Abstract: A pressurized hydraulic fluid system includes a charge pump, a hydraulic motor drivingly coupled to the charge pump, and a main hydraulic unit adapted to function as a pump to drive the hydraulic motor. The charge pump is in fluid communication with the main hydraulic unit for maintaining a sufficient inlet pressure in the main hydraulic unit when it functions as the pump. The system further includes a hydraulic fluid reservoir in fluid communication with an inlet of the charge pump, a hydraulic accumulator in fluid communication with the main hydraulic unit, and a return flow passage fluidly connecting the main hydraulic unit with the hydraulic fluid reservoir for returning an excess flow of the hydraulic fluid generated by the charge pump to the hydraulic fluid reservoir.

Abstract: A rotary flow combiner allows flow from multiple pressure compensated hydraulic pumps; with or without load sensing to be combined into a single outlet. The flows are combined in such a way that each input to the rotary flow combiner has equal flow. The flow from each pump is optimized in such a way that the output from the rotary flow combiner can achieve the maximum range of flow and pressure and so that all the pumps in the multiple pump system are supplying fluid flow at all times. A check valve can allow the rotary flow combiner to pull hydraulic fluid direct from a reservoir in parallel to a lower flow pump such that the volume of flow from the lower pump combined with the fluid drawn directly from the reservoir will match the flow from the higher flow pump.

Abstract: A system for providing a hybrid vehicle with a practical source of auxiliary power. The system includes two electric motor/generators connected to each other in such a fashion so that when one electric motor/generator functions as a motor, the other becomes a generator with their roles being reversed depending on whether the system is in an auxiliary power mode or energy storage mode. Connected to one motor/generator is the vehicle drive train. Connected to the other motor/generator is a pressure energy storage system, which in the energy storage mode converts the force of rotation into pressurized gas for storage in an energy system and delivered in the form of electric current by the one motor/generator, and in the energy delivery mode converts the stored energy of the energy storage system into electric current for delivery to the one motor/generator which is part of the vehicle drive train to provide auxiliary power for practical hybrid vehicles.

Abstract: The invention relates to a free-piston unit for pumping fluid from a low pressure to a high pressure. The free piston is displaced by a hydraulic part under the influence of the fluid pressure on a plunger which is connected to a combustion piston. The force exerted on the plunger by the fluid pressure in a pressure chamber during the compression stroke can be set using conversion means by setting a third pressure for fluid which is to be displaced via a pressure chamber from the first fluid source to the second fluid source.

Abstract: Hydraulic systems are disclosed for operating a press comprising a press ram, a press cylinder including a primary side for activating the press ram and press ram return cylinders for returning the press ram, and at least one flow amplifier comprising a piston including a primary side and a secondary side, the primary side of the piston including a large piston area and a secondary side of the piston having a small piston area, the primary side of the piston being connected to the primary side of the press cylinder and the secondary side of the piston being connected to the press ram return cylinder, at least a portion of the hydraulic system comprising the connection between the primary side of the piston and the primary side of the press cylinder is pressurized.

Abstract: To generate a magnetic resonance angiograph, a patient is injected with a contrast-enhancing agent (210). An ellipsoidal central portion of k-space (300) and a first surrounding region (310) are continuously sampled (220). A portion of each central data set (300, 310) is reconstructed (230) into a low-resolution volume and maximum-intensity-projected (240) onto a line. The maximum intensity projection (240) is processed (250) in order to detect the arrival of the contrast enhancing bolus within a volume of interest. Upon detection of the arrival of the bolus, the acquisition of a high-resolution magnetic resonance angiograph is triggered (260) in which higher phase encode portions (310, 420) of k-space are sampled. The central data set (300) along with the higher phase encode views (310, 420) are reconstructed (290) into a high-resolution magnetic resonance angiogram.

