Abstract: A hydraulic power steering system that maintains proportional pressure control between an input side of a gear and assist pressures internal to the steering gear by relying upon a control valve. A pressure differential is maintained between the input side of a gear and assist pressures internal to the steering gear throughout certain events. Those events include running the pump to fully charge the accumulator, idling the pump after fully charging the accumulator, discharging pressure from the fully charged accumulator at an onset of a steering event having a demand for steering load, recovering the discharged pressure of the accumulator by running the pump after turning on the pump at the onset of the steering event, and opening the relief valve in the valve manifold during the steering event.

Abstract: A hydraulic drive system for storing and releasing hydraulic fluid includes a high pressure storage device, a low pressure storage device, and a pump-motor operating at a range of pump-motor speeds for converting between hydraulic energy and mechanical energy. The pump-motor is disposed between the high pressure device and the low pressure device. In normal operation, the hydraulic drive system enters a motoring mode where hydraulic energy is released from the high pressure storage device and converted to mechanical energy using the pump-motor. It also enters a pumping mode where mechanical energy is converted into hydraulic energy. A neutral state exists where hydraulic energy is neither stored nor released from the high pressure storage device. An approach for compensating for temperature changes using varying pressure limits helps to maintain the hydraulic drive system in normal operation, thereby promoting efficiency within the hydraulic drive system.

Abstract: A shift controller for an automatic transmission mechanism is configured such that when the engine is in a driven state in which the engine is driven by a travel inertia force or the like and an accumulated pressure amount of the accumulator is equal to or less than a predetermined threshold, the excessive engine brake force, which is generated due to the accumulation of at least a portion of the hydraulic pressure generated from the mechanical hydraulic pump in the accumulator, is inhibited or reduced by conducting upshifting that relatively decreases the gear ratio of the automatic transmission mechanism. Therefore, the generation of the excessive engine brake force can be inhibited or reduced even when the engine is in the driven state and pressure accumulation is performed.

Abstract: A hydraulic power steering system that maintains proportional pressure control between an input side of a gear and assist pressures internal to the steering gear by relying upon a control valve. A pressure differential is maintained between the input side of a gear and assist pressures internal to the steering gear throughout certain events. Those events include running the pump to fully charge the accumulator, idling the pump after fully charging the accumulator, discharging pressure from the fully charged accumulator at an onset of a steering event having a demand for steering load, recovering the discharged pressure of the accumulator by running the pump after turning on the pump at the onset of the steering event, and opening the relief valve in the valve manifold during the steering event.

Abstract: A hydraulic drive system for storing and releasing hydraulic fluid includes a high pressure storage device, a low pressure storage device and a pump-motor operating at a range of pump-motor speeds for converting between hydraulic energy and mechanical energy. The pump-motor is disposed between the high pressure device and the low pressure device. In normal operation, the hydraulic drive system enters a motoring mode where hydraulic energy is released from the high pressure storage device and converted to mechanical energy using the pump-motor. It also enters a pumping mode where mechanical energy is converted into hydraulic energy. A neutral state exists where hydraulic energy is neither stored nor released from the high pressure storage device. An approach for facilitating the precharging of the high pressure storage device to a minimum threshold pressure promotes efficiency within the hydraulic drive system.

Abstract: A hydraulic drive system for storing and releasing hydraulic fluid includes a high pressure storage device, a low pressure storage device, and a pump-motor operating at a range of pump-motor speeds for converting between hydraulic energy and mechanical energy. The pump-motor is disposed between the high pressure device and the low pressure device. In normal operation, the hydraulic drive system enters a motoring mode where hydraulic energy is released from the high pressure storage device and converted to mechanical energy using the pump-motor. It also enters a pumping mode where mechanical energy is converted into hydraulic energy. A neutral state exists where hydraulic energy is neither stored nor released from the high pressure storage device. When the pump-motor includes a swash-plate or similar structure, compensating for drift during normal operation helps to promote efficient operation of the hydraulic drive system.

