Abstract: A control valve for a multi-stage hydraulic actuator includes a valve body defining a translation axis, a spool disposed within the valve body and movable along the translation axis, and a flange. The flange is fixed relative to the spool and has an aperture disposed externally of the valve body to removably fix the spool to a spool of a redundant control valve independently connected to the multi-stage hydraulic actuator for mitigating force fights between actuators coupled to the control valve.

Abstract: The invention provides a fluid working machine comprising: a cylinder block (1) having an axial bore (4); a crankshaft (2) which extends within the axial bore (4) and is rotatable about an axis of rotation (3); and first and second valve cylinder devices (13) provided in the cylinder block (1) arranged about and extending outwards with respect to the axial bore (4), the first and second valve cylinder devices (13) being axially offset from each other, the first and second valve cylinder devices (13) being offset from each other about the axis of rotation (3), and the first valve cylinder device having an axial extent which overlaps the axial extent of the second valve cylinder device, wherein the first and second valve cylinder devices (13) comprise first valves (14) having respective first working fluid ports (48, 49), the said respective first working fluid ports (48, 49) of the first valves (14) of the first and second valve cylinder devices (13) being in fluid communication with each other via a common co

Abstract: A drive device for a bending press, in particular a press brake, with a press frame includes a stationary press beam and has a press beam which can be displaced relative to the press beam by a beam adjusting device formed by a closed hydraulic system including a hydraulic pump with a controllable drive motor, at least one control valve and at least one hydraulic linear actuator. The linear actuator includes a first piston arrangement with a first piston dividing a cylinder chamber into a first pressure chamber and a second pressure chamber and, in another cylinder chamber, a second piston arrangement with another piston and at least one other pressure chamber. The first piston arrangement and the second piston arrangement are coupled with one another.

Abstract: An assembly in accordance with an embodiment of the present invention for providing a substantially uniform output flow from at least one piston of a pump powered by a prime mover includes at least a first power piston disposed in a cylinder and reciprocatingly movable within the cylinder between an extension direction when supplied with power from the prime mover and an opposite retraction direction, and a synchronization element attached to the power piston to control the speed of the power piston in the retraction direction.

Abstract: A selector valve operating mechanism is provided with operating pistons which are hydraulic pistons connected through an operation link to a spool of a PTO selector valve, an solenoid valve for hydraulically controlling reciprocation of the operating pistons, and a controller which is a control device for transmitting an operation signal to the solenoid valve. Control of operation of the solenoid valve moves the spool through the operating pistons and the operation link to switch the PTO selector valve.

Abstract: The catheter device comprises a drive shaft connected to a motor, and a rotor mounted on the drive shaft at the distal end section. The rotor has a frame structure which is formed by a screw-like boundary frame and rotor struts extending radially inwards from the boundary frame. The rotor struts are fastened to the drive shaft by their ends opposite the boundary frame. Between the boundary frame and the drive shaft extends an elastic covering. The frame structure is made of an elastic material such that, after forced compression, the rotor unfolds automatically.

Abstract: Disclosed is a variable displacement compressor having improved compressor performance such as reduced pulsation and improved durability and resistance to pressure and allowing smooth and high-precision control of a swash plate tilt angle at a target tilt angle by using an axial movement member.

Abstract: A hand tool that is preferably hydraulically actuable includes a working head and a body unit that remains in place with respect to the head, drive elements for driving the working head being provided in the body unit, for example a hydraulic pump and a hydraulic supply, a switching movement also allowing a powered movement of one or more working parts of the working head to be triggered and the working head being swivelably connected to the body unit in a rotary connection region. In order to configure and develop a hand tool so that safe working is assured by virtue of unambiguous and clear handling, by swivelling of the body unit relative to the working head about an axis of rotation provided in the region of the rotary connection of the working head to the body unit, switching over can be carried out with regard to the powered movement of the working part.

Abstract: A centrifugally activated variable damper assembly for a stopped-rotor aircraft is disclosed for adjusting dampening level of teetering motions produced by the rotors during the in-flight conversion process from rotary-wing to fixed-wing flight, or vise versa. The assembly includes a damper valve responsive to centrifugal forces produced by rotational speed of the aircraft rotor. The assembly also includes dampers within the rotor system that operate at variable damping levels in response to centrifugal forces acting upon the damper valve.