Abstract: A method of controlling an hydraulic activation unit includes the steps of using a characteristic diagram of a first hydraulic transformer as an input variable in the control unit; using a characteristic diagram of a second hydraulic transformer as an input variable in the control unit; and activating the hydraulic actuator responsive to the input variables. The hydraulic activation unit includes the hydraulic power unit, such as a hydraulic actuator or a hydraulic motor, for producing a force. The first hydraulic transformer is operably connected to a first side of the actuator for supplying a pressure. The second hydraulic transformer is operably connected to a second side of the actuator for supplying a pressure. The control unit for assessing the first and second hydraulic transformer operably activates the hydraulic actuator.

Abstract: The present invention provides a unitary sliding-vane type compressor-expander comprising a housing with a compressor inlet and outlet, and an expander inlet and outlet. A single rotor is disposed therein defining in cooperation with the housing a compression chamber on one side and an expansion chamber on the opposite side. The rotor includes a plurality of regularly spaced vanes slidingly disposed in slots about the periphery of the rotor. The bottoms of the vane slots may be vented through a passage in the housing to the inlet air, or alternatively through a groove between the vane and vane slot to the compression or exhaust chambers. Permanent magnets are used in the vanes and housing to increase or decrease the contact force between the vane tip and housing. An integral condenser-humidifier is provided in the path of the expanded gas exhausting from the turbine outlet for condensing water out of the expanded gas and returning the condensed water to the compressor-expander.

Abstract: A hydraulic circuit for a mobile handling device includes a lifting cylinder suitable for handling a variable load and an accumulator for recovering or recycling lowering load energy. The hydraulic circuit also includes a variable hydraulic machine, driven by a drive unit, capable of developing full system pressure in two flow directions, to either of two ports. One of the two ports is connected to the accumulator, by a first connecting line, and the other is connected to the lifting cylinder, by a second connecting line. A second accumulator is connected to the first and second connecting lines by a check valve.

Abstract: A hydraulic system, particularly suitable for use in a work machine, is provided with a hydraulic pressure source. A hydraulic transformer has an inlet and an outlet, with the inlet being coupled with the pressure source. A bypass valve operatively couples at least one hydraulic motor selectively either with the pressure source or the hydraulic transformer outlet, depending upon an operating characteristic associated with at least one hydraulic motor. Each hydraulic motor is operated at a high efficiency by providing the inlet hydraulic fluid at an amplified or non-amplified state.

Abstract: A hydraulic installation comprising a hydraulic motor for linearly or rotatively moving against a load, a first connection with a source of pressurized hydraulic fluid of mainly constant high pressure, a second connection with a source of pressurized hydraulic fluid of mainly constant low pressure, a hydraulic transformer for transforming a flow of hydraulic fluid of a first pressure into a flow of hydraulic fluid of a second pressure and connected to the first connection and the second connection and at least one connecting line connecting the hydraulic motor and the hydraulic transformer, the hydraulic transformer comprising a housing, a rotor freely rotatable in the housing, chambers in the rotor with means for changing the volume of the chambers between a minimum and a maximum value during a full rotation of the rotor and means for alternately connecting each chamber with the first connection, the second connection and the connecting line, and wherein the hydraulic motor and the hydraulic transformer are

Abstract: A unit which converts wasted water into electric power, varied in size depending upon the amount of power required. A micro turbine (1) is driven by water under pressure by way of a reservoir tank (12) and pump (10) to turn the generators or alternators (2) which produce power to the Circular Battery Storage System (3). Once the water is used it is then returned (19) to the reservoir tank (12) to be used continuously as the process is repeated. The water may be salty, dirty or polluted. Where water is supplied by mains or rainwater tanks a ball type microturbine can be fitted to pipe stacks, waste pipes, down pipes or swimming pools. Wasted water from various natural sources can be minimized by the use of a barrel type microturbine.

