Abstract: Embodiments of the disclosure relate to a system designed to compensate for flow disturbances when changing a flow rate in the system. The system includes a flow source device having an inlet and an outlet. The inlet is configured to receive fluid at a first pressure, and the outlet is configured to output the fluid at a second pressure that is higher than the first pressure. The system also includes a fluid control device having an inlet port and a drain port. The inlet port of the fluid control device is configured to receive flow from the outlet of the flow source device. Further, the system includes a constant flow regulator configured to provide a leakage flow to a drain output. The constant flow regulator is configured to decrease the leakage flow in response to the drain port of the fluid control device.

Abstract: A fluid actuated linear drive which includes a drive housing and a drive member which is movable relative to the drive housing. The drive force which is necessary for producing the drive movement is provided by a drive fluid which can be fed and discharged through housing channels of the drive housing. The housing channels each with a lateral coupling opening run out at a housing side surface of the drive housing. An L-shaped attachment coupling part which in the position of use is assembled on the drive housing has a coupling limb which is assigned to a housing rear surface and which is provided with two axial coupling openings. The axial coupling openings are in connection with lateral coupling openings via coupling channels. Hence there is the possibility of using the axial coupling openings for the feed and discharge of the drive fluid.

Abstract: A utility umbilical module may include an expandable frame, a plurality of extendable fluid lines arranged on the expandable frame and configured for fluid coupling between a utility plant and a drill rig, an expandable and retractable electrical system configured for electrically coupling a utility plant to a drill rig, and a ground engaging portion configured for over-the-road transport of the module.

Abstract: A rotating mechanism includes a holder assembly, a rotating assembly, and a valve assembly. The holder assembly includes a mounting block. The rotating assembly includes a shaft and a rotating block. The shaft is mounted to the holder assembly. The rotating block is sleeved on the shaft and is mounted to the mounting block. The valve assembly communicates with the mounting block so that gas is capable of coming in to the mounting block to drive the rotating block to rotate and make the shaft rotate.

Abstract: The invention relates to a hydraulic cylinder, for example for use in a hydraulic tool, comprising at least one piston/cylinder combination composed of a cylinder body and a piston accommodated in said cylinder body and provided with a piston rod that projects from said cylinder body, wherein the cylinder body and the piston body define a first cylinder chamber while the cylinder body, the piston body and the piston rod define a second cylinder chamber, and wherein during operation the piston performs alternating forward and return operational cycles under the influence of a fluidum under pressure that is conducted to the first and the second cylinder chamber through a first and a second line, respectively, and a control valve which regulates the supply of a fluid under pressure through the first or the second line to the piston/cylinder combination.

Abstract: A hydraulic actuation unit for controlling the starting and stopping of hydraulic motors includes a first main circuit and a second main circuit, a first recirculation circuit and a second recirculation circuit, a counterbalancing valve, which includes a shuttle, and a first discharge channel and a second discharge channel. The shuttle includes a first check valve and a second check valve. The first check valve includes at least one first flow control element that can move from an open position to a closure position. The second check valve includes at least one second flow control element that can move from an open position to a closure position. The first and second check valves respectively are provided with first damping means and second damping means in order to slow down the passage movement respectively of the first flow control element and of the second flow control element.

Abstract: The present invention relates to a vibration energy harvest device. In the present invention, the vibration energy harvest device is provided for being used to recycle the mechanical energy and thermal energy generated during the vibration, and effectively to improve the power generation efficiency with newly added hydraulic motor and electricity generating unit. Wherein by using an ameliorating valve module and removing the damping hole in the prior art, no matter the damping oil flows from inner cylinder module through hydraulic motor to outer cylinder module or the contrary direction, the flowing damping oil could avoid the hydraulic motor from reciprocating to improve the power generation efficiency.

