In an assembly including a diesel engine, a fluid coupling connected to the flywheel of the diesel engine, a comminuting machine and a conveyor for feeding the comminuting machine, a fluid coupling module is common to various output power train assemblies. Slip speed of the fluid coupling between impeller input and runner output shafts is measured, and modulates or regulates the process feed rate of the conveyer. An electrically actuated control valve acts as an oil flow diverter valve directing oil into the fluid coupling impeller when a signal to engage the coupling is given, and in response to a signal from an over-temperature sensor when the temperature of circuit oil leaving the element exceeds a preset set point value, diverts the oil to a reservoir, thereby permitting the impeller and runner cavity to evacuate, which separates the engine from the load.

Not applicable.
Not Applicable.
This invention has to do with a fluid coupling for use on diesel engine-driven mobile equipment such as wood chippers, rock crushers, road surface grinders (also known as scarifiers or road millers), and the like comminuting mills. This comminuting mill equipment is typically used in conjunction with feedstock conveyors, or in the case of the road surface grinder, used in conjunction with a method to move the grinder along the road to be ground. For controlling the speed and connecting and disconnecting the mills and engines, there are four types of clutch in common use. Three types can be engaged and disengaged with the engine running: a mechanical clutch, a hydraulically operated mechanical clutch, and a fluid coupling. One type must be engaged with the driver stopped and it is usually disengaged with the driver running: a mechanical torque limiter. The feedstock conveyors, or driving mechanisms of road grinders, are typically driven separately by hydraulic motors via hydraulic pumps that are mounted on and powered by the diesel engine, the conveyors being controlled by a manual control valve remotely operated by the operator of the mobile equipment. Heretofore, with a mechanical clutch, the conveyors have been run at a constant speed that may be set by the operator or at a speed that is directly proportional to engine speed. Because the hydraulic pumps and motors are positive displacement; if a jam develops in the mill, the operator operates the control valve to the reverse position, the feedstock conveyor stops and backs up for several seconds at the same speed as it goes forward, and then when the operator observes that the mill is cleared, the operator manually puts the valve into forward position and the conveyor returns to a normal forward feeding rate. A problem with this combination of a mechanical clutch and a manually operated conveyor or road grinder is that the operator""s reaction time is slow, compounded because the operator has much equipment to operate simultaneously, and therefore, it is relatively easy to jam a mill to a complete stop. If such a quick and immediate stop occurs, the diesel engine, especially certain susceptible components, such as turbochargers, can be expected to be damaged, often requiring repairs before restart.
These problems of damage to the diesel engine and its susceptible components are generally tolerable when the diesel engines being used are only up to 300 hp. However, the problems that result from a quick and immediate stop are exacerbated as the diesel engine sizes increase to the current levels of 1000 to 1500 HP and as the new electronically controlled fuel systems are introduced that measurably increase the power ratings of diesel engines without significantly changing the physical size and without significantly changing the physical strength of the engines.
Mechanical clutches have been widely used in such diesel engine driven mobile equipment applications. A mechanical clutch mechanism, such as manufactured and supplied by Twin Disc, Inc. of Racine, Wis., is mounted onto the flywheel housing of a diesel engine. In such a manually operated mechanical clutch, a lever is used to operate the clutch pack and requires an operator to be next to the diesel engine and clutch housing while engaging and disengaging the clutch. This arrangement functions reasonably well except when a very hard object or a large amount of feedstock is fed into the comminuting mill, for example, a hammer mill, and the hammer mill becomes overloaded and jams. In this case, the belts driving the hammer mill slip and wear, the bearings become overloaded, and the diesel engine stops almost instantaneously. This damages the bearings, the belts, the clutch, the diesel engine, and the turbocharger for the diesel engine.
As a mechanical clutch is used over time, the surfaces of the clutch plates wear and the linkage needs to be adjusted to make certain the clutch can be fully disengaged at one end of the clutch lever throw and fully engaged at the other end of the clutch lever throw. If the clutch cannot be fully disengaged, then a considerable amount of power can still be transmitted and the clutch plates will get very hot and possibly become severely damaged. If the clutch cannot be fully engaged, then the clutch will slip at high-power conditions and wear rapidly. Because lever activated mechanical clutches require the operator to be situated very close to the diesel engine, clutch, sheave and belts or other load equipment when the lever is actuated to engage and/or to disengage the load equipment, if the high-powered mechanical equipment breaks, parts may be thrown about and pose grave risk to the operator. Hydraulically operated mechanical clutches that use a lever operated master hydraulic cylinder and a slave hydraulic cylinder to operate the clutch permit the operator to be further removed, but the rest of the problems remain.
Another version of an hydraulically actuated mechanical clutch is one wherein the mechanical clutch pack is compressed and thereby engaged by means of hydraulic pressure, and the hydraulic pressure is controlled by an electronic controller, such as manufactured by Power Transmission Technology, Inc., of Ohio. In normal operation, the electronic controller, which is remote from the clutch, can be manually given a signal to engage, and the controller causes hydraulic pressure to act, engaging the clutch. Similarly, a manual signal to the controller can cause the hydraulic pressure to be released, and the clutch pack is released and almost no power is transmitted through the clutch. Under abnormal conditions such as a jam that develops over several seconds, the electronic controller, essentially a dedicated digital computer based controller, can sense a decrease in speed, and the controller can release the clutch pack and attempt to reengage the clutch a series of times. After a preset number of attempts to reengage the mill wherein the speed of the output shaft of the clutch does not increase to engine speed, the electronic controller will decide that the mill is jammed, and the controller can cause the clutch pack to remain released. In summary, this type of electronically controlled, hydraulically actuated mechanical clutch (a) in the case of a jam that develops over several seconds, can separate the engine from the mill when the mill is jammed, saving the engine and its susceptible components from damage, but, in the case of an instantaneous jam, cannot separate the engine from the mill fast enough to avoid stopping the engine and damaging susceptible components, and (b) can sense when there is too much wear of the clutch parts to assure full engagement, and can separate the engine from the mill in this case, or once separated, can maintain separation of the engine from the mill. However, this type of hydraulically actuated mechanical clutch suffers from the problem of all mechanical clutches: From time to time and depending upon operator care and the types of duty to which the mill is subjected, the transmission must be disassembled and the worn clutch plates must be replaced.
For lower power equipment, below perhaps 300 hp, mechanical clutches do not wear much during normal engagement and normal disengagement. However, as the power transmitted increases to the current levels of 1000 to 1500 hp, the wear of mechanical clutches during normal engagement and normal disengagement increases to the point that it is noticeable and is a concern. Due to the wear during normal engagement and normal disengagement, and due to the possibility of shearing shafts and couplings during a quick engagement event and throwing these parts about, it is common practice for manufacturers of all sizes of mechanical clutches to provide signs to be mounted on the equipment and visible to the operators, that the clutches must be engaged when the engine is operating at idle speed, and not above idle speed, and particularly, not at the normal running speed which is well above idle speed.
In recent years, mechanical torque limiters have been introduced and used to separate the engine from the mill in the case of a jam in the mill. A mechanical torque limiter is a mechanical device that can be mounted on the end of the output shaft of the mechanical clutch in direct drive arrangements. They can also be used with side load applications, and they function as described here. In a mechanical torque limiter, a housing part mounted on the driving shaft contains a series of radial or axial pins backed by springs and the mating part, a driven part, is attached to the driven shaft; this driven part having detents into which the ends of the pins are seated. The housing part and the driven part are held concentric to each other by rolling element bearings. When an over torque condition occurs, the pins slide up from the bottom of the deep-end groove and the springs overload and functionally break away, causing the two parts of the mechanical torque limiter to separate mechanically so that torque can no longer be transmitted from one part to the other part. For safety, the springs and pins of the mechanical torque limiter are retained in the housing part. After the driver is stopped, the springs and pins of the mechanical torque limiter can be manually reset. After the hammer mill is cleared, the diesel engine can be started and the equipment put back into service. The pins, detents, and rolling element bearings do experience some wear during each separation event, and therefore, they can be expected to require reconditioning maintenance from time to time, with the frequency in proportion to the severity of the duty.
Fluid drives for stationary equipment have been in service for several years, with the earliest ones being developed in approximately 1905. Three well-known manufacturers of this equipment today are Turbo Research, Inc (of the USA), Voith (of Germany) and Transfluid (of Italy). Three broad categories are (1) variable speed fluid drives, (2) constant speed fluid couplings that, after the start-up period on the order of seconds, have no means for any significant variance of the output speed which is slightly less than the speed of the driver, and (3) fluid couplings for which the output speed is either nearly zero or slightly less than the speed of the driver, and can be repeatedly cycled between these two states by operation of an oil flow control valve which controls the flow of circuit oil, respectively, by either bypassing oil to the reservoir in the xe2x80x9coffxe2x80x9d state or by directing oil to the fluid coupling in the xe2x80x9conxe2x80x9d state. Such a control valve may also be referred to as a diverter valve.
Variable speed fluid drives of type (1) above are described in U.S. Pat. Nos. 5,331,811, 5,315,825, and 5,303,801, and are manufactured by Turbo Research, Inc. and Voith. These patents are referenced to provide extensive background on fluid drive technology, since variable speed drives are not the subject of the present discussion.
Fluid couplings for stationary equipment identified as type (2) above have been in service for several years, particularly on stationary motor driven equipment, such as mills and conveyors. Two well-known manufacturers of this type are Voith (of Germany), and Transfluid (of Italy), represented by Kraft in the USA.