Abstract: A hydraulic system, particularly suitable for use in a work machine, is provided with a hydraulic pressure source. A hydraulic transformer has an inlet and an outlet, with the inlet being coupled with the pressure source. At least one hydraulic motor has an inlet. The hydraulic transformer and each hydraulic motor are disposed within a housing. The housing defines at least one fluid conduit which fluidly interconnects at least one hydraulic motor inlet with the hydraulic transformer outlet and/or pressure source. Since the housing defines the fluid conduits interconnecting the various components therein, the hydraulic pressure may be increased over conventional operating pressures.

Abstract: A hydraulic pressure transformer has a port block which is attached to an end cap. The end cap includes a plurality of ports opening at an end face and at least one actuation port opening at or near a peripheral surface. A barrel which is rotatable about an axis includes a second end face and a plurality of cylinders having respective cylinder ports which open at the second end face. A port block disposed between the first end face and the second end face is rotatable about an axis and has a first face surface, a second face surface and a plurality of ports extending between the first face surface and the second face surface. The port block includes a radial periphery and at least one vane extending radially outward from the radial periphery to a position adjacent the peripheral surface of the opening.

Abstract: A hydraulic drive with regeneration circuit comprises a pump, a hydraulic actuator and a rotary flow divider which operates in conjunction with valve means to provide regeneration flow for the hydraulic drive.

Abstract: A hydraulic transformer for controlling hydraulic fluid pressure and flow to a hydraulic device includes first and second variable flow rate gear pumps supplied with high-pressure hydraulic fluid and low-pressure hydraulic fluid such that the delivery pressure and flow can be controlled, as needed. First gears of the first and second gear pumps are disposed on a common first shaft, and second gears of the first and second gear pumps are disposed on a common second shaft. Relative axial movement between the first and second shafts causes increased or decreased engagement length between the first and second gears of both the first gear pump and the second gear pump.

Abstract: A hydraulic pressure transformer for the conversion of an input hydraulic power to an output hydraulic power, and particularly suitable for use in a work machine having a hydraulic work unit requiring a hydraulic input power, has a port block with improved balanced loading which is attached to an end cap in a simplified manner. The end cap includes an opening having a peripheral surface and a first end face. The end cap further includes a plurality of ports opening at the end face and at least one actuation port opening at or near the peripheral surface. A barrel which is rotatable about an axis includes a second end face and a plurality of cylinders having respective cylinder ports which open at the second end face. A port block is disposed within the end cap opening between the first end face of the end cap and the second end face of the barrel.

Abstract: Energy of returning pressurized fluid of an actuator is recovered and reused as energy for operating other accumulators. A first pump motor (16) and a second pump motor (17) are mechanically connected to form a pressure converter (18), and a first circuit (22), to which the returning pressurized fluid is supplied, is connected to the first pump motor (16). A pressure accumulator (27) is provided to a second circuit (25) connected to the second pump motor (17). The first circuit (22) is connected to a discharge passage (11) of a primary hydraulic pump (10) by a third circuit (29) and the pressure of a high pressure pressurized fluid is supplied to the discharge passage (11) by the pressure of the high pressure pressurized fluid, and is reused.

Abstract: A control system for a hydraulic transformer providing hydraulic pressure to a fluid actuator has a hydraulic system for providing a variable pressure input to the hydraulic transformer, and a controller connected to the hydraulic transformer and the hydraulic system for matching the flow demand from the hydraulic transformer to the flow produced by the hydraulic system.

Abstract: A hydraulic drive for a press and in particular for a press for the simulation of the operating conditions of mechancial presses for large parts or the like is proposed. In order to also make such a hydraulic simulation press available for pilot lots or small lots with a considerable improvement in efficiency, a so-called hydraulic transformer, which consists of hydraulic devices adjustable in angular travel, is assigned to the drive.

Abstract: The invention provides an improved fluid motor powered lift system having a valve arrangement for reducing or interrupting the fluid flow supplied to the motor when the pressure in the lift system exceeds a predetermined pressure. A valve arrangement is provided to shut-off or throttle back the fluid supplied to the fluid motor when the fluid pressure in the lift reaches a predetermined level. When the pressure in the lift system exceeds the predetermined level, pilot pressure is supplied to an automatic shut-off valve, and this in turn reduces fluid flow to fluid air motor thereby reducing or preventing pump pressure.

