Abstract: A directional-control valve is typically comprised of a valve spool that slides linearly within a valve body. The valve body typically includes five internal ports, which are covered or exposed as the spool slides within the body. The typical five-internal-port architecture precludes certain combinations of port connectivity when the spool is in the center position. For example, when the spool is in the center position, providing connectivity between the actuator ports, while simultaneously providing fluid isolation of the supply and exhaust ports, is not directly achievable with a standard five-port architecture. This application describes three embodiments that enable the aforementioned port connectivity when the spool is in the center position.

Abstract: The invention relates to a hydraulic drive device, comprising a piston which is guided displaceably in a cylinder chamber along a working axis and adjoins a working pressure chamber that can be pressurized by hydraulic fluid, and comprising a control means that is guided in the piston at least in some sections between different control states in order to control the flow of the hydraulic fluid from a high pressure supply into the working pressure chamber to move the piston in the working direction and from the working pressure chamber to a return flow chamber, wherein the region of the piston facing away from the working pressure chamber delimits a low pressure chamber that is pressurized by a low pressure supply for hydraulic fluid during the operation of the device such that the piston is moved back against the working direction when the control means connects the working pressure chamber to the return flow chamber. The invention furthermore relates to a method for operating a hydraulic drive device.

Abstract: A hydraulic servo drive device includes: a pilot spool for switching supply and shutoff of oil; a servo piston slid in accordance with the pilot spool; a stroke sensor for detecting a displacement of the servo piston; a first hydraulic chamber in which oil for moving the servo piston is flowed; a first piston oil path for communicating a pump port to which oil is supplied from a pump with a first hydraulic chamber; and a discharge circulating oil path for communicating the first hydraulic chamber with a drain port.

Abstract: The invention relates to a slide vane (20) for a hydraulic power steering of automotive vehicles with a tubular control sleeve (24). Said control sleeve is connected to an output shaft (28) and comprises first control grooves (32) in its inner surface (34). Further, there is provided a tubular sliding sleeve (26) that is disposed at least in portions within said control sleeve (24). On its outer surface (38), the sliding sleeve (26) comprises second control grooves (36) that may be brought to coincide with the first control grooves (32) of the control sleeve (24), said first control grooves (32) being disposed substantially in the circumferential direction of the tubular control sleeve (24) and said second control grooves (36) substantially in the circumferential direction of said tubular sliding sleeve (26). The relative position of said control sleeve (24) and of said sliding sleeve (26) being relatively variable in the axial direction.

Abstract: An electrohydraulic booster comprises an electromechanical transducer and a hydromechanical power stage which is connected to a pressurized medium supply and encompasses a cylinder and a piston that can be moved therein along the working axis. The electromechanical transducer acts on a spool valve which is associated with the hydromechanical power stage, is disposed at least in part inside the piston, is guided within a guiding bore in such a way as to be movable along the working axis, and has two first leading edges that cooperate with corresponding second leading edges located on the guiding bore in order to form a hydraulic sequential control. The guiding bore consists of two parts, i.e. a cylinder-mounted first section and a second section which can be moved along the working axis and comprises the second leading edges.

Abstract: A combined master cylinder and dump valve includes a piston slideable within a body bore that defines a master cylinder for pressurizing a brake port. The piston includes a piston seal for isolating a pressure port from a tank port, a piston bore, a first piston hole set for hydraulically connecting the pressure port to the piston bore and a second piston hole set for hydraulically connecting the piston bore to the tank port. A plunger slideably received in the piston bore has a plunger hole set for selectively connecting the first piston hole set with a plunger bore, and a plunger seal arrangement for selectively isolating the first piston hole set from the plunger bore. The plunger bore is hydraulically connected to the piston bore.

Abstract: A servo operation apparatus for a transmission comprising an input shaft to which the shift-change operation force is mechanically transmitted from a shift lever, a servo unit for boosting the shift-change operation force by feeding a working fluid, and a valve device which feeds the working fluid to, or drains the working fluid from, the servo unit depending upon the shift-change operation of the shift lever, wherein provision is made of an working fluid feed control means which feeds the working fluid in such a manner that the pressure of the working fluid in the servo unit is raised with a steep gradient in the former half until a predetermined initially raised pressure value is reached and, thereafter, is raised in the latter half with a gradient less steep than that of said former half.

