Abstract: An electrohydraulic system for control of a variable output pump includes a microprocessor-based controller receiving inputs from condition sensors coupled to the pump and command inputs from a remote master controller. The controller supplies outputs to an electrohydraulic valve for metering hydraulic fluid to a pump control port and thereby controlling pump operation in any one of a number of preselected and prestored pump control modes. A hydromechanical valve is connected in parallel with the electrohydraulic valve for controlling pump operation in the event of electrical malfunction or failure. Circuitry connected between the pump condition sensors and the control computer prevents aliasing errors due to mismatch between the computer sampling frequency and pump speed.

Abstract: A piston for a gas-operated linear actuator wherein a double-acting piston moves axially within a cylinder in response to gas pressure applied intermittently to chambers on either side of the piston. The piston has reservoirs in the form of holes in each of its faces and a pair of spaced-apart circumferential grooves, one communicating with the holes in one piston face and the other with the holes in the other piston face, the two sets of grooves and holes being kept out of communcation with one another. Gas under pressure introduced into one chamber forces the piston to move toward the opposite chamber, and a portion of the gas passes into the holes and out through the adjacent groove, providing a stream of gas between piston and cylinder walls, producing a gas-bearing effect.

Abstract: The invention relates to a safety arrangement for a controlled drive which is connected to a conduit with impressed pressure. When the safety arrangement responds the machine is separated via shutoff valves from the inlet and outlet and a via a switchover valve the pivot angle of the machine is set to the maximum value so that the largest possible braking torque can be automatically set.

Abstract: The feedback chamber of the pilot pressure valve is supplied with its discharge after it has been filtered whereby the pressure which is supplied to the feedback chamber is subject to the flow restricting effect of the strainer and increases the valve output to compensate for the flow restrictive nature of the strainer.

Abstract: The proportioning valve assembly (40, 140) may be screwed into a complementary-shaped opening in a master cylinder (10). The valve assembly (40, 140) includes a differential area piston (50, 150) biased by a spring (70, 170) toward the outlet (21, 121) which communicates with the rear brakes. The master cylinder (10) includes a pair of passageways (16, 18) which communicate primary fluid pressure and secondary fluid pressure directly to the differential area piston (50, 150) of the proportioning valve assembly (40, 140) to displace the piston (50, 150) to a balanced position. If there is a failure of pressure in the primary brake circuit, the proportioning valve assembly (40, 140) actuates the differential area piston (50, 150) to permit fluid flow to bypass the piston (50, 150) and be communicated directly to the rear brakes of the vehicle.

Abstract: In a damping flywheel which is associated with a fluid coupling device, the casing of the fluid coupling device is mounted in series with the damping flywheel, preferably through a resilient elment which forms part of an arrangement which allows variation to take place in the clamping torque exerted by friction means which form part of a torque limiter.

Abstract: A member oscillates on a face and another member pivots on a bed of the first member. Passages are provided through the members to lead a lubrication fluid under pressure into a fluid pocket between the mentioned face and one of the members. The fluid pressure in the pocket carries a major portion of the load of one of the members on the face. The oscillation of the members has one stroke under higher load and one under less load. The pivotal movement of the other member controls the flow of fluid through the passages to provide high pressure in the fluid pocket at the stroke under higher load and lower pressure in the pocket at the stroke under less load. The arrangement is especially suitable to be provided on pistons and piston shoes of radial piston machines. But it can also serve to carry load on other members of machines or vehicles, wherein at least two movements are taking place and a source of supply of fluid under pressure is available.

Abstract: A master cylinder assembly especially adapted for mounting in the passenger compartment of a motor vehicle in association with the clutch pedal assembly of the motor vehicle. The unit is permanently sealed and is non-serviceable so that no fluid leakage occurs in the passenger compartment as a result of attempts to service the unit. The master cylinder assembly includes a cylinder having an open rearward end and a closed forward end, an external mounting flange intermediate the ends, and an elongated reservoir mounted in piggyback fashion on the cylinder between the mounting flange and the forward end of the cylinder with the rear end of the reservoir pivotally secured to the mounting flange and with a discharge fitting on the forward end of the reservoir moving into telescopic sealing relation with a reservoir fitting on the forward end of the cylinder in response to pivotal movement of the rear end of the cylinder about the pivot axis defined between the rear end of the reservoir and the mounting flange.

Abstract: A hydraulic booster in which the booster piston return spring is formed as a tubular conduit to conduct hydraulic supply pressure to a closed center valve. Upon actuation, the valve opens to permit supply pressure to flow into the power chamber and by valving action controls the exhaust of pressure from the power chamber so as to establish the desired actuating pressure therein. The tubular conduit forming the power piston return spring and transporting the supply pressure to the closed center valve permits a shorter overall axial length of the hydraulic booster by accommodating the movement of the supply pressure chamber at the closed center valve. It also permits less charged supply pressure leakage by accommodating a better pressure seal arrangement.

Abstract: For the production and exact control and regulation of very high pressures, in particular for actuating a press, two pressure intensifiers are provided which each have a differential piston. The second pressure intensifier is connected via a shutoff valve to the first pressure intensifier and to the load or consumer. Both pressure intensifiers have a small volume compared with the volume required by the consumer. By activating the second pressure intensifier fluid can be exchanged between the consumer and the first pressure intensifier to replenish the first pressure intensifer in a pressure buildup phase and to empty the first pressure intensifier in a pressure relief phase.

