Abstract: A solenoid-operated valve particularly for use in a speed-responsive power steering system on a motor vehicle comprises a valve housing having two ports opening into a bore in the housing, a spool axially slidable in the bore and slot defining a bypass passageway extending between the two ports and variable in cross section upon axial movement of the spool. The spool is spring-biased in a direction to close the bypass passageway, but attractable by an energized solenoid to open the bypass passageway when the solenoid is supplied with an electric current dependent on the speed of travel of the vehicle. The spool has therein a restrictor disposed in the bypass passageway adjacent to the slot to restrict the flow of a fluid through the bypass passageway into and out of the bore in the housing.

Abstract: A vacuum actuator, suitable for use in an automatic belt tensioning system, oscillates automatically when connected to a source of constant vacuum.

Abstract: A power plant having a fluid powered flywheel is disclosed. The flywheel comprises internal cylinder spaces which extend radially outwardly from a central region of the flywheel but which curve in a particular circumferential sense about the axis of the flywheel. Helical structures are disposed within the cylinder spaces to define respective helical flow paths through the cylinder spaces. Power fluid is delivered to a central region of the flywheel for entry into the cylinder spaces. Exhaust ports are provided to extend between the outer perimeter of the flywheel and the radially outer end of each cylinder space so that the exhausting fluid is jet discharged. Pressurized fluid is delivered from a reservoir containing a gas-over-liquid power source. An impeller driven by the flywheel collects the fluid discharged from the perimeter of the flywheel and returns it to the reservoir.

Abstract: Apparatus permitting the utilization of large volumes of water in the harnessing and extracting of a portion of the power generated by the rise and fall of ocean tides, ocean currents, or flowing rivers includes the provision of a dam, and a specialized single cavity chamber of limited size as compared wth the water head enclosed by the dam, and an extremely high volume gating system in which all or nearly all of the water between the high and low levels on either side of the dam is cyclically gated through the single chamber from one side of the dam to the other so as to alternately provide positive air pressure and a partial vacuum within the single chamber.

Abstract: A hydraulic valve system particularly adapted for controlling a hydraulically powered elevator. The system involves essentially a bypass valve which selectively bypasses hydraulic fluid from the pump directly back to the tank during the up mode operation, thereby controlling the up speed of the elevator; and a down valve which selectively controls the escape of fluid from the elevator jack back to the tank, thereby controlling the down speed of the elevator. The down valve also serves as a check valve for retaining fluid pressure in the jack. Both the bypass valve and the down/check valve are each controlled by closely integrated cylinder-and-piston arrangement, with pressure to the cylinder being controlled by a control valve structurally interlinked to the respective piston. The bypass valve also serves as a check valve between the jack and the tank during the down mode of operation. The cylinder-and-piston control for the bypass valve makes possible an initial limit opening of the bypass valve, i.e.

Abstract: A piston composed at least in part of fiber-reinforced synthetic resin material, is provided with a piston base or bottom, a piston shaft or shank, and eyes for engagement with a member to be driven by or for driving the piston. According to the method of this invention, the piston bottom and piston shaft are fabricated separately and are form-fittingly interconnected while the eyes are enclosed in a body which is fixed to the piston shaft and abuts at opposite end this shaft and the piston bottom. At least this body and the shaft are formed by a winding of fiber roving impregnated with hardenable synthetic.

Abstract: A lift truck hydraulic control system designed to conserve energy includes a pair of separately controlled pumps (21, 22). One pump (21) supplies pressure fluid to a valve (12) for a steering cylinder (11) by way of a high priority port (34) of a priority valve (32) with the low priority flow passing to parallel connected lift and tilt valves (19, 18) which control operation of the lift cylinder (15) and tilt cylinders (16, 17), respectively. The capacity of pump (21) is sufficient to provide proper, effective operation of the steering and tilt functions but is not adequate to provide hydraulic fluid flow for high speed expansion of the lift cylinder (15). The other pump (22) is operated to supply additional pressure fluid flow for high speed lift only when the lift valve (19) is shifted to a raise position. In one embodiment, a low speed lift is obtained by using the output of the pump (21) and a high speed lift is obtained by selectively adding the output of the second pump 22.

Abstract: One pair of actuating piston and cylinder assemblies are operatively connected to the polish or sucker rod of the pump and are extended or retracted by hydraulic fluid. A further pair of piston and cylinder assemblies are operatively connected to the polish rod and are operatively connected on the underside thereof to an accumulator that includes an inert gas over oil with the gas being supplied under adjustable control conditions from a cylinder or source of high pressure gas so that these further pair of piston and cylinder assemblies counteract the weight of the pump system. On the downstroke, pressure is supplied to the upper sides of all four piston and cylinder assemblies with the two further piston and cylinder assemblies supporting the weight via the accumulator.

Abstract: Internal combustion engine piston of the composite type, having a steel upper portion surmounting an aluminum lower portion in which the piston ring grooves are provided.The lower portion (2) comprises a concentric circular cavity (3), open at the top and recessed from the ring grooves (5), said cavity being covered by an annular groove (7) in the lower surface of the steel upper portion (1) to form a dead space.

Abstract: A hydraulic rotation control circuit for a rotational actuator such as a hydraulic motor for rotating a rotary frame of a hydraulic crane, the circuit employing a combination of a number of check and variable reducing valves in a manner which allows smooth and delicate control of the rotation of the actuator to provide an operation performance equivalent to that of mechanical drive, including coasting operation of the motor.

