Abstract: The present invention relates to a hydro-transformer including a hydraulic machine, a switching valve and a control means. A work port of the switching valve, which may optionally be connected hydraulically with a pressure port of the switching valve or a drain port of the switching valve, is connected with a first port of the hydraulic machine. The second port of the hydraulic machine is in hydraulic connection with a drive member. The switching valve is driven by the control means in response to a signal characterizing the volume flow into the hydraulic machine. Where the driver member is a cylinder, its extension may be carried out at a constant velocity and independently of a load, and energy may be recovered upon retraction. Due to the provision of a further switching valve between the second part of the hydrostatic motor and the drive member, a higher pressure may be generated at the drive member in the presence of a low pressure at the pressure port of the switching valve.

Abstract: The present invention relates to a mobile handling device with a hydraulic circuit, which hydraulic circuit (L) comprises a lifting cylinder (1) arranged in a lifting device (100) suitable for handling a variable load and an accumulator (6) for recovering or recycling lowering load energy, the hydraulic circuit also comprising a variable hydraulic machine (3) with two ports (10, 11), which hydraulic machine is capable via a drice unit (D) of emitting full system pressure in two flow directions to said ports, one port (11) being connected to said accumulator (6) and the other port being connected to said lifting cylinder (1).

Abstract: A pressure oil energy recovery apparatus or pressure oil energy recovery/regeneration apparatus that does not require much room and can be mounted within a narrow space, capable of broadening the range of applications for recovered energy. A hydraulic pump motor is actuated by the inflow of the return pressure oil flowing out of a hydraulic actuator. The drive force of the hydraulic pump motor is input to allow an electric motor to generate electric energy. The electric energy generated by the electric motor is stored in a battery. When the energy of pressure oil is regenerated, the energy expended during the actuation of the hydraulic actuator by the hydraulic pump is supplemented with the electric energy stored in the battery.

Abstract: A vehicle including a battery (61) powering an electrical motor (60), the electric motor (60) operating when the vehicle is driving at a nominal speed in order to drive, at a constant speed, a variable displacement hydraulic pump (4) which is connected to at least one variable displacement hydraulic motor (3). The hydraulic motor indirectly drives wheels of the vehicle. The variable displacement pump is electronically controlled and managed by a circuit which monitors, manages and controls (9) an angle of a cam plate which controls variable displacement of hydraulic pump (4).

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 hydraulic control unit for a motor-vehicle braking system includes a pump (32) delivering hydraulic fluid under pressure, the pump being capable of being controlled by an electronic control unit (ECU) and supplying the hydraulic fluid for at least one braking device (22) which is coupled to a wheel of the vehicle, and also a first reservoir (34) for pressureless hydraulic fluid, which is assigned to the pump (32) on the input side, and a second reservoir (36) for hydraulic fluid under pressure, which is assigned to the pump (32) on the output side. In order to design the control unit for good packaging and installation space considerations, the pump (32), the first reservoir (34), and the second reservoir (36) are arranged in a common casing (60), and integrated as an electrohydraulic modular unit.

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: The invention relates to a drive device for a hydraulic elevator, the device comprising an actuator (1) whose pressure chamber (1a) is connected to a pump (11) via a down duct (15) and via an up duct (16). A pressure accumulator (4) is connected to the down and up ducts (15, 16) via parallel ducts (15a, 16a), each duct having an electrically controlled valve (2, 2a; 6, 6a). While the elevator is moving downwards, hydraulic fluid is transferred from the pressure chamber (1a) to the accumulator (4) via the down duct (15) and the parallel duct (16a). While the elevator is moving upwards, hydraulic fluid is transferred from the accumulator (4) to the pressure chamber (1a).