Abstract: A hydraulic control circuit for uniform controlled movement of stripping and guiding arms in a tree delimbing apparatus. The piston rods of said cylinders are mechanically coupled to rotate tubular sleeve members with affixed stripping and guide arms between outward and inward positions. The stripping levers and guide arms open and close about a felled tree in a uniform manner for delimbing operations. A valve is provided for actuation to permit the guiding arms to be held in an open position, while the stripping arms are closed about a tree to accommodate a bent trunk.

Abstract: A double acting reciprocating intensifier uses a single low pressure fluid stream as both the power supply and the source of fluid the pressure of which is to be intensified. The entire device, including flow paths, is confined within a compact cylindrical housing. Tandem drive pistons minimize operating frequency, while maximizing intensification ratio and output volume flowrate. Placement of both high pressure cylinders downstream of the drive cylinders permits simple routing of flows through the centers of the low and high pressure pistons. A check valve connected between the high pressure pistons eliminates one of the four high pressure check valves required in the prior art. A single reciprocating valve, whose state is determined by drive and high pressure piston position, coordinates all of the drive side flows. Various components perform multiple functions to permit the compact shape.

Abstract: A hydraulic control circuit for uniform controlled movement of stripping and guiding arms in a tree delimbing apparatus. A pair of flow divider combiner valves allow equal amounts of pressurized fluid to communicate with and actuate said cylinders. The piston rods of said cylinders are mechanically coupled to rotate tubular sleeve members with affixed stripping and guide arms between outward and inward positions. The flow divider combiner valves provide equal rates of said fluid to flow to said cylinders to insure said piston rods and mechanically affixed stripping arms and guide arms are moved at equal rates of speed. Thus the stripping levers and guide arms open and close about a felled tree in a uniform manner for delimbing operations.

Abstract: A fluid-pressure driving device including a main actuator unit having a piston adapted to travel a full part of a predetermined stroke and an accelerating actuator unit having a piston adapted to travel only a part of the stroke and being capable of operating only during the acceleration of the object to be actuated. These actuator units are operated under the control of a control valve such that, in the accelerating range in which the speed of the object is still low, both actuator units operate to produce a large actuating force, while, after the acceleration, only the main actuator unit operates to fully travel the required stroke.

Abstract: A pressure-medium-driven linear driving arrangement comprises a slide-shaped driving unit supported on a feed rack with a sliding curve. The driving unit comprising step-by-step elements in the form of piston-cylinder systems, which are controlled by a pressure medium via a rotary slide valve to produce a relative motion between the driving unit and the feed rack. The step-by-step elements each have a pivoted lever joined on one hand to the piston of the step-by-step element and on the other hand, joined to the slide housing, constituting self-centering feeding link driving elements.

Abstract: A method of controlling the revolution of the drive shaft of an external combustion engine comprises shaping a control signal for a switching member and converting said signal to mechanical movement of an actuating member. The control signal is shaped in the form of symmetric, periodic sustained vibrations of variable sign, the time intervals of positive and negative values of said vibrations being of equal duration, and the frequency of said vibrations is set equal to a preset number of drive shaft revolutions. The variation of said movement corresponds in time to variation of the control signal, an instantaneous value of the control signal is varied in proportion to the variation of load on the drive shaft, and the actuating member movement is converted to revolution of the engine drive shaft.

Abstract: A compact V-type engine arrangement wherein an odd number of cylinders are formed in opposite cylinder banks of differing lengths with the shorter bank having one less cylinder than the longer bank. A space adjacent the end of the shorter cylinder bank and generally opposite one of the cylinders of the longer bank is utilized to mount an engine driven mechanism, such as a diesel fuel injection pump, which is preferably connected to the individual cylinders for coaction therewith in timed relationship with the engine cycle. Novel compact means for driving the engine fuel injection pump or other mechanism, as well as other mechanical features, are also provided.