Abstract: A control system for a hydraulic transformer has a hydraulic system for providing hydraulic pressure to the hydraulic transformer, a controller connected to the hydraulic transformer, the controller for determining the input pressure provided to the hydraulic transformer and for controlling the operation of the hydraulic transformer based upon input pressure provided to the hydraulic transformer.

Abstract: A regenerative adaptive fluid motor control system integrating a load adaptive fluid motor control system and a load adaptive energy regenerating system having an energy accumulator. The fluid motor control system includes a primary variable displacement pump (90) being implemented for powering and controlling a fluid motor (1) accumulating a load related energy. The load related energy of the fluid motor is regenerated to provide a load adaptive exchange of energy between the fluid motor and the energy accumulator (122). This load adaptive exchange of energy is combined with a load adaptive primary energy supply for maximizing the over-all energy efficiency and performance potentials of the fluid motor control. The energy-regenerating adaptive fluid motor control can be used, for example, for constructing the high energy-efficient load adaptive motor vehicles.

Abstract: A discharged pressurized fluid of a primary hydraulic pump 2 driven by an engine 1 is supplied to an actuator 5 through an operating valve 4. A first hydraulic rotary machine 8 for rotating a cooling fan 7 is driven to rotate by a returning pressurized fluid of the actuator 5. A second hydraulic rotary machine 9 for rotating the cooling fan 7 is driven to rotate by the discharged pressurized fluid of an auxiliary hydraulic pump 3 which is driven by the engine 1. By utilizing the returning pressurized fluid of the actuator 5, the air blowing ability of the cooling fan is made high and the wasting of engine horse power is prevented.

Abstract: A hydraulic system includes a hydraulic transformer with a rotor which is coupled with the hydromotor. The hydromotor may be subjected to a variable load which has to be moved in different directions. By using various switching means, the combination hydromotor and hydraulic transformer has been made suitable for the necessary four-quadrant operation.

Abstract: A drive system for a mobile operating device. The drive system includes a drive motor driving a first variable-delivery hydraulic pump which is in fluid engagement with a first hydraulic motor, the first hydraulic motor being part of a hydraulic travelling drive. A second hydraulic motor drives at least one second variable-delivery hydraulic pump which is in fluid engagement with an operating hydraulic system for implementing device-specific functions.

Abstract: The invention relates to a pressure transformer for the conversion of a hydraulic power from a first fluid flow having a first pressure into the hydraulic power of a second fluid flow having a second pressure. In the housing (3) a rotor (26) is mounted, able to rotate around a rotation shaft (4) due to the effect of the pressure differences between the three pipe connections (16). Around the rotation shaft chambers (24) are distributed comprising displacement means (27, 29) such as pistons (27) which, when the rotor (26) in the housing (3) rotates, vary the volume in the chambers (24) between a minimum and a maximum value, and channels (19, 22) provided with valves (20, 21) activated by the rotation of the rotor (26) and connecting each chamber (24) alternately with the first, the second and the third pipe connection (16).

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 regenerative adaptive fluid motor position feedback control system integrating a load adaptive fluid motor position feedback control system and a load adaptive energy regenerating system having an energy accumulator. The fluid motor control system includes a primary constant displacement pump powering a spool valve controlling a fluid motor accumulating a load related energy, such as a kinetic energy of a mass load of the fluid motor or a compressed fluid energy of the fluid motor-cylinder. The load related energy of the fluid motor is regenerated to provide a load adaptive exchange of energy between the fluid motor and the energy accumulator. This load adaptive exchange of energy is combined with a load adaptive primary energy supply for maximizing the over-all energy efficiency and performance potentials of the fluid motor control. The load adaptability is achieved by regulating the exhaust and supply fluid pressure drops across the spool valve.

