Cellular or compact polyurethane moldings are produced by conveying at least one isocyanate component and at least one polyol component by a metering machine in dispensing manner into a mixing chamber via component lines to form a polyurethane reaction mixture. Subsequently, the polyurethane reaction mixture is discharged from the mixing chamber into a mold. The pressures of the components are registered by means of pressure transducers in the component lines and are transmitted to a monitoring device. The temporal profiles of the pressures are compared with reference pressure values stored in the monitoring device. A malfunction is signalled in the event of deviation of at least one of the measured pressure profiles from the reference pressure profile beyond a predetermined tolerance threshold.

The invention relates to a process for producing polyurethane moldings, wherein the reaction components are mixed under high pressure in a mixing head, the pressures and the positions of the mixing head slides or of the injector needles and the positions of the hydraulic valves are recorded, registered and evaluated by a monitoring device.
The production of polyurethane moldings can be undertaken in accordance with the so-called RIM (Reaction Injection Moulding) process, i.e., with molding tools in which the upper and lower parts of the mold have been moved together and consequently form a closed cavity. In this case, the mixing head with its outflow system is connected to the cavity via a runner. But the production of polyurethane moldings may also be undertaken with molding tools in which the upper part of the mold is first opened and the polyurethane reaction mixture is charged into the open cavity via the outflow system of the mixing head, and the upper part of the mold is closed after the end of the shot, that is, the mold is closed.
In the RIM process according to the state of the art (shown in FIGS. 1 and 2), at least two liquid components that react with one another are supplied by a metering machine to a mixing head in a predetermined mass-flow ratio via pipelines or hose lines. The mixing head has the task of mixing these components, as a rule isocyanate and polyol, homogeneously with one another and of emitting the polyurethane reaction mixture arising in the process via a runner, which is generally an integral part of the mold, into a mold (molding tool). The liquid reaction mixture that has been transferred into the mold cures after some time. After this, the mold, which as a rule is of multi-part construction, can be opened in order to remove the finished molding. Generally, the mold is integrated within a mold carrier (not illustrated) which opens and closes the mold and, in the closed state, keeps it closed by acting against the internal pressure arising in the mold. In the case of the RIM process, the mixing head is, as a rule, permanently attached to the molding tool. But it is also possible to dock the mixing head onto the tool prior to each shot with a special mixing head portal, or manually. The mixing heads that are employed in this case are so-called high-pressure mixing heads which operate, for example, in accordance with the counterflow injection process.
The production of the molding can be subdivided into phases that take place in succession. At the start of the production process, the hydraulically driven slide which is located in the interior of the mixing head is located in a position that permits the recirculation of the components via the mixing head. This means that the mass flow of the components, which is metered by the metering machine, flows to the mixing head via the inlet. In the mixing head the flow of the components is channelled by grooves and channels into the return flow. From there the mass flows of the components flow back to the metering machine. The channels in the mixing head which are flowed through by the components may also be formed by a different geometrical arrangement of mixing head casing and slide, or even by mixing head casing and several slides. The construction of the mixing head that is illustrated in the figures is only one possible variant. Starting from an empty closed mold (FIG. 1), one or more hydraulically driven slides are moved in the high-pressure mixing head. These slides have the task of channelling the fluid flows of the components to be mixed in such a way that they are combined and a homogeneously mixed reaction mixture arises which emerges from the mixing head and is emitted into the mold. In this connection, so much reaction mixture is emitted that the mold is filled (FIG. 2).
In order to emit the exact quantity required into the molding tool, the metering of the reaction components is undertaken with the aid of a metering machine. This machine meters each component at a rigidly defined mass flow-rate. All the components are metered for the same established period. This period is monitored via an electrical control system. The start and the end of the metering process are controlled by the movement of one or more hydraulically moved slides in the mixing head. After the mixing and filling process, the hydraulic slide or slides move(s) in such a way that residues of the polyurethane reaction mixture are totally ejected from the mixing head and the mass flows of the components recirculate again via the mixing head. Subsequently, the reaction mixture which has been introduced into the mold cures, and a solid polyurethane molding is formed which can be removed from the mold after the mold has been opened.
In the course of RIM production with add-on mixing heads, serious damage to the plant may occur for many reasons which lie outside the region of metering (metering machine, mixing head). For example, it is possible that residues of a finished molding in the sprue region of the mould are forgotten in the course of demolding. As a result of this, the outlet of the mixing head then becomes sealed, and during the metering process an inadmissible pressure arises in the component lines which connect the metering machine and the mixing head. This then results in the malfunction and automatic shutdown of the entire plant because the maximum admissible pressure has been exceeded. The shutdown is effected by the electronic control system of the plant.
Such a shutdown by reason of exceeding maximum admissible pressure may also occur as a result of problems in the metering area (metering machine, mixing head). For instance, it is possible for a nozzle in the mixing head to become clogged by particles of dirt. This brings about a higher flow resistance and leads to the exceeding of the maximum admissible pressure. Problems that are caused in the region of metering (metering machine, mixing head) can, as a rule, be recognized by the operator of the machine and also result in no damage to the plant when the plant is switched on again. In contrast, problems caused outside the system constituted by metering machine and mixing head may result in damage when the plant is switched on again.
If, for example, the runner is clogged, the pressure in one component line rises more quickly, for example by reason of a higher discharge capacity, than in the other. Therefore a partial flow of component is forced from the component line having the higher pressure into the line having the lower pressure via the mixing chamber 9 (FIG. 2) which is filled with reaction mixture. This is possible because the component lines expand in the event of a rise in pressure and consequently enlarge their volume. If, for example, the pressure in the isocyanate line rises more quickly than the pressure in the polyol line, isocyanate is able to enter the polyol line. This then results in the formation of a reaction mixture in the polyol line, and solid polyurethane is formed. If the plant is put into operation again after this occurs, the reaction mixture is entrained through the entire plant by the recirculation of the components. The result of this is that all of the hose lines and pipelines become clogged with solid, fully reacted polyurethane. If the switching-on of the plant again after such a fault were to be prevented, only the component lines that are located in the vicinity of the mixing head would be affected.
RIM plants known hitherto have been equipped with an automatic pressure monitoring system for the purpose of protecting the plant. This system shuts down the plant automatically if a maximum admissible pressure is exceeded in one of the component lines. However, this pressure shutdown only takes account of the result of the exceeding of the pressure, irrespective of when and in what connection it has occurred. This means that other parameters of the plant are not taken into account and cannot be considered in connection with the pressure shutdown, so that for the operator of the plant it is not evident where the cause of an automatic shutdown by reason of an exceeding of the admissible pressure is to be sought.

Process for producing polyurethane moldings


A movement auxiliary device for a machine stand includes a foot stand. Two sides of the lower end of the foot stand are provided with first and second side seats having vertical rail grooves, respectively. A movable lever, a pivot seat and a lifting roller assembly are provided between the two rail grooves. The foot stand is provided with a support seat. A connecting board having a pedal is pivotally connected between the support seat and the pivot seat, which can be pivoted on the pivot seat. The movable lever is pivotally connected with a pneumatic cylinder to provide a buffering function for the lifting roller assembly and the machine stand. The pedal is controlled for the connecting board and the pivot seat to generate a link pivot, such that the lifting roller assembly is descended to the ground or ascended upward.

Field of Invention
The present invention relates to a movement auxiliary device for a machine stand, and more particularly to a movement auxiliary device provided with a foot stand. The foot stand can be propped up by means of a stamping control way, such that the machine stand can be moved conveniently.
Description of Related Arts
As shown in FIG. 1, a conventional processing machine, such as a wood working lathe and a wood planing machine, is provided with a pair of symmetrical foot stands 11 under the machine stand 10. The bottoms of the foot stands 11 are provided with foot pads 12 to form four supports for maintaining the height and weight of the machine stand 10. However, due to work habits, gestures, material sizes or temporary conditions, a movement is required within a certain range. The machine stand 10 with the immovable foot stand 11 must be displaced manually. Sometime, it is necessary to use a special apparatus. The process of movement is very time-consuming and laborious. For many users, this causes a great trouble. Furthermore, during movement, the foot pads 12 rub against the ground, causing scratches on the ground and damage to the foot pads 12. This is inconvenient for use and needs improvement.
In view of this, it is necessary to make the machine stand 10 labor-saving and convenient for displacement. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems.

Movement auxiliary device for machine stand


The invention relates to a device for pumping a cryogenic fluid, consisting of a tank for storing a cryogenic fluid containing cryogenic liquid, a cryogenic pump having an inlet pressure loss, and a suction line connecting the tank to the pump, said pumping device including a system for controlling the pressure in the tank for selectively maintaining said pressure at least equal to the saturation pressure of the stored cryogenic fluid plus the inlet pressure loss of the cryogenic pump and optionally plus the value of the pressure losses owing to the pipes forming the suction line connecting the tank to the pump. The invention is characterized in that the pressure-control system includes a duct connecting a high-pressure outlet of the pump to the tank for selectively returning the pumped cold fluid to the tank, said duct including an expansion valve for returning cold gas to the tank.