One of the most common forms of type (2) fluid couplings is self-contained, and has all of the circuit oil stored in it. One part of the fluid coupling, the impeller and impeller casing assembly, which forms the entire outer shell, is mounted on an end of a motor shaft. The driven portion, including a runner, is mounted onto the shaft of the driven equipment such that the runner is inside the impeller and impeller casing assembly. These fluid couplings, which are almost invariably designed and manufactured with the impellers, runners, and casings made from aluminum for reasons which include lower weight and lower cost, have a series of fuse plugs mounted in the outer periphery. These fluid couplings are intended to be used for xe2x80x9csoft-startxe2x80x9d conditions, and are not expected to be used where jams are to be encountered, though occasionally jams are encountered. Often this type of fluid coupling has two functional chamber for containing oil, one chamber containing most of the oil when the fluid coupling is stopped, and a second chamber which is the fluid coupling chamber that contains the impeller and runner vaned structures used for transmitting torque from the impeller to the runner. Once the motor is started, oil moves from the storage chamber to fill the fluid coupling chamber containing the impeller and runner with oil and the oil can not be removed from the fluid coupling chamber without (a) either shutting down the motor or (b) opening (melting) the fuse plugs. When this type of fluid coupling is stopped under normal circumstances, the oil drains from the fluid coupling chamber back to the storage chamber. When in operation, heat is generated in the fluid coupling in proportion to the slip speed between the input shaft speed and the output shaft speed, and the slip speed increases in direct proportion to the torque transmitted. In normal operation, the cooling fins that are cast into the outer surface of the impeller and casing dissipate to the surrounding air the heat generated by the fluid slip process. Should the equipment become overloaded, or the load equipment jam, much heat will be generated in the oil and in order to protect the load equipment as well as to protect the aluminum parts of the fluid coupling from failing, the fuse plugs will melt, permitting the oil to be spewed out of the rotating impeller casing until empty, and this separates the load equipment from the motor, and the motor will operate essentially unloaded until it is shut down. Several gallons of very hot oil typically are spilled in such an event. This is dangerous for personnel in the area, can be a fire hazard, and, today, depending upon the amount of oil spilled in such an event occurring in the United States, it may well be a reportable event to the United States Environmental Protection Agency (EPA). Due to these safety and environmental issues, Turbo Research, Inc. has not manufactured this type of equipment.
A subsequent version of this equipment by Voith, and Transfluid for use with mobile equipment included a sealed external housing around the rotating element and oil circulating pumping and cooling equipment. The fluid coupling impellers, runners, and casings are still made from cast aluminum with the vanes being thin, and the impellers or impeller casings contain the fuse plugs so that during an overload event the fuse plugs melt, the oil spews out of the rotating element limiting the temperature to which the aluminum parts are exposed and the duration of the exposure, but the oil is contained in the sealed external housing and is not lost. The diesel engine can be stopped under a controlled stop sequence without damage. However, in order to be able to run again, the external housings of this design have to be opened and the fuse plugs have to be replaced. The fuse metal is contained somewhere in the oil reservoir, and unless the reservoir is completely cleaned out, the fuse metal can be drawn into the oil pump with the normal suction oil flow, and therefore, potentially, the fuse metal can pose problems to the oil circulating pump.
Fluid couplings of type (3) above are the primary focus of this document. Turbo Research, Inc., Voith and Transfluid have developed fluid couplings which can be turned on and off by changing the state of an oil flow control diverter valve, usually an electrically operated valve such as an electric motor operated valve or an electrical solenoid operated diverter valve. Some of the Voith and Transfluid fluid couplings use fuse plugs in the outer periphery of their fluid couplings and these fuse plugs melt during an over-temperature event, and must be replaced by opening the external housing, or at least by opening a port in the external housing. Turbo Research, Inc. fluid coupling design uses an over-temperature switch to continuously monitor the circuit oil temperature as it discharges through a series of orifice holes at the periphery of the impeller or impeller casing, and in response to an over-temperature condition, this over-temperature switch causes an electrically operated diverter valve to divert circuit oil from going to the fluid coupling element and to bypass the circuit oil flow stream to an oil reservoir. After such an over-temperature event occurs, the fluid coupling chamber evacuates, and the diesel engine can be caused to idle, which gives the various elements of the fluid coupling a period of time in which to cool gradually, avoiding excessively high thermally induced stresses, particularly in the components of the rotating element. Voith and Transfluid also incorporate the function of an over-temperature switch to monitor the circuit oil as it discharges from the circuit, though there may well be a different method of effecting this function, and such switch causes an electrically operated diverter valve to change state as described above upon sensing an over-temperature condition. With a fluid coupling in operation instead of a mechanical clutch, as the mill becomes overloaded, the output speed of the fluid coupling and the speed of the mill decrease substantially and in direct ratio to each other, while the diesel engine speed either remains constant or declines to a limited degree, but the diesel engine does not stop. In the case of a fluid coupling and a manually controlled feedstock conveyor, as above described, the reaction time of the operator is still slow, and therefore, it is still easy to jam a mill to a complete stop. However, with a fluid coupling with a circuit oil discharge temperature sensing device in service, if the circuit oil discharge temperature does increase above the pre-set trip point as occurs when the mill, the output shaft and attached runner stop, and the diesel engine and attached impeller will continue to rotate, while the fluid coupling system shuts down with no damage to the engine or to its components.
Turbo Research, Inc. developed fluid couplings with heavy duty steel impellers, runners, and casings so that these fluid couplings can be engaged and disengaged at any engine speed, including full engine operating speed, and can survive undamaged more severe over-temperature events than can be expected from fluid couplings made with cast aluminum components, particularly those having cast aluminum components with thin vanes. Experience with the Turbo Research, Inc. fluid couplings indicates that if the mill was not cleared and therefore is still jammed at the time that the fluid coupling is engaged, the circuit oil will get hot, the over-temperature switch will detect this and will trip the circuit oil control valve so that the circuit oil is diverted, and the fluid coupling returns to the disconnected state, with no damage to the fluid coupling or to the drive train.
Today many fluid couplings are designed with some means for continuously monitoring the circuit oil as it discharges from the element, with over-temperature switches, and with electrically controlled circuit oil flow diverter valves, and have no wearing parts such as the mechanical clutches have, have no resetable springs and detents such as the mechanical torque limiters have, and have no fuse plugs such as were previously used in the Voith and Transfluid fluid couplings. For this reason, it has been shown that the fluid couplings with the over-temperature switches and oil diverter valves are the lowest maintenance clutch means available.
One advantage of the fluid coupling over a mechanical torque limiter is that occasionally there are lumps in the feed stock entering the hammer mill that are big enough to cause a mechanical torque limiter to separate, even when set to separate at five times rated torque, but which can be chewed up and processed with a fluid coupling because the fluid coupling continues to transmit power in a substantially overloaded condition for some period of time. During the time period of this overload condition, the temperature of the circuit oil and of the fluid coupling continue to increase, but in that time period, hard lumps, if not too large or not too many, will be processed and the comminuting mill will dear itself. If the mill does not clear itself by the time that the circuit oil discharge temperature reaches the trip set-point, the over-temperature switch causes the circuit oil to be diverted to a reservoir, and the impeller-runner cavities will empty, thus reducing the torque transmission of the fluid coupling to a minimum, so that the diesel engine becomes unloaded and can be shut down in a normal shutdown method without damage, so that in this manner, the fluid coupling functions as a torque limiting device.
In some cases, the mobile equipment drive train can be assembled with a fluid coupling driven by an engine, the fluid coupling driving a mechanical torque limiter, the mechanical torque limiter in turn driving the mill, for the specific purpose of having the fluid coupling benefit of being able to chew through overload conditions as well as for having the mechanical torque limiter benefit of minimizing damage to the mill should a large chunk of steel enter the mill and be hit by a hammer causing a great impact sufficient to separate the parts of the mechanical torque limiter immediately thereby instantaneously terminating the power to drive the mill.
Voith and Transfluid typically manufacture the external stationary housings for their type (3) fluid couplings either as complete castings or welded fabrications including the oil reservoir, and they use a bearing arrangement with a bearing between the housing and the input end of the input shaft, two shaft bearings between the input and output shaft assemblies to resist side loading, and one bearing between the housing and the output shaft, so that one output shaft can be used for dual purposes: (a) mounting a flexible coupling hub for direct drive, or (b) mounting an overhung sheave with side loaded belts that does not require and does not permit a support bearing on the outboard end of the sheave. The Voith and Transfluid design with a bearing supporting the input end of the input shaft requires some form of radial flexibility between the input shaft of the fluid coupling and the flywheel of the diesel engine because there are substantial radial runouts in the nominal design of diesel engines, and consequently, this design uses a form of a Holset coupling with elastomeric elements between the coupling part fixedly mounted to the flywheel and the coupling part fixedly mounted to the input shaft.