Abstract: A compressed-air energy storage system according to embodiments of the present invention comprises a reversible mechanism to compress and expand air, one or more compressed air storage tanks, a control system, one or more heat exchangers, and, in certain embodiments of the invention, a motor-generator. The reversible air compressor-expander uses mechanical power to compress air (when it is acting as a compressor) and converts the energy stored in compressed air to mechanical power (when it is acting as an expander). In certain embodiments, the compressor-expander comprises one or more stages, each stage consisting of pressure vessel (the “pressure cell”) partially filled with water or other liquid. In some embodiments, the pressure vessel communicates with one or more cylinder devices to exchange air and liquid with the cylinder chamber(s) thereof. Suitable valving allows air to enter and leave the pressure cell and cylinder device, if present, under electronic control.

Abstract: A double-acting piston compressor (1) includes at least one cylinder (3) in which a double-acting piston (4) moves, the cylinder (3) and the piston (4) jointly defining an upper chamber (5) and a lower chamber (6) each provided with at least one intake duct (7) and at least one delivery duct (8), and each duct including at least one valve (90, 91), and a linking rod (10) connecting the double-acting piston (4) to a transmission member (11) collaborating, on the one hand, with a guide roller (12) and, on the other hand, with a pinion (15), at least one anchoring member (22) collaborating with the pinion (15), a connecting rod (25) to which the pinion (15) is articulated by a pivot pin (26), the connecting rod (25) being connected to the crank (28) of a crankshaft (27) housed in bearings formed in the compressor casing (2).

Abstract: A coupler for an excavator or other apparatus, the coupler comprising a body for receiving an excavator attachment; a first latch member movable into and out of a latching state in which it is capable of retaining the attachment on said body; said first latch member being movable into and out of said latching state by means of a hydraulic or pneumatic actuator, wherein a gravity operated valve, for example a non-return valve, is associated with the actuator, said valve having a first state, wherein fluid can flow through the valve as the latch member is moved out of its latching state, and a second state, wherein fluid is prevented from flowing through the valve thus preventing operation of the actuator to move the latch member out of its latching state, said valve being adapted to adopt said first state when the coupler is in a non-working orientation and said second state when the coupling is in a working orientation.

Abstract: A hydraulic load control valve (10) accommodated between a hand valve (H) and a hydraulic engine (D) has got at least one proportional load control valve (E), controlled by the pump pressure independent of the flow of hydraulic fluid to the engine. The flow to the engine (D) flows via a non-return valve (12), that is prestressed to open at a pump pressure above the upper limit before a given pressure interval, within which the load control valve (E) is adjusted between completely closed and completely open position of the pump pressure.

Abstract: The invention relates to a valve and suitable hydraulic circuit, especially for camshaft adjusters of an internal combustion engine. The hydraulic circuit comprises a number of check valves or two-way valves operating as check valves, in order to provide a rapid camshaft adjuster with a high regulating quality.

Abstract: A control system for a reciprocating device includes a switching valve, a toggle for operating the valve, a trigger associated with the reciprocating device to actuate the toggle, and biasing means disposed on the trigger for applying a biasing force to the toggle. The valve includes a first drive line, a second drive line, a fluid supply inlet and a fluid exhaust outlet. The valve switches between the first and second drive lines upon actuation of the toggle by the trigger, to switch direction of the reciprocating device.

Abstract: An electromagnetic valve, a circuit board on which a control circuit for controlling the electromagnetic valve is mounted, and a cover for covering the electromagnetic valve and the circuit board are installed on a device-attaching surface of an adapter plate disposed at one end in a direction of an axial line of an air cylinder, in a manner so as to be housed within a surface area of the device-attaching surface, and an output port of the electromagnetic valve and a pressure chamber of the air cylinder are allowed to communicate with each other through an air through-hole provided in the adapter plate.

Abstract: An actuator includes a piston within a cylinder, the cylinder having a first fluid port in communication with an open side of the piston, and a second fluid port in communication with a shaft side of the piston. The piston travels in a first direction, toward the shaft side of the piston and in a second direction, toward the open side of the piston. The actuator includes a valve circuit configured to selectively couple the first fluid port with a high-pressure fluid source when piston travel in the first direction is desired, and with a low-pressure fluid source when piston travel in the second direction is desired. The valve circuit is further configured to couple the second fluid port to the high-pressure fluid source when piston travel is desired in the first or second direction, and to close the first and second fluid ports when no piston travel is desired.