Field of the Invention
The present invention relates to a device and to a method for pumping a cryogenic fluid.
The invention relates more particularly to a device for pumping a cryogenic fluid, comprising a storage tank for storing a cryogenic fluid containing cryogenic liquid, a cryogenic pump having an inlet head loss (NPSH), and a suction line connecting the tank to the pump.
The invention finds a particularly advantageous application in the field of the pumping of low-density cryogenic fluids containing gases such as hydrogen or helium, and isotopes thereof.
Related Art
Compressing liquid hydrogen makes it possible to reduce the compression costs by comparison with compressing gaseous hydrogen given that it is easier to compress a volume of incompressible liquid than a volume of gas.
Generating this high pressure is extremely expensive in terms of compression energy. In addition, the evaporative losses of liquid hydrogen in a pump may also be high if the pump is not used optimally. Reducing the losses (both friction losses and gas losses) is therefore a key issue in optimizing the costs of obtaining high-pressure hydrogen.
One of the problems with cryogenic pumps in general and with liquid hydrogen pumps in particular is that the fluid that is to be pumped is very low density (70 g/l at 1 bar). It is therefore difficult if not impossible to provide the pump with the suction pressure it requires simply by physically installing the source tank on the pumping installation with a head of pressure (hydrostatic head). The problem is that the suction pressure has to take account of the pump inlet head loss (NPSH=Net Positive Suction Head, that is to say the difference in pressure between the saturation pressure of the gas that is to be pumped and the fluid suction pressure needed for the pump to operate in a pure liquid phase without cavitation).
For example, a liquid hydrogen (LH2) pump at 700 bar has a head loss (NPSH) of around 250 mbar, which corresponds to a 35 m head of liquid hydrogen. It is impossible to run the pump with a source tank installed on the pump with a pressure head of 35 m (and even if this were industrially possible, the head losses in the lines would counterbalance the fact that the tank had been installed with such a pressure head). One solution is therefore to "supercool" the liquid and to suck up this liquid in its supercooled state. Supercooling involves increasing the pressure of a fluid to saturation or reducing its temperature, at constant pressure, without waiting for a new liquid-vapor equilibrium to become established.
Pressurized hydrogen, however, is even less dense than hydrogen at atmospheric pressure. For example, the density of saturated hydrogen at 1 bar absolute is 70 g/l whereas it is 56 g/l at 7 bar absolute. Given that liquid hydrogen pumps are positive-displacing systems, it is therefore beneficial to suck up the hydrogen when it is as dense as possible, and therefore when it is saturated at the lowest possible pressure (as cold as possible), the purpose of this being to optimize the quantities pumped.
The invention described hereinbelow notably makes it possible to use a liquid hydrogen pumping plant continuously from a hydrogen source in liquid/gas equilibrium at a low pressure (of between 1 and 12 bar) and to optimize the operation of such a plant by allowing the pump to operate continuously while at the same time maximizing the density of the pumped hydrogen, and therefore maximizing the pumped output.
In existing solutions, the tank is pressurized using thermosiphon (a heater that establishes atmospheric pressure) or directly using high-pressure hydrogen from cylinders at ambient temperature.
During the running of these known systems, the hydrogen at ambient temperature injected into the roof of the tank gradually heats up the liquid, reducing the available level of supercooling.
This then increases the rated pressure of the tank, with the effect of reducing the pumping time available before the tank reaches its maximum operating pressure.
Document WO2005/085637A1, in the name of the applicant company, notably describes a pumping system comprising pressure control means capable of keeping the pressure in the suction line of the pump at most equal to the saturation pressure of the cryogenic fluid increased by the inlet head loss of the cryogenic pump.
It is one object of the present invention to alleviate all or some of the abovementioned disadvantages of the prior art.

Device and method for pumping a cryogenic fluid

L'Air Liquide Société Anonyme Pour L'Étude Et L'Exploitation Des Procedes Georges Claude


The invention relates to a pelletized organopolysiloxane material, to a process for producing the pelletized material, and to the use of the pelletized organopolysiloxane material as an additive for thermoplastics.

1. Field of the Invention
The invention relates to a pelletized organopolysiloxanes, to a process for their preparation, and to their use as an additive for thermoplastics.
2. Background Art
Silicone-based monomers and polymers are increasingly used in the plastics industry, from polymer preparation through polymer compounding and final product manufacture. By way of example, low-molecular-weight organopolysiloxanes with viscosities up to 1000 mm2/s are widely used in the plastics industry as external mold-release agents. Relatively high-molecular-weight organopolysiloxanes in the viscosity range from 10,000 to 100,000 mm2/s have been used for about 30 years as internal additives in thermoplastic polymer to provide processing advantages and improvements in surface properties, among which, by way of example, are low coefficient of friction, better slip properties, better abrasion resistance, better wear values, better scratch resistance and surface gloss, better demoldability, lower rejection rate, easier processing, better throughput, lower energy consumption during processing, and faster cycle times in shaping processes.
In addition, organopolysiloxanes have better stability than conventional processing aids and lubricants, for example, waxes and fatty acid derivatives. Ultrahigh-molecular-weight organopolysiloxanes with viscosities of from 1,000,000 to 100,000,000 mm2/s have additive properties comparable to those of relatively high-molecular-weight organopolysiloxanes, generally with better effectiveness and higher efficiency. This improved property profile is attributed to a higher level of mechanical interaction between the long-chain ultrahigh-molecular-weight organopolysiloxanes and the polymer chains of the thermoplastics, and results in greater permanency, reduced migration, and better printability, adhesive properties, and weldability.
However, liquid organopolysiloxane additives, especially those with relatively high viscosities, have the disadvantage that their introduction into thermoplastic melts during the extrusion process is difficult, and in general, only achievable by use of specialized technical equipment. Extrusion processes preferably use solid constituents, most preferably in the form of conventional pelletized material. A disadvantage of solid constituents in powder form is that it is more difficult to manufacture homogeneous premixes in the form of dry blends from plastics pellets and pulverulent additives, and that such premixes, even when used, have greater susceptibility to segregation during storage and metering than premixes manufactured from two or more different pelletized materials. Segregation and irregular metering are problematic especially when pulverulent additives, the amounts of which are generally very small, are blended with pelletized polymer material. Non-uniform metering leads to inhomogeneous product quality, which is undesirable. For this reason, concentrates or masterbatches have been developed comprising relatively high-viscosity and ultrahigh-viscosity liquid organopolysiloxanes in the form of pellets. However, these organopolysiloxane concentrates have a number of disadvantages. For example, the organopolysiloxane content ranges only from 20% to a maximum of 50%, the remainder being a thermoplastic carrier material. The presence of such carrier materials limits the range of applications of the pelletized material, because the carrier has to be matched to the particular plastic to which the concentrate is added. In view of the wide variety of thermoplastics, this consequently requires providing a wide variety of concentrates of organopolysiloxane in different thermoplastic carriers. This is especially disadvantageous for plastics compounders or final processors who utilize a wide variety of different plastics and consequently have to inventory a correspondingly wide variety of organopolysiloxane concentrates.
Organopolysiloxane powders do not have the disadvantage of incorporation of different carrier materials. U.S. Pat. No. 5,346,941 describes pulverulent compositions comprising a liquid organopolysiloxane, silica, and a specific silicone resin, and its use for modifying thermoplastics. U.S. Pat. No. 5,391,594 describes compositions comprising a plastic and a silicone powder with a particle size of from 1 to 1000 μm which includes a polydiorganosiloxane and silica. However, pulverulent organopolysiloxane additives have the disadvantage, described at the outset, of segregation and inhomogeneity with pelletized materials. In the case of additives employed in small amounts, this is particularly undesirable, resulting in variable product quality.


The electromagnetic drive mechanism for the control rods of a nuclear reactor has a stationary gripper and coil, a movable gripper and coil, and a lifting armature and coil for moving the movable gripper to advance or retract the control rods in steps. A coil current driver responsive to a controller provides currents to the coils individually and in combinations. During the operations, coil current signals are sensed, sampled, digitized and processed to generate coil current data such as amplitude as a function of time. The measured coil current data is compared to nominal current data as well as historical current data, and the historical data is updated or appended to include the measured data. The comparison includes a check for correct timing relationships, such as the timing of the current notch occurring due to increased inductance upon pull-in of a gripper. Additionally, voltages or currents between the ac power source and the coils can be monitored for isolating a failure to particular circuit elements.