Turbo Research, Inc. developed a fluid coupling module that can be used with, and bolted to, any of several output power train assemblies such as, for example, clamshell with sheave and outboard bearing for side loads, direct drive housing with outboard bearing, parallel offset gears and gear housing, and right angle gears and gear housing, wherein each fluid coupling module and output drive train assembly use the appropriate output shaft for the fluid coupling runner and the specific drive train selected. Further, the Turbo Research, Inc. fluid couplings are designed with a bearing arrangement having two high capacity bearings supporting the output shaft and, in the case of the side load drive train, straddling the sheave or gear, and the inboard end of the output shaft, which is overhung into the fluid element cavity, supports one inter-shaft bearing to one end of the input rotating assembly. In this design, the input end of the input shaft, impeller and impeller casing assembly is supported by a series of thin flexible diaphragms that, near the outer periphery, are fixedly bolted to the diesel engine flywheel, and near the inner edges, are fixedly bolted to the input shaft, providing axial and angular bending flexibility between the input shaft of the fluid coupling and the diesel engine crankshaft and flywheel assembly, and therefore, in this arrangement, the bearings of the diesel crankshaft functionally support the input end of the fluid coupling input shaft and impeller assembly. The advantages of this design include (a) the ability of the large straddle bearings of the output shaft to handle repeatedly extremely large side loads concomitant with a jam of a mill, (b) a very substantial reduction in overall length provided by the use of a flexible diaphragm disc coupling instead of a Holset style coupling between the flywheel and the fluid coupling input shaft, which is beneficial to those applications where the axis of the engine and fluid coupling drive train is transverse the mobile equipment trailer, and therefore, perpendicular to the length of the drive train, and (c), due to (b), a reduction in the overall trailer width, reducing or eliminating the need for special permits for the trailer to travel on the highways.
The diaphragm discs used in the subject fluid couplings are adapted from diesel engine driven electric generators made by Onan of Minnesota, in which application the diesel engine crankshaft and crankshaft bearings support through the flywheel and disc-pack the inboard end of an electric generator. Individual discs are on the order of 0.040 to 0.060 inches thick, and multiple discs are used in a disc pack the number of discs depending upon the torque transmitted. The discs are made by a stamping process using accurate dies, and are commercially available. Such disc packs are radially stiff, have limited flexibility in relative axial displacement between the connected shafts, and are quite flexible in angular bending between the connected shafts. Similar disc packs are used in a variety of flexible couplings connecting two adjacent shaft ends, are available in many sizes, are sold under the trade name of Thomas, are made by Rexnord, and are also commercially available. The application of a flexible disc-pack to a fluid coupling driven by a diesel engine as done herein has, to our knowledge, not been done before.
In the assemblies of a mobile equipment trailer having certain combinations of equipment that include fluid couplings, allocations of space may be such that it is beneficial to have the reservoir located remotely from, yet at a level below, the bottom flange of the fluid coupling. This can be accommodated with the use of a conduit of sufficient diameter between the bottom flange of the fluid coupling and the reservoir, and with a pump directly driven by an electric motor or a hydraulic motor. Preferably, the inlet to the pump is below the oil level of the reservoir. The pump may be located in the reservoir or separate from the reservoir.
In accordance with this invention, generally stated, a fluid coupling module is provided that incorporates an input (impeller) section and its means for connection to a prime mover, a fluid coupling section, an oil pumping and oil conditioning system, including a reservoir and an included pump located vertically below the fluid coupling sections, and remotely mounted controls and control logic. This fluid coupling module is then common to output power train assemblies taken from the group consisting of a clam-shell housing, sheave and straddle bearings for side load; a straight-through drive housing and outboard bearing for direct drive; a parallel offset gear and housing assembly; and a right angle gear and housing assembly, whereby the same fluid coupling module can be employed by any of the output power train housing assemblies using an appropriate output shaft for the fluid coupling runner and output power train assembly selected.
In the preferred embodiment, flexible diaphragm plates are fastened near their outer periphery to the fly wheel of a diesel engine, and near their radially inner edges to an outer end of an input shaft to the impeller of the fluid coupling, whereby the input shaft is supported at its outer end by the flexible diaphragm plates and crank shaft bearings of the diesel engine.
Also, in an assembly including a prime mover (generally a diesel engine) for driving a fluid coupling, a rotating comminuting machine such as a hammer mill, an output power train between the fluid coupling and the comminuting machine, and a conveyor for feeding material into the comminuting machine, the fluid coupling having an impeller and a runner, means are provided for measuring the slip speed between the impeller and the runner, and for regulating the speed of the conveyor or, for example, for regulating the speed of movement of the road grinder, in response to the slip speed relative to the set point slip speed. Preferably, the slip speed differential is calculated as a percent, whereby the regulation is substantially independent of the running speed of the prime mover. The means for regulating the speed of the conveyor, for example, can include a multi-toothed wheel and a mating speed pickup, mounted on the output shaft of the fluid coupling, a signal from the engine speed detector such as is used by the engine speed governor, and an electronic controller with suitable programming, whereby the electronic controller modulates the speed the feed stock conveyor in order to maintain the slip speed of the fluid coupling at a preset set point value, for example 2.5% or 3%, with the preset set point value being selected to optimize the production according to certain objectives desirable to the operator, such as chip size, type of material being processed, tons processed per gallon of diesel fuel, or simply, tons processed per operating hour. An advantage of using the slip speed to control the conveyor speed arises from the development of new engines and controls. In older diesel engines, the governors, which controlled fuel flow to maintain a pre-set engine speed, were primarily mechanical in nature, and permitted some droop in the speed of the engine in response to an increase in the load. In this situation, the conveyor can use the droop of the engine speed as an indicator of load. In newer engines, the governors or fuel flow controllers, are very precise and can maintain a given speed with almost no droop in actual engine speed over the entire load range until the full fuel flow condition is reached, and for further increases in load, the speed droops dramatically. For this type of governor, engine speed is almost of no value to control the conveyor speed because there is no speed change until overload condition occurs, which is what is trying to be avoided. Then, an overload of feed stock is what causes the engine to go into overload condition and the speed to droop, but the overload has already occurred and could not be detected until after the fact. With a fluid coupling, the slip speed is directly related to torque transmitted in a linear relationship: if there is no torque transmitted, there is no slip. As the load increases, the slip increases, so with the slip speed as the measure, it is now easy to determine the degree of loading of the power train and the approach to an overload condition can be detected before it occurs, even though the engine speed remains constant or almost constant over the entire load range up to the point of overload. Hence, for either the mechanically controlled governors or the newer electronically controlled governors, the slip speed of the fluid coupling provides a better indicator of load and a better indicator of approach to an overload condition than was heretofore available with either type of governor. Alternatively, because the speed of the output shaft is a function of the slip speed, in that the greater the differential in speed between the input and output shafts, the greater the slip speed differential, a multitoothed wheel mounted on said output shaft and a mating speed pickup can be used to control the speed of the conveyor, whereby the speed of the conveyor is a function of the speed of the output shaft. An electrical or electronic speed determining device can be used instead of the multitoothed wheel.
In the variable speed method of the present invention for controlling the feed stock conveyor, the feed stock conveyor can at times be driven substantially faster than the present common fixed conveyor speed, because most of the time the mill is under-loaded, so that speeding up the conveyor when it is under-loaded and the slip speed is below the set point slip speed will send up more feed stock into the hammer mill in a given period of time. Then when the hammer mill is heavily loaded so that the actual slip speed, for example, 3.7%, is larger than the set point slip speed, say 2.5%, then the controller slows down the conveyor. Control programs using PID (proportional, integral and differential) are readily available and are well known by control designers today. Another reason for using slip speed is that the engine speed is variable and can be set anywhere in the range of 1800 to 2300 rpm, for example, depending upon several variables, including the type of material available, its condition, and the size of the chip desired to be made. In any case, modulating the rate of feed into the mill in order to maintain a given slip ratio will optimize the tons milled per hour and the tons milled per gallon of diesel fuel used, and will keep engine load in normal operating range for a greater portion of the operating time, thereby minimizing air pollution due to abnormal fuel/air ratios.
Input and output shafts of the fluid coupling are oriented substantially horizontally. A removable reservoir, located vertically below the level of impeller and runner casings and input and output shafts, contains a circulating oil pump within the reservoir, positioned with an intake submerged in circulating oil, so as to be self priming. The circulating oil includes both circuit oil, which fills impeller and runner cavities, and lubricating oil for the bearings. A heat exchanger for the circulating oil is provided with a vent line at its top communicating with the oil reservoir to ensure that the heat exchanger does not become air locked. A temperature control valve is provided to mix cooled oil from the heat exchanger with hot oil that bypasses the heat exchanger to provide oil at a preset temperature to the fluid coupling. A filter is provided to assure that no significant particulate matter enters the bearings. A heating element is provided in the oil reservoir to warm the oil prior to starting the fluid coupling and the diesel in cold weather conditions. An electrically actuated control valve is provided as an oil flow diverter valve that directs circuit oil into the fluid coupling element when the signal to engage the coupling is given, and an over-temperature sensor is provided such that when the temperature of the circuit oil leaving the element exceeds a preset set point value, as occurs when the mill jams, the sensor sends a signal to the controller and on to the diverter valve to divert the circuit oil to the reservoir, thereby permitting the impeller and runner cavity to evacuate, which separates the engine from the load, and the engine can then be brought to idle and cooled down and shut down in a normal manner without damage to any part of the entire power train, and in so doing permit the entire train to be brought back into service after the mill is cleared. The operation of the diverter valve does not affect the operation of the bearing oil lubrication system, which continues as long as the impeller casing is rotating.
By making the fluid coupling a part of a module that includes the fluid coupling housing, the reservoir and its pump, the diverter valve, heat exchanger, temperature control valve, filter, piping, and controls including a programmable controller for the feedstock feeding process, and by providing for bolting to the output shaft end of the housing various forms of power train, including the clam-shell housing with belt sheave, the module can be supplied to a manufacturer as a unit, for use with whatever type of power train is required.