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 hydraulic lifting-lowering-system for a working table, a couch or lying furniture or another heavy object allows the height level or position to be frequently adjusted or changed. The system includes a predetermined amount of hydraulic fluid, a hydraulic fluid accumulator, the fluid pressure of which on the hydraulic fluid side is adjustable, a single acting hydraulic cylinder with two end caps, a piston pressure chamber and a piston rod which, via a piston rod sealing ring, extends sealingly out through the one end cap of the cylinder. The piston pressure chamber is pressure fluid connected to the hydraulic fluid side of the accumulator. The hydraulic cylinder is of the plunger piston type, and the cylindric tube of the hydraulic cylinder is slideably and telescopically mounted in a cylindrical guiding tube, which surrounds the piston rod in its entire length and is rigidly secured to the one end of the piston rod via a cross plate or similar construction part.

Abstract: A device to save energy for hydraulically-operated tool shanks uses a piston-type accumulator having a housing in which at least two longitudinally displaceable pistons are arranged and are connected to by a coupling part. The coupling part is guided to be longitudinally displaceable in a partition wall of the housing which bounds two fluid chambers with the two pistons. At least one of the pistons bounds at least partially, a fluid chamber and a pre-loaded chamber with presettable internal gas pressure on the opposite sides. A wider range of possible applications is achieved for hydraulically-operated tool shanks using this energy saving device.

Abstract: A system by which the air exhausted from either end of a pneumatic cylinder is directed, by an arrangement of control valves, to external surge tanks of appropriate volume where it is compressed to produce a deceleration effect at the end of each stroke before being released to the atmosphere.

Abstract: A system that can recover flows of a hydraulic pressure fluid returned from a plurality of hydraulic actuators is disclosed which includes a plurality of fluid recovery circuits (15, 19, 25 and 27) into which flows of a hydraulic pressure fluid returned from such a plurality of actuators are admitted, and a main fluid recovery circuit (36). There is provided a selector means (30, 31, 32, 33, 34, 35, 37) for permitting at least one of the plural fluid recovery circuits (15, 19, 25 and 27) selectively to communicate with the main fluid recovery circuit (36). The system, by permitting at least one of a plurality of fluid recovery circuits to communicate with a main fluid recovery circuit, enables a hydraulic return pressure fluid from at least one of a plurality of actuators to be recovered and hence is applicable to a working machine involving a plurality of hydraulic actuators.

Abstract: What is disclosed is a method for controlling a hydraulic cylinder acting against a load, and a hydraulic installation of a utility vehicle operating in accordance with this method, wherein the pressure in the supply line to the effective areas of the hydraulic cylinder is maintained at a level that approximately corresponds to the pressure level in a hydraulic accumulator for supplying the hydraulic installation.

Abstract: A slide driving device employs a variable-displacement pump/motor for driving a rotating element of the slide driving device. The displacement volume of the variable-displacement pump/motor, whose output drives the slide, is varied in response to deviation of measured driver parameters from commanded driver parameters. An energy storage device temporarily absorbs excess energy during a portion of a molding cycle, and returns the energy to the system for re-use. In one embodiment, the energy storage device is an accumulator. In a second embodiment, the energy storage device is a flywheel. The combination of variable displacement volume and energy storage maintains the fluid pressure substantially constant during a cycle of the slide driving device.

Abstract: A pneumatic piston-cylinder apparatus of single acting type which performs a working stroke in one working direction, and is returned to its initial position without any external supply of compressed air comprising a cylinder part with cylinder jacket (1), a front end (2), a rear end (3), and a piston (5) which is reciprocatable in the cylinder. Connected to the rear end (3) is a supply of compressed air and within the cylinder is a return channel (10) used for draining the air on the unloading side of the piston.

