam turbine, the risk of fire is especially low. Moreover, the actuating drive can be installed in any desired installation position and, in particular, may be employed without high outlay as a replacement for an actuating drive with a decentral hydraulic supply. The electric motor can be adapted to different requirements in a particularly simple way by means of suitable activation, so that the actuating drive is especially flexible. The transmission device, in particular the crank mechanism, can likewise be adapted in a simple way to the different requirements. The components of the actuating drive, in particular the electric motor and the electromagnetic denture clutch, can be produced by simple means and are therefore particularly maintenance-friendly.

Electromechanical actuator for a valve and steam turbine


A novel smokable thermoplastic film, smokable by both liquid smoke and gaseous smoke, that may be produced as a film or a tube, as in a food casing. This newly disclosed film is a blend of a polyamide base, an amorphous polyvinyl alcohol and, optionally, an antiblocking agent.

Historically, various foodstuffs such as sausages and cheeses have been produced in casings that were either natural, for example, as derived from animal intestines, or synthetic, such as those made from collagen or cellulose. The foodstuff is introduced into the casing and because of the permeability of these types of casing, the foodstuff, such as sausage meat, can be exposed to wood smoke, available in both gaseous and liquid forms, which imparts a flavor and/or color component to the sausage.
Currently, sausage manufacturers are interested in having another type of synthetic casing based on polymers and, in particular, thermoplastics available. These thermoplastic casings need to be porous enough to be smokable by liquid and/or gaseous smoke. Although plastic casings are well-known in sausage manufacturing, smokable plastics pose unique problems because of their impermeability to air and liquids.
Currently, thermoplastic casings are primarily larger sized casings, and because of their oxygen barrier properties, may remain on the meat product after processing. However, there is a demand for smaller diameter casings to produce hot dog-type sausages, and generally these types of casings must be removed from the processed sausage, although some manufacturers may prefer to leave the casing on as an oxygen barrier when sold to the consumer, who will remove it prior to heating and eating.
Some thermoplastic casings are made from polyamides, either monolayer or multilayer films having at least one polyamide (nylon) layer. Casings comprising a blend of nylon with polyester are also known, as are multilayer casings of nylon with ethylene polymers or copolymers. These types of casings also may have a moisture content ranging from about 1-3 weight % (wt. %). Multilayer casings, such as those having an outer layer of nylon and an inner or food contact layer of an absorbent material such as a cellulosic film or a polymer with an open cell structure, are also known. There are thermoplastic casings that are smokable with gaseous smoke and that produce a range of colors and flavors, from slightly reddish to that approximating the color seen when cellulosic casing is used and smoked.
Smoke is available in both liquid and gaseous forms. Both are well-known to those in the sausage and food processing industry. The liquid version is often used in processing operations where linked sausages are sprayed or pulled through baths of the liquid smoke, generally at room temperatures. The moisture barrier properties of thermoplastic casings generally impede the transfer of liquid smoke through the casing to the enclosed meat. Cellulosic casings are preferred for color and taste transfer using liquid smoke, as well as with gaseous smoke.
What is still needed are plastic casings that may be produced at high speeds, that will be stiff enough to maintain their shape once stuffed with the foodstuff, that do not wrinkle during sausage production, and that are porous enough to allow smoke components present in both liquid smoke and gaseous smoke to pass through to the encased food.
As discussed in U.S. Pat. No. 4,303,711, "Tubular film for packing and casing paste-type foodstuffs especially sausage and cheese," Erk et al., issued Dec. 1, 1981, "single-layer, unstretched plastic casings consisting of higher homo-polyamides (polyamide 11 and polyamide 12)" are known, as well as plastic casings consisting of such polyamides coextruded in two layers with polyamide 6 as the outer layer. These polyamide casings may be easily made by the blown film technique, but typically suffer from a lack of dimensional stability and uniformity, being deformed upon stuffing so that production of stuffed sausages to a uniform diameter is difficult. The '711 patent further indicates that these unstretched films suffer from an undesirably wrinkled appearance after cooking and chilling. These casings are meant to be left on the finished sausage and, therefore, a wrinkled appearance is a negative trait. Additionally, this casing is not meant to be porous, but rather to be impermeable to moisture and oxygen.
The contents of each patent and publication identified herein are incorporated herein to this application in their entirety by this reference.
To overcome the defects or inadequate performance of seamless thermoplastic casings produced by blown film technology, plastic casings have been produced using stretch orientation.
Also, various attempts have been made at making stretch oriented polyamide casings. Uniaxially stretched casings, which are only stretched in the longitudinal ("machine") direction ("MD"), reportedly have the same disadvantages as unstretched casings regarding insufficient dimensional stability, nonuniformity of diameter, and excessive wrinkling.