Lower Providence Township, Montgomery County


The invention relates to reduced power cells. Some embodiments of the invention provide a memory circuit that has a storage cell. The storage cell contains several electronic components and an input. The electronic components receive a reduced voltage from the input to the cell. The reduced voltage reduces the current leakage of the electronic components within the cell. Some embodiments provide a memory circuit that has a level converter. The level converter receives a reduced voltage and converts the reduced voltage into values that can be used to store and retrieve data with stability in the cell. Some embodiments provide a method for storing data in a memory circuit that has a storage cell. The method applies a reduced voltage to the input of the cell. The method level converts the reduced voltage. The reduced voltage is converted to a value that can be used to store and retrieve data with stability in the cell. The reduced voltage reduces a current leakage of electronic components within the cell.

Volatile memory circuits are quite common today. Such memory circuits can be contained in an individual integrated circuit (IC) chip or can be part of other IC's. These IC's include a configurable IC that uses a memory circuit to store configuration data. The configurable IC can be configured to perform a set of operations based on the stored configuration data.
The use of configurable IC's has dramatically increased in recent years. One example of a configurable IC is a field programmable gate array (FPGA). An FPGA is a field programmable IC that has an internal array of logic circuits (also called logic blocks) that are connected together through numerous interconnect circuits (also called interconnects) and that are surrounded by input/output blocks. Like some other configurable IC's, the logic circuits and the interconnect circuits of an FPGA are configurable. In other words, each of these circuits receives configuration data that configures the circuit to perform an operation in a set of operations that it can perform. One benefit of configurable IC's is that they can be uniformly mass produced and then subsequently configured to perform different operations.
As mentioned above, configurable IC's typically store their configuration data in memory cells. FIG. 1 illustrates a memory circuit 100 of a configurable IC. As shown in this figure, the memory circuit 100 includes: (1) a storage cell 128 for storing a configuration data value; (2) a VDDcell line 106 for supplying power to the storage cell 128; (3) true and complement bit lines 110 and 115 for reading and/or writing the contents of the storage cell 128; (4) pass gates 120 and 125 for connecting the bit lines 110 and 115 to the storage cell 128; and (5) output lines 160 and 165 for outputting, through configuration buffers 140 and 145, the contents of the storage cell 128 without the need for a read operation.
The typical storage cell 128 in the art requires that the voltage within the cell 128 and through the buffers 140 and 145 be driven to the rails in order for the cell 128 to retain stable values and output a useable configuration value (i.e., VDDcell 106 is typically VDD). If the voltage within the storage cell 128 is less than the voltage on a word line used to read the cell, then a read operation could cause instability in the value stored by the storage cell 128 by undesirably altering the value stored in the storage cell 128. This condition is also known as "read upset."
However, requiring the voltage within the cell 128 and through the buffers 140 and 145 to be driven to the rails exasperates current leakage from the cell, since current leakage from the memory cell is non linearly (e.g., exponentially) proportional to the voltages that are used to store data in the memory cell. Specifically, in the memory cell 100 there are two kinds of leakage that are problematic: sub threshold leakage and gate leakage.
FIG. 2 illustrates an example of sub threshold leakage through an NMOS transistor 200 that is commonly used in memory circuits. In FIG. 2, the gate and source leads of the NMOS transistor 200 are short circuited to represent that their voltage difference is zero (i.e., Vg−s=0). Even though the transistor is "off" in this sub threshold condition, there is still undesirable leakage current through the transistor 200, as shown in FIG. 2.
FIG. 3 illustrates an example of gate leakage through an NMOS transistor 305. Electron tunneling through the gate oxide of a transistor causes gate leakage current. For a 90 nm electronic component (e.g., a transistor), gate oxide can be about fourteen angstroms or approximately seven silicon dioxide atoms thick. This distance is sufficiently short to allow tunneling current to flow through the gate oxide even at voltage levels as low as one volt. Gate leakage in N-channel devices is significantly worse than in P-channel devices.
With the size of electronic components continually becoming smaller due to improvements in semiconductor technology, leakage current is a continually growing problem. Leakage current in a standard (six transistor) memory cell is exponentially proportionate to voltage. So if the voltage in the cell can be reduced, then the amount of leakage (i.e., both gate and sub threshold leakage) in the cell can be exponentially reduced. However, a typical memory cell has particular voltage requirements in order for the cell to function properly. Thus, if the voltage within the cell is reduced too much, then the cell becomes unstable and unable to store and output data reliably, as seen in the case of the read upset condition. Thus, there is a need in the art for a useable reduced power configuration storage cell, such that the leakage from electronic components within the cell is reduced, while retaining useable output configuration signals.

Method and apparatus for reduced power cell


Variable marks are applied to the outside of bales of hay that assign each bale to a group based on pre-selected parameters collected during baling.

The primary use of hay that is packaged by a baling implement is to feed livestock. Hay is cut, sometimes raked or otherwise manipulated, and then can be packaged with a baling implement. Each individual bale has different values of feeding quality even though multiple bales can appear the same especially when viewed from the exterior of the bale. The differences in feeding quality for each bale are a result of variation in multiple factors, most notably, the properties of the crop before it is cut, the moisture of the hay as it is baled, the duration between cutting and harvesting and the effect of later manipulation on the windrow. These factors can be measured during the baling process by methods such as sensing position of the baler in the field as it is baling, recording the time and date of baling, determining moisture with sensors mounted in the baler, and density calculations of the bale that indicates the feed quality of the bale as disclosed by Roberts in A method for Calculating Feed Value of Alfalfa Hay Using Information Available at Time of Baling. In the system and method that has been invented, factors affecting feed quality are measured at time of baling, values are grouped by a processor and exterior markings are applied to each bale based on the group the measured value places the bale in.

System and method for marking bales of hay based on parameters collected during baling


Some of the embodiments of the present disclosure provide apparatuses, systems, and methods for reducing the likelihood of cache line overlaps in a multi-processor system having a shared memory cache. A transformation function module coupled to the shared memory cache is configured to transform an index associated with a cache operation associated with a processor of the plurality of processors using a transformation function to generate a transformed index. In embodiments, groups of one or more processors have different or unique transformation functions associated with them in order to decrease the tendency or likelihood of their respective cache lines in the shared memory cache to overlap. Other embodiments are also described and claimed.

The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that do not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Processor memory transactions are frequently characterized in locality, meaning that most reads and writes by a single processor to a main memory during a certain time frame are to memory locations that are clustered together within the main memory space. Because physical memory addresses are contiguous, processor transactions that are characterized in locality will result in a large number of memory transactions to memory addresses that are numerically close together, or clustered within a certain range of contiguous memory addresses (although the actual memory addresses of the individual memory transactions are not themselves necessarily contiguous, although they may be). Because memory data are allocated to cache lines (such as in system level cache) in which the cache lines have indexes that match the least significant bits of the memory addresses, data from memory transactions that are characterized in locality will tend to be allocated to cache lines that are also clustered together in cache lines within a range of contiguous indexes (although the actual indexes of the cache lines are not themselves necessarily contiguous, although they may be). An Asymmetric Multi-Processor (AMP) system is a multi-processor core system with a shared system level memory cache (such as an SL2 cache). In conventional AMP systems, needs of the different processor cores are accommodated by rigidly or flexibly partitioning the space in the system level cache.

Cache operations using transformed indexes


A locking system for a cotton candy machine includes a pair of rotatable cam members that are selectively engagable and disengagable from a motor mount of the machine to alternatively lock and unlock the machine. A rotatable handle or a pair of rotatable levers are operatively connected to the cam members to selectively rotate the cam members to the locked and unlocked positions.