1. Field of the Invention
The invention relates to analyzing over time the performance of a control rod drive mechanism of a nuclear reactor, and its associated control system, by digitizing, storing and analyzing current level signals developed during stepwise lifting and lowering of control rods using electromagnetically driven sequential gripping and moving devices.
2. Prior Art
In a nuclear reactor for power generation, such as a pressurized water reactor, heat is generated by fission of a nuclear fuel such as enriched uranium, and transferred into a coolant flowing through a reactor core. The core contains elongated nuclear fuel rods mounted in proximity with one another on a fuel assembly structure through and over which the coolant flows. The fuel rods are spaced from one another in coextensive parallel arrays. Some of the neutrons and other atomic particles released during nuclear decay of fuel atoms in a given fuel rod pass through the spaces between fuel rods and impinge on the fissile material in an adjacent fuel rod, contributing to the nuclear reaction and to the heat generated by the core.
Movable control rods are dispersed throughout the nuclear core to enable control of the overall rate of fission, by absorbing a portion of the neutrons passing between fuel rods, which otherwise would contribute to the fission reaction. The control rods generally comprise elongated rods of neutron absorbing material and fit into longitudinal openings or guide thimbles in the fuel assemblies running parallel to and between the fuel rods. Inserting a control rod further into the core causes more neutrons to be absorbed without contributing to fission in an adjacent fuel rod; and retracting the control rod reduces the extent of neutron absorption and increases the rate of the nuclear reaction and the power output of the core.
The control rods are supported in cluster assemblies that are movable to advance or retract a group of control rods relative to the core. For this purpose, control rod drive mechanisms are provided, typically as part of an upper internals arrangement located within the nuclear reactor vessel above the nuclear core. The reactor vessel is typically pressurized to a high internal pressure, and the control rod drive mechanisms are housed in pressure housings that are tubular extensions of the reactor pressure vessel.
One type of mechanism for positioning a control rod is a so-called magnetic jack, operable to move the control rod by an incremental distance into or out of the core in discrete steps. The control rod drive mechanism has three electromagnetic coils and armatures or plungers that are operated in a coordinated manner to raise and lower a drive rod shaft and a control rod cluster assembly coupled to the shaft. The three coils are mounted around and outside the pressure housing. Two of the three coils operate grippers that when powered by the coils engage with the drive rod shaft, one of the grippers being axially stationary and the other axially movable.
The drive rod shaft has axially spaced circumferential grooves that are clasped by grip latches on the grippers, spaced circumferentially around the drive rod shaft. The third coil actuates a lift plunger coupled between the movable gripper and a fixed point. If control power to the control rod drive mechanism is lost, the two grippers both release and the control rods drop by gravity into their maximum nuclear flux damping position. So long as control power remains activated, at least one of the stationary gripper and the movable gripper holds the drive rod shaft at all times.
The three coils are operated in a timed and coordinated manner alternately to hold and to move the drive shaft. The sequence of gripping actions and movements is different depending on whether the stepwise movement is a retraction or an advance. The stationary gripper and the movable gripper operate substantially alternately, although during the sequence of movements both grippers engage the drive shaft during a change from holding stationary to movement for advance or retraction. The stationary gripper can hold the drive shaft while the movable gripper is moved to a new position of engagement, for lowering (advancing) the drive shaft and the control rods. The movable gripper engages with the drive shaft when moving it up or down as controlled by the lift plunger. After the movable gripper engages the drive shaft, the stationary gripper is released and then the plunger is activated or deactivated to effect movement in one direction or the other. Typically, each jacking or stepping movement moves the drive rod shaft 5/8 inch (1.6 cm), and some 228 steps are taken at about 0.8 seconds per step, to move a control rod cluster over its full span of positions between the bottom and top of the fuel assembly.
More particularly, for lifting (retracting) the control rods, the following steps are accomplished in sequence, beginning with the stationary gripper engaged in a drive rod groove and the movable gripper and plunger both being deactivated:
1. the movable gripper is energized and engages a drive rod groove; PA1 2. the stationary gripper is de-energized and disengages from the drive rod; PA1 3. the lift coil is energized and electromagnetically lifts the movable gripper and the drive rod an elevation equal to the span of the lift plunger; PA1 4. the stationary gripper is energized, re-engages and holds the drive rod (i.e., both grippers are engaged); PA1 5. the movable coil is de-energized and disengages the drive rod; PA1 6. the lift coil is de-energized, dropping the movable coil back to its start position, namely one step lower on the lifted drive rod. PA1 1. the lift coil is energized, moving the movable gripper one step up along the drive rod; PA1 2. the movable gripper coil is energized and the movable gripper grips the drive rod; PA1 3. the stationary coil is de-energized, releasing the drive rod; PA1 4. the lift coil is de-energized, dropping the movable coil and the drive rod by one step; PA1 5. the stationary coil is energized and the stationary gripper engages the drive rod, at a position one step higher than its previous position; and, PA1 6. the movable coil is de-energized and the movable gripper disengages from the drive rod.
Similarly, for lowering (advancing) the control rods, the following steps are accomplished in sequence, again beginning with only the stationary gripper energized:
A number of particular coil mechanisms and gripper mechanisms are possible. Examples of coil jacking mechanisms with a stationary gripper, a movable gripper and a lifting coil as described are disclosed, for example, in U.S. Pat. No. 5,307,384--King et al., U.S. Pat. No. 5,066,451--Tessaro and U.S. Pat. No. 5,009,834--Tessaro, all of which are hereby incorporated.
Whatever mechanical arrangement is employed for the grippers and lifting coil/armature arrangement, a discrete time interval is needed to complete each sequential operation. In order to move the control rods quickly, reliably and efficiently, the respective grippers and coils must be operated accurately as to their timing. This requires that the coil energizing electric power signals to the respective coils be accurately timed.
The power level of coil energization can be simply on and off, or preferably the coils can be energized at different levels during different operations in the sequence. For example, the lift coil signal can have an intermediate or "hold" current level for the lift coil, between the de-energized (zero) level and the full-on lifting level. At the intermediate level, the lift coil maintains the position of the movable coil. An intermediate current level may also provide sufficient power to move the movable gripper when it is disengaged from the control drive rod. An intermediate current level can be used with the stationary gripper coil for holding, as opposed to a higher level for positive initial gripping.
The coil signals are switched between the levels in a coordinated manner by a logic controller. The logic controller generates timed signals to switch power regulation circuits on and off or between current levels. The timing relationships between and among current pulses applied to the stationary gripper coil, the movable gripper coil and the lift coil, are adjusted manually when setting up the control rod drive mechanism, and remain set. For example, an oscilloscope or chart recorder is set up to record the three coil currents. A timing signal at a known frequency can be provided and recorded together with the coil current signals as a reference. The actual determination of timing is done by reviewing the recorded signals and spacing the operations in time sufficiently to complete each step in the sequence before undertaking the next.
The power regulation circuits attempt to maintain the required coil currents at the required times in the sequence of operations. However, the actual coil currents have current variations that reflect the status of the electromechanical operation. For example, the drive currents to the gripper coils typically show a brief reduction or notch in current when the associated gripper fully pulls in and the inductance of the gripper coil increases. The notch disappears as the power regulator responds to bring the current level to nominal. By noting the occurrence of the notch in the gripper coil current signal, the technician can determine the point in time at which the gripper engaged. The timing of the next operation, which depends on successful gripper engagement, is then set to occur at a slight delay after the gripper engagement time noted.
Various circuit elements can be used in the control logic circuits to trigger the power regulator to generate the necessary control currents at preset times in the sequence. For example, cycles at a known frequency (such as the recorded timing reference signal) can be digitally counted, and a particular power regulation switching operation can be triggered by a signal gated from a cycle counter at a predetermined count. Alternatively, the timing can be set using other means such as adjusting the RC delays of monostable multivibrators that trigger one another in a cascade sequence. In any event, the timing is predetermined and set, giving some leeway or extra time to ensure completion of each operation before commencing the next, while nevertheless enabling the rods to be advanced or retracted relatively promptly through their span of movement.
It would be advantageous to provide a more automated control mechanism that is responsive to operation of the device rather than preset timings based on the expectation that current levels will be reached and mechanical actions will occur at the needed times. It would also be advantageous if the control mechanism could include ongoing diagnostic and feedback capabilities, such that deviation from expected operation can be detected by comparison with historical or nominal operation and suitable corrective action taken.