Abstract: Provided in series between pump and tank in a control device for a hydraulic control motor are two throttle devices, between which a line leading to the control motor branches off. One of the throttle devices is made up of a controllable throttle valve having a piston, of which one side supports a valve head, which forms the boundary of an annular gap between an inflow duct and an outflow duct. The pressure drop at the annular gap is continuously controllable by a throttle needle, which is arranged on the other side of the piston, in a hydraulic control path. The hydraulic control path extends from the inflow duct through the throttle opening to the tank, running through a precontrol bore in the piston. When the control device functions according to the open-center principal, an unwanted leakage fluid stream through the precontrol bore to the tank is formed when the annular gap is completely opened.

Abstract: A leakage compensation system in a control device (S) has a fully hydraulic steering system (1) with a supply connection arrangement having a high-pressure connection (P) and a low-pressure connection (T). A working connection arrangement has two working connections (CL, CR), a control section between the supply connection arrangement (P, T) and the working connection arrangement (CL, CR). A control element (2) for activating the control section, a steering member (3) and an auxiliary fluid path (12) has a valve arrangement (A6, A7), through which hydraulic fluid can be supplied or drained off.

Abstract: A hydraulic device includes a passage block with a first hole, an internal body received in the first hole connected to a hydraulic module and an actuator. The actuator has a cylindrical shell integrally connected at its one side to the passage block and projecting at its other side from the passage block. The passage block has a first and second passageway to communicate the hydraulic module with a groove means on the internal body, and a third passageway to communicate the groove means with a first chamber of the actuator. A connecting member connects the fluid distributor unit to the other side of the actuator to communicate the groove means with a second chamber of the actuator.

Abstract: In a fluidic device, a space (35) is formed in a passage block (26) to which a plurality of fluidic modules are connected and which is provided, in its inside, with fluid passages (43, 47, 51) for connecting the plurality of fluidic modules to one another. An internal body (36) is received in the space (35). Channels (37, 38, 39) are formed in an outer surface of the internal body so that the channels (37, 38, 39) constitute part of the fluid passages.

Abstract: A pusher which has a stroke shorter than that of a piston at either position on a head side or a rod side in a cylinder main body and which serves as both means for pushing the piston from a stroke end back to an intermediate stopping position and means for stopping the piston at the intermediate stopping position is disposed so as to be movable independently from the piston, and pressing means for causing the pusher to displace to the intermediate stopping position is provided.

Abstract: An actuator assembly has a first and second pilot valve. Each valve has inlets in communication with a fluid supply source and outlets in communication with the control valve. An in-line actuator housing disposed between the fluid powered device and a low connector supports the pilot valves. An elongated sleeve being axially slidably mounted over the in-line housing covers the in-line housing. A radially extending actuating member is coupled to the elongated sleeve whereby movement of the sleeve in one direction operates the first pilot valve to provide a fluid pressure necessary to actuate a first portion of the control valve so that fluid pressure is introduced into the fluid-powered device on the front side of the piston, and movement of the sleeve in the opposite direction causes operation of the second pilot valve so that fluid pressure is introduced into the fluid powered device on the back side of the piston causing the fluid powered device to move in a direction opposite of the first direction.

Abstract: A riding lawn mower is provided that has an engine, a device that requires control and a vacuum actuated control mechanism for controlling the device. The vacuum actuated control mechanism includes a vacuum actuator having first and second chambers separated by a movable membrane, first connecting means for operatively connecting the vacuum actuator to the device, vacuum means for providing a vacuum to the vacuum actuator, activating means for selectively activating the vacuum actuator and securing means for securing the vacuum actuator in place. The securing means also secures the device in place.