Abstract: The present invention relates to a control apparatus for a construction machine such as a hydraulic shovel, and the control apparatus for a construction machine includes a revolving operation member for operating a construction machine revolving unit (14), a fluid pressure pump (2) and an accumulator (5) for accumulating working oil from the fluid pressure pump (2), a fluid pressure actuator (7) for driving the construction machine revolving unit (14) to revolve with the working oil from the fluid pressure pump (2) and the accumulator (5), a first control valve (8) interposed between the fluid pressure actuator (7) and the fluid pressure pump (2), a second control valve (11) for controlling an inflow condition of the fluid from the fluid pressure actuator (7) into the accumulator (5), and control means (9) including first valve control means (9a) for controlling the first control valve (8) and second valve control means (9b) for controlling the second control valve (11).

Abstract: The invention discloses a power unit (1) which comprises: an accumulator battery (2); an electric converter (3) supplied by said accumulator battery (2); an electric motor (30) supplied by said converter (3); a hydraulic pump (4) mechanically connected to said electric motor (30), suited to put under pressure a liquid (50) which supplies one or more actuators (9) in order to lift a load (11) connected to them. Said pump (4) is of the reversible type and operates as a hydraulic motor suited to drive into rotation said electric motor (30) which operates as a generator supplying said battery (2) by means of said converter (3) whenever the descent by gravity of the load (11) supported by said one or more actuators (9) puts under pressure the oil held therein which passes through said pump (4) entering from the delivery opening (42) and coming out of the inlet opening (41).

Abstract: There is disclosed a workhead for timber processing, the workhead having a main body and a jaw assembly for grappling timber. The jaw assembly includes first and second cooperating pairs of jaw arms that are pivotally mounted to the main body. The first of the cooperating pairs of jaw arms provides cutting blades for delimbing. The workhead further includes a feed roller assembly for translating a felled tree through the cutting blades. First and second feed rollers of the feed roller assembly are associated with the jaw arms of the second cooperating pair of arms of the jaw assembly. A third feed roller is provided on the main body for pivotal movement relative to the main body. The feed rollers also effect compression debarking of the felled tree as it is translated through the cutting blades. Each roller has projecting engaging bars which extend in a generally helical configuration along the outer surface of the roller and between its opposed terminal ends.

Abstract: Regenerative hydraulic power transmission for subsurface pumps, including a power source, a variable flow rate hydraulic pump, means to reverse flow through the hydraulic pump responsive to change in direction of the subsurface pump stroke, and an inertial assist for the power source which gathers energy from the downstroke of the subsurface pump and utilizes the gathered energy to power the upstroke of the subsurface pump. The transmission can vary upstroke speed apart from downstroke speed, pump stroke length and dwell time of change in stroke direction.

Abstract: A method and apparatus for braking a rotating element including a reversible eccentric ring or axial piston pump which may be selectably operatively connected to a rotating element. When either pump is configured to compress ambient fluid into a reservoir, the compressive resistance is transmitted to the rotating element, braking it. When either pump is configured to expand fluid from the reservoir, the resultant torque generated is transmitted to the rotating element, driving it. The invention provides mechanisms for rapidly configuring either pump to compress or expand fluid, and for adjusting pump displacement, respecting a user's demand.

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 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 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 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 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 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: The present invention relates to a method and system for controlling a split torque transmission having a hydrostatic transmission and a mechanical transmission. The control system employs a transmission control and includes a transmission input speed sensor, a transmission output speed sensor, a motor speed sensor, a speed input mechanism, a direction control mechanism, and a range selector mechanism. A microprocessor including a fuzzy controller controls the transmission in response to a input from the speed sensors and the speed input mechanism, the direction control mechanism and the range control mechanism.

Abstract: A continuously variable transmission, which allows recovering braking energy from a vehicle for later use in accelerating the vehicle and/or engine starting, includes a vane type pump and stator in a case, each with flexible cam rings. The pump cam ring and the stator cam ring can both be flexed to change the displacement of the pump and the stator. A first connection establishes fluid communication between a tapering volume sector of the pump swept volume and a tapering volume sector of the stator unit working volume, and a second connection establishes fluid communication between a flaring volume sector of the pump swept volume and a flaring volume sector of the stator unit working volume. A valve is connected to the first and second connections and a hydraulic accumulator.