Machines for spinning granular sugar into sugar filaments or so-called cotton candy are known and have been employed for some time to produce cotton candy. One known cotton candy machine, designated by numeral 10 in FIGS. 1, 2A and 2B, includes a base 12, a motor 14 housed within the base 12, and a spinner head 16 connected to the motor 14 through a rotatable shaft (not shown). Controls 18 are provided on a front panel 20 of the base 12 for controlling operation of the machine 10 as will be understood by those of ordinary skill in the art. A pair of handles 22 are mounted on opposite sides of the machine 10 so that a user can carry or transport the machine 10 to different locations.
In use, granular sugar is introduced into the spinner head 16 which includes heating elements and the like for melting the granular sugar. The rotation of the spinner head 16 causes the melted granular sugar to be spun out of holes or slots 24 in the spinner head 16 and onto the inner surface of a bowl or basket 26 (shown in phantom) mounted to the base 12 of the cotton candy machine 10. The sugar filaments adhered to the basket 26 may then be transferred to a paper tube or the like by rolling one end of the tube about the circumference of the basket to collect the cotton candy on the tube end.
In one type of cotton candy machine, the motor 14 of machine 10 is connected to a motor mount 28. The motor mount 28 includes a motor mounting wall 30, a depending skirt wall 32 and a radially outwardly directed flange 34 at its lower end. The upper end of the motor 14 is connected to the wall 30 of the motor mount 28 though multiple circumferentially spaced fasteners 36.
To reduce undesirable vibration of the cotton candy machine 10 during operation of the motor 14 to spin the spinner head 16, the motor mount 28 is suspended from a top wall 38 of the base 12 through multiple circumferentially spaced springs 40. The springs 40 are connected to and positioned between the top wall 38 of the base 12 and the radially outwardly directed flange 34 of the motor mount 28 as shown in FIGS. 2A and 2B so that the motor mount 28 is able to float relative to the base 12 during operation of the cotton candy machine 10. In this way, vibrational forces generated by the motor 14 during use of the cotton candy machine 10 are not imparted to the base 12 of the machine. This helps to reduce vibrational noise and unwanted movement of the machine 10 during the production of cotton candy.
In the past, a locking system 42 as shown in FIGS. 2A and 2B has been provided to enable a user to lock the cotton candy machine 10 for safe transport of the machine to different locations. The locking system 42 is provided to rigidly support or lock the motor mount 28 relative to the base 12 when the cotton candy machine 10 is transported so that the motor 14 and motor mount 28 will not be jostled against the base 12. Prior to use, the cotton candy machine 10 is unlocked through operation of the locking system 42 so that the motor mount 28 is again suspended by the springs 40 to float relative to the base 12.
As shown in FIGS. 2A and 2B, the locking system 42 includes a pair of threaded screws 44 that are each mounted to a fixed bracket 46. Each threaded screw 44 is also connected to a movable bracket 48 and a threaded knob 50. To unlock the cotton candy machine 10 as shown in FIG. 2A, the user turns the threaded knobs 50 in one direction so that the movable brackets 48 are lowered and disengaged from the radially outwardly directed flange 34 as shown in FIG. 2A. In the unlocked position as shown in FIG. 2A, the motor mount 28 is suspended by the springs 40 so that it, and motor 14 supported thereby, float relative to the base 12.
Prior to transport of the cotton candy machine 10, the user locks the machine 10 as shown in FIG. 2B by turning the threaded knobs 50 in an opposite direction so that the movable brackets 48 are raised and engage the radially outwardly directed flange 34. As the user continues to turn the threaded knobs 50 to lock the machine 10, the movable brackets 48 continue to move upwardly and urge the motor mount 28 upwardly to compress the springs 40. In the locked position of the machine 10 as shown in FIG. 2B, the motor mount 28 is rigidly supported or locked relative to the base 12.
While the locking system 42 provides for safe transport of the cotton candy machine 10, the locking system 42 requires coordinated manipulation of the threaded knobs 50 by the user to lock and unlock the machine 10. Also, the locking system 42 is not configured to prevent a user from inadvertently transporting the machine 10 in an unlocked position or attempting to operate the machine while it is in the locked position. Either of these conditions could result in damage to the machine 10.
Accordingly, there is a need for an improved locking system for cotton candy machines that is easily manipulated by the user to lock and unlock the cotton candy machine.
There is also a need for an improved locking system for cotton candy machines that prevents a user from inadvertently transporting the machine in an unlocked position or attempting to operate the machine while it is in the locked position.

Locking system for a cotton candy machine


A gasket of a data processing device controls the number of released storage locations of a buffer where read and write access requests are stored so that more read access requests can be stored without a corresponding increase in the amount of space at the buffer to store write access requests. An interface of the gasket accepts new access requests from one or more requesting modules only when a number of released storage locations at a buffer associated with the interface (referred to as an outbound buffer) is above a threshold number. As long as the number of stored access requests at the outbound buffer are less than a threshold amount, a buffer location can be immediately released. In addition, the gasket is configured to issue read access requests from the outbound buffer without regard to whether the inbound buffer has space available.

A data processing device typically employs one or more interfaces to facilitate transfer of information between modules of the data processing device. For example, some data processing devices include an interconnect that routes communications between device modules, including processor cores, memory modules, input/output modules, and the like. The interconnect typically includes one or more protocol translation modules, referred to as gaskets, to translate access requests and information between various protocols (formats). For example, the gasket can translate information between a proprietary format associated specifically with the data processing device to a standardized format, such as peripheral component interconnect express (PCIE) format. In addition, to improve communication bandwidth, a gasket can include buffers to temporarily store both received read and write access requests and information responsive to the access requests. However, using large buffers at the interface, while providing a desirable communication bandwidth, can consume an undesirable amount of integrated circuit area. Further, the buffering of access requests can increase latency at the interconnect, thereby reducing data transfer bandwidth.

Read stacking for data processor interface


A pneumatic accumulation conveyor has an anti-singulation control capable of deactivating the drive of a zone if the product sensor for that zone and substantially all of the product sensors downstream of that zone sense the presence of product in order to produce an accumulation portion with no zones actuated and is capable of activating the drive of a zone if any of the drives downstream of the associated zone are actuated in order to produce a transport portion in which all zones upstream of any actuated drive are actuated to transport product without singulation of any upstream grouped product. The accumulation conveyor is controlled by retractable product sensors positioned at particular locations along the product conveyor in order to sense the presence of product at the particular locations. Each of the product sensors includes an arm that is selectively positioned in the path of the product being conveyed by the product conveyor, a switch having an actuation member juxtaposed with the arm and a force-producing connection from a drive actuator of a downstream zone in order to move the arm from a position in the path of the product being conveyed to a retracted position. A mode control is provided for selecting one of first, second and third modes. In a first mode, the control actuates a discharge conveyor section and causes all sensors to be retracted from their sensing position to provide a slug discharge mode in order to clear out accumulated product without singulation. In a second mode, the control actuates the discharge conveyor but extends one group of sensors to a sensing position. This provides singulation between packages at the location of the sensor rollers to provide a singulation discharge mode in which gaps are drawn between packages. In a third mode, the discharge conveyor is deactuated and all sensors are allowed to be in their extended position in order to accumulate product.

This invention relates to accumulation conveyors and, more particularly, to pneumatically controlled accumulation conveyors. The invention is especially useful with high-speed conveyor systems.
In commonly owned U.S. Pat. No. 5,191,967, entitled CONVEYOR SYSTEM HAVING NON-SINGULATING ACCUMULATION CONVEYOR, a pneumatically controlled accumulation conveyor is disclosed which is intended, in part, to overcome problems associated with the accumulation conveyor disclosed in U.S. Pat. No. 3,768,630 issued to Russell A. Inwood et al. for an ACCUMULATOR WITH CONVEYOR OVERRIDE. Inwood et al. provide a series of tandem conveyor zones which are each responsive to actuation of the downstream zones in order to actuate that zone if any downstream zone is being actuated. In an accumulation mode, a case stop is raised and cases accumulate behind the stop to the point of actuating a sensing roller to deactivate an associated zone in order to keep articles closely spaced. However, it accomplishes this result using a shuttle valve associated with each zone, which receives its operating pressure in the appropriate circumstances from a series path extending through one or several downstream shuttle valves. During a clear-out mode, all zones are actuated through such series path. The result is a sluggish response to changes in operating states.
U.S. Pat. No. 5,191,967 overcomes this problem by providing an anti-singulation control which deactivates the driving means of an associated zone if the product sensing means for that zone and all of the product sensing means downstream of that zone sense the presence of product in order to produce an accumulation portion in which no zones are actuated. The control activates the drive means of an associated zone if any of the zones downstream of the associated zone are activated in order to produce a transport portion in which all zones upstream of any actuated zone are actuated to transport product without singulation of any upstream grouped product. The driving means for each zone is connected directly to a source of actuating fluid in order to actuate the drive means directly from the source. This provides an increase in product throughput by avoiding singulation between groups of moving packages in an exceptionally responsive manner because actuation through a series of shuttle valves is avoided. Such control may be embodied in first and second pneumatic devices at each sensing roller. The first pneumatic device responds to product actuating the sensing roller associated with that zone in order to connect the drive means of that zone directly with a source of actuating fluid. The second pneumatic device responds to actuation of the drive means of the downstream zone in order to connect the drive means of the controlled zone directly with a source of actuation fluid irrespective of whether any product is actuating the sensing roller associated with that zone.
In a subsequent development by another, such direct connection with a source of actuating fluid is accomplished in the same manner by attaching a pneumatic solenoid, or cylinder, to the arm of the sensing roller of the controlled zone and actuating the solenoid from the air diaphragm which actuates the drive means of the zone downstream of the controlled zone. With the pneumatic solenoid operatively positioned to engage the sensor valve for the controlled zone, the precise same operation as set forth in the U.S. Pat. No. 5,191,967 is accomplished. When any product sensing roller downstream of a zone does not sense the presence of a product, its sensor valve actuates the air diaphragms in order to drive that zone. This, in turn, actuates the solenoid of the upstream zone which retracts the sensing roller and actuates the sensor valve for that zone which drives the upstream zone. This operation cascades upstream in order to retract the sensor rollers for all zones upstream of a zone that do not sense the presence of product in that zone.
While such retractable sensor pneumatic control scheme is a convenient manner to implement the principles of the invention of the U.S. Pat. No. 5,191,967, it is not without its drawbacks. The mounting of the pneumatic solenoid on the movable arm of the sensor roller is a difficult mounting arrangement, both mechanically and pneumatically, because of the requirement that pneumatic lines be plumbed to a movable member. Furthermore, field retrofit is difficult and time-consuming. An additional difficulty is that packages may have bottom surfaces that are somewhat chamfered or otherwise damaged which creates the possibility that a package in a line of packages accumulating on the accumulation conveyor may not properly actuate a sensing roller. If this occurs, or if a pneumatic solenoid or sensing valve malfunctions, the driving means of all zones upstream of the zone having the malfunction will continue to be actuated resulting in an unacceptable increase in product line pressure.