Abstract: A wobble piston apparatus incorporates a cup-type seal seated on a land formed about the head of the piston, and secured by an annular ring. The head of the piston and the ring have chamfered edges which facilitate an engagement of the ring with the piston head, on assembly, and the chamfered edge of the ring further cooperates with the piston to define a void which accommodates therein an extruded expansion of an innermost, peripheral edge of the seal.

Abstract: A method and apparatus for reducing the intensity of the sound that accompanies a rapid decompression in a pressurized hydraulic system such as that of an injection molding machine. The apparatus includes a reduced area valve that interconnects the high pressure system with a low pressure system, with the valve connected with a tubular muffler so that high pressure fluid is initially released through the valve and into the muffler. The muffler includes a plurality of spaced apertures that face a rigid structural surface so that the high pressure fluid passing through the muffler issues from the several apertures and impinges on the rigid structure to dissipate the pressure shock accompanying decompression, and thereby modulate the intensity of the sound of decompression.

Abstract: An improved fluid transformer which is capable of controlling the position of the operating pistons within the apparatus so that pressure equilibrium is maintained and the movements of the pistons are limited to predetermined locations within the cylinders. The transformer is capable of operating in a contaminated environment by purging unwanted fluid contamination from the internal workings of the transformer. Dynamic piston and cylinder seals are positioned such that destructive pressure forces are counteracted by opposite frictional forces during operation, thereby allowing the seals to remain effective at high pressures for long periods of time.

Abstract: A servo system includes a tubular drive shaft journalled in a housing. A screw is engaged threadably with a nut which is fixed in the drive shaft. A driven body is secured to an end of the screw so that the screw can effect a rectilinear movement with the driven body but cannot rotate. A motor can rotate the drive shaft in an infinite angle through a gearing so that the drive shaft can move in a first direction continuously. Then, an end of a fork is rotated by an abuttment element which is sleeved on the drive shaft. At this time, the other end of the fork activates a hydromechanical servo, and hence a hydraulic driving unit, to move the drive body in a second direction which is equal and a opposite the first direction. After which, the drive shaft is moved back to the original position by the driven body. The driven body is therefore moved a predetermined distance.

Abstract: An electrically driven master cylinder assembly and various vehicle control systems utilizing the master cylinder assembly. Several forms of master cylinder assemblies are disclosed. In the preferred form, the assembly includes an electric DC motor directly coupled to a master cylinder unit with the central axis of the motor coaxial with the central axis of the bore of the master cylinder, a ball nut is positioned within the housing of the electric motor for rotation with the armature of the motor, and a ball screw is positioned on the axis of the motor and is driven linearly in response to rotation of the armature.

Abstract: A master cylinder includes a valve that is slidably mounted in a movable piston means for limited axial movement therein between a closed position wherein the valve is sealingly engaged with the piston and an open position wherein a gap is maintained between the valve and the piston. The valve includes a passage for providing fluid communication between the supply chamber and the pressure chamber when the valve is in the open position. An orifice in the piston limits the flow of fluid from the pressure chamber to the supply chamber at least during the limited movement of the valve from the open position to closed position. An overflow arrangement on the piston is responsive to movement of the piston against the bias of a biasing device for establishing fluid communication between the passage and the supply chamber only when the valve is in the closed position.

Abstract: Uniquely contoured interior surfaces have been found to stabilize the flow patterns through centrifugal pumps of the volute type, especially pumps having wide impellers and wide volutes for pumping slurries. The contoured interior surfaces may be provided in the pump casing, but are preferably defined by a volute liner. The interior surfaces comprise a volute region and a discharge nozzle region which both are at least in part contoured interior surfaces and which cooperate to provide a flowingly contoured interior surface of changing axial cross-section.

Abstract: An oil pump of an automatic transmission, which comprises a casing having an oil pump gear chamber formed therein, the casing having first and second bores exposed to the oil pump gear chamber, the first and second bores being coaxially spaced from each other with an interposal of the oil pump gear chamber therebetween; gears operatively disposed in the oil pump gear chamber of the casing; a first splined portion formed on a leading end portion of a stator shaft of a torque converter; and a second splined portion formed on an inner surface of the second bore, wherein the stator shaft is thrusted through the first and second bores in this order into a fixed position wherein the first and second splined portions are operatively engaged.

Abstract: A brake failure warning system for a dual hydraulic master cylinder for use with a motor vehicle. The warning system employs a pair of Hall Effect magnetic sensors which are positioned on the exterior of a plastic cylinder in association with the two pistons mounted within the bore of the cylinder. The pistons have ferrous frustoconical portions which coact with the respective sensors to generate position signals that vary as the pistons move in the bore past the respective sensors. The two position signals are fed to a logic board which compares the signals and generates an error or warning signal in the event that the difference between the two signals exceeds a predetermined amount indicative of failure of one of the two braking systems of the vehicle.

Abstract: Flow amplified control systems are useful in pilot operated steering systems. The load responsive flow amplified control system includes a directional control valve movable to an operating position to direct fluid from the operating fluid circuit through a variable orifice to a steering motor and to direct control fluid from a control fluid circuit through another variable orifice to be combined with the fluid going to the steering motor. The operating fluid circuit and the control fluid circuit are provided with fluid from a common variable displacement pump. The directional control valve is moved to an operating position by the control fluid acting thereon and is pressure compensated insofar as the flow of control fluid passing through the another variable orifice such that a substantially constant predetermined pressure differential exists across the another variable orifice.