Abstract: A regenerative adaptive fluid motor control system integrating a load adaptive fluid motor control system and a load adaptive energy regenerating system having an independent regenerating circuitry containing an energy accumulator.The fluid motor control system includes a primary variable displacement pump powering a spool valve controlling a fluid motor accumulating a load related energy, such as a kinetic energy of a mass load of the fluid motor or a compressed fluid energy of the fluid motor-cylinder. The load related energy of the fluid motor is regenerated to provide a load adaptive exchange of energy between the fluid motor and the energy accumulator. This load adaptive exchange of energy is combined with a load adaptive primary energy supply for maximizing the over-all energy efficiency and performance potentials of the fluid motor control. The load adaptability is achieved by regulating the exhaust and supply fluid pressure drops across the spool valve.

Abstract: A regenerative adaptive fluid motor position feedback control system integrating a load adaptive flujid motor position feedback system having an energy accumulator. the fluid motor control system includes a primary variable displacement pump powering a spool valve controlling a fluid motor accumulating a load related energy, such as a kinetic energy of a mass load of the fluid motor or a compressed fluid energy of the fluid motor-cylinder. The load related energy of the fluid motor is regenerated to provide a load adaptive exchange of energy between the fluid motor and the energy accumulator. This load adaptive exchange of energy is combined with a load adaptive primary energy supply for maximizing the over-all energy efficiency and performance potentials of the fluid motor control. The load adaptability is achieved by regulating the exhaust and supply fluid pressure drops across the spool valve.

Abstract: A regenerative adaptive fluid motor control system integrating a load adaptive fluid motor control system and a load adaptive energy regenerating system having a built-in regenerating circuitry containing an energy accumulator. The fluid motor control system includes a variable displacement pump powering a spool valve controlling a fluid motor accumulating a load related energy, such as a kinetic energy of a mass load of the fluid motor or a compressed fluid energy of the fluid motor-cylinder. The load related energy of the fluid motor is regenerated to provide a load adaptive exchange of energy between the fluid motor and the energy accumulator. This load adaptive exchange of energy is combined with a load adaptive primary energy supply for maximizing the over-all energy efficiency and performance potentials of the fluid motor control. The load adaptability is achieved by regulating the exhaust and supply fluid pressure drops across the spool valve.

Abstract: A regenerative adaptive fluid motor control system integrating a load adaptive fluid motor control system and a load adaptive energy regenerating system having an energy accumulator. The fluid motor control system includes a primary constant displacement pump powering a spool valve controlling a fluid motor accumulating a load related energy, such as a kinetic energy of a mass load of the fluid motor or a compressed fluid energy of the fluid motor-cylinder. The load related energy of the fluid motor is regenerated to provide a load adaptive exchange of energy between the fluid motor and the energy accumulator. This load adaptive exchange of energy is combined with a load adaptive primary energy supply for maximizing the over-all energy efficiency and performance potentials of the fluid motor control. The load adaptability is achieved by regulating the exhaust and supply fluid pressure drops across the spool valve.

Abstract: A regenerative adaptive fluid motor output feedback control system integrating a load adaptive fluid motor output feedback control system and a load adaptive energy regenerating system having an energy accumulator. The fluid motor control system includes a primary variable displacement pump powering a spool valve controlling a fluid motor accumulating a load related energy, such as a kinetic energy of a mass load of the fluid motor or a compressed fluid energy of the fluid motor-cylinder. The load related energy of the fluid motor is regenerated to provide a load adaptive exchange of energy between the fluid motor and the energy accumulator. This load adaptive exchange of energy is combined with a load adaptive primary energy supply for maximizing the over-all energy efficiency and performance potentials of the fluid motor control. The load adaptability is achieved by regulating the exhaust and supply fluid pressure drops across the spool valve.

Abstract: A hydraulic pressure amplifier has a hydraulic motor for driving a single cam and follower in a piston chamber. A number of conduits and chambers with automatically actuated valves controlling the flow between them are provided, such that, in operation, low pressure fluid introduced into the device to drive the motor will be automatically increased in pressure for discharge-.