Abstract: An accumulator system is configured to store energy and includes an accumulator having a liquid chamber coupled to a liquid port and an air chamber coupled to an air port. The liquid chamber and the air chamber are separated by a moveable isolation barrier. An air motor/compressor coupled to the air port is configured to receive a mechanical input and responsively pump air into the accumulator, and to receive pressurized air from the air port and responsively provide a mechanical output. A liquid reservoir is coupled to the liquid port to receive liquid from the liquid chamber as air is pumped into the air chamber and to provide liquid to the liquid chamber as air is removed from the air chamber.

Abstract: A hydraulic power steering system that maintains proportional pressure control between an input side of a gear and assist pressures internal to the steering gear by relying upon a control valve. A pressure differential is maintained between the input side of a gear and assist pressures internal to the steering gear throughout certain events. Those events include running the pump to fully charge the accumulator, idling the pump after fully charging the accumulator, discharging pressure from the fully charged accumulator at an onset of a steering event having a demand for steering load, recovering the discharged pressure of the accumulator by running the pump after turning on the pump at the onset of the steering event, and opening the relief valve in the valve manifold during the steering event.

Abstract: A hydraulic drive system for storing and releasing hydraulic fluid includes a high pressure storage device, a low pressure storage device, and a pump-motor operating at a range of pump-motor speeds for converting between hydraulic energy and mechanical energy. The pump-motor is disposed between the high pressure device and the low pressure device. In normal operation, the hydraulic drive system enters a motoring mode where hydraulic energy is released from the high pressure storage device and converted to mechanical energy using the pump-motor. It also enters a pumping mode where mechanical energy is converted into hydraulic energy. A neutral state exists where hydraulic energy is neither stored nor released from the high pressure storage device. An approach for compensating for temperature changes using varying pressure limits helps to maintain the hydraulic drive system in normal operation, thereby promoting efficiency within the hydraulic drive system.

Abstract: A hydraulic drive system for storing and releasing hydraulic fluid includes a high pressure storage device, a low pressure storage device and a pump-motor operating at a range of pump-motor speeds for converting between hydraulic energy and mechanical energy. The pump-motor is disposed between the high pressure device and the low pressure device. In normal operation, the hydraulic drive system enters a motoring mode where hydraulic energy is released from the high pressure storage device and converted to mechanical energy using the pump-motor. It also enters a pumping mode where mechanical energy is converted into hydraulic energy. A neutral state exists where hydraulic energy is neither stored nor released from the high pressure storage device. An approach for facilitating the precharging of the high pressure storage device to a minimum threshold pressure promotes efficiency within the hydraulic drive system.

Abstract: A hydraulic system comprising a pump for feeding hydraulic fluid from an inlet side to an outlet side, wherein a pressure accumulator is disposed at the outlet side, wherein between the pump and the pressure accumulator a hydraulic control valve is disposed, which has at least two valve positions, wherein the outlet side of the pump is connected to the pressure accumulator in a first valve position, and separated from the pressure accumulator in a second valve position, wherein the outlet side of the pump is connected to the inlet side through the control valve in the second valve position.

Abstract: A hydraulic service module is provided for a hydraulic fluid system, which includes a fluid reservoir for storing an appropriate amount of a hydraulic fluid. The hydraulic service module comprises an outer casing defining an enclosure therewithin including an air chamber in fluid communication with an ambient air. The hydraulic service module houses one or more fluid pressure accumulators mounted within the enclosure and a heat exchanger provided for cooling the hydraulic fluid.

Abstract: A hydraulic control system for a work machine is disclosed. The hydraulic control system has a source of pressurized fluid and at least one actuator having a first and a second chamber. The hydraulic control system also has a first independent metering valve disposed between the source and the first chamber, and a second independent metering valve disposed between the reservoir and the second chamber. The first and second independent metering valves each have a valve element movable from a flow blocking to a flow passing position to facilitate movement of the at least one actuator. The hydraulic control system further has an accumulator and a third independent metering valve disposed in parallel with the first independent metering valve and between the accumulator and the first chamber. The third independent metering valve is configured to selectively communicate the accumulator with the first chamber to cushion movement of the at least one actuator.

