Abstract: An hydraulic power system comprising a dual acting work piston adapted to be operatively connected to an external mass to be moved, the piston being instantly directionally responsive to a pair of control valves adapted to be sequentially opened and closed to actuate the work piston for movement in opposite directions, the control valves each having a series of sequentially acting valve elements which control fluid flow to and from the work piston, the system forming an hydraulic closed loop which is completely filled with fluid during both charging and discharging, the work piston and control valves working at all times against solid columns of fluid under controlled positive pressures, the system being capable of developing accelerating forces having a magnitude up to 500 G's and of being operated both directly or remotely utilizing electronic, mechanical or hydraulic actuating means with no appreciable phase lag between initial actuation and the completion of the work stroke.

Abstract: Generally described is a hydraulically-actuatable elevator system wherein the vertically reciprocatable cargo-carrying carrier member is suspended from a lofty superstructure by at least one hydraulically-actuatable elongate piston of the casing/plunger type. An electrically powered pump means, having a fluids reservoir co-movably mounted with the carrier, forceably introduces hydraulic fluid along a primary-line into the piston casing thereby decreasing the piston overall length causing the carrier to ascend, and controlled withdrawal of hydraulic fluid from the piston to the reservoir through a secondary-line (provided with an electrically governable checkvalve) allowing the weighty carrier member to descend.

Abstract: An injection molding machine wherein the ram in the injection cylinder can be moved at several speeds and can be subjected to different fluid pressures by an apparatus having a two-way valve whose inlet is connectable to one or more pumps by way of discrete check valves and whose outlet is connected with a chamber of the injection cylinder by a conduit containing an electrically adjustable pressure relief valve. The valve member of the two-way valve is movable between a first position in which it completely seals the inlet from the outlet and several second positions in which it acts as a flow regulating means to permit the fluid to flow from the inlet to the outlet at a selected rate. The valve member is movable by a solenoid-operated pilot valve which cooperates with a stop extending into the path of movement of the valve member and being movable axially by a reversible motor which is controlled by the programming system of the injection molding machine.

Abstract: A valve piston in an automotive power-steering system has a pair of inner peripheral grooves, defined by confronting lands of adjoining piston heads, normally communicating with the high-pressure side of an oil pump via symmetrical branch channels and with the low-pressure side of that pump via a common return channel. The piston also has a pair of outer peripheral grooves, normally cut off from the adjoining inner grooves, connected to opposite cylinder chambers of a hydraulic servomotor. The inner grooves communicate with a pair of axial piston bores receiving fixed or spring-loaded plungers for exerting a counteracting hydraulic pressure upon the piston upon a displacement thereof from its centered position, such displacement also opening the path from one branch channel via the corresponding inner groove and the adjoining outer groove to a corresponding servomotor chamber.

Abstract: An injection-molding machine has a drive ram with a pressurizable chamber that can be connected either to the high-pressure side or the low-pressure side of a source of fluid under pressure. A control system operating this machine has a pressure-reducing valve with an inlet port connected to the high-pressure side of the source, an outlet port connected through a cut-off valve and a throttle to the chamber of the ram, and a pilot port pressurizable to control the pressure at this outlet port. A pressure-relief valve has an inlet port connected to the pressurizable ram chamber, an outlet port connected to the low-pressure side of the pressure source, and a pilot port pressurizable to control the pressure differential across this pressure-relief valve.

Abstract: Disclosed herein is an apparatus including a member mounted on a frame and biased for movement in one direction, a hydraulic cylinder-piston assembly connected between the frame and the member and including a piston and a cylinder which houses the piston and includes opposed ends, together with a first fluid line extending from the one of the cylinder ends toward which the piston moves incident to movement of the member in the one direction, a second fluid line extending from the other of the cylinder ends, a control valve operatively connected to a source of pressure fluid and to the first and second fluid lines and including selectively operable means for supplying and draining fluid from the cylinder, a first safety valve in the first fluid line and first hydraulic means operatively connected to the first valve member for displacing the first valve member from a flow permitting position and second hydraulic means operatively connected to the second valve member for displacing the second valve member from a

Abstract: A hydraulic booster has its piston located in a normal passive position so that hydraulic fluid supplied to the cylinder through an inlet port enters the cylinder on both sides of the piston. Normally open valve means establishes communication through the piston from one side thereof to the other, and operating means is provided for closing the valve means and moving the piston past the inlet port to a position wherein hydraulic fluid flows through the inlet port into the cylinder on only one side of the piston. The normally open valve means includes an elongated valve sleeve slidably mounted in a piston bore having an enlarged intermediate portion defining a cavity surrounding the sleeve member. The sleeve member has a large external area within the cavity facing in one direction than in the other direction, and a leakage path is provided for communication of the cavity with the cylinder on one side of the piston.

Abstract: A circuit breaker actuating device comprising valve means interposed between a high pressure section of an operation fluid and a low pressure section thereof to preclude communication therebetween and adapted to cause a variation in pressure to occur either in a high pressure source or low pressure source when actuated to establish communication between the high pressure section and the low pressure section, so as to thereby actuate piston means and cause a circuit breaker to perform a current interrupting operation.

Abstract: A brake actuator for a vehicle having air brakes is disclosed in which air pressure is expelled through the actuator upon release of the brakes in order to purge the latter of contaminants. The actuator includes a housing in which a piston reciprocates. Fluid pressure is admitted to the chamber defined between one side of the piston and the corresponding end of the housing in order to urge the latter in a brake actuating direction. The piston includes a passage extending therethrough to connect the chambers defined between opposite sides of the piston and the corresponding ends of the housing, and a shuttle valve carried within the passage in order to close the passage upon brake application and open the passage to permit fluid communication between the chambers upon brake release. An articulated guide rod is pivotally mounted on the end wall of the housing and extends into the piston to guide the shuttle valve during operation of the actuator.

Abstract: A lock valve assembly is provided in a hydraulic control system for a double acting hydraulic jack which is adapted to permit the desired substantially unrestricted flow of inlet fluid selectively to either end of the jack under all operating conditions and is automatically self-conditioning to either restrict when necessary or not to restrict the flow of outlet fluid from either end of the jack as may be required.

Abstract: A hydraulic interlock arrangement for ensuring that an inlet valve is closed before a discharge valve is opened, and vice versa, each inlet or discharge valve having a hydraulic piston-cylinder unit for actuating the same, a hydraulic pilot valve for operating the piston-cylinder unit and a blocking member for preventing actuation of the pilot valve, the first blocking member being connected to the pressure chamber of the second piston-cylinder unit, and vice versa, so that when the pressure chamber in one piston-cylinder unit is under pressure, the pilot valve of the other piston-cylinder unit cannot be actuated.

Abstract: A fill and relief valve arrangement for the introduction of fluid into and the selective venting of fluid from a fluid chamber includes a body having a stepped open-ended bore extending therethrough and an annular shoulder formed at one end of the bore. A valve seat element is sealingly secured within the other end of the bore and has a passage formed therein communicating with a passageway which communicates the bore with the fluid chamber. A fill valve is adjustably positioned within the bore and has a first position in engagement with a valve seat element for isolating the fluid chamber from a vent port open to the atmosphere and a second position for establishing communication between the passageway and the vent port for venting the fluid chamber to the atmosphere. The fill valve is confined between the valve seat element and the annular shoulder.