Abstract: The brake booster has an envelope (10) with an axis of symmetry (X-X') separated sealingly by at least one movable partition (12) to define at least a first chamber (14) connected permanently to a source of low pressure and at least a second chamber (16). The second chamber (16) being selectively connected to the first chamber (14) or a source of high pressure through a three way valve structure actuated by a control rod (30,130). The three way valve structure has a plunger (28,128) which slides in a bore (26,126) of a piston (20,90) is connected to a control rod (30,130). The position of the plunger (28,128) in bore (26,126) selectively controls the communication between the first chamber (14) and the second chamber (16) or communication between the second chamber (16) and the source of high pressure.

Abstract: An actuator system having a motor that drives a pneumatic spool valve to a known position based upon the number of step commands delivered to it. Valve ports or passages uncovered by the net position difference between the spool valve and a piston create gas flow to or from a control chamber. This gas flow causes a pressure differential across the face of the piston, inducing the piston to follow the spool valve. In this two-stage system, the piston acts as a force amplifier so that large forces and/or inertias may be actuated by positioning the motor. During steady state conditions, the piston achieves the same position as the spool valve is. Proportional control and very accurate positioning of the piston are provided without active position or position rate feedback control.

Abstract: A control valve for controlling the pressurisation of a power chamber of the booster comprises a spool working in a bore in a boost piston. The spool carries longitudinal spaced radial seals, a first one of the seals being disposed so as to prevent fluid from a radial high pressure supply port entering the power chamber through the spool at least when the booster is in an inoperative position. Movement of the spool in a forward operating direction, in response to an input force, causes the first one of the seals to uncover the port so that fluid can enter the power chamber through the spool. The other seal is adapted to uncover a radial return port connected to a reservoir when the input force is released.

Abstract: A hydraulic drive in accordance with the invention includes an axial piston hydraulic motor provided for forming a power drive with a follow-up control valve provided for controlling the pressure medium supply with the follow-up control valve being electronically controlled by a desired position value presetting and mechanical actual position value acknowledgement. An electric motor is provided for the desired position value presetting which can be activated by output signals of a central CN or CNC control unit. The rotor of the axial-piston hydraulic motor is rotatably supported with a circular-cylindrical tubular section of an output shaft thereon on an outer casing surface of an axial extension which is a hollow tubular shape and forms a pivot pin for the rotor of a housing section accommodating the electric motor provided for the desired value positioning control.

Abstract: A pump/motor control mechanism comprising a first actuator for actuating forward a forward/backward member when a fluid pressure is introduced into a first cylinder chamber located in the forward/backward member, a second actuator for actuating backward the forward/backward member when a fluid pressure is introduced into a second cylinder chamber located in the forward/backward member at a position oppositely facing the first actuator, a spool holding hole which is provided in the forward/backward member and has an axis center parallel to the forward/backward direction, a spool which is slidable fitted in the spool holding hole and has on its outer periphery a high-pressure groove connected to a high-pressure fluid source and a low-pressure groove opened to a low-pressure zone, input means for driving forward or backward the spool, a first pressure introducing path whose one end is connected to the first cylinder chamber and whose other end is opened to an area which is on the inner periphery of the spool hol

Abstract: A control system and method for controlling a flight control member employs a hydraulic control valve which is responsive to input from the pilot in a manner to start and stop a hydraulic motor which in turn starts and stops movement of the control member so that the control member assumes the desired flight control position.

Abstract: A multiplexed hydraulic control system having a plurality of channels and a common source of modulated hydraulic fluid. The common source is shared among the plurality of channels by providing a plurality of selector valves, one for each channel, with electrical solenoids for the selector valves being individually controlled by a control means. In a normal operating mode, the selector valves are operated individually and the modulating means is controlled to direct fluid to the selected channel in accordance with the demands placed on movement of the actuator in that channel. In a second slewing mode, multiple selector valves are energized at the same time and the modulator is controlled to produce sufficient fluid flow to slew all of the actuators in the selected channels at a desired rate.