Abstract: This invention is a means for storing kinetic energy for later use as a driving force. This is accomplished through the use of an elastomeric member that can be multi-strand if desired, trained over a plurality of offset pulleys mounted on a pair of parallely disposed support shafts. One end of the elastomeric member is tethered and the other end is connected to a low stretch member which is trained onto a take-up reel. This reel through a remotely controlled clutch is connected to a gear box that is in turn connected to a drive source such as ground engaging wheels. A separate power source can also be connected to the gear box such as an engine. A control means such as a microprocessor can be used in controlling the storage of kinetic energy by winding the low stretch member onto the take-up reel to linearly stretch the elastromeric member and to release the stored energy by allowing the elastomeric member to cause the low stretch member to unwind from the take-up reel.

Abstract: A Hydraulic Pumping Unit equipped with a flywheel, a high-slip electric motor and a reversible hydraulic pump such that during the downstroke of the Unit, the hydraulic pump operates as a hydraulic motor, accelerating the flywheel and accumulating in this way the energy of the downgoing rodstring in the form of kinetic energy.The interaction between the flywheel, electric motor and weight of the rodstring adjusts automatically the range of speed variation.The upward and downward speeds of the Hydraulic Pumping Unit can be adjusted by hand or automatically by electronically commanded step motors, in such a way that the Hydraulic Pumping Units adjusts itself to the varying conditions of the oilwell.

Abstract: Procedure for operating an elevator, in which the power for moving the car as well as the accelerating/decelerating power of the whole system is, in all motional states of the elevator, obtained from/returned to a hydraulic pressure accumulator (1) charged by an auxiliary gear (3). The elevator machine comprises a hydraulic pressure accumulator (1), hydraulic actuators (2) for adapting the power taken from/fed into the pressure accumulator to the motional state of the elevator car, and an auxiliary gear (3) for pumping hydraulic energy into the pressure accumulator.

Abstract: A single rod three chamber fluid cylinder is driven in an initial rapid advance forward stroke by a main pump, pumping fluid through a proportional directional control valve to act against a first equal area at the head end of the piston. Fluid expelled from a second equal area at the rod side of the piston is returned to the reservoir through a proportional directional control valve which is in a first position while a two position valve is in its first position allowing an accumulator to fill a third chamber exposed to a third area of the head side. When shifting to the feed stroke, the two position valve switches to its second position disconnecting the accumulator to the third area and connecting the main pump to the third area while also connected to the first equal area. Upon the return stroke of the piston, the fluid from the first equal area is returned to the sump and the fluid from the third area is routed to the accumulator.

Abstract: Engine output speed is controlled for optimum efficiency by adjustment of input speed of a continuously variable transmission (CVT). Where power in excess of that provided by the engine is required, additional power is input to the drivetrain from a fluidic motor driven by fluid pressure stored in an accumulator. In driving conditions where the engine, operating at optimum efficiency, produces power in excess of that demanded by of the vehicle, the fluidic motor is reversed for operation as a pump and excess engine power is utilized to drive the pump and store energy in the accumulator in the form of fluid pressure. A CPU determines power output required of the engine as a sum of that indicated by a sensor which senses power demanded of the vehicle by a driver and an increment of power required to maintain the pressure of the accumulator above a threshold amount.

Abstract: A device for recovering energy, in particular potential energy in working machines, has a hydraulically actuatable working cylinder linked to a hydropneumatic storage. At least another working cylinder is provided. The two working cylinders are mutually linked by their rod end chambers to transfer fluid and are linked to a hydraulic circuit having at least one pump. The other working cylinder is also linked at its piston end chamber to a hydraulic circuit having a pump. The energy generated by the movements of the working machine can be effectively stored in a failure-proof manner and called back at defined moments in time.