U.S. Pat. No. 4,560,520, "Single-layer elastic tubular film of polyamide used for packaging paste substances and a process for the production of such film," Erk et al., issued Dec. 24, 1985, discloses forming multiaxially stretched, monolayer, polyamide, tubular films, e.g., of nylon 6 or nylon 66, which have elastic properties and which are to be used for packaging table sausages and boiled sausages. The disclosed films are "fixed thermally" and shrunk after stretching, e.g., by subjecting the tube to controlled shrinkage of at least 15% and at most 40% at temperatures above 90° C. and also subjecting the film to infrared irradiation. This is to produce a nylon casing that does not have shrinkage at temperatures under 90° C. This pre-shrunk casing is used for stuffing with meat emulsion and relies upon its elastic properties to provide wrinkle resistance. Again, this casing is meant to be left on the finished sausage, and to protect it from air and water while so encased. It is not permeable to any coloring or flavoring agents used on the outside of the encased sausage.
Additionally, orientation of seamless tubes of nylon by biaxial stretching is difficult. Extrusion and orientation of multilayer tubes, especially coextruded tubes, containing mixed layers of polyamides and other materials having different melting points, melt viscosities, and a different affinity for water can be very difficult. For example, U.S. Pat. No. 4,892,765, "Heat-shrinkable laminate film and process to produce the same," Hisazumi et al., issued Jan. 9, 1990, notes that although it is desirable to extrude films for packaging hams and sausages in tubular form, it is difficult to make a stretched tubular polyamide film of uniform thickness. Hisazumi et al. disclose production of a heat-shrinkable multilayer film having a core layer of a polyvinylidene chloride copolymer attached to opposing polyamide layers (e.g., of nylon 6/66 copolymer) by opposing adhesive layers. This film is made using an orientation process that utilizes water to soften and plasticize the nylon to a degree sufficient to allow or facilitate orientation.
Generally, attempts at biaxially stretching nylon multilayer casings have used polyamide as the outer layer of the tube. The orientation processes employed for nylon multilayer casings have tended to involve complicated apparatus and processing such as that found in U.S. Pat. No. 4,886,634, "Process and apparatus for the production of an extruded, stretched, seamless tube," Strutzel et al., issued Dec. 12, 1989.
This type of casing or film is not meant to be permeable to air or water and, therefore, is of no use when producing sausages or food products treated with coloring or flavoring agents during the processing cycle.
A number of other thermoplastic casings that have a degree of permeability have been described in the literature.
In EP 0139888, "Process for smoking in thermoplastic casings foodstuffs that are either heated after packing or packed in a hot fluid state," Erk et al., published May 8, 1985, linear aliphatic polyamides combined with other polymers such as an ionomer resin, modified ethylene vinyl acetate copolymers and/or modified polyolefins are taught for making smokable casings. Although under wet smoking conditions taste and fragrance is transferred, these casings have low gas permeability and it is believed that they result in products that are more moist than generally acceptable, and cannot replace cellulose or other natural casings.
Other high barrier casings in respect to oxygen and vapor have been described. For example, coextrusion of polyvinylidene chloride copolymers ("PVDC") with polyamides or polyolefins have proven difficult because PVDC is very temperature and shear sensitive during extrusion. These copolymers are extrudable only over a narrow temperature range without causing degradation of the polymer in the extruder or die, which causes imperfections in the film. Polyamides require much higher temperatures for extrusion—generally about 200° C. or higher. At these higher extruder and die temperatures, coextrusion of polyamide with PVDC is difficult and degradation of the PVDC may be expected, even if the PVDC layer is insulated from polyamide layers by intermediate layers. Resulting imperfections in the film may detrimentally affect the appearance, strength, and barrier properties of the film and/or ease of orientation or biaxial stretching. In U.S. Pat. No. 5,084,310, "Smoked food-package and smoking process," Hisazumi et al., issued Jan. 25, 1992, a mixture of PVDC and a low melting point polyamide is taught, producing a smokable polyamide. The resultant product allows the passage of a small amount of water vapor, but the smoked taste of the final product is much less than that of sausages made with conventional smoked cellulose casings.
U.S. Pat. No. 7,361,392, to Borodaev et al., titled "Packaging from a polymer film for food products," issued Apr. 22, 2008, teaches a polymer film that is primarily polyamide with a hydrophilic compound, that forms a highly dispersed phase and is capable of mixing with at least 10 wt. % of water. Among the examples, two films are produced using two different polyvinyl alcohols as the hydrophilic component. One polyvinyl alcohol produced an acceptable film (i.e., smokable, good mechanical properties) while the other did not.
U.S. Pat. No. 4,851,245, "Smokable synthetic food-packaging film," Hisazumi et al., issued Jul. 25, 1989, teaches a smokable food-packaging film comprising at least one layer of a mixture of polyamide and alpha-olefin vinyl alcohol copolymer. This film is claimed to have both gaseous permeability and oxygen barrier properties.
U.S. Patent Application Publication 2005/0163948 A1, "Smokable Polymeric Casing," Owen J. McGarel, published Jul. 28, 2005, describes a thermoplastic casing made with a novel polyvinyl alcohol/nylon blend, which, when exposed to gaseous smoke, produced some color on the encased sausages.
In summary, although several of the aforementioned plastic casing products have gained varying degrees of commercial acceptance in different market segments, their advantage compared to the traditional cellulosic casing has been chiefly one of cost, but having a number of problems including those of dimensional stability, uniformity of diameter, lack of permeability to smoke or only of a low to moderate level of permeability to gaseous smoke and not liquid smoke, and wrinkling.