Abstract: A brake booster which includes a control slide that is displaceably supported in a servo piston and acted upon by a piston rod under the influence of brake pressure. The control slide has bores that establish communication between a pressure chamber and a pressure source or return for power brake fluid in the pressure chamber. The control slide is intended to penetrate a control bush in a stepped bore in the servo piston, which has a radial bore for connecting the pressure source with a radial bore in the control slide toward the pressure chamber. The control bush is supported radially movably in the stepped bore.

Abstract: A piston is moveably arranged in a cylindrical bore of a housing and the piston rod extends through one end of the housing for connection to a unit to be controlled. A very high variable control rate of the piston is made possible by a control slide valve formed as a hollow cylinder that is moveable within a coaxial bore of the piston rod. The hollow, cylindrical, control slide valve contains a plurality of apertures that cooperate with ports formed in the piston rod that extends on either side of the piston. A chamber formed on one side of the piston is connected to a source of pressurized fluid and a chamber at the other side of the piston is connected to a return for such pressurized fluid. A control rod is connected to the control slide valve for moving same within the coaxial bore of the piston rod and by specially forming the guiding or leading edges of the apertures formed in the control slide valve, high variable control rates are possible.

Abstract: A hydraulic booster has a boost piston (19) which receives the thrust of boost pressure generated in a boost chamber (15) to move the boost piston for urging a master piston (12) of a master cylinder in a brake applying direction. An input member (17) is relatively movably with respect to the boost piston (19). A pressure regulating device has an input directional control valve (22, 45) for allowing or cutting off communication between the boost chamber (15) and an auxiliary power source (14). An output directional control valve (24, 46) establishes or cuts off communication between the boost chamber (15) and a reserve tank (9). The boost piston (19), the input member (17) and the pressure regulating device are arranged inside a housing (1). An input member positioning device brings the rear end of the input member (17) into contact with a stop member (51) which is anchored to the housing (1), when a pedal force is zero for stopping a rearward movement of the input member.

Abstract: A rotary drive fourway spool valve with rotary feedback includes a spool and a seat sleeve both rotatable within and the spool axially slidable in the valve body and connected by a straight screw thrust. Belleville springs center the sleeve azimuthically relative to the spool.

Abstract: A power-assisted gear shift mechanism for a manual transmission includes a lateral casing mounted on a transmission housing, a first lateral shaft rotatably mounted within the casing and being operatively connected to a manual shift lever to be rotated in shifting operation of the shift lever, and a second lateral shaft in the form of a hollow shaft rotatably and axially slidably mounted on the first lateral shaft and being operatively connected to the manual shift lever to be axially moved in selecting operation of the shift lever, the second lateral shaft being integrally provided with a shift-and-select lever which extends into an interior of the transmission housing to be selectively engaged with a plurality of shift heads in axial movement of the second lateral shaft.

Abstract: A vehicle four wheel steering system including a rear wheel steering mechanism with a power assist device. The rear wheel steering mechanism includes a steering rod extending transversely of the vehicle and having the opposite ends connected with tie rods which are in turn connected with knuckle arms of the rear wheels. The steering rod is provided with a power cylinder in which a piston is slidably disposed. The piston is provided on the steering rod and defines hydraulic chambers in the cylinder. A control valve is provided to control hydraulic oil supply to the power cylinder. The control valve has a casing which is connected with the steering rod through an interconnecting section and hydraulic oil passages are formed in the interconnecting section for passing hydraulic oil to and from the power cylinder.

Abstract: A pulsation limiter for a manually actuated hydraulic valve includes a spring biased, motion retarding plunger in an auxiliary bore within the valve housing and having a helical groove disposed on its periphery abuts against the input sleeve during the initial portion of its travel to actuate the brakes, a check valve in the plunger allowing filling of the expanding cavity in the auxiliary bore behind the motion retarding plunger. When the brake pedal is released partially or completely, the input sleeve moves until it abuts against the plunger. Thereafter, the pressure buildup in the auxiliary bore cavity closes the check valve in the plunger and the input sleeve can only move relatively slowly back to its initial position as the fluid trapped in the auxiliary bore cavity exits through the helical groove.