Accumulation conveyor with retractable sensor


A stretcher comprising an upper frame for placing a litter thereon, having casters on a front leg and a rear leg; a constant load spring serving as a slide mechanism for changing the position of the upper frame vertically; a pin lock mechanism for fixing the upper frame having been moved vertically at an arbitrary position; a trapezoidal concave-shaped fitting groove for fixing the head side of a litter to the front end part of the upper frame; and a C-shaped hook for fixing the foot side of the litter to the rear end part of the upper frame, characterized in that a vertically and longitudinally adjustable lock supporter engaging with a lock piece for fixing the stretcher installed on the cargo bed of an ambulance or the like is provided in the rear part of the stretcher, and the pin lock mechanism is mounted with an emergency lever.

Regarding a stretcher placed on the cargo bed of an ambulance or the like and a litter placed on the stretcher, there has been reported a stretcher which can be placed on a cargo bed of an ambulance or the like and fixed easily, and the height of which can be adjusted easily so as to match the position of an acute patient at a first-aid rescue site. Further, on the shape etc. of the litter placed on the stretcher for carrying the acute patient, many improvements have been proposed.
Patent Document 1 has disclosed a stretcher characterized in that a constant load spring is used for a slide mechanism for changing the position of the upper frame of stretcher vertically; a mechanical lock mechanism is provided to stop the upper frame of stretcher at an arbitrary position; and further there are provided a lock mechanism for fixing the slide of a front leg aiding frame for aiding the front leg of stretcher, and a roller for smoothening the slide between support parts of a front leg, a front leg aiding frame, and a rear leg aiding frame for aiding a rear leg and a center rail, and a litter placed on the stretcher.
Patent Document 2 has disclosed a knee drawing-up type stretcher in which a bending angle adjusting means of an upper leg support part and a lower leg support part is configured at a low cost; adjustment can be made while saving the labor and time; the position of a leg fixing element fitted in the leg part of the knee drawing-up type stretcher can be adjusted easily and rapidly; and the raising/falling operation of a protecting frame installed on both right and left sides of the knee drawing-up type stretcher can be performed easily and rapidly.
Patent Document 3 has disclosed "an ambulance bed fixing device comprising a hollow bar fixed along the inner wall of an ambulance body; a fixing hook provided in one end part of the hollow bar to hook one leg part of bed; a positioning piece provided in the other end part of the hollow bar to make contact with the other leg part of bed; a movable hook holding the leg part between the positioning piece and the movable hook; and an operating rod for the movable hook, provided projectingly at the other end of the hollow bar, the operating rod comprising a pipe part mounted slidably in the outer peripheral part of the hollow bar to always urge the movable hook toward the positioning piece side in cooperation with the movable hook; a control lever provided integrally at the end of the pipe part to turnably lock the pipe part at the separation position of the movable hook with respect to the positioning piece; and an unlocking actuator for unlocking the pipe part by reversing it by contacting with the bed" described in claim.
Patent Document 4 has disclosed "a vehicle with a fixture, characterized by having a holder for fixing a stretcher provided on a floor panel; a second holder arranged on the floor panel to fix an incubator; and a holding means that turnably supports the second holder, and turns the second holder to retract it from an indoor occupation region that the stretcher occupies when the stretcher is fixed by the first holder" in claim 1. The fixture of stretcher in Patent Document 1 fixes the stretcher together with the second holder urging the first holder at the front and a spring at the rear.
Patent Document 5 is a patent document relating to a stretcher fixture that fixedly places a stretcher in a first-aid vehicle, and has disclosed a stretcher fixture capable of alleviating the worker's burden and preventing noise through an increase in an urging force of an urging means by using a configuration in which an operating force need not be applied continuously to an operating grip. The construction is disclosed as "the stretcher fixture in accordance with the present invention includes a body pipe fixed in a substantially horizontal state in the vehicle; a front locking claw fixed in the front part of the body pipe to lock one leg pipe at the front or rear of the stretcher; a positioning piece fixed in the rear part of the body pipe to determine the locking position of the other leg pipe at the front or rear of the stretcher; an operating grip arranged on the rear end side of the body pipe, in which the operation force to the front is applied from the outside; an operating rod the rear end of which is connected to the operating grip and which is provided on the inside of the body pipe so as to be capable of advancing and retreating; an urging means arranged in the body pipe to always apply an urging force to the rear with respect to the operating rod; and a rear-side locking claw that is connected to the operating rod, advances and retreats according to the movement of the operating rod, and, at the time of retreat, pushes the other leg pipe on the positioning piece by means of the urging force of the urging means to lock the other leg pipe by pushing the other leg pipe on the positioning piece, and is characterized in that a stopper is provided between the positioning piece and the rear-side locking claw; when the operation force to the front is applied to the operating grip from the outside, the stopper projects to the outside in the radial direction of the body pipe to allow the rear-side locking claw to be locked; and when the rear-side locking claw is in a locked state, if being pressed by the other leg pipe, the stopper retracts to the inside in the radial direction of the body pipe to allow the rear-side locking claw to retreat" from the second line of paragraph [0007].    Patent Document 1: WO2004/078087    Patent Document 2: Japanese Unexamined Utility Model Application Publication No. 06-75466    Patent Document 3: Japanese Examined Utility Model Application Publication No. 02-33773    Patent Document 4: Japanese Unexamined Patent Application Publication No. 09-327481    Patent Document 5: Japanese Patent Application No. 2000-217864
Although the stretcher and the litter placed on the stretcher have been improved variously, a satisfactory stretcher and a satisfactory litter have not yet been realized. It is desired to realize a litter capable of being placed on a stretcher quickly, capable of being fixed to the stretcher reliably, and capable of being placed on a stretcher on which a patient is examined at the time of first aid or is put on a drip.
Also, in order to place the stretcher on the cargo bed of an ambulance or the like and to carry it, it is necessary to firmly fix the stretcher to the cargo bed of the ambulance or the like so that the stretcher does not move even during the time when the ambulance or the like runs. However, when the stretcher is fixed to the cargo bed of the ambulance or the like, not only the stretcher must be fixed firmly so that the stretcher does not move even during the time when the ambulance or the like runs, but also the stretcher must be taken out of the cargo bed of the ambulance or the like quickly to receive a patient quickly when the ambulance or the like arrives at the first aid rescue site. In order to receive the patient and to place and fix the stretcher to the cargo bed of the ambulance or the like quickly, it is necessary that the stretcher be attached and detached easily and can be fixed firmly. Therefore, it is desired to realize a litter capable of receiving a patient safely and quickly and a fixture etc. for easily fixing the stretcher on which the litter is placed to the cargo bed of the ambulance or the like.
In the present invention, an ambulance or the like means an automobile provided with equipment (referred to as "a stretcher") having a structure for carrying a patient etc. when the patient etc. enter or leave a medical institution, go to a hospital regularly, transfer to another hospital, or are picked up and dropped off at a social welfare facility etc. (hereinafter referred to as "a patient carrying automobile")


A groundwall insulation system for use in dynamoelectric machines carrying voltage above 4 kV, and preferably in the order of 13.8 kV, or higher has two layers of insulation wound onto the conductors of the high voltage winding. The first layer of insulation has a first permittivity that is greater then the permittivity of the second layer of insulation wound onto the first layer of insulation. As a consequence, at the juncture between the first and second layers there is a sharp increase in the electric field profile as seen through the groundwall insulation.