Method and apparatus for control rod drive mechanism analysis using coil current signals


A system is provided for the provision of DVR playlists. DVR playlists allow for consumers to manage the availability, arrangement, and type of content to be provided from a DVR such that content items are intelligently added, arranged, played back, and deleted via the DVR playlist. Aspects of the system allow playlists to be created by the system, by the consumer, and in co-operation between the system and the consumer. Content items may also be provisioned, such that a DVR playlist limits playback, while still providing variety and consumer choice. Aspects of the system allow for various seed attributes to affect which content items are automatically chosen to comprise the DVR playlist. Content items may be shared amongst user accounts under a subscriber account so that space on a DVR is more efficiently provisioned.

Digital Video Recorders (DVRs) allow consumers of video content to record video content for later viewing. DVRs may be either local or networked-based, and both allow consumers to record and play content on various display devices.
One frequent frustration for consumers is the difficulty and hassle in accessing recorded content from DVRs in a particular order or in frequent succession. Consumers are often forced to manually control the playback of recorded content and must access recorded content separately from streamed content.
Moreover, when multiple consumers are associated under one subscriber, such as the case when a family or set of roommates share a main account with a service provider, video content downloaded may be prematurely deleted by one consumer who has watched the video content before other consumers have had a chance to watch it, forcing repeated downloads and wasting time. Alternatively, the last consumer to watch the video content may not delete the video content, which wastes space on the DVR that could be used for different content items.
It is with respect to these and other considerations that aspects of the present disclosure will be made.


To maintain the amplitude of an oscillating signal within a defined range, the detected peak level of the oscillating signal is compared to a reference voltage. If the detected peak level is determined as being greater than the reference voltage, the common source/drain voltage of a differential amplifier driving the crystal oscillator across its input terminals is reduced so as to lower the amplitude of the oscillation signal. If the detected peak level is determined as being smaller than the reference voltage, the common source/drain voltage of the differential amplifier driving the crystal oscillator is increase so as to raise the amplitude of the oscillation signal.

The present invention relates to integrated circuits, and more particularly to regulating the amplitude of an oscillating signal.
Crystal oscillators are widely used in electronic circuits and use stable electromechanical resonance characteristics of a piezoelectric crystal, such as quartz, to generate a clock signal. When a quartz crystal is cut along certain crystal axes to form parallel-plate electrodes, it can be made to resonate when excited. The resonant frequency depends on the material and dimensional properties of the crystal, such as the size, the orientation of the crystal faces, and the mounting of the crystal on its mechanical supports. Because of their insensitivity to time and temperature variations, crystal oscillators are widely used in applications requiring clock signals.
FIG. 1 is a transistor schematic diagram of an oscillator 10 as known in the prior art. Oscillator 10 is shown as including a crystal 20 disposed between input and output terminals of a CMOS inverter formed by PMOS transistor 12 and NMOS transistor 14. The oscillation signal generated between nodes X1 an X2 has an amplitude that varies between supply voltages Vdd and ground. Oscillator 10 is thus inappropriate for use in applications requiring relatively high accuracy oscillation frequency driven by small time-varying signals.


A gas distribution assembly includes an outer pipe and an inner pipe, defining a gas supply chamber therebetween. Furthermore, the gas distribution assembly includes a unit for supplying compressed gas to the gas supply chamber, a first end connection connecting first ends of the outer pipe and of the inner pipe, and leaving an orifice of the first end of the inner pipe open outwards, a second end connection connecting second ends of the outer pipe and of the inner pipe, and leaving an orifice of the second end of the inner pipe open outwards. The inner pipe includes a first pipe member including the first end of the inner pipe and a second pipe member including the second end of the inner pipe, which pipe members are in telescopic engagement with each other.

In a waste water treatment process, one important process step is to oxygenate the waste water in order to promote biological consumption and removal of dissolved and suspended waste material. Aeration/oxygenation is performed in a natural waste water impound, such as lakes, ponds, or the like, or in a man-made waste water impound, such as tanks, basins, racetracks, lagoons, or the like, by using submerged gas distribution systems comprising a large number of diffuser members, also called aeration devices. In most cases the waste water impound is made of metal of concrete. Such gas distribution systems are also known as gas distribution grids. Compressed gas, such as air or other treatment gas containing some form of oxygen, is supplied to the submerged gas distribution system and then the compressed gas is diffused/discharged into the liquid by means of said numerous diffuser members as small bubbles. As these bubbles rise buoyantly through the liquid, oxygen in the bubbles dissolves into the waste water. Bacteria are supplied to the waste water in the treatment process in order to consume the waste in the liquid, and the life processes of bacteria is supported by the oxygen. Other treatment gases, not necessarily containing oxygen, may be distributed through the gas distribution system for other purposes, such as for cleaning the small discharge openings of the diffusers.
In many applications the gas distribution system is liftable, i.e. removable from the basin, in order to facilitate the service and cleaning of the gas distribution system and the basin, respectively. In order to make the anchorage as well as the removal of the gas distribution system easier, prior art gas distribution systems according to the introduction above have been developed, i.e. gas distribution systems as the one disclosed in DE 36 24 580 and DE 35 14 028. Older gas distribution systems needed a lot of additional weights to outweigh the large buoyancy of the gas distribution system, however the extra weights also made the gas distribution system more cumbersome to remove from the basin. Gas distribution systems according to DE 36 24 580 and DE 35 14 028 comprise an internal space delimited by an open ended inner pipe, which internal space is filled with liquid during lowering in order to reduce the buoyancy, during hoisting the liquid is automatically emptied from the internal space when the gas distribution system is hoisted above the liquid surface.
However, known low buoyancy gas distribution assemblies according to the introduction, and shown in DE 36 24 580 and DE 35 14 028, are only made for tube diffusers of limited length. Thereto, it is time consuming to arrive at the exact corresponding length of the inner pipe and the outer pipe, which is crucial in order to obtain a faultless and leakage free tube diffuser of the known type.


The present invention presents an apparatus to facilitate the loading of specific fuel rods into the specific grid cells of the grids of a fuel assembly. The loading apparatus utilizes air-pressure operated loading cylinders to push out the specific fuel rods from a fuel rod magazine into the corresponding grid cells. The loading apparatus operates in conjunction with a series of fuel rod support rollers which provide support to the fuel rods, being charged into the grids, from the underside of the fuel rods to prevent sagging of the tip end, thus avoiding scraping against the straps of the grids when entering the grid cells, and causing potentially harmful surface scratches on the fuel rods.

1. Field of the Invention
The present invention relates to an apparatus for assembling a nuclear fuel assembly for nuclear reactors, and in particular to a simple apparatus for loading fuel rods into the fuel assembly efficiently.
2. Background Art
A conventional fuel assembly such as the one disclosed in a U.S. Pat. No. 5,068,081, shown in FIG. 2, is known.
In this figure, the numerals 1 and 2 refer to top and bottom nozzles, respectively, which are disposed vertically and oppositely spaced apart, and having a plurality of rigidly fixed control-rod guide pipes 3 (hereinbelow referred to as guide pipes 3) between the top nozzle 1 and the bottom nozzle 2. In the mid section of the guide pipes 3 are a plurality of grids 4 disposed vertically and spaced apart from each other.
The grids 4 are, as shown in FIGS. 3 to 5, constructed of a plurality of straps 7 made of thin metal strips having slits 8 formed in the longitudinal direction thereof, and by interlocking the slits 8 to form lattices. The structure formed by the lattices is known as the grid cells 5, and a dimple 9 and spring 10 are formed on each of the opposing walls of the grid cells 5. A fuel rod 6 inserted into a grid cell 5 is pressed against the dimple 9 by the spring 10, thereby holding the fuel rod 6 firmly in the grid cell 5 therebetween.
A method of inserting a fuel rod 6 in a grid cell 5 is known, for example, in Japanese Patent Application, Laid-open publication (Kokai) H2-181,699 which involves the use of a key device to deactivate the spring 10, and gripping the tip of a fuel rod 6 by means of a pull-in device, which then enables the fuel rod 6 to be pulled into the grid cell 5.
However, such methods presented problems because of the necessity of pull-in device and other ancillary control devices, and the complexities of the devices mean that the operations become cumbersome and lengthy.

Apparatus for assembling nuclear fuel assembly


An antenna system is comprised of a plurality of independently constructed and operated antenna units, upon which are mounted a plurality of transmit and receive antenna pairs. This structure provides a means for the antenna system to be arranged to provide substantially hemispherical radio coverage. By adjusting the phase of each version of a radio signal to the transmitter or received, the signal may be formed into a beam according to known techniques of directional beam forming providing the antenna system with directional gain. Additionally, using a plurality of transmit and receive antenna pairs reduces the energy transmitted by each transmit antenna alone to a level which permits a branch line coupler to be sufficient to orthogonally polarize the transmitted and received radio signals negating the requirement for the duplexing filter for duplex operation.