Abstract: A pressure-unbalanced hydraulic amplifier valve assembly has an axially slidable amplifier piston and a control plunger axially slidably arranged in the amplifier piston with a loose fit to permit a slight radial movement thereof in the amplifier piston. For providing a tight seal in the zone of control ports arranged in the amplifier piston, the control plunger is urged in that zone radially against the amplifier piston by a transverse piston continuously exposed to the system pressure. A pressure piston engages one end of the control plunger and is exposed to an external force (such as a braking force applied by a pedal) for axially displacing the control plunger. In order to eliminate undesired axial force components from the force applied by the transverse piston, a force-transmitting ball contacts the transverse piston and an inner wall of the control plunger forming a throughgoing axial bore and constituting an axially linear track for the ball.

Abstract: In a vehicle hydraulic system of the open center kind, hydraulic fluid for operating vehicle services is circulated continuously, normally by an engine-driven pump. A closed center booster which requires a substantially constant pressure differential to operate it, is included in the open center system, the pressure differential being provided by a fixed restriction. The fixed restriction may be operative when the pump is operative, or only when the booster is operative. The booster is arranged so that in operation, high pressure fluid entering a boost chamber displaces an equal volume of fluid from a forward chamber into the system. The booster may also include a one-way valve allowing flow of fluid from the forward chamber to the boost chamber.

Abstract: An unbalanced hydraulic valve assembly includes a first plunger element slidably and transversely displaceably received in a second plunger element wth a loose fit; a work chamber; a pressure supply conduit provided in the valve assembly for introducing pressurized hydraulic fluid thereinto; a control port arrangement in one of the plunger elements in an asymmetrical relationship relative to the circumference of the plunger elements. The control port arrangement permits or blocks flow from the pressure supply conduit to the work chamber dependent upon the relative axial position between the plunger elements. A force transmitting member is supported in the second plunger element for displacement transversely to the direction of relative axial motion between the plunger elements. The force transmitting member engages the first plunger element and is exposed to pressurized hydraulic fluid for pressing the first plunger element against an inner wall face of the axial bore provided in the second plunger element.

Abstract: An integral power steering gear assembly includes a piston and cylinder combination having greater output efficiency through improved fluid balancing and cushioning of the piston at its ends. The improved cushioning utilizes oil capillary slots in lieu of previously proposed epoxy resin strips. The slots may be fed with high pressure fluid filled by feed grooves along the sides of the piston adjacent the output rack. The slots are designed to have a shallow depth, preferably 0.001 inch - 0.0025 inch, which is sufficient to provide for high capillary attraction of the oil molecules to the slot. The trapped oil molecules prevent slip stick action, that is molecular interaction between the piston and cylinder wall, but at the same time, the oil molecules remain trapped or isolated within the walls of the slot thereby minimizing leakage from the slot.

Abstract: An hydraulic booster has a housing provided with a bore, an inlet connected to a source of high pressure fluid, an outlet connected to a reservoir and a boost piston working in the bore. The boost piston is advanced in response to pressurization of a boost chamber by fluid from the source, under the control of a valve mechanism operated by an input member. The diameters of the bore and the boost piston are arranged to provide an annular chamber round the boost piston connected to the inlet, with the sealing diameter at the rearward end greater than that at the forward end of the chamber, where the boost piston is spaced from the bore. The forward end is sealed by a seal mounted in the bore so that it is radially deformable and able to tolerate the radial clearance between the piston and the bore. The seal is preferably a P.T.F.E. ring backed by an O-ring.

Abstract: A hydraulic power booster in a hydraulic brake system for an automatic vehicle includes a booster housing having inlet and outlet ports respectively connected to a fluid reservoir. A piston is slidably received within the booster housing and is connected with a master cylinder of the brake system. The piston is operated by the motion of a spool valve slidably disposed within the piston responsive to depression and release of the brake pedal. The spool valve is operated by a plunger interpositioned between the spool valve and the brake pedal. The plunger slidably extends through an outer cylindrical member which is received within the booster housing. The outer cylindrical member is cooperatively connected with the piston so that it can move in accordance with the movement of the piston. The plunger and outer cylindrical member are exchangeable to vary the ratio of the reaction force with respect to the boost force built up in the booster.

