Abstract: A power steering system has a pump, a steering gear and pressure and return passages. The pump does not include a cover member which conventionally provides space for the storage of excess fluid. The return passage has an expansible chamber included therein which accommodates the fluid volume change within the system resulting from fluid temperature changes thus permitting hermetic sealing of the system. An aspirator can also be included within the expansible chamber to improve the inlet pressure condition at the pump.

Abstract: Disclosed are methods and apparatus for controlling the flow of hydraulic fluid to and from a work cylinder. The disclosed system includes a reversible variable displacement pump interconnected between a work cylinder and a selector valve which may connect the pump with any of a plurality of fluid reservoirs. The fluid reservoirs contain hydraulic fluid at variable pressures so that the pressure at the work cylinder may be raised to pressures well above the pressure differential capacity of the pump at maximum flow rate by selectively increasing the pressure on the reservoir side of the pump. The system includes means for controlling the pressure at each port of the pump so that the pressue on the output port is always greater than the pressure on the input port regardless of the direction of flow through the pump and regardless of pressures at other points in the system.

Abstract: The adaptation of a compressed-fluid (such as compressed-air) powered turbine in conjunction with the use of a flywheel as a hybrid propulsion system for nonstationary applications, such as vehicle drive, is shown and its practicality demonstrated. This propulsion system requires a nonpolluting fluid, such as air, and a source of mechanical or electrical energy to compress said fluid and energize said flywheel, both of which act as energy storage media. An expander/compressor unit, such as a turbine, is used for converting the stored energy of said compressed-fluid into shaft power by expanding said fluid, and recovering the braking energy during vehicle deceleration by compressing and storing the atmospheric air (if air is used). Said flywheel is used not only for providing peak powers necessary for vehicle acceleration but also for recovering the braking energy during vehicle deceleration and refilling said compressed-fluid in an emergency.

Abstract: A gas-oil drive for forward and reverse mechanical adjusting movements. Gas, which is available for every direction of movement of an adjusting drive at a pressure greater than atmospheric pressure, conveys its pressure in a pressure tank to control oil which flows to an adjusting device for carrying out a control operation. For both oppositely directed adjusting movements of the gas-oil drive, a single pressure tank for delivering control oil under pressure to the respective corresponding position of the adjusting device, and a single unpressurized container for receiving expelled, unpressurized control oil are provided. The unpressurized container is located above the level of the pressure tank, and a bore on the unpressurized container is connected with a bore on the pressure tank by means of a control oil line in which is located a check valve which closes in a direction of flow toward the unpressurized container.

Abstract: A hydraulic system for supplying hydraulic fluid to a hydraulically operated device alternately at pressures of different values, said system comprising a first hydraulic circuit arranged to be supplied with hydraulic fluid at a low pressure by a pump and for supplying the hydraulic device with fluid at said low pressure through a pilot operated valve, a second hydraulic circuit provided with a pressure multiplier piston device which produces hydraulic fluid at a pressure greater than that of the low pressure fluid and having a first chamber connected to the first hydraulic circuit and a second chamber of smaller area than the first chamber connected to the second hydraulic circuit, the second hydraulic circuit being provided with a pressure accumulator for maintaining high pressure in the second hydraulic circuit and said second hydraulic circuit being provided with a second pilot operated valve for supplying the hydraulic device with fluid at said high pressure.

Abstract: A system for converting wave energy from the sea into electrical energy, comprises a floatable assembly which, in use, is moored at sea and which is capable of internal movement in response to the action of waves. The assembly includes a hollow body mounted on a shaft and reciprocable angularly about the axis of the shaft in response to said internal movement. The body and the shaft define respective parts of a pump which also comprises a pair of spaced, opposed annular cam tracks extending around the axis of the shaft and rigidly connected to one of the pump parts defined by the body and the shaft, and at least one piston and cylinder arrangement disposed between the cam tracks and rigidly secured to the other of the pump parts so as to extend substantially parallel with the shaft axis.