1. Field of the Invention
The present invention relates generally to the field of antennas and, more particularly, the present invention relates to improved radio telecommunication antennas.
2. Description of the Related Art
Information is communicated in radio communication systems through the transmission and reception of electromagnetic waves. Data to be communicated modulates an electromagnetic wave at a transmitter which produces signals that are radiated by an antenna. An antenna at a receiver detects the electromagnetic wave which is demodulated by the receiver, thereby reproducing the transmitted data. Electromagnetic waves containing data which are used for communication in this manner are known as radio signals. Antennas which are used in transmitting and receiving the electromagnetic signals provide gain to both transmitted and received radio signals.
In areas of radio communications such as satellite communications, the direction in which radio signals are transmitted and received is important. In satellite communications, radio signals must travel over large distances through a variety of unknown media. This results in a significant decrease in the power of the transmitted radio signal which ultimately reaches the receiver. In order to form an effective radio communication link, optimum use must be made of the transmitted and received radio signal power. For this reason, radio telecommunication systems often use antenna systems which maximize the gain of a radio signal transmitted in or received from a given direction.
An antenna system which is known in the art that operates to utilize the direction of transmission or reception of a radio signal is a planar phased array antenna. Such a planar phased array is comprised of a plurality of antennas arranged on a plane surface. Each antenna may transmit or receive a version of the radio signal. In the case of reception, for example, each antenna of the planar phased array delivers a version of the radio signal, although shifted in phase in accordance with the spatial separation of each antenna relative to the direction of arrival. A schematic diagram of such a planar phased array in which three antennas are incorporated is set forth in FIG. 1.
In FIG. 1, a planar phased array 1 is shown which is comprised of three antennas 2, 3, 4. Radio waves transmitted by a distant source (not shown) are received by the three antennas 2, 3, 4. Three versions of the received signal 5, 6, 7 are delivered by the three antennas 2, 3, 4. As a result of the spatial separation of the antennas, the received signals are displaced in time with respect to each other, resulting in the three versions of the received signal exhibiting a phase displacement in correspondence with the spatial separation of each antenna. Let r.sub.x (t) be the signal received by an antenna x at a time t, where, in this case x=1 to 3 for the three antennas 2, 3, 4. If the version of the signal received by the first antenna is given by equation (1), then the versions of the signal received by the second and third antennas 3, 4, will be those given by equations (2) and (3), where R.sub.x is the power in each version of the signal. Each version of the signal is then combined by a summer 8, to produce a resultant signal r(t). The combined received signal is represented by equation (4). ##EQU1##
As illustrated in FIG. 1, the planar phased array, is less suitable for detecting a radio signal 9, which has an angle of incidence which is greater than sixty degrees from the perpendicular 10. This will be discussed below.
A conventional planar phased array is mechanically steered to a desired direction in which the reception of a radio signal is optimized. The optimum direction of reception or transmission is that which causes the phase of each version of the signal to be the same. The phased array therefore operates so that the versions of the radio signal add constructively. As can be seen from the example in FIG. 1, this is achieved by steering the array until the axis upon which the antennas are mounted is perpendicular to the direction of propagation of the signal to be received. This causes the relative delays between each version of the received signal to be reduced to zero, resulting in no corresponding phase displacement. The signals therefore add constructively. Likewise a radio signal may be transmitted in a desired direction, by steering a corresponding phased array so that it points accordingly in a desired direction.
A known technique in which radio signals may be transmitted in, or received from a direction by an array of spatially displaced antennas, which does not involve mechanical movement of those antennas, is known as electronic beam steering. With this technique, the phase of each version of the radio signal is arranged to be shifted electronically, so that the versions of a radio signal add constructively for transmission or reception in a desired direction. The versions of the radio signal are therefore focussed into a beam pointing in the direction of transmission or reception. The direction in which the beam is focused is controlled electronically, providing means for the direction of focus to be dynamically adjusted.
Radio communication systems are designed to both transmit and receive information contemporaneously. An item of radio communications equipment which is provided with means for both transmission and reception of information is known within the art as a transceiver. The technique of contemporaneous transmission and reception is known as duplexing. Frequency division duplexing is a known duplexing technique in which the carrier frequency of transmitted and received radio signals is arranged to be different and separated by a suitable guard band of frequency. To separate the transmit signal from the received signal, a duplexing filter is required. The duplexing filter operates to prevent energy from the transmitted signal from corrupting the received signal. The duplexing filter must provide sufficient attenuation to a transmitted signal, so that little or no energy from the transmitted signal is present within the frequency band of the received signal.
One disadvantage of conventional planar phased arrays is that a separate duplexing filter is required for each antenna in the array. This increases both cost and size of the antenna system.
A further disadvantage of the planar phased array is that it is only suitable for steering a beam within a limited angle of incidence from a plane perpendicular to the axis in which the antennas are aligned. This is indicated in FIG. 1, where the planar phased array 1 is not suitable for beam steering by a radio signal 9 which has an angle of incidence greater than about sixty degrees from the perpendicular 10. To provide an antenna system with a hemispherical radio coverage pattern, for example, multiple planar phased arrays are required, making construction and testing of an antenna system difficult and further increasing its cost and size.
It is here stated that the term radio coverage where used herein means a volume which an antenna system is capable of illuminating with radio signals or from which an antenna system is capable of detecting radio signals with sufficient strength to effect radio communications.
It is an object of the present invention to provide an antenna system in which the aforementioned disadvantages of known antenna systems using planar phased arrays are eliminated.


Internet web pages displayed via an Internet web browser or other applications are automatically customized. Dynamic “Web Components” are used to automatically customize web pages. Further, these Web Components use the same script and HTML for all implementations or instantiations of the Web Component regardless of which, or how many, unique local clients make use of the Web Component. This code reuse is accomplished by using entry web pages, or “entry points,” as described in further detail below, to set the value of function properties or parameters of the Web Component for dynamically and automatically generating a web page. The script and/or HTML source code of the Web Component pages does not change based on each new implementation or instantiation. Consequently, little setup work is required for each implementation, and only a basic verification test pass is needed for each unique automatically customized Internet web page.

1. Technical Field
The invention is related to a system and process for automatically customizing an Internet web page displayed via an Internet browser or other application for displaying Internet web pages.
2. Related Art
By way of background, using existing schemes, third parties desiring to use features of other Internet web sites must either accept the feature-set and presentation of the existing web pages, or copy these pages to another web location, and alter the script and/or HTML defining the existing web pages to provide the customization desired. Consequently, more than one source-code base must be maintained for the same or similar web pages, with setup and server configuration changes necessary each time a new web page feature, such as, for example a calculator applet or credit card processing form, is implemented. Further, full test passes of the resultant HTML, and script that was modified, are typically performed to ensure error free web page operation.
Therefore, what is needed is a system and method for automatically customizing web pages without the need to manually copy and alter the script and/or HTML defining such web pages. In other words, this system and method should allow the reuse of a single code base to automatically provide a plurality of uniquely customized web pages. Further, this system and method should operate without the need to perform full testing of each instantiation of an automatically customized web page.

This patent is subject to a terminal disclaimer.

Using dynamic Web Components to automatically customize web pages


In a biological sample analyzing apparatus and method, an assay sample is prepared by mixing a reagent with a biological sample which may contain assay material. Then, a first information relating to the assay material is collected from the assay sample, and when the first information satisfies predetermined condition, the assay material is analyzed based on the first information. However, when the first information does not satisfy the predetermined condition, a second information related to the assay material is collected from the assay sample, and the assay material is analyzed based on the second information.