Abstract: A method for manufacturing a piston for internal combustion engines, compressors and the like, comprising a head portion articulately connected to a separate skirt portion, wherein the skirt portion comprises a steel tubular part obtained by cutting, bending and closing of a piece of steel strip, the outer surface of said tubular part being covered by a layer of antifriction material bonded to said outer surface prior to the cutting, bending and closing of the steel strip.

Abstract: A locking device is integrated in a coupling fixed on a ram cylinder for feeding the cylinder with a first fluid. The circulation of that fluid is controlled by a second fluid. The device has (1) a cylindrical member with a tightening head at a first end, a second threaded end to engage in the cylinder, and an intermediate portion between the two ends. The intermediate portion has an axial outlet passage to the cylinder, and a lateral opening terminating at the passage. The device has a coupling head with a through bore, and an internal passage for the first fluid. The bore is shaped to receive the intermediate portion and to couple the opening to the feed passage. The device has movable internal members to modify circulation of the first fluid by moving under the combined effects of a resilient element and the pressure of a second fluid applied to an external locking inlet.

Abstract: A hydraulic control system of a transport vehicle, wherein the flow of hydraulic fluid from the source of pressure is fed to the servomotor through a control hydraulic circuit which incorporates a fluid directional control device mechanically linked to a steering unit of a transport vehicle, a number of hydraulic lines and at least one throttle regulator, and through the actuating hydraulic circuit which incorporates a number of hydraulic lines, a throttle regulator and a discrete-type three-position fluid directional control device controlled by a pressure of the fluid flows admitted along the hydraulic lines communicated with the fluid directional control device of the control hydraulic circuit.

Abstract: Pump-motor hydraulic power system incorporation means to limit the power transmitted and the pressure in the transmission lines. High pressure line is connected to one end of a servo motor comprising a cylinder with a spring loaded piston therein. When the pump pressure increases above a certain amount it overcomes the spring and moves the piston and the piston rod to a blocking position, acting to limit movement of the three way control valve or to move the three way control valve back if it already exceeds the limit imposed by the power limiter's piston rod.

Abstract: In a steering control valve device of the kind utilizing a metering pump and a torsional stress means for returning the flow control valve sleeve to a neutral position, there is provided a coupling sleeve between the manually operable steering spindle and the valve sleeve. Such coupling sleeve is for the purpose of providing an intermediate actuating member between the steering spindle and the valve sleeve to overcome errors in alignment and other disadvantages which can occur in conventional constructions where the steering spindle directly actuates the valve sleeve wherein rotation of the steering spindle effects axial shift of the valve sleeve for flow control purposes. The invention is particularly advantageous where the means of translating rotary motion of the steering spindle to axial movement of the valve sleeve is effected by threaded coaction.

Abstract: A hydraulic control system with a pipeline antiburst safety device for a double acting drive cylinder, more particularly for adjusting and securing the position of a driven guide roller in the strand guide of a continuous casting plant which exerts an operationally conditioned reaction force, applied by the strand, on the piston of the drive cylinder.

Abstract: An electronic constant speed control for a hydrostatic transmission having a variable displacement hydraulic pump with a displacement controlling member movable to various positions at either side of a neutral position and having an input shaft connectable to a prime mover and a hydraulic motor having an output shaft, an electric controller for positioning siad displacement controlling member, a command potentiometer for establishing a set constant speed signal representing a desired constant speed between zero and maximum speed in either direction of rotation for said output shaft, a speed detecting device for establishing a pump input shaft speed signal, a circuit for generating a position control signal representing the required position of the displacement controlling member for the set speed which is responsive to the constant speed and pump input shaft speed signals, a speed detecting device for establishing an output shaft speed signal, a circuit for comparing the output shaft speed signal with said se

Abstract: A downhole oil well hydraulic pump has a reciprocating piston assembly with a piston ring mounted in a groove around the piston. This piston ring groove has a main portion which loosely mounts a piston ring and an auxiliary portion joining the main portion which accumulates well fluid to lubricate the piston ring during operation of the pump.

Abstract: In a crank press having a pedestal and a rotatable crank shaft journaled thereon and connected to a reciprocal top platen guidably mounted on the pedestal to form work pieces, the improvement which comprises a hydraulic motor mounted on the pedestal having a reversible drive shaft connected to the crank shaft, and a hydraulic transmission connected to the hydraulic motor. The transmission includes a pump assembly connected to a reservoir for delivering the pressure fluid selectively under the control of a servo directional valve in a closed hydraulic loop to the hydraulic motor for selective forward and reverse drive together with a safety control to automatically neutralize the pump assembly and control automatic braking of the hydraulic motor drive shaft.

Abstract: A steering system .Iadd.40 .Iaddend.for an articulated vehicle .Iadd.10 .Iaddend.having a pair of double acting steering cylinders .Iadd.24, 26 .Iaddend.and power steering means .Iadd.44 .Iaddend.consisting of a pump .Iadd.48 .Iaddend.and a hydrostatic steering unit .Iadd.50 .Iaddend.to which the steering wheel .Iadd.42 .Iaddend.of the vehicle is interconnected. Control means .Iadd.46 .Iaddend.are disposed between the power steering means .Iadd.44 .Iaddend.and the double acting cylinders .Iadd.24, 26 .Iaddend.for causing fluid to be directed from the power steering means .Iadd.44 .Iaddend.to both of the first and second cylinders .Iadd.24, 26 .Iaddend.during rotation of the steering wheel .Iadd.42 .Iaddend.at a first steering ratio when the pump .Iadd.48 .Iaddend.is in operation, and at a second higher steering ratio when the pump .Iadd.48 .Iaddend.is not in operation to permit manual steering of the vehicle .Iadd.10.