Abstract: A pump jack drive apparatus includes a pair of hydraulic cylinders connected to a walking beam of the pump jack for reciprocating the horsehead, and a pair of microswitches or proximity switches which are closed by the walking beam at the limits of the stroke thereof for controlling such stroke. The cylinders are driven and controlled by a pump and control unit which includes a valve for feeding hydraulic fluid to one or the other of the hydraulic cylinders, a control cylinder for controlling the valve, and two solenoid operated control valves for controlling movement of the control cylinder in response to closing of the switches by the walking beam.

Abstract: An improvement in a reciprocating engine used in an energy recovery system wherein the inlet valves to the cylinders of the engine are operated by independently time adjustable actuating means.The system for recovering energy from a pressured reactor comprising a reactor, a reciprocating engine connected to the reactor to receive reaction effluent from said reactor thereby driving the pistons of the reciprocating engine by expansion of the effluent and recovery apparatus downstream of the engine for recovering products from the effluent.The expanding reactor effluent is used to drive the pistons which are especially valved in conjunction with the effluent inlet port in the cylinder to facilitate handling the effluents to adjust the flow into an expansion chamber to obtain maximum recovery, the pistons in turn operate a crankshaft through a crosshead which may power compressors or operate a generator to produce electricity.

Abstract: An engine is provided which converts pressurized gas into useful mechanical energy. The engine uses pressurized gas in such a way to avoid contact between the gas and sliding metal parts. As such, the engine is particularly adapted for use with naturally pressurized geothermal gases which may contain substances harmful to metal. In the preferred form, the engine includes a plurality of reciprocating plungers which serve as energy transfer means. Deformable enclosures such as spheroidal hollow balls made of an elastomer material are positioned on opposite sides of each plunger along its axis of movement. The deformable enclosures exert a force against the plungers to move the plungers when filled with pressurized gas. Each plunger alternately collapses each of the deformable enclosures as it reciprocates. A valve system for controlling the ingress and egress of pressurized gas to the deformable enclosures is responsive to the motion of the plungers.

Abstract: A fluid operated linear actuator control system for drive arrangements of the type wherein two fluid operated linear actuators act upon a shaft at an angle with respect to each other for causing rotation thereof is disclosed. The control system includes a fluid pressure source including a reservoir means, fluid passages connecting the pressure source with each of the fluid operated linear actuators, and control means for communicating the first of the linear actuators with fluid from the pressure source and fluid from the other with the reservoir means to displace the drive arrangement through a first arc sector, and for changing-over the communication to communicate the reservoir with fluid from the one actuator and the other actuator with fluid from the pressure source causing displacement of the drive arrangement through a second arc sector, wherein one of the actuators is in a driving mode while the other actuator is in a floating mode.

Abstract: In a vehicle including a stick cylinder movable to change the attitude of a stick relative to a boom, and an implement cylinder movable to change the inclination of an implement relative to the stick, hydraulic circuit means are provided for serially connecting the cylinders so that as the stick cylinder moves the stick in one direction, discharge of fluid from the stick cylinder is used to actuate the implement cylinder to maintain substantially the same attitude of the implement relative to the ground. A flow divider is interposed between the cylinders to provide the desired degree of actuation of the implement cylinder in response to actuation of the stick cylinder. A dual pressure-responsive bypass valve provides a relatively high pressure relief to the implement cylinder when the implement cylinder is operated independently of the stick cylinder and provides a relatively low discharge path for the implement cylinder when operated in series with the stick cylinder.

Abstract: Apparatus for controlling the ignition timing of an internal combustion engine provided with an exhaust gas recirculation system. A vacuum advancer has a diaphragm mechanism to control the vacuum ignition timing in response to negative pressure in the carbureter when a part of the exhaust gas is recirculated from the exhaust manifold to the intake manifold. A vacuum transmitting valve restricts the transmission of negative pressure in the carbureter to the vacuum advancer, whereby vacuum ignition timing advance of the engine during acceleration is delayed.

Abstract: An oscillatory electro-hydraulic system for a material handling bucket and including two hydraulic cylinder assemblies connectable with the bucket for tipping the bucket, and including a hydraulic pump and control valve and pressure relief valve and a reducing valve, all for directing flow to the respective cylinder assemblies. An electric system is interconnected with the assemblies and with one of the control valves, for controlling the flow of fluid to one of the two cylinder assemblies.