Abstract: The piston of a pile driving hammer is raised by hydraulic (water) pressure. As the hammer is permitted to fall, the water pressure is diverted from the cylinder, until the cycle begins again. Pressure surges, upon switching to and from pressure diversion, are turned to advantage by providing large pressure vessels with bag accumulators upstream and downstream of the hydraulic pressure supply pump. The water pressure is selectively throttled to control the frequency and amplitude of the stroke. The pressure vessel may be a pressure tank containing an air cushion. In this way, much of the pressure accumulated or reduced while the pump is working against an isolated pressure vessel acts in concert with the pump to advance the water when the respective pressure vessel is reconnected.

Abstract: A hydraulic actuator for a gate or like valve such as the main steam isolation valve in an electric power plant characterized in that the actuator is a compact self-contained unit secured to the valve housing and comprises a hydraulic cylinder having its piston rod connected to the movable valve member to open or close the valve, an air-driven hydraulic pump for pressurizing dual hydraulic circuits (active and standby) each of which includes an accumulator, an air-piloted accumulator control valve, an air-piloted directional control valve for the hydraulic cylinder, and solenoid-operated pilot valves for said control valves in a pneumatic circuit including an air pressure reservoir. The hydraulic actuator is further characterized in that fast closing or opening of the valve is achieved by combined accumulator and pump discharge through the directional control valve and slow opening of the valve is achieved by pump discharge alone.

Abstract: A hydraulic brake booster provides two independent accumulators for assisting a brake application when insufficient pressure is communicated to the hydraulic brake booster for braking. The first accumulator is connected to the hydraulic brake booster housing, and the second accumulator is remotely disposed to the housing with a conduit forming a connection therebetween. A spool valve, slidably mounted in the housing, is engageable with a pair of check valves to communicate the first and second accumulators with a pressure chamber within the housing. A pair of bores within the housing receive the check valves and a unitary relief and charging valve is slidably carried in each bore for communicating an inlet port with each accumulator.

Abstract: A hybrid hydraulic-pneumatic thrust generator wherein pneumatic action is used for cocking and for cushioning while hydraulic action is used for providing the driving force. The output can be increased by reducing the cocking or cushion gas pressure required to dislodge the poppet valve from its seated position in the driving port by introducing pressurized oil into the driving port between the poppet valve and poppet actuator. The thrust generator of this invention has a relatively flat thrust pattern making it especially suitable as a driving mechanism for high velocity water jets for fracturing concrete and the like.

Abstract: An emergency hydraulic ram valve actuator having redundant power sources and controls. At least two pressure fluid sources, such as hydraulic accumulators, are connected through separate controls to the cylinder head. Check valves in the cylinder head and base prevent outward flow to insure containment of the fluid even when dismantled for service. Both sets of controls are contained in manifolds connected between the pressure sources and pressure and exhaust lines to and from the cylinder. Flow from each accumulator is normally prevented by a pilot check valve, but selectively operated valves initiate flow which, in turn, biases the pilot check valves to full flow. As full flow commences a portion thereof is diverted to open the exhaust pilot check valves which allow cylinder evacuation. In the event one power and/or control system is disabled, the other will function independently. The pressure and exhaust lines are contained within protective shields throughout their lengths.

Abstract: A valve for use in applying brake releasing pressure to brake chambers in a vehicle air brake system having reservoirs each containing air for either service or emergency use and having air pressure supply lines. The valve includes a housing. A chamber is formed in the housing. A port permits air communication between the valve and a supply line. A passage interconnects the port and the chamber. Reservoir ports interconnect through the passage. A first plurality of one-way check valves in the passage permit air to pass therethrough from the port to the reservoir ports. A second plurality of one-way check valves in the passage permit air to pass therethrough from the reservoir ports to the chamber.

Abstract: Dual system hydraulic braking apparatus for a vehicle comprising a piston slidable in a cylinder, the opposite ends of the piston being adapted to engage with either of two valve seats disposed on the opposite ends of the cylinder to stop fluid flow therethrough when the piston moves, the valve seats being connected respectively to two separate braking circuits, each chamber defined between each end of the cylinder and the adjacent end of the piston being connected to a hydraulic pump through respective check valve, the piston being biased to the central position by springs disposed in the chambers.