Methods for quantifying assay material contained in a biological sample include methods in which material in an assay sample is agglutinated using a substance to induce an antigen-antibody reaction with the assay material, and the concentration of the assay material is calculated based on the degree of agglutination. Examples of such methods include immunoturbidity, immunonephelometry, counting immunoassay (CIA) and the like.
A calibration curve, which represents the relationship between the concentration of the assay material and information reflecting the degree of agglutination of the material in the assay sample, is used when calculating the concentration of the assay material by these methods. FIG. 14 shows an example of a calibration curve when the information reflecting the degree of agglutination of carrier particles is the absorbance in the immunoturbidity method using carrier particles. In FIG. 14, when the concentration of the assay material is in the low concentration range, the absorbance gradually increases in conjunction with the increase in the concentration of the assay material. However, above a certain concentration of the assay material (high concentration range), there is a reduction in the absorbency (referred to as a 'zone phenomenon'). As shown in FIG. 14, when the zone phenomenon occurs, two concentrations (C1 and C2) are obtained in the low concentration range and high concentration range of a single absorbency level A, such that the concentration of the assay material cannot be ultimately determined. Therefore, the concentration range in which the assay material can be measured is limited.
Japanese Laid-Open Patent Publication No. 61-280568 discloses a method for measuring an assay material even when the specimen contains a high concentration of assay material. This method utilizes CIA using carrier particles as the principle of measurement. CIA first mixes a specimen including an assay material and carrier particles on which antibody or antigen against the assay material is immobilized, and agglutinates the carrier particles by an antigen-antibody reaction. After a predetermined reaction time, the degree of agglutination is detected and the carrier particle distribution is obtained, then the degree of agglutination of the carrier particles is analyzed from the particle distribution, and the concentration of the assay material is calculated based on the degree of agglutination. The predetermined reaction time in this case is the time interval from the initiation of the antigen-antibody reaction until agglutination is detected.
In the method disclosed in Japanese Laid-Open Patent Publication 61-280568, a calibration curve is prepared across the entire region including the low concentration range and high concentration range, and the agglutination of the carrier particles is determined for the reaction time T1 and reaction time T2 of the antigen-antibody reaction. Then, a concentration is calculated from the degree of agglutination and calibration curve at reaction time T1, and another concentration is calculated from the degree of agglutination and calibration curve at reaction time T2. In this way the concentrations are compared for the reaction time T1 and reaction time T2, and a concentration common to both reaction time T1 and reaction time T2 is designated as the final assay material concentration.
The method of Japanese Laid-Open Patent Publication No. 61-280568 is described below using FIG. 15. FIG. 15 shows the calibration curves at reaction time T1 and reaction time T2 (where T1<T2). In FIG. 15, calibration curve T1 is the calibration curve at reaction time T1, and calibration curve T2 is the calibration curve at reaction time T2. For example, when the agglutination at reaction time T2 is designated B, the concentration of the assay material is either C1 or C2. Likewise, when the agglutination at reaction time T1 is A1, the concentration C1, which is common to each reaction time on the calibration curves, becomes the concentration of the assay material in the specimen. Similarly, when the agglutination at reaction time T1 is A2, the concentration C2, which is common to each reaction time on the calibration curves, becomes the concentration of the assay material in the specimen.
However, the value of the degree of agglutination at reaction time T2 is indispensable for determining the concentration of the assay material in this method. That is, the degree of agglutination at both reaction times T1 and T2 are invariably required in this method.


A method and a device for identifying errors in emission-relevant control devices of a vehicle, such as the injection of fuel into a cylinder, allows error identification even if none of the sub-systems exceeds a predetermined threshold value. The method has the following steps: determining whether at least one parameter, which permits conclusions to be drawn about the emission behavior of the respective control device, lies in a desired range; if the parameter lies outside said desired range, an error value that correlates to an increase in emissions is stored; if the parameter is in the desired range, an error value of zero is stored; a total error value is formed from all error values of the control device and an error message is output if the total error value exceeds a predetermined threshold value.

At emission-relevant automotive control devices diverse methods of detecting faults are carried out for statutory reasons. On the one hand, many methods are a direct legal requirement and in most of these a fault has to be detected and the driver has to be alerted by means of a malfunction indication lamp if a specific emission limit is exceeded. At a data communication interface for the workshop codes, such as for example DTCs (diagnostic trouble codes), for each detected fault are made available in order to facilitate fault diagnosis.
In previous systems, such as are known from the background art, the fault detection of each individual method is independent of the fault detection of the other detection methods. For example, a problem regarding the injection quantity of an individual cylinder is only identified as an emission-relevant fault if this problem alone already results in the emission limit being reached. In other words, it is only when one of the cylinders exceeds the defined emission limit value that a fault is detected. If, however, the problem is less serious in terms of emission deterioration, then no emission-relevant fault is detected and/or communicated to the driver. If in the latter state there are further non-serious faults for example at one or more of the other cylinders, the overall system possibly exceeds emission limits but none of the individual methods detects an emission-relevant fault. In other words, in the situation where none of the individual cylinders exceeds the emission limit value but all of the cylinders combined exceed the emission limit value, this is not detected as a fault.
From DE 102 57 686 A1 moreover a method of adapting an injection characteristic is known. Here, an injection valve characteristic of an activated fuel injection valve that represents a reference injection behavior is adapted to ageing-related changes of an actual injection behavior. Here, during an operating state that requires no fuel injection, the injection valve is intermittently activated. In this case, at least one working cycle with activation precedes a working cycle without activation of the injection valve. In this case, in each case a rotational speed value of the internal combustion engine is detected for the working cycle with activation and at least one such value for the working cycles without activation. The difference of the detected values is then used to carry out a correction of the injection characteristic.

Method and device for identifying errors in emission-relevant control devices in a vehicle


A support assembly for supporting a flexible duct includes a radius strap for maintaining the desired angle of bend for the flexible duct. The radius strap retains its shape through ribs along the back side of the strap. The assembly is secured at both ends to the flexible duct via arms branching off of cross pieces which branch off from the radius strap. The arms contain slots which allow varying connection devices to pass through and across indentations at the ends of the ribs to secure the flexible duct to the assembly itself and to varying pieces of HVAC equipment.

1. Field of the Invention
The present invention relates generally to ductwork for heating, ventilating and air conditioning ("HVAC") systems, and in particular to a support for protecting a length of flexible ductwork from crimping.
2. Description of the Related Art
Hoses, ducts and conduits in various sizes and configurations are commonly utilized for conveying, routing and directing various substances and objects. In dynamic systems, examples of such substances include air which has been heated or cooled by heating and air conditioning equipment. In the construction industry, such systems are commonly referred to as heating, ventilating, and air conditioning ("HVAC") systems.
Typical HVAC systems include runs of ductwork extending from the heating and air conditioning equipment to additional air handling equipment, or to distribution devices, of which supply diffusers, duct collars, duct taps, duct take-offs, register boxes, energy recovery ventilators, heat recovery ventilators and filter boxes are just examples. Additional air handling equipment examples include variable air volume ("VAV") boxes which are located in plenum spaces in many commercial structures. Heated and cooled air is typically introduced into the occupied spaces of buildings by diffusers which direct the airflow in predetermined distribution patterns for maximizing the comfort of the occupants.
Routing ductwork from the HVAC equipment to the supply diffusers or other equipment often involves ducting routes which turn, bend and intersect with various components and with other runs of ductwork. To accommodate such curved, angled, and bent routing, flexible duct is commonly used for the final portions of the duct runs, which terminate at diffusers or other components. Flexible duct also has the advantage of being easily reconfigurable to accommodate changed space configurations and the like. Another advantage of flexible duct is that it is available with insulation to avoid condensation and energy loss during cooling operation and is therefore widely used in spaces above ceilings. Flexible duct is often used in residential attic spaces and crawl spaces because it is insulated and easily manipulated in tight spaces.
However, a disadvantage of flexible duct is that it tends to crimp when bent. For example, 90° turns into diffusers can crimp unprotected flexible ducts. Crimping tends to restrict air flow and lower overall system efficiency. HVAC equipment thus works harder and consumes more power to overcome flow resistance associated with crimped flexible ducts.
A prior art solution to the problem of flexible duct crimping at diffusers and other bending locations is to install metal elbows. However, such additional components involve additional labor and material costs, as well as the possible need to insulate the metal elbow.
Other prior art solutions involving flexible duct sleeves to protect the curve of the flexible duct do not alleviate the cost issue. Prior designs use a lot of material, are difficult to manufacture, require time to strap onto the device, and are not as cost-effective as they could be.
The present invention addresses all of the disadvantages of prior art solutions to flexible duct installations. Heretofore there has not been available a support for flexible duct with the advantages and features of the present invention.


A carpet extractor (10) operable in either a restorative cleaning mode or a maintenance cleaning mode includes a constant rate pump (96) which dispenses clean solution through a manually operated valve (98) to one of two lines (100, 102) having nozzles which restrict dispensing to high and low solution flow rates. In the preferred form, clean solution is dispensed at the high flow rate directly upon the carpeted surface and at the low rate upon the agitating brush (88). When restorative cleaning is desired, the valve (98) is manually moved to dispense at the high flow rate and a switch (110) is also manually moved resulting in the chassis (18) being propelled at a slow working speed. When maintenance cleaning is desired, the valve (98) is manually moved to dispense at the low flow rate and the switch (110) is also manually moved resulting in the chassis (18) being propelled at a fast working speed.