A central control apparatus and a plurality of terminal apparatuses are connected through a line. In the central control apparatus, a plurality of images are stored in an optical disk in accordance with a hierarchical structure having four hierarchical levels of cabinet, binder, document, and page, and retrieval information constituted by a plurality of keys each for retrieving a corresponding image is stored in a magnetic disk with different title structures (key structures) in units of binders. A desired image is retrieved from the optical disk in accordance with designation of the retrieval information stored in the magnetic disk. A metabinder having a plurality of binders having the same title structure of the retrieval information has a level higher than that of the cabinet. In the central control apparatus, a title table group of the metabinders is stored in the magnetic disk independently of the binders. When an image is to be retrieved in the central control apparatus or a terminal apparatus, the title table group of the metabinders stored in the magnetic disk is retrieved.

1. Field of the Invention
The present invention relates to an electronic filing system and, more particularly, to an electronic filing system such as an image filing system for performing, for example, registration, retrieval, and deletion of an image.
2. Description of the Related Art
In recent years, an image filing apparatus has been put into practical use wherein images of a large amount of documents are read, the read images are stored in an optical disk, a selected one of the stored images is retrieved and read out, and the readout image is output in a visible state on an output unit such as a CRT (Cathode Ray Tube) display unit or a recording unit.
As network formation and systematisation have progressed, another type of image filing system has been put into practical use. This system includes a single central control apparatus for performing registration, deletion, and retrieval processing. The central control apparatus is connected, via a LAN (Local Area Network), to a plurality of terminal apparatuses. and Retrieval processing is performed while the terminal apparatuses communicate with the central control apparatus over the LAN.
However, in the network-type image filing system, when the central control apparatus is performing registration of an image, the terminal apparatuses cannot perform retrieval processing. Conversely, when a terminal apparatus is performing retrieval processing, the central control apparatus cannot perform registration of an image.