Abstract: A rotary hydraulic actuator including a sealed vessel including brackets and a casing, a partition vane attached to a shaft supported by the brackets for dividing an inside of the sealed vessel into a first pressure chamber and a second pressure chamber and pivoting the shaft by a pressure difference between the first and the second pressure chambers, suction and exhaust hydraulic ports and a drain port installed to the casing, a hydraulic control valve mounted to the casing for conducting a hydraulic control along with the suction and exhaust hydraulic ports and the drain port, groove-like hydraulic pressure supply paths installed to a face of one of the brackets in contact with the casing for communicating the first pressure chamber and the second pressure chamber respectively to the suction and exhaust hydraulic ports and a groove-like drain path installed to a face of other one of the brackets in contact with the casing for communicating to the drain port.

Abstract: An improved control system for a movement actuator is disclosed for moving a member between a retracted position and an extended position. The movement actuator comprises a cylinder having a piston with a fluid supply providing pressure to a first and a second side of the piston. A control applies a first and a second fluid pressure on the first and second sides of the piston for moving the member from the retracted position toward the extended position with a force related to a difference between the first fluid pressure and second fluid pressure for reducing the possibility of damage to an unintended object in the path of the member. The control applies the first fluid pressure on the first side of the piston upon the member being in proximity to the extended position for moving the member into the extended position with a force related to the first fluid pressure for insuring proper positioning of the member.

Abstract: A three position four way directional control valve having a single spool is typically used for controlling fluid flow from a pump to a cylinder and from the motor to a tank. The present invention includes a pair of electrohydraulic control valves with one of the control valves controlling pump-to-cylinder communication between a pump and the rod end and head end chambers of a hydraulic cylinder while the other control valve controls cylinder-to-tank communication between the rod end and head end chambers and the tank. Each of the control valves includes a displacement controlled proportional valve for controlling the position of a pilot operated valve member. Actuation of the hydraulic cylinder requires moving the valve member of one control valve to control pump-to-cylinder communication to one of the chambers while simultaneously moving the valve member of the other control valve for establishing cylinder-to-tank communication between the other chamber and the tank.

Abstract: A double-acting hydraulic cylinder is controlled by a pair of three-way solenoid valves respectively fluid connected to the two ends of the cylinder and energized in parallel with a continuous stream of pulse width modulated (PWM) pulses to create a mean effective fluid pressure balance at the cylinder ends that hold a desired position of a connected load and mean effective fluid pressure imbalances in the cylinder ends that produce variable rate load movement in either of two directions to a desired new position, all determined by the pulse duty cycle.

Abstract: A gear shift device for gear boxes for vehicles, comprising at least one pair of mutually connected, double-acting hydraulic cylinders (1,2), where the pair consists of a master cylinder (1) and a slave cylinder (21). The master cylinder can be operated via a gear lever and the slave cylinder moves a mechanism which is connected to gear selector carriers in the gearbox. According to the invention each end section of the master cylinder's (1) piston (4) has an outer (54 or 55) and an inner (56 or 57) piston sealing ring which are arranged at intervals, calculated in the piston's longitudinal direction, and in these end sections there is provided a drilling (52 or 53) whose first end leads into the piston surface between the respective end sections outer and inner sealing rings (54, 56 and 55, 57 respectively), and whose second ends leads into the adjacent end face of the piston (4).

Abstract: An electrohydraulic regulating device, particularly for a motor vehicle rear axle steering assembly, includes an adjusting cylinder. An electrically actuated control valve controls a hydraulic fluid flow to the adjusting cylinder. At least one electrically actuated switching valve blocks or admits a hydraulic fluid flow. A control unit generates control signals for the control valve and the switching valve. A regulating circuit supplies a pulse-width-modulated regulating signal for regulating a mean current of the control valve. A pulse-width-modulated control signal controls a mean current of the switching valve. The same supply voltage is applied to the switching valve and to the control valve. A pulse-duty factor of the control signal for the switching valve is referred to a pulse-duty factor of an adjusting signal for the control valve.

Abstract: A hydraulic system has a pump (1) with at least one load (4, 5) and accompanying bi-directional valves (8, 8a). A first comparator (A) establishes which motor line (6, 7) is carrying the higher load pressure. A second comparator (B) establishes whether the input-side motor line (6, 7) allocated a directional signal identifying the direction of the valve displacement is carrying the higher pressure or whether a load (4, 5) is being operated with negative loading. Depending on the result of the comparison, the load pressure signal (y1, y2) can be processed differently.