Abstract: The load element state detecting portion 72 detects the completion of the filling of the hydraulic oil into the clutch 62 and the working limit of the accumulator 64 on the basis of the displacement of the spool valve element 42. That is, since the completion of the filling of the hydraulic oil into the clutch and the working limit of the accumulator 64 are directly detected, so that the completion of the filling of the hydraulic oil into the clutch 62 and the working limit of the accumulator 64 can be detected with high precision regardless of differences among products and the time-lapse variation. Furthermore, they can be detected without equipping any special device to the hydraulic control circuit, and thus there is an advantage that the device construction is simple.

Abstract: A hydraulic arrangement is provided with at least one pressure accumulator for a hydraulic fluid, a hydraulic cylinder with at least one chamber to which pressure can be applied, a connecting line, on the basis of which the at least one accumulator is connected with the chamber, and a control unit. In order to provide an electronic pipe break safety device, an electronically controlled on-off valve is mounted in the connecting line and coupled for receiving control signals from the control unit, and a signal transmitter, which is coupled for monitoring the pressure in the connecting line is also connected to the control unit. If a pressure drop occurs in the connecting line, a signal change is generated by means of the signal transmitter, whereupon the control unit sends a signal effecting movement of the shut-off valve to its closed position.

Abstract: An air compressor includes a tank unit storing a compressed air used by a pneumatic tool, a compressed air generator which generates the compressed air and supplies the compressed air to the tank unit, a motor driving the compressed air generator, a drive portion including the motor, a controller portion controlling the drive portion and a pressure sensor detecting an air pressure of the compressed air in the tank unit, in which the controller portion controls a rotation speed of the motor at multiple levels based on a detection signal P1 of the pressure sensor, a first differential signal which is a differential value d(P1)/dt of the detection signal P1, and a second differential signal which is a differential value d(P2)/dt of a detection signal P2 obtained by removing a pulsatory element from the detection signal P1.

Abstract: Described are a method, a computer program, and a control unit for operating a vacuum reservoir provided in an internal combustion engine of a motor vehicle for a servo booster or power-assist unit of the internal combustion engine, which is coupled to an intake manifold of the internal combustion engine and to an electrical suction pump. The pressure prevailing in the vacuum reservoir is determined by a computational model in which quantity flows are fed to the vacuum reservoir when at least one servo unit is actuated, quantity flows are removed from the vacuum reservoir when the pressure prevailing in the intake manifold is lower than the pressure prevailing in the vacuum reservoir, i.e., when the electrical suction pump is switched on. The total pressure prevailing in the vacuum reservoir is calculated from the balance of these flow quantities.

Abstract: A switching device for a machine, especially a digger, has at least one supply connection and one useful connection in addition to at least one hydraulic accumulator. An on-off valve is arranged between the supply connection and the useful connection, and separates the supply connection at least partially from the useful connection in one of its switching positions, in addition to ensuring that the hydraulic accumulator is charged on the fluid side via the supply connection. In another switching position, the supply connection is connected to the useful connection. A substantial improvement relative to conventional switching devices is attained by being able to guarantee an emergency function before the machine is used to perform work.

Abstract: A method of determining shift points in a step gear transmission system to maximize fuel economy is disclosed. In operation, the method uses fuel economy data from a first gear ratio to determine a first series of constant fuel consumption curves for the first gear ratio. The method then uses fuel economy data from a second gear ratio to determine a second series of constant fuel consumption curves for the second gear ratio. Next, the method determines points of intersection where a respective fuel consumption curve for the first gear ratio intersects its corresponding fuel consumption curve for the second gear ratio. A decision curve is generated from the points of intersection.

Abstract: A free piston engine system, particularly suitable for use in a motorized vehicle, is provided with at least one hydraulic pump, each pump having a first fluid port and a second fluid port. A free piston internal combustion engine includes a combustion cylinder and a hydraulic cylinder. A low pressure accumulator is fluidly coupled with the hydraulic cylinder. A first control valve interconnects the low pressure accumulator with the hydraulic cylinder. At least one high pressure accumulator is fluidly coupled with the hydraulic cylinder. At least one second control valve is provided, with each second control valve interconnecting a respective high pressure accumulator with the hydraulic cylinder. A third control valve interconnects the hydraulic cylinder with the first fluid port of each pump. A fourth control valve interconnects the hydraulic cylinder with the second fluid port of each pump. A first working pressure accumulator is coupled between each pump and the third control valve or fourth control valve.