The present invention relates to an insulation system for use in windings of a dynamoelectric machine. In particular it relates to an insulation comprising inner and outer layers having differing permittivities to create a more advantageous stress distribution within the dielectric.
Insulation systems for large AC dynamoelectric machines are under constant development to increase the voltages at which these machines operate while at the same time minimizing the thickness of the insulating material.
In such insulation systems it is common to utilize mica in a variety of forms from large flake dispersed on a backing material, to the product known as mica paper. While the low tensile strength of mica paper does not lend itself to use in such insulation systems, mica paper has superior corona breakdown resistance countering the coronal discharge occurring in high voltage windings that tends to shorten the life of the insulation. To compensate for the low tensile strength of the mica paper, the mica paper is bonded to glass fibers which also tends to prevent the shedding of mica flakes from the mica tape during a taping operation.
More recently a corona resistant polyimide and composite insulation tape has been employed in the insulation systems. This tape has exceptional insulation qualities and good corona discharge resistance. This film may be used independently or as a backing on a mica paper, glass fiber composite tape. The addition of enhanced corona resistant tape insulation provides an insulation system which is electrically more enhanced than standard systems.
However, the magnitude and profile of the local electric field within the groundwall insulation has not been considered to date in the development of insulation systems and tapes for the groundwall. This electric field generated in the groundwall insulation as a result of the high voltage applied to the conductor has a direct effect on the insulation life. As various initiatives are in place to reduce the groundwall insulation thickness it should be understood that the effect of the electric field as it is distributed across the groundwall also has an effect on the performance of the insulation system and the life of the groundwall insulation system. Accordingly, there is a need to develop a groundwall insulation system for use in windings for dynamoelectric machines that takes into consideration the effects of the localized electric field generated in the groundwall insulation as a result of the voltage difference across the insulation.
In accordance with the present invention there is provided an insulation system for use in windings of dynamoelectric machines that results in a graded or sharp increase in the electric field as distributed through the insulation from the interior of the insulation adjacent the conductor bar or conducting elements to the outer armor or grounded armor of the insulation.
It should be understood that the term xe2x80x9cgraded increasexe2x80x9d in the electric field relates a significant change in the electric field profile across a cross section of the groundwall insulation. In accordance with the present invention, the electric field profile across a xe2x80x9cflatxe2x80x9d cross section exhibits a sharp step increase part way across the cross section compared with a flat electrical field profile in the past. With respect to a corner section of the insulation, the electric field profile gradually decreases away from the conductors and again exhibits a sharp step increase part way across the corner cross section.
To accomplish the forgoing aspect of the graded change in the electric field profile of the insulation of the present invention, there is provided an insulation system that has a conductor of a dynamoelectric machine which is insulated with layers of insulation. The insulation has a first inner layer of insulation and a second layer of insulation outer relative to the first inner layer. Both the first and second layers of insulation have predetermined thickness so as to provide for the proper insulation characteristic needed for the insulation itself. However, the permittivity of the first inner insulation layer is chosen to be greater than that of the second insulation layer such that the electric field in the second insulation layer increases sharply at the juncture between the first inner and second layers of insulation.
It has been determined that by providing for a relatively higher permittivity on the inner layer, the electric field adjacent the conductor has a reduced magnitude. While the overall electric field distributed across the insulation may not be less, it should be understood that the magnitude of any sharp occurrences of the electric field in the insulating layer adjacent the conductor are reduced. This is a considerable undertaking because the insulation is designed and developed for its weakest areas in the insulation which occur at the corners of the insulation adjacent the conductors where the highest magnitudes of electric field have been experienced in the past. Thus by reducing this magnitude in electric field, the requirements for the thickness of the insulation is reduced thereby minimizing the thickness of the insulation while not adversely effecting the voltages carried by such conductors or the insulation life. It should be understood that in accordance with the present invention it is envisaged that these conductors carry voltages in the order of 4 kV and greater.
It is also envisaged that in alternative embodiments of the present invention the insulation may comprise more than two layers of insulation applied over each other in succeeding layers where each succeeding layer has a permittivity less than the preceding layer of insulation.
A preferred application of the insulation system of the present invention is as a groundwall insulation for conductors in the winding of a dynamoelectric machine carrying voltages of 4 kV and greater. In applications where the voltage is in the order of 13.8 kV, the thickness of the groundwall insulation is in the order of 3.2 mm.
In accordance with a preferred aspect of the present invention there is provided a groundwall insulation for use on a conductor of a dynamoelectric machine that has a graded electric field profile across the groundwall insulation. The groundwall insulation comprises a first inner insulation layer and a second outer insulation layer. The first inner insulation layer is applied over the conductor and has a first predetermined thickness and first predetermined permittivity. The second outer insulation layer is applied over the first inner insulation layer and forms a juncture therewith. The second outer insulation layer has a second predetermined thickness and second predetermined permittivity wherein the second predetermined permittivity is less than the first predetermined permittivity of the first inner insulation layer creating the graded increase in the electric field in the groundwall insulation at the juncture of the first inner and second outer insulation layers.

Graded electric field insulation system for dynamoelectric machine


A method for producing a zeolite catalyst includes mixing a zeolite material with a filler material comprising transition phase and alpha alumina, a porosity enhancing agent, and water to produce a paste; mulling the paste; extruding the paste to produce a shaped extrudate; and drying and calcining the shaped extrudate to produce a zeolite catalyst, wherein the zeolite catalyst has a total porosity greater than about 0.60 ml/gm and greater than 15% of a total pore volume of pores in the range from about 550 Å to about 31,000 Å.

The alkylation of aromatic hydrocarbons such as benzene with olefins having two, three, or four carbon atoms (hereinafter referred to as "light" olefins), such as ethylene and propylene, is a commercially important process. The production of ethylbenzene is used to provide a feedstock for styrene production, while the alkylation of benzene with propylene produces isopropylbenzene (cumene). Cumene is an important feedstock to make phenol as well as a good gasoline blending component. Numerous other uses exist for such alkylated aromatic hydrocarbons. In these alkylation processes, new catalysts are continuously needed that have a high overall conversion of the feedstock and have a good selectivity of alkylated benzenes.
Zeolite catalysts (hereinafter referred to collectively as "zeolites") have been found to be particularly well-suited for use in the alkylation of aromatic hydrocarbons. Zeolites are crystalline aluminosilicate compositions that are microporous and that are formed from corner sharing AlO2 and SiO2 tetrahedra. Numerous zeolites, both naturally occurring and synthetically prepared, are used in various industrial processes. Synthetic zeolites are prepared via hydrothermal synthesis employing suitable sources of Si, Al, and structure-directing agents such as alkali metals, alkaline earth metals, amines, and/or organoammonium cations. The structure-directing agents reside in the pores of the zeolite and are largely responsible for the particular structure that is ultimately formed. These species balance the framework charge associated with aluminum and can also serve as space fillers. Zeolite catalyst compositions also typically include a filler or binder material mixed with the aluminosilicate material, which helps to form the zeolite catalyst into a desired shape. Zeolites are characterized by having pore openings on the external surface of the catalyst, having a significant ion exchange capacity, and being capable of reversibly desorbing an adsorbed phase, which is dispersed throughout the internal voids of the crystal without significantly displacing any atoms which make up the permanent zeolite crystal structure.
While zeolites have been shown to be useful for the alkylation of a variety of aromatic hydrocarbons with a variety of light olefins, testing has shown that alkylation reactions using zeolite catalysts are highly diffusion limited. The reaction rate is so fast and the diffusion of olefin into and throughout the catalyst to reach all the zeolitic active sites is the rate limiting step. Diffusion within the catalyst depends, in part, on the overall porosity and pore structure of the catalyst and in part on the dispersion of zeolite throughout the matrix. In order to disperse the zeolite throughout the matrix mechanic force through a process such as mulling is applied. However, the compaction invariably reduces the catalyst porosity, increasing the diffusion resistance and thus lowering the catalyst activity.
Accordingly, it is desirable to provide methods for producing zeolite catalysts that have better diffusion characteristics and thus improving the utility of zeolite throughout the entire catalyst. The effect of diffusion resistance on active site utilization and thus catalyst activity is especially evident in the aromatic alkylation with olefin including propylene and ethylene. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

Methods for producing zeolite catalysts and methods for producing alkylated aromatic compounds using the zeolite catalysts


An interferometric measuring device, especially for measuring the shape of a surface of an object, includes a radiation source emits a short coherent electromagnetic radiation, a component, in particular a beam splitter, to form an object beam that is guided to the object via an object light path, and a reference beam guided to a reference plane via a reference light path, and a pickup element, by the use of which an electromagnetic radiation, that is reflected by the object and the reference plane and brought to interference, is able to be picked up. In this context, an adaptive optical element is provided, with the aid of which the imaging of the object on the pickup element and/or the wave front of the reference beam and/or the optical path length in the reference light path and/or in the object light path may be influenced.