The present invention generally relates to apparatus for cleaning floor surfaces, particularly to floor surface cleaning apparatus which applies cleaning solution to the floor surface and then vacuums the soiled cleaning solution from the floor surface, more particularly to carpet extractors, and specifically to carpet extractors having the ability to do both restorative cleaning and maintenance cleaning of carpeted surfaces.
The most common method of cleaning carpeted surfaces is with a carpet extractor. These machines consist of a clean solution tank with some means to apply solution to the floor surface, an agitation means for cleaning the floor surface, a dirty solution tank, and a vacuum means to pick the dirty solution off the floor surface after it is agitated. The tanks and systems performing these operations are usually attached to and carried by some type of chassis, which also may have provisions for a power source, wheels, and a means to transport the machine.
There are two types of carpet extraction, restorative and maintenance. Restorative cleaning is a deep cleaning process that is performed to remove soil and stains that normal dry vacuuming can not. Restorative cleaning requires a relatively high volume of solution to wash and flush soil and stains from deep within the carpeted surface. One of the negatives of restorative cleaning is the amount of cleaning solution that is retained within the carpet fibers and backing when the process is completed. Until the retained solution evaporates from the surface, the carpeted surface typically is not used, as soil that comes in contact with the carpeted surface while it is damp tends to stick to the surface.
Maintenance cleaning involves a cleaning of the upper exterior of the carpeted surface only. Maintenance cleaning requires a relatively low volume of solution resulting in less residual solution left in the carpeted surface and a shorter dry time.
Prior to the present invention, carpet extractors have been set up to do either maintenance cleaning or restorative cleaning. Since the solution typically is dispensed at a fixed rate, the only way to vary the amount of solution applied to a given area of carpeted surface was by varying the speed of the machine.
Thus, a need exists for floor surface cleaning apparatus which is selectively operative in one of two cleaning modes, and in the preferred form, restorative and maintenance carpet extraction.


There is provided a service method in a mobile terminal supporting a telephone call service and a plurality of additional services. Upon receipt of a priority designation request for a first selected one of the additional services from a user, the mobile terminal designates the first selected additional service as a high-priority service. Upon receipt of an incoming telephone call during a selected second one of the additional services, the mobile terminal determines whether the first selected additional service is identical to the second selected additional service. When the first selected additional service is identical to the second selected additional service, the mobile terminal maintains the selected additional service.

1. Field of the Invention
The present invention relates generally to a mobile terminal, and in particular, to a service method in a mobile terminal.
2. Description of the Related Art
A mobile terminal, i.e., a typical mobile telephone, provides various additional services such as a phonebook function for recording some 100 phone numbers in association with names of the phone number users' and a schedule management function for managing important schedules of the telephone user, as well as the existing telephone call service. The mobile terminal also supports a short message service (SMS). In addition, the mobile terminal has recently developed into a complex mobile terminal capable of supporting various multimedia services. In most cases, however, the telephone call service has priority over the additional services.
FIG. 1 illustrates an exemplary operation in which the conventional mobile terminal gives priority to the telephone call service. More specifically, FIG. 1 shows how the mobile terminal operates upon receipt of an incoming call while a user makes an SMS composition. FIG. 1 shows various displays of a display unit of the mobile terminal during this operation.
To make an SMS composition, the mobile terminal user selects an "OUTGOING MESSAGE" item by selecting an item number 2 on a Message Management menu shown in FIG. 1. Upon receipt of an incoming call while the user makes an SMS composition, the mobile terminal automatically stores the SMS message now under composition in a memory and at the same time, displays a message, e.g., "MESSAGE NOW UNDER COMPOSITION IS STORED", on the display unit. Subsequently, the mobile terminal switches from the additional service for the SMS composition to the telephone call service. In this state, if the user presses a CALL key, the mobile terminal transitions to a telephone call state and at the same time, displays a message "BUSY".
As described above, in the conventional mobile terminal, the telephone call service takes precedence over the additional services, so that a previously executed additional service resumes after completion of the telephone call service. Therefore, the conventional mobile terminal may be inconvenient to the user who desires to give priority to a specified one of the additional services rather than the telephone call service.


Control of an induction motor is carried out to limit damaging arcing stress and mechanical stresses placed on the control contactor assembly and the induction motor resulting from the simultaneous or synchronous breaking and making of contactors employed to connect the windings of the motor to a power supply. Asynchronously connecting the windings to the power supply via the asynchronous or non-simultaneous closing of the contactors of a modular contactor assembly reduces the potentially damaging transient current, the associated torque oscillations, and mechanical stresses. The present invention is particularly applicable to delta motors that are started with its windings in a star or wye configuration followed by the reconnection of the windings in a delta configuration when the motor is at normal running speed.