Abstract: A booster for a vehicle braking system has an input piston, a boost piston and an output piston working a bore, the boost piston being advanced in the bore in response to pressure fluid from a source pressurizing a boost chamber under control of a valve.The operation of the valve is dependent on the pressure in the system, and the valve has a valve mechanism working in a bore in the boost piston of which one part has a pressure-responsive face, the valve being operative, on initial movement of the input piston to cause pressurization of the braking system to the threshold level, and application of pressure fluid to the pressure-responsive face to move the part relative to the input piston to place the boost chamber in communication with the pressure source. Threshold pressurization of the braking system may be achieved by pressurization of the boost chamber, or an auxiliary chamber forward of the boost piston to a predetermined level.

Abstract: A fluid actuated positioner for producing a mechanical output signal proportional to a fluid input signal. Input signal acts on input rod of input cylinder to control a main valve which controls flow between chambers of a hydraulic power cylinder. Power cylinder has output piston rod connected to device to be controlled, and fluid forces on output rod are determined by pressure differences across faces of output piston, which differences are determined by amount of metering of main valve. Valve can be simple clearance passage maintained open to permit steady flow therethrough in non-changing signal, or can be spool valve which stops flow during non-changing. Both devices do not require exceptionally close tolerance manufacture, and creep problems are reduced.

Abstract: A hydraulic amplifier having a housing provided with pressure and return conduits, an amplifier piston, and a control slide. The piston is slidably arranged in an axial bore of the housing and itself has a blind axial bore within which the control slide is arranged. The piston and slide together constitute a unit which is free of pressure equalization and which is provided with two sets of passages for selectively placing the face of the piston in communication with the pressure and return conduits, respectively, depending on the axial position of the slide in the blind bore of the piston. The passages are asymmetrical with respect to the peripheral surface of the slide and are so constructed and arranged that whichever set of passages is closed, the slide is pressed radially against the closed passage under the influence of certain pressure differences which prevail in the hydraulic amplifier.

Abstract: A hydraulic booster comprising a booster piston, an annular piston bearing against the booster piston and a central piston which is movable within limits relative to the annular piston by the brake pedal to control flow of a pressurized fluid. The central piston and the annular piston are coupled together to move as a unit after the force of a spring is overcome. The central piston is subject to the pressure acting on the booster piston. In order to reduce the force reaction on the brake pedal, the central piston is operated by the brake pedal through a pin subjected to the pressurized fluid, the pin extending centrally through the annular piston in a sealed relationship thereto.

Abstract: A hydraulic power boost apparatus for use with the braking system of an automotive vehicle includes a power piston cooperating with a slide valve to define a plurality of spool valves to regulate the flow of a pressurized fluid therethrough to selectively apply the fluid to boost the force applied to the power piston. A resilient member is positioned within the power piston blind bore to modulate the force transmitted from the slide valve to the power piston. The power piston also includes an annular ridge for engaging a mating annular ridge of the slide valve to limit the travel of the slide valve to prevent the resilient member from being deformed beyond its elastic limit.

Abstract: A relief valve mechanism for a hydraulic booster provides in an open position a by-pass passage leading to a power steering and relieves excess pressure on the upstream side of the hydraulic booster. The relief valve in the open position forms a second throttle besides a normal fixed orifice to decrease through flow rate to the drain to thereby supply sufficient quantity of oil to the power steering when steering is steeply operated.

Abstract: An adjustable guide pin arrangement for an integral power steering gear is provided. A reciprocating valve is provided within the piston of the gear to selectively distribute pressurized fluid to the end of the piston for steering action. An input shaft engages the valve to move the valve providing the input signal. An output pinion engages the piston along the side. The guide pin is mounted in the piston and has two pairs of tapered flat guide surfaces at its distal end. One pair of guide surfaces engages a corresponding tapered slot in the valve for each adjusted position. Screw threads are provided to adjustably move the pin inward for less clearance and outwart for more clearance between the guide surfaces and the sides of the slot. The taper of the distal end of the pin is approximately 2.degree.-21/2.degree.. Each quarter turn preferably provides a differential clearance of approximately 0.001 inch. A tool-engaging slot on the head of the pin provides for easy visual adjustment during assembly.

Abstract: An integral power steering gear with a spool-like valve within the piston is provided with washer springs to center the valve and self locking adjusting nuts for the springs. Nylon locking balls are positioned in radial holes to perform the locking function and are equally spaced around the nut so that the nut is maintained in the centered position for accurate spring loading at all times. Each of the balls is frictionally held within the mounting hole so as to be retained prior to installation. The balls are positioned substantially flush with the top of the threads of the nut. As the nuts are installed, the mating threads in the piston deform each ball providing full frictional engagement with at least one thread, and by bulges with the sides of adjacent threads. Bulges of the deformed ball also serve to stabilize the ball in the holes.