Abstract: A variable pressure hydraulic system includes a hydraulic pressure source which is selectively connected to a hydraulic system or to drain, via a control valve and a pressure transducer; the control valve in a first position isolating the pressure source from the hydraulic system and connecting it to the pressure transducer and in a second position connecting the pressure source to the pressure transducer and the hydraulic system.

Abstract: A slide driving device employs a variable-displacement pump/motor for driving a rotating element of the slide driving device. The displacement volume of the variable-displacement pump/motor, whose output drives the slide, is varied in response to deviation of measured driver parameters from commanded driver parameters. An energy storage device temporarily absorbs excess energy during a portion of a molding cycle, and returns the energy to the system for re-use. In one embodiment, the energy storage device is an accumulator. In a second embodiment, the energy storage device is a flywheel. The combination of variable displacement volume and energy storage maintains the fluid pressure substantially constant during a cycle of the slide driving device.

Abstract: Hydraulic apparatus including hydraulic supply means and an accumulator with an accumulator piston and a means for sensing the accumulator piston position to indicate a load requirement to a control means to selectively actuate the hydraulic supply means to satisfy the hydraulic load requirement and to provide a relatively pressure pulse-free operation by actuating the hydraulic supply means in response to the position and motion of the accumulator piston.

Abstract: A load valve apparatus having a control valve which can be connected to a pump and an accumulator and which in a first position connects the pump to the accumulator and in a second position isolates the pump from the accumulator, and the pump and the accumulator are isolated from one another when the accumulator pressure exceeds a certain value, and a connected consuming device is isolated from the accumulator in such a way that the load pressure of the consuming device does not affect the accumulator. The pressure of the pump and/or of the accumulator is used to regulate the pump.

Abstract: A power assisted steering apparatus for a vehicle having a driving source, such as an engine, has an actuator, a hydraulic pump, a working oil pressure passage, and a drive switch. The actuator, which is in the vehicle steering mechanism, receives a supply or exhaust of a working oil to assist the steering operation. The pump is selectively driven by an engine via a clutch mechanism. The working oil discharged from the pump is introduced into the actuator via the passage. The check valve is interposed within the passage to enable flow in one direction away from the pump. The drive switch structure is disposed within the passage, downstream from the check valve. With this arrangement, the drive switch structure can be activated by pressure in the passage downstream of the check valve to control the clutch mechanism.

Abstract: The energy conversion system of the subject invention converts the energy from a source of pressurized fluid, such as a free-piston engine and a storage accumulator, to a work system at various pressure levels. This is accomplished by providing power modifying units which act to efficiently reduce the pressure level of the fluid from the source of pressurized fluid to the various pressure levels. A control arrangement monitors the operating pressures in the actuators and selects the path of pressurized fluid having the lowest pressure level needed to perform the task. Additionally, exhausted fluid containing energy is utilized by regenerating the fluid back to the inlet of the actuator or by directing it through the appropriate power modifying unit to amplify the pressure therein and supplement or recharge the source of pressurized fluid.

Abstract: A method of supplying driving energy to subassemblies of a vehicle having an engine, a braking system including a brake pedal, a hydraulic machine, a hydraulic accumulator and a clutch having an engaged state for connecting the engine to the hydraulic machine for driving the hydraulic machine from the engine and a disengaged state for disconnecting the engine from the hydraulic machine.

Abstract: An actuation system for a vehicle in which a pump (10b) draws fluid from a reservoir (10a) to supply one or more first consumers, such as steering valve (50). One of more second consumers, such as a clutch actuator (12), are actuated via a solenoid valve (12a) from an accumulator (10c) charged by the pump. The solenoid valve connects each second actuator (12) to the accumulator or to the reservoir. When the pressure in the accumulator is below a predetermined charge pressure, flow to the first consumer is restricted to a level sufficient to ensure effective operation of the first consumer, while generating a back pressure sufficient to ensure charging of the accumulator. The flow restriction to the first consumer may be achieved by the solenoid valve (12a) or by a separate charging valve (20).