Abstract: The present invention comprises a double acting actuator having a piston movable within a cylinder, a main poppet control valve connected to a fluid pressure source, and first and second poppet valves connected in series to a rod side chamber of the cylinder. The piston is extended upon actuation of both first and second poppet valves, while allowing retraction of the piston upon release of either the first or the second poppet valves.

Abstract: In a hydraulic slide valve control for working cylinders with unequal piston speeds, in which the volume stream of the hydraulic working medium that loads the piston is adjusted to the prevailing piston speed and the direction of motion of the piston is set with a pilot-operated distribution valve, it is provided according to the invention that the redirecting valve (S3) is hydraulically pilot-operated with a pilot valve (A), which is adjustable by the control impulses for the working cylinder (1) and that between the pilot control paths (11, 12) from the pilot valve (A) to the redirecting valve (S3) a hydraulically pilot-operated control valve (B) is installed, through which runs one of the two volume streams of the hydraulic working medium, where a piston speed is assigned to each position of the control valve (B).

Abstract: A pilot operated directional control valve communicates fluid between a hydraulic actuator, a pump and a reservoir. A lockout valve is connected between each main control valve work port and a corresponding cylinder port, and operates to reduce fluid leakage therefrom. Each lockout valve includes a pressure responsive poppet valve member which is exposed to fluid pressure in a lockout chamber. A vent control valve is connected between each lockout valve and a corresponding one of the pilot valves. Each vent control valve includes a vent check valve which controls fluid venting from the lockout chamber and a vent piston which is biased to urge the vent check valve to a closed position thereby trapping fluid in the lockout chamber. When both pilot valves are energized, both lockout valves are vented and a float valve moves to a position wherein both cylinder ports are communicated, via the lockout valves and the float valve, with each other and with the reservoir.

Abstract: A piston-slide valve including a housing in which a piston with at least one oil groove and control edge is guided shiftable or slidable in a bore characterized thereby that the oil groove of the piston is manufactured via wire erosion. Also the control edges of the piston are manufactured by wire erosion. The bore of the sleeve bushing is manufactured by wire erosion. The piston is made out of a needle roller. The piston has a length of approximately 13 mm and a diameter of approximately 2 mm. The wire for eroding of the piston as well as the sleeve bushing has a diameter of approximately 2/10 mm. Longitudinal sides of a multiple edged groove base or bottom of the oil groove of the piston and control edges therewith are formed in a first working step procedure and the remaining longitudinal edges of the oil groove and the remaining control edges are formed in a further working step. The piston occupies one position and another working position displaced by 900.degree. from each other.

Abstract: The invention relates to a system for powering the driving actuator of an aircraft undercarriage, the system including a hydraulic generator capable of delivering fluid under pressure to one or the other of two chambers of the driving actuator. According to the invention, the power supply system includes a safety device enabling any overloading of the actuator rod under the effect of pressure peaks to be avoided: said device comprises two pressure relief valves, the first valve limiting the pressure delivered to the annular chamber and being under the control of the pressure in the full-section chamber, and the second pressure relief valve being of the differential type and continuously controlling the pressure difference between the two chambers of the actuator. The invention is applicable to providing very safe power supply systems for aircraft undercarriages.

Abstract: A hydraulic drive is actuated by a CNC means via an electrically actuable valve. The pressure applied to the hydraulic drive or the force excerted by the hydraulic drive is supplied in the form of a signal to a pressure control means or a force control means. The output signal of the pressure- or force control means is supplied via a switch means--shortly prior to reaching the desired position value of the drive--to the electrically operated valve as a control signal. Simultaneously, the output signal of the switch means, which can be supplied to the valve, is interrupted, wherein the switching range shortly prior to reaching the desired position value is smaller than the admissible differential value, determined by the CNC means, i.e.