Abstract: A power sensing regenerator includes a pair of displacers (24 and 26) connected in tandem for dividing a flow of fluid from a pump (12) into predetermined proportions for servicing one or more loads (42). Flow control valves (32 and 34) regulate respective flows from the displacers (24 and 26) to the one or more loads (42). A control system, which includes differential pressure regulators of the flow control valves (32 and 34), responds to a difference between discharge pressures of the displacers (24 and 26) for reducing discharge pressure of the pump (12).

Abstract: A regenerator for a fluid power system is arranged to control flow rates while converting pressure drops accompanying resulting changes in flow rates into useful work. A gang of displacers are incorporated into a fluid flow network that also includes an array of selectable flow paths through the displacers. A control system, responsive to changes in demand for the flow of fluid, selects among the flow paths to operate the displacers in various combinations as motors, pumps, and recirculators for dividing the flow of fluid into two variably sized portions. One portion of the flow is sized to match the demand for fluid flow, and the other portion of the flow is converted into useful work.

Abstract: An hydraulic liquid system wherein a pump moves liquid from one location to another such as in supplying one or more loads in an underwater environment. The system includes two hydro-pneumatic chambers utilized such that one is filled by liquid from the pump while the other supplies the load, and as one hydro-pneumatic chamber empties, valves reconfigure the system such that the hydro-pneumatic chamber reverse roles. Each hydro-pneumatic chamber includes a liquid side and a gas side separated by a movable barrier with the gas sides of the hydro-pneumatic chambers being connected to one another thereby providing a large acoustic transmission drop across a liquid-gas boundary and subsequent gas-liquid boundary to interrupt the liquid noise path from the pump to the load.

Abstract: A regenerator for a fluid power system is arranged to control flow rates while converting pressure drops accompanying resulting changes in flow rates into useful work. A gang of displacers are incorporated into a fluid flow network that also includes an array of selectable flow paths through the displacers. A control system, responsive to changes in demand for the flow of fluid, selects among the flow paths to operate the displacers in various combinations as motors, pumps, and recirculators for dividing the flow of fluid into two variably sized portions. One portion of the flow is sized to match the demand for fluid flow, and the other portion of the flow is converted into useful work.

Abstract: A power generating system comprising a hydraulic transmission driven by an electric motor. The hydraulic transmission drives electric generators for recharging the electric motor battery, and a speed reducing mechanism and reverse speed reducing mechanism before and after the hydraulic transmission, respectively, allow the system to operate in optimum efficiency.

Abstract: An apparatus for controlling flow of a fluid having two speed-controlled positive displacement devices for supplying a load with fluid under pressure from a supply at a different pressure with interposed variable-volume buffer containers.

Abstract: A hydrostatic machine having a fixed displacement volume which is connected to the operating chamber of a hydraulic cylinder which machine is mechanically coupled to a second hydrostatic machine having a variable displacement volume to control the force exerted by the hydraulic cylinder. When control liquid is displaced from the working chamber of the cylinder the first machine acting as a motor drives the second machine which displaces control liquid into an accumulator. Vice versa, liquid is taken from the accumulator and the second machine acting as a motor drives the first machine which feeds liquid into the working chamber. The pressure in the working chamber, or, respectively, the force exerted by the cylinder is maintained constant by a corresponding adjustment of the displacement volume of the second machine.

Abstract: A hydrostatic drive in which the ratio of pressure to force is constant is provided having a consumer of hydraulic energy connected to a high pressure system line, a first displacement means interposed between the consumer and the pressure system line, speed regulating means acting on the first displacement means to regulate the speed thereof, a second displacement means connected to the first displacement means by a drive shaft and receiving fluid from the pressure system line, volume output adjusting means acting on one of said first and second displacement means to adjust the volume output per revolution and coupling means connecting the adjustable displacement means with the consumer of hydraulic energy.