Abstract: In a hydraulic driving apparatus with a bladder-type accumulator connected to a fluid supply pipe extending from a hydraulic fluid source to at least one actuator, the apparatus comprises a hydraulic pressure sensor attached to the fluid supply pipe in the vicinity of the bladder-type accumulator and a control unit responsive to a detected pressure detected by the hydraulic pressure sensor for controlling the hydraulic fluid source. The control unit carries out the steps of judging, at the start of the hydraulic driving apparatus, an initial gas pressure supplied to the bladder-type accumulator with reference to a gradient of variation of the detected pressure detected by the hydraulic pressure sensor; monitoring, during a normal operation of the hydraulic driving apparatus, a difference .DELTA.P between the initial gas pressure and the detected pressure; and judging occurrence of a trouble when the difference .DELTA.P becomes smaller than a predetermined first difference .DELTA.P1 or when the difference .

Abstract: An improved sampling pump has utility for withdrawing fluid from a pressurized source and outputting fluid to a sampling container. The fluid pump assembly of the present invention includes an operator unit for reciprocating a plunger, and a side body port positioned within the pump body for receiving a removable filter. A pressure regulator has an inlet positioned within a side body port of the pump body and regulator outlet port in fluid communication with the operator unit. A collar rotatable with respect to a regulator housing is provided for reducing installation costs and for optionally removing condensate from the regulator. An adjustable discharge valve is pressure balanced for increasing the reliability of the pump. An improved seal is utilized for dynamic seal engagement between the pump body and the pump plunger.

Abstract: A hydraulic system which includes a pump for supplying hydraulic fluid to a load by a fluid supply line and receiving hydraulic fluid from the load by means of a fluid return line. The pump, as well as a drive motor therefore is enclosed within a pressure vessel, having a gas interior which forms an acoustic impedance mismatch so that the pump is acoustically isolated from the surrounding water medium. The fluid return line is connected to a reservoir having a moveable piston which separates the reservoir into two compartments, one filled with oil and the other with gas. The reservoir is sealed so that its internal pressure which is relatively low, for example between 10 and 100 psia is completely independent of the pressure of the surrounding water medium and maintains the return line pressure at that same low value.

Abstract: An apparatus for driving a piston with fluid power is disclosed. The apparatus includes a fluid filled cylinder having an inner and an outer wall and defining a longitudinal axis. A piston is slidably positioned in the cylinder to move along a path of travel parallel to the longitudinal axis. A magnet is coupled to the piston for movement with the piston, The apparatus further includes a pump in fluid communication with the cylinder and being selectively actuated to intermittently pump pressurized fluid into the cylinder to apply force to and move the piston in a first direction along the path of travel. A fluid releasing apparatus is provided to release fluid from the cylinder to move the piston in a direction opposite the first direction. The apparatus also includes a Hall effect sensor situated at a location along the outer wall of the cylinder for sensing a position of the piston by sensing a magnetic field associated with the magnet at the location of the sensor.

Abstract: A load control device applicable on agricultural machinery in general and in particular on machinery used for direct planting, so that the working components in contact with the ground will maintain the same load constantly at all times for any ground profile condition. An oil-pneumatic device is provided with a fluid compressor connectable to the tractor's power take-off by a cardan shaft and an electromagnetic clutch that can be powered from the tractor's electrical system or by an independent source, including a compressor with its associated pressurestat which governs it in order to maintain the air pressure required by the circuit. The compressor supplies a tank of compressed air, to which is connected at least one hydraulic cylinder whose upper and lower chambers are each connected to intermediate air and oil collecting reservoirs.

Abstract: A marine hydraulic system for operation of a power steering assembly includes a pressure accumulator to provide pressurized hydraulic fluid and valving that permits the transfer of hydraulic fluid within the cylinder to provide efficient use of hydraulic fluid.

Abstract: A pressure source for a pressure device has a pump for pumping fluid from a tank, an accumulator connected to the pump and to a pressure device, a device for detecting the pressure in the accumulator, and a control system for controlling the operation of the pump in an ON/OFF manner based on results of detection of the pressure detecting device. The pressure detecting device includes a pressure switch to detect pressure in the accumulator to produce an ON/OFF signal, and a pressure sensor outputting a pressure signal corresponding to pressure in the accumulator. The control system judges whether the pressure sensor is normal or out of order, and when the pressure is normal, controls the operation of the pump with the pressure signal. The pressure signal and the ON/OFF signal are compared with each other, and when these signals do not correspond, the pressure switch is determined to be out of order, and when the pressure sensor is out of order, the pump operation is controlled with the ON/OFF signal.