Abstract: A hydraulic control system for controlling the motion of a double acting hydraulic actuator determines the flow to and from the actuator in accordance with1. the desired movement of the actuator2. the measured hydraulic pressures on opposite sides of the piston of the actuator3. a selected, predefined model of the system of which the actuator forms a partand sets the valves controlling the flows accordingly.

Abstract: A hydraulic actuating system and method comprises a pump which continuously circulates hydraulic fluid out of a reservoir into a pressure line limited to a predetermined maximum pressure by a pressure-limiting valve and a control valve connected to the pressure line controlling flow of hydraulic fluid to an operating cylinder. A clearance volume in communication with the pressure line collects compressed air entrained in the hydraulic fluid flow which upon opening of the inlet valve expands to displace a portion of the volume of flow of hydraulic fluid required for actuation of the operating cylinder.

Abstract: An in-line hydraulic dashpot is disclosed that effectively decelerates the iston of a power cylinder by controllably choking off the oil which is providing pressure to the piston. The in-line hydraulic dashpot of the invention includes a valve spool member movable between an open and closed position along a fluid flow path that supplies oil to the power cylinder. An actuator rod is cooperative with the valve spool member and the piston shaft of the power cylinder to move the valve spool member between its open and closed positions. The in-line hydraulic dashpot eliminates the clashing of mechanical parts and therewith eliminates the noise that would otherwise be generated thereby. The in-line hydraulic dashpot of the present invention makes possible the adaptation of a fixed stroke power cylinder to applications that call for a variable stroke length.

Abstract: An actuator device for mechanisms located within a pressurized environment including a double acting piston and cylinder combination operating in the same environment. The motive power for the piston is provided by pressurized gas from the pressurized environment or from a substitute source, whereby complex and elaborate sealing systems are eliminated.

Abstract: A port mounted fluid control valve construction (18) is mounted to a pneumatic cylinder (10) through the first port (31) and second port (37) of the cylinder. The construction includes a removable valve body portion (22) which is detachable from a manifold portion (20). A tube (34) extends from the manifold portion to an adapter body (36). The manifold portion includes a first inlet (42) which extends to a first outlet (50) through a first passage (52). An ear (44) extends in the first passage. A spud fitting (100) which includes cutouts (110) which enables fluid to pass therethrough, is mounted in the first port of the cylinder. The spud fitting includes a threaded opening which accepts a fastener (102). The fastener extends through ear (44) and holds the manifold adjacent the cylinder. The adapter body includes first aperture (122) which is in fluid communication through the adapter body with the tube. A second spud fitting (100') is mounted in the second port of the cylinder.

Abstract: In a pilot operated control valve system provided with a plurality of valves for controlling a plurality of hydraulic devices such as hydraulic cylinders, there is employed a plurality of valves each of which does not interfere with each other in operation and requires a minimum mounting space in the system to enable the system to be a small system having a construction easily adapted to control a plurality of hydraulic devices and also adapted to simultaneously supply the pressure oil to the hydraulic devices from a pair of hydraulic pumps through the same hydraulic circuit as needs require.

Abstract: In a control valve system provided with a plurality of valves for controlling a hydraulic equipment such as hydraulic cylinders, there are employed a plurality of valves each of which does not interfere with each other in operation and requires a minimum mounting space in the system to enable the system to be a small-sized system having a construction easily adapted to control a plurality of hydraulic equipments.

Abstract: The hydraulic piston cylinder assembly which operates the governor of a turbine which powers a hydropower generator has a servo valve capable of flowing only a portion of its flow requirements during normal low power fluctuation conditions of the turbine's operation. During high power fluctuation conditions of the turbine's operation, such as during start-up, hydraulic fluid also flows to and from the piston and cylinder assemblies through high flow pressure and return conduits that bypass the servo valve. Control of fluid flow in the high flow conduits is accomplished by a proportional throttling valve located in the high flow return line. The servo valve and proportional throttling valve together have a flow capacity which is equal to the flow requirements of the piston and cylinder assembly and they are both actuated by the same electronic controller.