Abstract: The disclosed oil pressure booster includes a spool to be actuated as a brake pedal is depressed, which spool has movable parts of a throttle valve, a return path valve and a control valve, and as the spool is moved in a direction of depressing the brake pedal, the throttle valve is at first closed and then the return path valve is closed, and thereafter the control valve starts to open.

Abstract: An integral power steering gear assembly includes a piston and cylinder combination having greater output efficiency through improved fluid balancing and cushioning of the piston at its ends. The improved cushioning utilizes oil capillary slots in lieu of previously proposed epoxy resin strips. The slots may be fed with high pressure fluid filled by feed grooves along the sides of the piston adjacent the output rack. The slots are designed to have a shallow depth, preferably 0.001 inch-0.0025 inch, which is sufficient to provide for high capillary attraction of the oil molecules to the slot. The trapped oil molecules prevent slip stick action, that is molecular interaction between the piston and cylinder wall, but at the same time, the oil molecules remain trapped or isolated within the walls of the slot thereby minimizing leakage from the slot. The operating oil is delivered with higher efficiency in the power steering unit by a bifurcated oil delivery passage communicating with the inlet slot of the piston.

Abstract: An integral power steering gear includes a valve within the piston exhibiting improved responsiveness and overall operation. The piston incorporates a rack along the side in engagement with an output pinion. Dual washer springs are provided at the ends of the valve mounted in face-to-face, sliding contact. The spring rate that is thus doubled provides an improved response pattern for the power steering gear. The neutral flow of hydraulic fluid is reduced by narrowing the opening between the adjacent grooves in the valve and the piston. These features together give an improved performance envelope in both of the critical parameters; i.e., steering wheel movement versus net output and steering wheel torque input versus net output. Essentially, the envelope is substantially closed with these improvements giving the desirable improved responsiveness and better feel to the steering.

Abstract: A power assist remotely controlled servo controller for proportionally controlling the operation of a directional control valve, the controller including a servo-controlled force amplifying piston assembly to operate the directional control valve and a pilot pressure balanced piston connected to the servo-controlled piston assembly to control the directional control valve. The balanced pilot pressure forces acting on the pressure balanced piston being controlled by either a hydraulic or electric controller from a remote location.

Abstract: A conventional hydraulic braking system using a master cylinder and a force ooster means between the brake pedal and master piston. The force booster means comprises a liquid cylinder and control valve means for selectively communicating the cylinder with a hydraulic pressure source or drain, depending on the application or non-application of manual force to the brake pedal. The control valve is designed to regulate the cylinder movement in accordance with pedal movement while increasing the force applied to the master piston.

Abstract: A rack and pinion power steering system includes a housing within which a rotatable pinion engages a rack to impart movement thereto. The rack is substantially U-shaped having a pair of arms with coaxial openings to slidably receive a rod. The rod extends from the housing to operatively engage a pair of dirigible wheels and the rod is movable relative to the housing when the rack is moved to change the direction of the pair of dirigible wheels. A sleeve on the rod is disposed between the pair of arms and is provided with a valve member to communicate pressurized fluid from a pressure source to a pressure chamber to assist the movement of the rod.

Abstract: A rack and pinion power steering device includes a housing within which the pinion engages the rack to impart movement to the rack upon rotation of the pinion. The rack includes a bore for slidably receiving a pair of plugs which support the rack and a rod which extend through the plugs and housing to engage a pair of dirigible wheels. The plugs cooperate with the rod to form pressure chambers and a valve member carried by the rack cooperates with projections on the rod to communicate pressurized fluid from a pressure source to either of the pressure chambers whereupon the pressurized fluid therein urges the rod to move relative to the housing. The rod also provides for communication of pressurized fluid from the pressure source to the valve member via a passage therein.