Abstract: The steering of a motor vehicle is assisted by a power steering means including a hydraulic distributor which is supplied with pressurized fluid by a pump from a reservoir. The vehicle also has a clutch having hydraulic servo assistance supplied by a servo unit. The distributor of the power steering system and the clutch servo unit are both supplied with hydraulic fluid from the same pump and reservoir, through a distribution unit which is so arranged that the power steering system has first call at all times on the available pressurized fluid. The distributor unit includes a flow distributing valve, fed from the pump and dividing the flow between a main circuit which leads to the steering distributor, and a secondary circuit which leads to the servo unit. A pressure regulating valve is connected to both the main circuit and the secondary circuit so as to regulate the pressure in each of these circuits according to the demand of the power steering system.

Abstract: A marine hydraulic system for operation of a power steering assembly includes a pressure accumulator to provide pressurized hydraulic fluid and valving that permits the transfer of hydraulic fluid within the cylinder to provide efficient use of hydraulic fluid.

Abstract: A continuously active pressure accumulator power transfer system for a vehicle or a like comprises an engine, a pump driven by the engine, a main pressure accumulator maintained at a substantially constant fluid pressure and fluid volume by the pump during operation, a fluid motor for propelling the vehicle which is supplied with driving fluid pressure from the pressure accumulator and auxiliary units for operating the vehicle. The auxiliary units are also operated by fluid pressure from the pressure accumulator. The fluid motor(s) and the auxiliary units are operated directly by fluid pressure from the accumulator without any direct connection with the engine.

Abstract: A pressurized fluid reservoir having a variable working volume includes a cylinder body having a fixed storage volume and a first inlet and exhaust structure for allowing a compressible fluid to enter and leave the cylinder. A second inlet and exhaust structure is also provided for allowing a substantially incompressible fluid to enter and leave the cylinder. A first charge mechanism pumps the compressible fluid into the cylinder. A second charge mechanism pumps the substantially incompressible fluid into the cylinder to reduce the cylinder fixed storage volume to a desired working volume into which the compressible fluid can be pumped by the first charge mechanism.

Abstract: A hydraulic pump composed of a pump and an accumulator combined therewith has an outer shell divided into an accumulator cylinder of metal and a tank of resin. The accumulator cylinder and said tank have thicker side portions, respectively, which define therein an outlet oil passage and an inlet oil passage, respectively.

Abstract: In a brake system (10) having a fluid pressure servomotor (12) with a housing having an operational chamber (30) connected to an intake manifold (102) of a vehicle and a control chamber (32) connected to an accumulator (50). A wall (28) which separates the operational chamber (30) from the control chamber (32) carries a valve (38) connected to receive an input from an operator by way of pedal (20). In the rest position, the valve (38) allows the vacuum created at the intake manifold (102) to evacuate air from the operational chamber (30) and control chamber (32). When an operator desires to effect a brake application, an input force applied to the valve (38) by way of pedal (20) allows air from the accumulator (50) to be communicated to the control chamber (32) and create a pressure differential across the wall (28).

Abstract: A marine hydraulic system for operation of a power steering assembly includes a pressure accumulator to provide pressurized hydraulic fluid and valving that permits the transfer of hydraulic fluid within the cylinder to provide efficient use of hyraulic fluid.

Abstract: A hydrostatic power transfer system for transferring power from a rotating power input shaft to a rotating output shaft comprises a fluid pump driven by the power input shaft. A pump outlet supplies pressurized fluid to a pressure accumulator disposed downstream of the pump. The accumulator has an outlet for discharging fluid under pressure from the accumulator to at least one fluid motor. The accumulator includes two chambers and a pressure transmissive member separating the two chambers. The pressurized fluid from the pump is supplied to and discharged from one of the two chambers and the other chamber includes a spring cushion such as a pressurized gas acting against the pressure transmissive member for insulating the system against vibration transmission through the accumulator.