Abstract: A machine with a movable element, such as a machine tool and its spindle carrier, that is powered by a motive means to move the element is provided with a counterbalancing system having at least two counterforce means operably connected to the movable element for exerting a counterbalance force on the movable element in opposition to the first force and wherein a first one of the counterforce means has a controllable servomotor means. The control means controls the servomotor means so as to cause the counterbalancing system to exert a substantially constant counterbalance force on the movable element in opposition to the first force. The second one of the counterforce means may be a hydraulic means having a hydraulic cylinder operably connected to an accumulator and a hydraulic piston operably disposed in the cylinder and connected to the movable-element.

Abstract: A hydraulic system incorporating a double acting piston and cylinder and a bi-directional pump/motor derives energy from a drive system when operating in the pump mode and delivers energy to the drive system when in the pump mode and includes a circulation valve for supplementing fluid flow to and from and fluid supply in accordance with the unequal demands of the chambers driving the hydraulic actuator in one direction or the other by circulating fluid between the chambers.

Abstract: A counterforce cylinder and piston exert an upward force on the vertically movable slide of a machine. The cylinder pressure line handles reverse flows during operations of the slide. A pilot-operated checkvalve (normally closed) is inserted in the cylinder line between a pressure source and the counterforce cylinder, and is held open during usual operation of the machine. An accumulator is branch-connected to the cylinder line, at a point between the checkvalve and counterforce cylinder. During machine operations, the accumulator stores pressurized fluid; at shutdown of power, the fast-acting checkvalve closes and reliably seals the cylinder line while the accumulator provides pressure to maintain the counterforce cylinder and slide in a substantially constant holding position for several days.

Abstract: A first cylinder chamber of a hydraulic cylinder is connected to a pair of variable displacement pumps of which the first one is connected to a reservoir and second one is connected to the second cylinder chamber. This allows to bias the piston by a hydraulic force acting on either side of the piston corresponding to the direction of motion. This is obtained by adjusting the delivery volume of both the pumps such that the volume supplied is larger than the volume drained. Metering the difference of both the delivery volumes results in the desired biasing counter-pressure.

Abstract: Compensated controls for a negative type load which, without degrading the quality of the control, permit direct use of the fluid power energy of the negative load for control of a resistive or positive type load, thereby greatly increasing the efficiency of the control system.

Abstract: An apparatus for managing liquid under pressure having a first volume containing a liquid at a first pressure and a second volume containing liquid at a second, lower, pressure and energy storage means to receive and store energy derived from said first volume as a result of said first volume containing liquid under said first pressure and using said stored energy to increase the pressure in the second volume.

Abstract: A system for storing deceleration energy from a motor vehicle and for using the stored deceleration energy to assist in accelerating the motor vehicle. In one embodiment, the system comprises a generator mechanically coupled to the drive train for converting deceleration energy to electrical energy, means electrically coupled to the generator for storing the electrical energy outputted by the generator, a motor mechanically coupled to the drive train and electrically coupled to the storing means for converting the stored electrical energy to mechanical energy used to assist in accelerating the motor vehicle, and a detector/switch for determining whether the motor vehicle is decelerating, accelerating, or neither and for switching the generator on and the motor off when the motor vehicle is decelerating for switching the generator off and the motor on when the motor vehicle is accelerating, and for switching the generator off and the motor off when the motor vehicle is neither accelerating nor decelerating.

Abstract: A regenerative braking system for a car in which the pumping capacity of a pump/motor is responsive to the inner pressure of a hydraulic circuit by determining exhaust/engine brake equivalent torque corresponding to car speed and gear position when the car speed exceeds a predetermined speed. A manual operating device for an exhaust brake is or is not operated, so that the engine of the car is decoupled, the hydraulic oil circuit is closed, the pumping capacity is controlled, and an electromagnetic clutch is coupled to accumulate the deceleration energy of the car into the high pressure accumulator as if an exhaust/engine brake works.