Multiple user electronic filing system for image data using a keyed hierarchical file structure


A ladder tube (10, 12) for use in a ladder section of a collapsible ladder (1) is provided. The collapsible ladder comprises several ladder sections (5, 5a-5j), where each ladder section comprises two ladder tubes (10, 12) arranged parallel to each other and interconnected by a rung (20) to form the respective ladder section, and where each ladder tube (10, 12) is telescopically inserted into a ladder tube (10, 12) of a lower section to form the collapsible ladder (1). The ladder tube (10, 12) is characterized in that it has a cross-sectional shape comprising at least one straight section (16) which at each end is connected at an angle larger than 90 degrees to at least one additional section (18) of the cross-sectional shape.

As well known by persons skilled in the art of collapsible ladders, such ladders usually comprise a number of tube portions having various diameters and which hence are telescopically insertable into one another. Every upper end of any of the tube portions are fastened to one end of a ladder step, whereas the other end of the ladder step is fastened to an upper end of a tube portion having the same diameter, the two tube portions and the ladder step forming a ladder section, the tube sections of which being insertable into an adjacent ladder section comprising tube portions having a larger diameter.
The resulting ladder can hence be collapsed by inserting higher ladder sections into lower ladder sections, and the ladder can be extended by extracting higher ladder sections from the lower ladder sections. A pin extending through the holes in the outer walls of two adjacent tube portions locks the tube portions to prevent the extended ladder from collapsing. Ladders having collapsible and expandable ladder sections are used in order to make the ladder smaller for storage and transport purposes.
The manufacturing process of a ladder tube involves several crucial steps, for example extrusion of the profile and measuring and drilling holes. Due to the construction of the ladder tubes in prior art, the manufacturing process is prone to mistakes leading to lower durability of the ladder.
It is the object of the present invention to provide a ladder tube and its corresponding collapsible ladder where its manufacturing process is improved and where the durability of the ladder is increased.


An image forming apparatus includes a plurality of process units contacting a continuous recording medium and transferring images on the recording medium, a separating and contacting mechanism for controlling at least one of the recording medium and each of the process units to a separated state where the recording medium and the process unit are separated from each other and a contacting state where the recording medium and the process unit contact each other, and a controller for controlling the separating and contacting mechanism at a position where the process unit confronts a non-printing region on the recording medium so as to put the recording medium and the process unit to the contacting state.