Abstract: A Gas Energized Engine System, according to the present invention, is adapted to drive a piston type gas energized engine having a piston and cylinder system that is operatively interconnected with a crankshaft that transmits rotary force to any suitable load. The piston type engine is provided with gas intake and exhaust systems. The gas intake system is interconnected with a gas supply system having a high pressure supply vessel and an operating pressure supply vessel that are interconnected by a pressure regulator. A converter system which is an engine and compressor system that is separate from the gas energized engine, and has a gas inlet that receives the exhaust of the gas exhaust system of the engine and functions to compress the exhaust gas to a high pressure and communicate the high pressure to the high pressure vessel of the gas supply system and to modify the exhaust atmosphere of the gas energized engine.

Abstract: In a preferred embodiment, for a turbine driven by hydraulic fluid, the combustion cylinder's piston is lubricated by the hydraulic fluid and drives the hydraulic fluid, and during the driven movement of the piston, movement of that piston causes the return reciprocal movement of another piston of another hydraulic combustion cylinder, and a starter motor is connected to drive both the turbine and the reciprocatable pistons.

Abstract: A hydropneumatic system, especially for operating landing gear of truck trailers, is operable from a source of pressurized air. The system includes separate first and second hydraulic fluid sources. Dual hydraulic cylinders are operated by the fluid. Each has a piston and an extensible member connected to the piston for providing extension and retraction of the gear legs in response to hydraulic pressure in chambers on opposite sides of the pistons. An air valve provides the pressurized air to one of the fluid sources for enabling it to provide hydraulic fluid. An air-operated hydraulic pressure boosting pump is selectively operable to boost the hydraulic fluid pressure thus provided to much greater than air pressure.

Abstract: An improved arrangement for operating a hydraulic hammer at a distance from the hydraulic supply. The hydraulic hammer which can be used for breaking rocks, concrete, and the like is disposed at the end of a movable boom, remote from its pressurized hydraulic supply. The hammer is connected to the pressurized hydraulic supply by flexible lines and is movable with respect to the pressurized supply. Disposed in series in the pressurized hydraulic supply line is a hydraulic motor. The hydraulic motor is mounted in close proximity to the hydraulic hammer at the end of the boom. The outlet port of the hydraulic motor connects to the inlet port of the hydraulic hammer. The hydraulic motor drives a suction pump which is also located at the end of the positionable boom. The hydraulic motor and the suction pump are movable with a mounting assembly which supports the hydraulic hammer at the end of the boom. The suction inlet of the hydraulic pump is directly connected to the outlet port of the hydraulic hammer.

Abstract: A power transfer unit for transferring power between two separate hydraulic circuits comprising a casing, a pair of cylinder blocks in the casing, cylinders within each cylinder block, a piston in each cylinder, a leakage chamber within the casing, cam means located in said chamber for causing joint reciprocation of the pistons, pistons or extensions thereof extending from the cylinders to the cam means in the chamber, first valve means co-operating with the cylinders of the first block, second valve means co-operating with the cylinders of the second block, first leakage collecting means for the first valve means separate from said chamber, second leakage collecting means for the second valve means separate from said chamber, and a vent for said chamber separate from said leakage collecting means.By this arrangement any leakage to the chamber may be from either or both circuits and by virtue of the vent may be disposed of rather than fed back to either circuit.

Abstract: A hydraulic intensifier system having an axial piston pump-motor unit with fluid control circuitry associated therewith including porting in the unit whereby hydraulic fluid supplied under pressure to the unit drives the unit, and with part thereof ported to an accumulator for intensification of pressure thereof in an intensify mode of operation. In a start mode, the higher pressure fluid from the accumulator is delivered to the unit to cause rotation of the unit in an opposite direction.

Abstract: An electrohydraulic press drive system comprising a pressure transformer h variable ratio of displacement volume connected in series in a drive hydraulic circuit between a gas-hydraulic accumulator and a press cylinder. The pressure transformer consists of a hydraulic motor, which is connected mechanically with a hydraulic pump, the source of drive power of the pressure transformer being the gas-hydraulic accumulator.