Abstract: In a die cast machine of the type wherein the piston of an injection cylinder is advanced by pressure gas admitted into the rear chamber of the cylinder while discharging pressurized liquid in the fore chamber, and the piston is retracted by pressurized liquid admitted into the fore chamber while forcing the gas in the rear chamber back into a gas accumulator, a control valve device is provided in the path of the pressurized liquid discharged from the fore chamber, and the control valve device is controlled so as to vary the flow quantity of the discharged pressurized liquid in accordance with the position of the piston during its forward movement. There are also provided two gas accumulators which are connected to the rear chamber of the cylinder through a valve device which is controlled so as to adjust the rate of increase of the pressure applied to the molten metal at the final stage of the injection casting operation.

Abstract: An hydraulic power transmission circuit comprises a high-pressure section and a low-pressure section, which together include (a) an internal or external combustion free-piston engine to each of whose pistons is attached one piston pump, the pump piston and the engine piston being rigidly connected for the purpose of joint axial motion; (b) at least one rotary motor or linear actuator adapted to be driven by the hydraulic fluid pressurized by the said piston pumps; (c) valve means for directing the hydraulic fluid to and from the motors or actuators; (d) a charge pump; (e) accumulator means for balancing the fluctuations of pressure and quantity of the hydraulic fluid; and (f) means for controlling the operation of the free-piston engine, said means comprising a rotary auxiliary hydraulic motor of the positive displacement type in the low-pressure section of the circuit, which motor is provided with transmission means for driving a rotary distributor at a number of revolutions governed by the frequency of the

Abstract: A hybrid hydraulic-pneumatic thrust generator wherein pneumatic action is used for cocking and for cushioning while hydraulic action is used for providing the driving force. The thrust generator of this invention has a relatively flat thrust pattern making is especially suitable as a driving mechanism for high velocity water jets for fracturing concrete and the like.

Abstract: A double-acting rotary hydraulic jack having two jack compartments, comprising a rotary hydraulic joint for the supply of hydraulic liquid to and the evacuation of hydraulic liquid from the compartments. The two compartments of the jack each communicate with at least one axial boring in a rotary part of the jack which is not axially movable. In this boring a movable piston bears against the head of a guide rod for a spring which itself bears against the rotary part of the jack. The ends of the rods, externally of the borings, are secured to a member coaxial with the jack, for example a sleeve, whose axial position is monitored by a displacement detector, so as to give an indication of the working pressure in the active jack compartment.

Abstract: A power shovel comprising a body; a front end assembly mounted on the body including a dipper; means for crowding the dipper; means for hoisting the dipper; and an energy regeneration system including an energy storing means and means actuated by a predetermined movement of at least one component of the front end assembly for charging the energy storing means, the energy storing means providing in the loaded condition a force applicable to a component of the front end assembly for at least biasing such component toward a predetermined movement.

Abstract: A control system for hydraulic presses comprising a plurality of press rams, an intensifier having a primary chamber which is connected by a supply conduit to a pump, and a valve which is associated with the primary chamber and when open permits the liquid under pressure to return through a return conduit into a reservoir, the primary chamber being constantly supplied by the pump with high-pressure liquid at a constant rate, and the valve associated with the primary chamber being controlled to move in synchronism with the reciprocating motion of the press rams so that it is closed during the forward stroke and open during the return stroke of the press rams.

Abstract: A hydraulic system for use in the propulsion of motor vehicles includes at least two volume multipliers each having a high pressure port, a low pressure port, and a piston in a chamber separating the high and low pressure ports. A prime mover and associated main hydraulic pump is arranged to alternately supply high pressure fluid to the high pressure ports of the multipliers, so as to produce a reciprocating motion in the pistons and create a continuous flow of high pressure fluid from a reservoir through the pump, into the high pressure port of one volume multiplier, out of the high pressure port of the other multiplier, and back to the reservoir. The reciprocating pistons are used to create a second, separate continuous flow of low pressure hydraulic fluid which circulates from the low pressure port of one volume multiplier through one or more hydraulic driving motors adapted to propel the vehicle, and back to the low pressure port of the remaining multiplier.