The present invention generally relates to image forming apparatuses, and more particularly to an image forming apparatus which is provided with a plurality of process units which record images on a recording medium such as a continuous recording paper using the electrophotography technique.
When recording images on both sides of the recording paper using a single process unit, the recording paper is turned over after recording the image on a first side of the recording paper, and the image is thereafter recorded on a second side of the recording paper. For this reason, there is a limit to increasing the image recording speed, and a method has been proposed to use two process units for respectively recording the images on the first and second sides of the recording paper.
On the other hand, when recording a color image, there is a method which uses a single process unit. In this case, the single process unit is used to successively record images of each of the colors such as yellow, magenta, cyan and black on the recording paper in an overlapping manner, and there is also a limit to increasing the image recording speed. Hence, a method has been proposed to provide a plurality of process units, and to record the image of each color using one of the process units.
Conventionally, in a printer which uses the electrophotography technique and records the image on the continuous recording paper, if one print operation (job) ends and a next job does not occur for a predetermined time, a portion of the paper printed with the last line remains within a paper transport path within the printer. Accordingly, the recording paper is fed forward manually or automatically so as to eject the portion of the paper printed with the last line outside the printer, so that the recording paper can be cut along a perforation provided subsequent to the portion of the paper printed with the last line.
However, when the next job is started in this state, the printing is started in a state where the amount of recording paper which is fed forward to remove the print result of the previous job precedes the first line of this next job. As a result, the amount of the recording paper which is fed forward is wasted, and the utilization efficiency of the recording paper is poor.
Accordingly, a so-called back-feed is conventionally carried out if one job ends and the next job does not occur for a predetermined time. This back-feed feeds the recording paper forward if one job ends but the next job does not occur for the predetermined time, and returns the recording paper by a predetermined amount before the next job starts. As a result, the utilization efficiency of the recording paper is improved. A photoconductive body of the process unit and the recording paper are separated from each other when carrying out the back-feed.
Similarly, in the case of the printer which successively records images by the first and second process units, for example, the last line that is recorded is located on a downstream side of the second process unit in a transport direction of the recording paper at a point in time when one job ends. Hence, if the next job starts in this state, the portion of the paper between the first and second process units is wasted. For this reason, a method has been proposed to also carry out the back-feed described above in such a case.
However, in the case of the printer which successively records the images by the first and second process units, if a single fixing unit is used to simplify the printer construction, this fixing unit is provided on the downstream side of the second process unit which is provided on the most downstream side along the transport direction of the recording paper. Consequently, when the above described back-feed is carried out, the image recorded on the recording paper by the previous job is not yet fixed. Therefore, when the photoconductive body of each process unit and the recording paper make contact at the start of the next job, there was a problem in that the image which is not yet fixed may be disturbed by the shock of the contact between the photoconductive body and the recording paper. If the image which is not yet fixed is disturbed, the image recording quality greatly deteriorates and it becomes necessary to carry out the two jobs over again, thereby introducing another problem in that the performance of the printer greatly deteriorates.


A sheet feeding apparatus which includes a sheet holder holding at least one sheet to be fed. A pick-up roller feeds the at least one sheet from the sheet holder in a sheet feeding direction. A separating roller is provided at a lower reach of the pick-up roller. This separating roller receives a reverse torque in an opposite direction of the sheet feeding direction through a torque limiter. A feeding roller is provided opposite the separating roller and feeds the at least one sheet from the pick-up roller in the sheet feeding direction. Further, a frictional element is provided to increase a rotational load of the separating roller.