Abstract: A variable displacement, hydraulic pump/motor has its rotatable cylinder block concentrically affixed to a drive shaft segment of a self-propelled vehicle, the pump/motor has selected pump and motor modes. An hydraulic accumulator is charged and discharged from the pump/motor when it is in its pump and motor modes, respectively. A fluid reservoir supplies and receives low pressure fluid when the accumulator is being charged and discharged, respectively. Preferably the reservoir is a combination of an aft chamber of the accumulator, a low pressure chamber defined by the pump/motor cylinder block and its housing, and a low pressure fluid path between the two. The pump/motor is unloaded when the vehicle is being operated in reverse or when neither the brake nor accelerator is being actuated. The pump/motor is in the pump mode whenever the vehicle is moving forward and the brakes are applied, and it is the motor mode whenever the vehicle is in forward gear and the accelerator is actuated.

Abstract: Hydrostatic drives for wave generating apparatus in swimming pools require a large amount of energy. A hydrostatic drive for the wave generating apparatus is provided which allows that part of the kinetic energy of the rearwardly moving water to be transformed into hydraulic energy, which in turn is used to impart onto the water a forward movement.

Abstract: A cylinder unit is supplied with pressurized fluid from a hydraulic machine which is variable in speed and/or displacement. The machine may be operated as a pump and as a motor to increase the pressure or, respectively, to decrease the pressure so that the piston of the cylinder unit may be actuated in both directions and, furthermore, the brake energy is recovered by the machine when the piston is driven through an external load. This results in an increased efficiency of the control apparatus for the cylinder unit avoiding any problems arising from heat.

Abstract: The torque of a hydraulic machine is dependent of the fluid pressure delivered to the machine and is further dependent of the adjustment of its volume of through-put. In response to a load coupled to the machine, a speed results which is controlled by a speed control system acting on the adjusting system of the hydraulic machine. According to the invention, an electro hydraulic speed control comprises a pair of control circuits which are connected to, but operate independent of each other. Thus the electrical control circuit produces a control signal y.sub.e1 from the difference of the actual value and the desired value of the speed for adjusting a hydraulic restricting means which produces a hydraulic pressure signal p.sub.st in the hydraulic control circuit which pressure signal is compared with a hydraulic reference signal p.sub.o to produce a differential pressure signal p.sub.o -p.sub.st which is applied to the adjusting cylinder of the hydraulic machine.

Abstract: A method and apparatus for preparation and delivery of an intravenous therapeutic agent with features that minimize the possibility of contamination, exposure and improper dosage level of the drug. One container is pre-filled with a diluent. Another container is pre-filled with a dry form drug. The containers are joined with a flow connector in between. When the drug is prescribed, the diluent is allowed to flow into the drug container for mixing and is administered.

Abstract: The invention involves pressure-counterweighted oil-well pumping apparatus in which derrick structure of elemental simplicity involves components which are readily assembled and disassembled, such that a given pumping apparatus can be loaded on a single truck and transported from one to the next desired well-pumping location. For a given capacity pumping system, overall height requirements for the derrick structure are less than one half those of U.S. Pat. No. 4,631,918. And power-integrator complexity is substantially reduced by employment of a fixed-displacement variety in conjunction with a variable speed a-c motor as the prime mover, under control of solid-state devices and pressure-sensitive transducer elements which determine upper and lower limits of the reciprocating stroke.

Abstract: A hydraulic drive system to actuate the piston of a cylinder unit comprises a first hydrostatic machine having variable displacement, a second hydrostatic machine mechanically coupled to said first machine and operating as a signal generator either in a pump mode or a motor mode, and a third hydrostatic machine of fixed displacement mechanically coupled to said first machine, which third machine is hydraulically connected to said cylinder unit. In response to zero speed or rotation of the drive system the piston of the cylinder unit may be stopped in any position, or, respectively, raised or lowered. The variable displacement machine may operate as a pump and as a generator in which latter case energy is recovered in lowering a load.