Such an interferometric measuring device, referred to as a white light interferometer, offers an interferometric measuring method established under the concept of white light interferometry, in which a short-coherent light source is, as a rule, used in conjunction with a Michelson interferometer. In this regard, we refer, for example, to T. Dresel, G. Haeusler and H. Venzke, Applied Optics vol. 31 (1992), page 919, or P. de Groot and L. Deck, "Surface profiling by analysis of white light interferograms in the spatial frequency domain", Journal of Modern Optics, vol. 42, (1995, pages 389 to 501. In this context, the object is imaged via an objective lens on a CCD camera and superimposed by a flat reference wave. A depth scan of the object surface in the z direction may be carried out as scan of the reference mirror or of the object. In a scan of the object, the image plane of the objective and the reference plane are in the same plane, i.e. the object is only moved in the depth axis relative to the reference plane. In a scan of the reference mirror, on the other hand, only the reference mirror is moved, i.e. the object remains immobile with respect to the objective. In this procedure, the depth measurement range is limited by the depth of field of the objective lens.
A white light interferometer is discussed in German patent document no. 199 48 813 A1 that has an intermediate image of the object in the reference light path. The depth scan, in this context, may be implemented as scan of the reference or as intermediate image scan according to German patent document no. 101 15 524 A1. In a scan of the reference mirror, the reference mirror is moved, i.e. the object remains immobile to the objective. The depth measurement range is limited by the depth of field of the objective lens.
In German patent document no. 101 31 778 A1 a white light interferometer is shown having a panoramic view optical system, i.e. an objective optical system that can take a shot around 360° of a nearly radially symmetrical object region. A depth scan, in this context, may be implemented as scan of the reference or as intermediate image scan according to German patent document no. 101 15 524 A1. In a scan of the reference mirror, the reference mirror is moved here too, i.e. the object remains immobile to the objective in this connection too. The depth measurement range is also limited by the depth of field of the objective lens.
White light interferometers are also known in which a CCD camera may be shifted relative to the ocular lens with the aid of a linear shifting table. This makes it possible to set focusing corrections for different objects or object ranges, in case the object lies wholly or partially outside the depth of field of the objective. However, this solution is comparatively costly from an apparatus point of view, and in addition it is too inflexible when adjusting the focus.
White light interferometry was able to be developed further by the aforementioned techniques altogether in such a way that, for example, valve seats may be measured completely even in narrow and deep bores.
An important requirement remaining with interferometric measuring devices is, above all in connection with measuring narrow and deep bores, to make different objectives and endoscopes at the measuring device easily exchangeable. Besides that, the measuring range is still restricted by the depth of field range of the objective and the optics of the eyepiece. Finally, in special applications, a depth scan may be carried out only as a scan of the reference mirror, since a scan of the object is technically too costly.


A circuit for a dimmer system is disclosed, in which a phase-cut dimmer output signal is converted to a dimming control level signal. The phase-cut dimmer output signal is used to generated a pulse modulated signal indicative of the duty cycle of the phase cut dimmer output signal, and the pulse modulated signal is directly converted to a piece-wise linear dimming control level signal. By directly converting the pulse modulated signal to a piece-wise linear dimming control level signal, no further processing is necessary to produce a dimming signal which closely resembles the ideal logarithmic response of the human eye.

Phase cut dimmers are widely used in a range of applications, including but not limited to lighting applications. A conventional phase-cut dimmer uses a switch to switch off or "cut" part of the mains cycle—or more accurately, half-cycle. Either the leading or trailing edge, or even both edges of the phase can be cut, depending on the type of switch used. Normally either a transistor or a triac is used.
Although this is effective for conventional incandescent lighting, phase cut dimmers can be problematic for more energy efficient types of lighting, such as compact fluorescent lights (CFL), tube lighting (TL), or solid-state lighting (SSL), which are not well suited to cope with the "missing" parts of the mains cycle. Such energy efficient types of lighting are often controlled by means of a switched mode power supply, which switches at frequencies much higher than that of either a 50 Hz or 60 Hz mains cycle—typically several kHz up to several MHz.
For phase cut dimmers to be compatible with such types of lighting, the phase cut power needs to be processed to be usable by the lighting circuit. However, it is important that in such processing, that the information regarding the desired level of dimming, which is included in the phase cut signal, is not lost but is recovered as a dimming control level signal.
Conventionally, a control voltage to indicate the desired level of the dimming is generated by making an integrated signal from the dimmer output signal. This signal will have a level which is proportional to the area under a plot of the dimmer output voltage against time, and is thus a function of not just the dimmer phase angle but also of the mains voltage level. So, fluctuations in mains voltage affect the control level, and thus the apparent dimming setting. Moreover, the integrator needs a time constant the order of seconds for the signal to have minimum ripple, which is not compatible with prompt responsiveness to a user when changing the dimmer level.
An alternative solution has been proposed, for instance in International Patent Application Publication number WO2008/112,735 in which a duty cycle signal is generated from the output of the dimmer. The duty cycle signal, which may take the form of a pulse modulated signal, is indicative of the proportion of the mains cycle during which the switch is on. However, this is not representative of the fraction of the mains power which would be supplied during this proportion of the cycle, due to the sinusoidal nature of both the voltage and current supplied.
Moreover, the response of the human eye to a dimmed light level is generally approximately logarithmic rather than linear, so it be would be preferable if the power supply it to the lighting and could be adjusted so as to be nonlinearly, and ideally logarithmically or nearly logarithmically, related to the phase angle of the dimmer.
It is proposed in WO2008/112,735, to provide such a nonlinear response by post-processing the dimming control level signal using a lookup table. However, such a solution is difficult to implement in a primarily analog circuit, and requires both complex circuitry and significant processing power to implement.
It would therefore be desirable to have a circuit in which the nonlinear response is directly derived from the duty cycle signal.

Generation from phase cut dimmer output with fast response to changes in dimmer position

Abstract: A corresponding method for a dimmer system is also disclosed, as is a dimmer system.


An assembly for making a wax pattern of a hollow component includes a pattern die and a noncircular core which is located within the pattern die. The pattern die is a split die and includes two halves which have shaped internal surfaces to define the external shape of the wax pattern of the hollow component. The core has shaped external surfaces which define the internal shape of the wax pattern of the hollow component. The core has coaxial circular cross-section projections which locate within correspondingly shaped and dimensioned apertures in the pattern die. One of the apertures in the pattern die has a radially extending pin which is arranged to mate in a groove on the projection to locate the core longitudinally. The core is allowed to rotate within the die so that chaplets on the core position the core accurately without imposing strains on the core.

In the lost wax casting process a wax pattern of a component is produced. The wax pattern is a replica of the component to the produced. Usually a number of wax patterns are assembled together on a wax gating tree to form a cluster or wax mould assembly. The wax mould assembly is immersed in a liquid ceramic slurry which quickly gels after draining, strengthening refractory granules are sprinkled over the ceramic slurry covered wax mould assembly and the refractory granules bond to the slurry coating to produce a ceramic layer on the wax mould assembly. This process is repeated several times to produce many ceramic layers which have a total thickness of about 1/4 inch (6 mm) to 1/2 inch (12 mm) on the wax mould assembly. The wax is then melted out leaving a ceramic shell mould having an internal cavity identical in shape to that of the original wax cluster. This ceramic shell mould is called an investment casting mould. The mould is fired at a high temperature between 950.degree. C. and 1100.degree. C. to purify it by removing all traces of residual wax, while at the same time curing the ceramic shell mould. The ceramic shell mould is then transferred to a casting furnace, which may be operated at either vacuum conditions or at atmospheric conditions. A charge of molten metal is then poured into the ceramic shell mould and the mould is allowed to cool to room temperature, after which the ceramic shell mould is removed leaving the cast component or components.
In the lost wax casting of hollow turbine blades or turbine vanes, the wax patterns of the hollow turbine blades or turbine vanes are produced by injecting wax into a pattern die which has one or more preformed ceramic cores located therein. The pattern die has convex and concave aerofoil shaped surfaces and the ceramic core is spaced from the convex and concave shaped surfaces of the pattern die by chaplets to ensure the correct thickness gap exists between the surfaces of the die and the ceramic core surfaces. The ceramic core has shaped projections which locate in correspondingly shaped apertures in the pattern die. The ceramic core is prevented from moving longitudinally in the pattern die by a precisely positioned pin and slot arrangement.
It is difficult to optimise the position of the ceramic core relative to the pattern die surfaces due to the manufacturing tolerances of size and shape of the ceramic core and also because of distortions within the ceramic core making process. It is particularly difficult to optimise the trailing edge position of the ceramic core relative to the pattern die surfaces due to the distortions of the ceramic core, because the relationship between the trailing edge and the shaped projections of the ceramic core suffers the greatest dimensional variations. The larger the ceramic core the more pronounced is the distortion.
The chaplets fitted to the core are positioned to ensure that the correct thickness of wax is achieved, but where distortion is excessive the point load exerted onto the ceramic core by the chaplet strains the ceramic core, because they are trying to correct the distorted shape against the restraint imposed by the shaped projections of the ceramic core locating in the corresponding shaped apertures in the die. In the extreme case the strain is enough to fracture the brittle ceramic core thus scrapping the wax pattern. If the strain is insufficient to break the ceramic core, there is a residual strain imposed in the ceramic core which, when the wax is removed from the ceramic shell mould, causes the ceramic core to spring back to its free state and subsequently produces a cast turbine blade or turbine vane which has a thin wall section.

Assembly and method for making a pattern of a hollow component