1. Field of the Invention
The present invention generally relates to a sheet feeding apparatus equipped in a copier, facsimile, image-scanner, or similar equipment, for feeding original documents or recording sheets one by one.
2. Description of the Background Art
FIG. 1 is a cross-sectional view of a portion of a sheet feeding apparatus of a background art device which includes a separating roller 3. FIG. 2(a) is a perspective view of a supporting mechanism of the separating roller 3 of FIG. 1, and FIG. 2(b) is an exploded view of the separating roller 3. In FIG. 1, the sheet feeding apparatus includes a feeding tray 1 for holding a stack of recording sheets PP as a sheet locating portion, a press lever (not shown) for pressing a top of the stack of recording sheets PP toward the tray 1, arranged above the tray 1, and a stopper (not shown) for locating the sheets PP at a predetermined loading position on the tray 1.
In addition, the sheet feeding apparatus includes a pick-up roller 2 contacting the top of the stack of sheets PP to pick-up a topmost sheet P. The pick-up roller 2 may be formed of, for example, a circular or non-circular shaped roller, an eccentric roller, a non-circular eccentric roller, a circular or non-circular shaped roller with a frictional member wound along a rim, etc. The type of pick-up roller is chosen in relation to a structure of the loading portion. As another type of loading portion, a sheet feeding cassette is disclosed in Japanese Laid-Open Utility Model Application No. 06-87348.
Furthermore, the sheet feeding apparatus of FIG. 1 includes a separating roller 3 arranged at a lower reach of the pick-up roller 2 and a feeding roller 10 arranged at an opposite position to the separating roller 3. The feeding roller 10 is rotated by a feeding torque in a sheet feeding direction.
Next, referring to FIG. 2(a), a mechanism for driving the separating roller 3 is described. The driving mechanism includes a driving shaft 4, a driving gear 5, a follow gear 8, and a torque limiter 9. These members act to transmit a rotational power to the separating roller 3 to rotate separating roller 3 in a reverse direction against a sheet feeding direction. Further, a bracket 6 is movably supported by the driving shaft 9, and supports the driving gear 5, the follow gear 8, the torque limiter 9, and the separating roller 3 using a follow shaft 7 as a center axis. A spring 11 pushes the bracket 6 toward the feeding roller 10, see FIG. 1.
Next, referring to FIGS. 2(b) and 3, a torque mechanism is described. As shown in FIG. 2(b) and FIG. 3, the following shaft 7 has a pin 7a, and the pin 7a is inserted into a gap of the follow gear 8 to mesh with the driving gear 5, for fixing each other. As shown in FIG. 3, the torque limiter 9 includes a follow part 9b and a driving part 9a, and when a torque greater than a predetermined upper limit acts between follow part 9b and driving part 9a, the follow part 9b slips against the driving part 9a. On the other hand, the driving part 9a is connected with the pin 7a and, therefore, the driving part 9a rotates with the shaft 7 integrally on all occasions. The separating roller 3 is connected and fixed with the follow part 9b in relation to a rotating direction. Therefore, when an acting torque between the follow part 9b and the driving part 9a is less than the upper limit, the separating roller 3, and the follow part 9b as an axis of the separating roller 3, integrally rotate with the driving part 9a, the follow shaft 7, and follow gear 8. On the other hand, when an acting torque is greater than the upper limit, the separating roller 3 and the follow part 9b can rotate independently.
Next, referring to FIGS. 1 to 4(a) and 4(b), a separating movement of a background sheet feeding apparatus is described.
To the begin with, stack of sheets PP is set on the feeding tray 1 and a tip of sheets PP is pushed on a stopper (not shown) so as to locate the sheets PP at a predetermined loading position. As the sheets PP are fed, a lever (not shown) presses and gives the sheets PP on the tray 1 a prefixed moving friction, and the stopper leaves from the tip of the sheets PP. Then, a motor (not shown) transmits a torque to the pick-up roller 2 via a clutch mechanism (not shown), which rotates the pick-up roller 2 exactly by one turn each one action. Thereafter, as shown in FIG. 1, the pick-up roller 2 rotates to feed a topmost sheet P of the stack of sheets PP, and at an infant phase, the pick-up roller 2 stops contacting a surface of the fed sheet P. In other words, the pick-up roller 2 contacts a surface of the topmost sheet P for only a part of a phase-section. In this operation, a power for feeding the topmost sheet P acts directly on the topmost sheet P. However, an indirect feeding force also acts on a lower second sheet or further sheets under the topmost sheet P by friction occurring between the topmost sheet P and the lower second and further sheets. As a result, one or some further sheet(s) below the topmost sheet P may be (are) pushed out and inserted to a nip portion between the feeding roller 10 and the separating roller 3. That is, an improper feeding of several sheets, rather than just the topmost sheet P, can occur.
A reverse torque transmitted from the driving shaft 4 causes the separating roller 3 to rotate in an opposite direction (e.g., counterclockwise) of the feeding direction via the torque limiter 9. On the other hand, a feeding torque transmitted from a motor causes the separating roller 3 to rotate in a feeding direction (e.g., clockwise) via the feeding roller 10.
When there is none or only one paper sheet between the separating roller 3 and the feeding roller 10, as shown in FIG. 4(a), since the feeding torque is relatively larger than the reverse torque, the separating roller 3 is rotated in a feeding direction subordinately by the feeding torque. That is to say, in the torque limiter 9, the follow part 9b is slipped against the driving part 9a so that the separating roller 3 rotates in a feeding direction (e.g., clockwise) as shown in FIG. 4(a).
On the other hand, when two or more sheets of paper P,PPP are at the nip between separating roller 3 and feeding roller 10, or when the separating roller 3 does not contact the feeding roller 10 altogether, as shown in FIG. 4(b) the feeding torque is relatively smaller than the reverse torque, and as a result, the separating roller 3 is rotated in a reverse direction (e.g., counterclockwise) against the feeding direction by the reverse torque. This results because friction occurring between the topmost sheet P and a second sheet PPP, which is smaller than a friction occurring between the top sheet P and the feeding roller 10, reduces a torque transmitted from the feeding roller 10 to the separating roller 3. Therefore, in the torque limiter 9, the follow part 9b rotates in a same direction with the driving part 9a.
Consequently, by this action, the sheet PPP is pushed back toward the feeding tray 1, and only the topmost sheet P is fed in the feeding direction.
In a sheet feeding and separating action mentioned above, in the first place, as shown in FIG. 4(a), a topmost sheet P is inserted and fed at the nip between the separating roller 3 and the feeding roller 10, and accordingly the separating roller 3 subordinately rotates in the feeding direction shown by F in FIG. 4(a). And then later, as shown in FIG. 4(b), the sheet PPP is inserted and fed by a frictional force between the sheet PPP and the sheet P. While there are at least two sheets between the nip, the separating roller 3 rotates in the reverse feeding direction shown by R in FIG. 4(b) and the separating roller 3 pushes back the sheet PPP to ensure proper feeding of only the topmost sheet P.
However, a drawback with this operation is that after the separating roller 3 pushes back the sheet PPP, the separating roller 3 starts to rotate in the feeding direction again, and the sheet PPP may then be fed in the feeding direction again during a conveyance of the sheet P. The separating roller 3, therefore, switches repeatedly between rotating in the feeding direction (e.g., clockwise) and the reverse feeding direction (e.g., counterclockwise) during conveyance of the sheet P. A torque reaction of this repeated switching action issues a shock and a vibration to the separating roller 3, and the shock and the vibration are propagated to the feeding roller 10 or the follow shaft 7, or the driving shaft 4, or the bracket 6, etc., and this results in mechanical noise. Further, a frequency of the vibration and a level of the noise increase with an increasing in a rotational speed of the separating roller 3. Especially, when the vibration-frequency approaches a resonance frequency region of the follow shaft 7, or bracket 6, etc., the noise is amplified by the resonance phenomenon. The shock, moreover, is increased with shortening of a period of the repeated action. In the other words, as a transitional period from a slipping condition to a following condition, or from a following to a slipping of the follow part 9b in regard to the driving part 9a, is shortened, a level of the shock increases.
Accordingly, it may become necessary to decrease the noise or the shock by making parts around the separating roller 3, such as the follow shaft 7, bracket 6, etc., of high stiffness-materials, or the torque limiter 9 may have a characteristic prolonging of the transitional period.
However, these measures have problems such that the sheet feeding apparatus then becomes expensive or complex.