Abstract: The accumulator comprises a vessel which is in communication with a hydraulic circuit and which contains a liquid occupying a portion of the space inside the vessel. The level of the liquid contained in the vessel is regulated by controlling the volume of gas overlying the liquid. The regulation apparatus essentially comprise a calibrated injector device for injecting gas under pressure into a first cavity, and a mechanically controlled gas bleeder device in a second cavity separated from the first cavity by a partition having at least one calibrated orifice situtated in a zone which is safe from being submerged in the liquid, and an opening situated in the liquid level control zone and extending on either side of the level of the interface between the liquid and the gas.

Abstract: An apparatus for suppressing vibratory or quaky movements in travel of mobile type cranes, which facilitates the operation of re-starting the vehicle after temporarily stopping the engine, for example, at a gas station for fuel replenishment as well as operations for switching the mode of operation between vehicle travel and working modes. The apparatus includes for this purpose a memory means for storing at least information as to the mode of operation under engine working conditions before an engine cut-off, and a controller adapted to reproduce automatically the mode of operation before the engine cut-off, by setting a mode selector means in a reproducing position upon re-starting the engine based on the information stored in the memory means.

Abstract: A wave power generating system for generating electricity using natural wave power, includes wave energy converters for converting wave energy into air pressure, a constant air pressure tank for storing the air pressure from the wave energy converters to equalize the fluctuation of the air pressure, an air turbine stationarily driven by the equalized air pressure, and an electric generator for generating stable electricity using the rotating power of the air turbine. The wave energy converters are settled to the bottom of the sea and are sufficiently tall to function as wave dissipation facilities. The air pressure in the constant air pressure tank is automatically controlled toward a target value by a controller and the target value is calculated by the controller in accordance with measured values of wave amplitude and period and the current air pressure of the constant air pressure tank.

Abstract: A hydraulic control system for, e.g., electrically driven vehicles, comprising a hydraulic, double-acting steering piston-cylinder device which co-acts with a control unit which is actuable by means of a steering member, and which is connected to a hydraulic pump, driven by an electric motor, and to a tank, and which includes a control signal outlet through which a control signal is delivered for maintaining and interrupting the supply of steering hydraulic fluid to the steering-piston cylinder device.

Abstract: A controller for a three wheel turbocharger receives input parameters from throttle or fuel rack position, manifold absolute pressure and accumulator pressure. The operating parameters are used by the controller to control the amount of hydraulic fluid applied to the third turbine wheel of the turbocharger through various operational modes including pump bypass, power transfer, lugging or override, and accumulator charging modes. The controller is designed so that a simple moveable shuttle within a cylindrical housing provides various valve functions interconnecting the various components.

Abstract: A variable displacement, hydraulic pump/motor has its rotatable cylinder block concentrically affixed to a drive shaft segment of a self-propelled vehicle, the pump/motor has selected pump and motor modes. An hydraulic accumulator is charged and discharged from the pump/motor when it is in its pump and motor modes, respectively. A fluid reservoir supplies and receives low pressure fluid when the accumulator is being charged and discharged, respectively. Preferably the reservoir is a combination of an aft chamber of the accumulator, a low pressure chamber defined by the pump/motor cylinder block and its housing, and a low pressure fluid path between the two. The pump/motor is unloaded when the vehicle is being operated in reverse or when neither the brake nor accelerator is being actuated. The pump/motor is in the pump mode whenever the vehicle is moving forward and the brakes are applied, and it is the motor mode whenever the vehicle is in forward gear and the accelerator is actuated.

Abstract: A high-pressure source of hydraulic fluid and a sump are connected to a cyclically operating user of hydraulic fluid having a hydraulic accumulator by a high-pressure feed line having one end connected to the source and an opposite end connected to the accumulator and user. A pressure-limiting valve has an input side connected to the high-pressure line between the ends thereof and an opposite output side connected to the sump. This valve opens only when pressure in the line exceeds a preset maximum to allow flow between its sides. A detector is connected to the output side of the valve for measuring the peak pressure thereof over several operating cycles of the user and a controller is connected to the detector for operating when the peak pressure detected over several operating cycles exceeds a predetermined threshold.