The present invention relates generally to an electrical switching device, and more particularly, to a method and apparatus of asynchronously controlling contactors to reduce mechanical stresses on an induction motor during transition between modes of operation.
Typically, contactors are used in starter applications to switch on/off a load as well as to protect a load, such as a motor, or other electrical devices from current overloading. As such, a typical contactor will have three contact assemblies; a contact assembly for each phase or pole of a three-phase electrical device. Each contact assembly typically includes a pair of stationary contacts and a moveable contact. One stationary contact will be a line side contact and the other stationary contact will be a load side contact. The moveable contact is controlled by an actuating assembly comprising an armature and magnet assembly which is energized by a coil to move the moveable contact to form a bridge between the stationary contacts. When the moveable contact is engaged with both stationary contacts, current is allowed to travel from the power source or line to the load or electrical device. When the moveable contact is separated from the stationary contacts, an open circuit is created and the line and load are electrically isolated from one another.
Generally, a single coil is used to operate a common carrier for all three contact assemblies. As a result, the contactor is constructed such that whenever a fault condition or switch open command is received in any one pole or phase of the three-phase input, all the contact assemblies of the contactor are opened in unison. Similarly, when a closed circuit or conducting condition is desired, all the contact assemblies are controlled to close in unison. Simply, the contact assemblies are controlled as a group as opposed to being independently controlled.
This contactor construction has some drawbacks, particularly in high power motor starter applications. Since there is a contact assembly for each phase of the three-phase input, the contact elements of the contact assembly must be able to withstand high current conditions or risk being weld together under fault (high current) or abnormal switching conditions. The contacts must therefore be fabricated from composite materials that resist welding. These composite materials can be expensive and contribute to increased manufacturing costs of the contactor. Other contactors have been designed with complex biasing mechanisms to regulate "blow open" of the contacts under variable fault conditions, but the biasing mechanisms also add to the complexity and cost of the contactor. Alternately, to improve contact element resistance to welding without implementation of more costly composites can require larger contact elements. Larger contacts provide greater heat sinking and current carrying capacity. Increasing the size of the contact elements, however, requires larger actuating mechanisms, coils, biasing springs, and the like, which all lead to increased product size and increased manufacturing costs.
Additionally, a contactor wherein all the contact assemblies open in unison can result in contact erosion as a result of arcs forming between the contacts during breaking. When all the contact assemblies or sets of contacts are controlled in unison, a detected abnormal condition, such as a fault condition, in any phase of the three-phase input causes all the contact assemblies to break open because the contact assemblies share a bridge or crossbar. Therefore, breaking open of the contacts of one contact assembly causes the contacts of the other contact assemblies to also open. As a result, the contacts may open at non-ideal current conditions. For example, the contactor may be controlled such that a fault condition is detected in the first phase of the three phase input and the contacts of the corresponding assembly are controlled to open when the current in the first phase is at a zero crossing. Since the second and third phases of a three phase input lag the first phase by 120 and 240 degrees, respectively, breaking open of the contacts for the contact assemblies for the second and third phases at the opening of the contacts of the contact assembly of the first phase causes the second and third contact assemblies to open when the current through the contacts is not zero. This non-zero opening can cause arcing between the contact elements of the second and third contact assemblies causing contact erosion that can lead to premature failure of the contactor. This holds true for both abnormal switching as stated above as well as normal duty.
This unison-controlled construction also has disadvantages associated with the closing of contacts to cause high transient current conduction between a power source and a load. The closing in unison of all the contacts can cause mechanical torque oscillations that are often negative. As a result, the windings of a motor as well as the mechanical components of the system are subjected to damaging stresses. Additionally, the motor circuit protection disconnect (breaker or fusing) may have to be oversized to avoid unwanted, or "nuisance", tripping by this high transient current. This is particularly problematic for motor starting applications.
A common technique for starting a three-phase induction motor involves the simultaneous application of full voltage to all three windings of the motor. This technique is generally referred to as Direct on Line (DOL) switching. Generally, a three-phase electromagnetic contactor assembly is used to control the application of voltage to the motor windings. At start-up of the motor, the three sets of contacts of the contactor assembly are closed simultaneously to apply full voltage to all three windings of the motor. For motors with six terminals (two terminals accessible for each stator winding) the contacts are connected so that upon closure, all three windings are energized simultaneously. Heretofore, this simultaneous closure has been achieved with an electromagnetic contactor consistent with that described above where the three sets of contacts share a common actuating assembly.
The drawbacks of such an in-unison contactor assembly design can be particularly damaging for motor starting applications. That is, the build up of torque in the motor generally associated with DOL starting is accompanied by a strong initial transient torque pulsation, as a result of the sudden application of voltage and current. The torque may oscillate between both positive and negative values, and the swing may be many times the normal full load torque of the motor. The effect of this pulsation is to place high mechanical stress on the motor and the whole drive train—the shaft coupling, the shaft itself, any gears driven by the shaft, and the load being driven. The stator windings also experience an equal and opposite reaction to the forces generated.
Moreover, if all the poles of a motor starter contactor assembly are closed simultaneously, power is applied simultaneously to all three windings of the induction motor that can inject a DC transient current in addition to the AC current to the motor. This superposition of the DC and AC currents can then cause high inrush currents, current imbalances, and strong torque pulsations until the DC current gradually decays with the magnetization time constant of the motor.
The DC transient resulting from the simultaneous application of power to the three windings of an induction motor will now be set forth mathematically. The three-phase supply voltage may be described by a space vector ūs(t) given by:ūS(t)=uSej(wt+α)  (Eqn. 1),where us is the supply phase voltage amplitude, and the space vector ūS(t) rotates at the angular frequency ω of the supply; and α is the supply phase angle at the time t=0 when power is applied.
The build up of flux ψ in the motor according to Faraday's Law is given by:
                                          ⅆ                          ψ              _                                            ⅆ            t                          =                                                            u                _                            s                                                  (              t              )                                =                                    u              s                                                  ⅇ                              j                                                                                wt                                                                                ⅇ                α                            .                                                          (                  Eqn          .                                                    2                )            Integration therefore yields:
                                                        ψ              _                                                  (              t              )                                =                                                    u                s                                                                            ⅇ                                      j                                                                                wt                                                                    j                                                                                ω                                                                          ⅇ                                  j                                                                                α                                                      +                                          ψ                _                            DC                                      ,                            (                  Eqn          .                                                    3                )                                                                                =                                                                                ψ                    _                                                                          (                    t                    )                                                                    Steady                                                                                state                                            +                                                ψ                  _                                                  DC                                                                                transient                                                              ,                                    (                  Eqn          .                                                    4                )            where ψDC transient is the constant of integration required to satisfy initial conditions. When ūS(t) is applied to the motor at t=0 and at phase angle α with no flux in the motor (i.e. ψ=0), then:
                                          ψ            _                                          (            0            )                          =                  0          =                                                    u                s                                                                            ⅇ                                      j                                                                                α                                                                    j                                                                                ω                                                      +                                                            ψ                  _                                DC                            .                                                          (                  Eqn          .                                                    5                )            Hence, the DC transient flux can be given by:
                                                        ψ              _                        DC                    =                                                    -                                  u                  s                                                                                ⅇ                                      j                                                                                α                                                                    j                                                                                ω                                                      =                          j                                                                                u                      _                                        s                                                                          (                    0                    )                                                                    j                                                                                ω                                                                    ,                            (                  Eqn          .                                                    6                )            and therefore the general solution for the flux in the motor can be characterized by:
                                                        ψ              _                                                  (              t              )                                =                                                    -                j                                                                                u                      _                                        s                                                                          (                    t                    )                                                  ω                                      +                          j                                                                                u                      _                                        s                                                                          (                    0                    )                                                  ω                                                    ,                            (                  Eqn          .                                                    7                )                                                                            =                                                                      ψ                  _                                                                  (                  t                  )                                                            Steady                                                                                state                                      +                                                            ψ                  _                                                  DC                                                                                transient                                            .                                                          (                  Eqn          .                                                    8                )            which yields:
The factor −j multiplying the voltage space vector ūS(t) in Eqn. 7 suggests that the steady state flux rotates with ūS(t) but lags behind in rotation by ninety degrees. The DC transient flux ψDC is, on the other hand, fixed in orientation ninety degrees ahead of the direction of the initial supply vector ūS(t) at the moment of contactor switch-on or initial voltage application, and only gradually decays. In addition, the steady state flux ψSS(t) has a constant amplitude and rotates in a manner determined by the transient ψDC which decays slowly. Hence, as ψSS(t) rotates, the presence of the DC flux ψDC causes the amplitude of the resultant flux ψ(t) to oscillate strongly. The effect is strong torque pulsations and unbalanced currents until the DC transient decays away. These starting pulsations can cause stress during motor operation and directly lead to wear, increased maintenance costs, and, ultimately, premature motor breakdown.
Torque oscillations or pulsations can be particularly problematic for a motor having its windings arranged in a delta configuration. As shown in FIG. 37, severe torque pulsation occurs with full DOL starting of a "delta" motor with simultaneous closure of the contacts for the three-phases of the motor. While this torque does decay over time, relatively strong mechanical stresses are placed on the motor from the moment of contactor closure until the decaying is complete.
The problems associated with torque oscillations are also relevant to "wye-delta" switching of delta-connected motors. Larger delta-connected motors are commonly started using a wye-delta switching method wherein the motor windings are first connected in a star or wye configuration, and the three pole contactors are closed simultaneously to supply power to all three windings. At some moment thereafter, and generally when the motor is up to normal operating speed, the contactors open and then reclose in such a manner to reconfigure the motor windings in a delta configuration. Heretofore, a timer has been used to initiate the switching from the wye to the delta configuration. Moreover, similar to the initial closure of the contactors to connect the windings in a star configuration, the contactors also re-close simultaneously when connecting the windings in the delta configuration without regard to any back force, or rotor electromotive force (emf), present in the motor as the motor slows from being disconnected from a power supply. The aim is to re-apply the supply voltages simultaneously to the three delta-connected windings with minimal delay.
The benefit of starting a motor with its windings in a wye configuration is that the motor draws only one third of the line current that it would draw if started directly with the windings in a delta configuration. This reduces adverse impact on the supply of the normally high starting current of the motor (typically 6-8 times full load current). The motor is only switched into delta configuration when sufficient time has elapsed for the motor to be running at high speed, when it draws less current. Generally, with wye-delta switching, the initial stator voltage is reduced by half and the torque and line currents are reduced by a factor of three. Nevertheless, as shown in FIG. 38, standard wye-delta switching remains susceptible, albeit to a lesser degree, to torque pulsations at both the initial wye switch-on, and at the wye-delta switch-over.
One proposed solution to reduce torque oscillations that result at the switch-over from a wye configuration to a delta configuration is to allow the back electromotive force present in the motor to decay. That is, when the motor is running with its windings in a wye configuration and the contactors are simultaneously opened, the rotor of the motor will continue to rotate. Depending upon the characteristics of the motor, the rotor will quickly or slowly expend its kinetic energy. Simply, despite no current in the stator windings, there will still be current in the rotor bars during this slow-down in rotation. The current in the rotor bars will thus induce an alternating emf that can be observed at the motor terminals. The currents decay with the rotor time constant Lr/Rr, and cause the rotor to behave as a decaying magnet that rotates at the shaft speed. Due to the slowing of the rotor under load, the back emf can be in or out of phase with the voltage supply when the contactors are re-closed in the delta configuration. If the back emf is out of phase at the moment of re-connection of the power supply to the motor windings, relatively large transient current and torque pulsations may occur. It is therefore advantageous to allow the back emf to decay before simultaneously re-closing the contactors to connect the motor windings in delta. However, as shown in FIG. 39, simply allowing the back force, or rotor emf, to decay does not eliminate torque pulsations or oscillations when the contactors are re-closed simultaneously. In FIG. 39, the emf was allowed to decay ninety percent (90%) before simultaneous re-closure of the contact to connect the motor windings in a delta configuration.
It would therefore be desirable to design a system to control power application to a motor or other power system during transitioning from one mode of operation to another mode of operation, such as from motor start-up to motor running. In this regard, negative torque oscillations and potentially damaging stresses on the motor and its components are reduced.

Method and system of controlling asynchronous contactors for a multi-phase electric load


In an example embodiment, an air diversion device comprises a cover adaptable to be coupled to a wall-mounted hand dryer, the cover at least partially surrounding an inner volume, a first aperture disposed in the cover and adaptable to bring a hand dryer output of the wall-mounted hand dryer into fluid communication with the inner volume, and a wand coupled to the cover and in fluid communication with the inner volume, wherein the wand comprises a flexible tube and a wand aperture disposed distal to the flexible tube and the cover.

Wall-mounted hand dryers typically comprise a single air output that is actuated by a button, sensor, or the like. Actuation typically causes heated air to be forced from the air output for a short duration. However, the drying efficacy of such hand dryers decreases if the user's hands are not in close proximity to the air output. Moreover, such hand dryers are often mounted at a vertical distance from the ground suitable only for adults of average height. As a result, wall-mounted hand dryers are less effective for certain individuals, such as children or wheelchair users, and for non-conventional uses, such as drying objects other than a user's hands.

Air diversion devices, systems, and methods