A process for selecting a surrogate part for metallic plating, the metallic plating of the surrogate part predicting results for the metallic plating of a new or predetermined part is disclosed. The process can include providing a reinforcement learning system having a memory circuitry and a processing circuitry. The memory circuitry can have a database with data associated with a plurality of surrogate parts and data associated with the predetermined part can be entered into the data input module. The processing circuitry can compare the data associated with each of the plurality of surrogate parts and the data associated with the predetermined part and select a surrogate part that affords predicting a plating result of the predetermined part.

Metallic plating of various objects, components, instruments and the like is known. In addition, metallic plating, for example "chrome" plating, of various components that are included as part of a motor vehicle is also known. Considerations for metallic plating of such components can include overall size of a component, difficult to reach locations on and/or within a component, material of construction for a component, specific type of metallic plating to be applied to a component, and the like.
Heretofore practices for selecting a particular processing route and/or processing parameters, in order to plate a predetermined part or component that has not been plated before, have typically included trial and error with or without knowledge obtained from experienced personnel. Although such practices can be successful, they practices can also lead to excessive cost and time when a "best guess" fails. In addition, such practices can fail to take full advantage of prior successful metallic platings on previous components. As such, a process for selecting a part or component that has been previously metallic plated, with the selected part or component assisting in predicting a metallic plating result of a new component, would be desirable.

Toyota Motor Engineering & Manufacturing North America, Inc.