Abstract: A fluid-operated actuator (2) is connected to a pumping unit (12) through a control unit (10) in which are mounted control valves (30,32) for regulating the movements of the actuator. The control valves communicate with the actuator and the pumping unit through conduits in replaceable adaptor plates (60a,60b,60c). By changing the adaptor plates, different operating modes of the actuator can be selected. The pumping unit is carried on the control unit through a rotationally adjustable connection to permit it to be mounted upright although the orientation of the actuator and control unit may vary.

Abstract: A directionally controllable air cylinder has a set of circumferentially disposed air passages formed at each end of a closed tube. A sleeve manifold surrounds the tube and is pneumatically sealed thereto by means of a plurality of O-rings. The O-rings are positioned such that they selectively expose the sets of air passages to the manifold for receiving compressed air and to the atmosphere for venting. The direction of piston movement is determined by the set of passages exposed to compressed air. A pilot piston moves the manifold in response to a pilot air signal in one embodiment and an electrically operated solenoid moves it in another version. The manifold may also be manually or mechanically moved to operate the air cylinder. Hydraulic cylinders utilizing fluids, other than air, are also disclosed.

Abstract: A movable carriage of a support unit is guided via bearing surfaces along a base. A double acting piston and cylinder unit is formed within a bore located in the base. A piston divides the cylinder into front and rear chambers and a piston rod thereof extends through the rear end of the cylinder and is connected to the carriage for movement therewith parallel thereto. A first pressure fluid connection extends through the front end of the cylinder into the front chamber. The bore has a sleeve, the outer surface of which partly defines a channel extending along the exterior of the cylinder. A second fluid pressure connection is also arranged at the front end of the cylinder, but it communicates with the channel to communicate with the rear cylinder chamber.

Abstract: A hydraulic actuator for automobiles includes a hydraulic actuator body composed of a hydraulic cylinder and a plurality of solenoid valves, and an electric control circuit disposed adjacent to the hydraulic actuator body for controlling the operation of the solenoid valves. The electric control circuit operates upon receipt of an execution signal, an analog desired-position signal, and an actual-position signal delivered from a position sensor. The hydraulic actuator thus constructed has an improved degree of compatibility.

Abstract: The invention relates to hydrostatic steering control apparatus of the type having a hydrostatic steering motor which is connected to wheels to be steered and a steering wheel controlled metering or quantity setting device for controlling the hydraulic fluid supplied to the steering motor. A hydraulic amplifier connected to the steering motor has the characteristics of generating and transmitting undesired pressure pulses to the steering motor during steering switching operations. One way pre-stressed check valves are disposed respectively between the quantity setting apparatus motor ports and the steering motor ports. The check valves open in the direction of the steering motor ports and operate to allow bypassing the amplifier during the steering switching operations.

Abstract: A hydraulic control system comprising a hydraulic actuator having opposed openings adapted to alternately function as inlets and outlets for moving the element of the actuator in opposite directions and a variable displacement pump with loading sensing control for supplying fluid to said actuator. A pilot operated spool type meter-in valve is provided to which the fluid from the pump is supplied and a pilot controller alternately supplies fluid at pilot pressure to the meter-in valve for controlling the direction and displacement of movement of the meter-in valve and the direction and velocity of the actuator. A pair of lines extends from the meter-in valve to the respective openings of the actuator and a pilot operated meter-out valve is associated with each line of the actuator for controlling the flow out of the actuator when that line to the actuator does not have pressure fluid from the pump applied thereto.

Abstract: A base means (12) for directing fluid from a pneumatic control assembly to a number of pneumatic cylinders wherein the base means (12) is remotely mounted from the pneumatic cylinder and the pneumatic control assembly is mounted to the base means (12) and is in fluid communication with the base means (12) through base ports (38,40) which extend completely through the base means (12). The base means includes an upper and lower support surface (28,30), as well as side walls (31,32) and end walls (33,34) extending therebetween, and also includes communication ports (35,36) disposed on the faces of the walls. Flow passeges provide (44,46) fluid communication between the base ports (38,40) and the communication ports (35,36) and delivery means (48) extend between the communication ports (35,36) and cylinder ports located on either side of the piston in a pneumatic cylinder.