Abstract: A rack and pinion power steering gear assembly includes a housing with a longitudinal bore and a sleeve slidably mounted in the longitudinal bore. The rack is slidably mounted within the sleeve and cooperates with the sleeve to communicate an inlet port to either a first working chamber or a second working chamber when the rack moves from a first position to a second position. The rack and sleeve also cooperate with each other to define a pair of feedback chambers and the rack moves from a first position to communicate the inlet port with the first feedback chamber to a second position to communicate the inlet port with the second feedback chamber.

Abstract: A reaction mechanism of a hydraulic control valve including a control valve for regulating hydraulic pressure by controlling hydraulic fluid disgorged from a pump, an input member mechanically connected to the control valve and operated by a driver, the input member having a smaller diameter portion and a larger diameter portion, an annular reaction regulating member into which the smaller diameter portion of the input member is slidably inserted, a diameter of the annular member being equal to or less than the larger diameter portion of the input member, a biasing member for normally urging the annular member toward the larger portion of the input member, and a member for supplying the hydraulic pressure regulated by the control valve into an area between the annular member and the large diameter portion of the input member to displace the annular member from the larger diameter portion of the input member against the biasing member.

Abstract: A hydraulic brake booster operatively connects with a pressurized fluid source and a master brake cylinder to convert the pressure within the pressurized fluid source to a power assist to the master brake cylinder during a brake application. The booster includes a cylindrical housing defining a bore and a piston is slidably mounted in the bore to define a pressure chamber and to operatively connect with the master brake cylinder. A valve member is slidably disposed within a bore within the piston and is movable upon a brake application to communicate the pressurized fluid source to the pressure chamber which urges the piston into engagement with the master brake cylinder. In a rest position inlet and outlet openings on the piston communicate fluid through the piston without any transfer of the force within the pressurized fluid to the piston.

Abstract: An integral power steering gear with a valve in the piston is provided having a short piston and cylinder to conserve space and weight. The input shaft is mounted on a bearing carried by an inwardly projecting annular portion on the bearing cap. The projecting portion mates with a recess in the end of the piston when the piston is moved to the full extreme in that direction. The valve guide pin has been relocated at the input shaft end of the valve where maximum support of the valve is realized and improved reversibility of the valve under all conditions is gained. In the bearing cap, both a high pressure seal and a low pressure weather seal are provided. An insert ring between the two seals serves as backup to the high pressure seal. In an alternative embodiment, the insert ring may be tapered toward the inside of the gear to allow use of a thin wiper-type seal.

Abstract: A load-controlling piston of the double-action type, dividing an associated cylinder into two compartments, is positionable by a hydraulic servomechanism comprising a block wherein a high-pressure supply port and a low-pressure discharge port communicate with a pair of pressure cylinders occupied by respective plungers which are hydrostatically linked with the piston through conduits connecting the compartments of the piston cylinder with respective pressure chambers of variable volume formed by the two pressure cylinders. Each plunger has an axial bore accommodating a valve stem with a tapering head which is surrounded with small clearance by a valve chamber communicating at one end with the discharge port and at the opposite end via an internal passage with a gap adjacent a plunger face remote from the corresponding pressure chamber.

Abstract: A fluid operated motor amplifies input force and communicates a greater amount of output force to a reaction device. Input effort is directly proportional to the amplified output effort. A power piston residing in a cylinder bore has an input rod, having a spool valve and a reaction piston, laterally movable through a bore in the power piston. Fluid flow is metered to a working chamber by the spool valve in response to the position of the input rod. An output rod moves with the power piston to deliver an amplified force to a linkage.

Abstract: A hydraulic servo-motor for the control of an internal combustion engine which is equipped with a servo-piston, with a fuel quantity control mechanism and with a control slide valve member arranged coaxially to the servo-piston which itself is in operative connection with a centrifugal governor; a working medium under pressure is supplied by a pump driven directly or indirectly by the internal combustion engine; an auxiliary piston arranged coaxially to the servo-piston and to the control slide valve member is acted upon by the pressure of the working medium and permits in case of an existing pressure of the working medium, a stroke of the control slide valve member in one direction which is limited by the servo-piston and a stroke of the control piston in the other direction which is limited by the auxiliary piston; a spring supported at the servo-piston acts on the auxiliary piston opposite the pressure of the working medium and clamps together the control slide valve member and the servo-piston in case of

Abstract: A pump control assembly for a variable displacement pump has adjustable biasing means for providing improved control of the pump.