Abstract: A pneumatic-hydraulic control valve includes a valve base and a valve stem movably disposed in the valve base. A first inner oil guiding hole of the valve stem communicates with a first outer oil guiding hole of the valve base. A second inner oil guiding hole of the valve stem does not communicate with a second outer oil guiding hole of the valve base when the valve stem is closed, and communicates with the second outer oil guiding hole of the valve base when the valve stem is opened. Further, the valve stem has a first stressed portion for bearing a fluid closing force and a second stressed portion for bearing a fluid opening force. The outer diameter of the first stressed portion is larger than that of the second stressed portion. Thus, the present invention reduces a valve opening force without affecting the sealing effect.

Abstract: A mast assembly for a mobile drilling machine may comprise: a mast frame including a back, a first side, and a second side, the first side and the second side diverging from the back to form an open front along substantially an entire length of the mast frame; a drill motor assembly movably attached to the mast frame, wherein the drill motor assembly is configured to rotate a drill pipe; and a drill drive assembly configured to drive the motor assembly up and down along a length of the mast frame, the drill drive assembly including: a sheave assembly comprising a plurality of sheaves, wherein the plurality of sheaves include a first sheave aligned generally parallel to the first side of the mast frame and a second sheave aligned generally parallel to the second side of the mast frame.

Abstract: A rotation apparatus is usable with a control drum in a nuclear environment. The control drum is situated on a shaft that is rotatable about a horizontal axis of rotation, and the control drum includes an absorber portion and a reflector portion. The rotation apparatus includes a rotation mechanism that is structured to apply to the shaft in an operational position a force that biases the shaft to rotate toward a shutdown position, with the force being resisted by a motor to retain the shaft in the operational position when the motor is powered. The force is not resisted when the motor is unpowered. The rotation apparatus further includes a rotation management system that controls the rotation of the shaft.

Abstract: A method for controlling a pneumatic actuator (1) of a transmission having at least one sealing element (6, 7) that is arranged between two elements (2, 3) of the actuator (1) that move relative to one another, and within a specifiable operating temperature range in which a leakproofness of the actuator (1) is ensured. The pneumatic actuator is acted upon with compressed air from an air supply system for actuating a transmission component. When a temperature of the actuator (1) is below a glass transition temperature of the at least one sealing element (6, 7), the actuator (1) is acted upon with pre-heated compressed air from the air supply system to warm up the at least one sealing element (6, 7) above the glass transition temperature.

Abstract: A liner hanger features a pressure balanced setting sleeve system that applies no net force to the slips when internal pressure is raised in access ports associated with opposed actuation sleeves such that applied pressure results in opposed forces that cancel each other out. When one of the sleeves is isolated from tubing pressure and the other port to the other sleeve is pressurized, the bi-directional slips are extended and their extended position is locked with a lock ring to hold the set of the liner hanger against release.

Abstract: A safety device for maintaining a load raised cylinder linkage in selected extended position. A combination cylinder engagement rod and locking sleeve with a piston rod engagement channel that will adjustably secure and extended piston rod from a cylinder assembly in a safe secure locked extended position. The cylinder safety stop of the invention is interposed between the cylinder sleeve and the piston end block by the incrementally adjustable engagement panel's positioning via removably positioned stop adjustment pin. An intermediate incrementally adjustable fitting provides for positioning between multiple aligned stop pin engagement apertures.

Abstract: In a reciprocating piston compressor with delivery rate control, the electromagnetic actuating device (3) of the valve lifter (2) has a separate positioning drive (10) for adjusting the working stroke range of the magnetic actuator (5) used, whereby this can be chosen to be small and highly dynamic and only low power losses occur.

Abstract: A hydraulic shifting device for an automatic transmission for engaging and disengaging a parking lock. The shifting device comprises a parking lock cylinder (203) for actuating the parking lock, and a parking lock valve (201) which, for hydraulic control of the parking lock cylinder (203), can be switched to at least first and second shift positions. In this case the hydraulic shifting device comprises a further parking lock valve (202), and the two parking lock valves (201, 202) and the parking lock cylinder (203) are designed and connected with one another in such manner that the parking lock can only be disengaged by pressurizing the parking lock cylinder (203) if the two parking lock valves (201, 202) are each switched to a particular shift position.

Abstract: In one embodiment a system is disclosed that includes an actuation device coupled with a turbomachinery mechanism. The actuation device can include multiple fluid pathways and a valve to alternatively place each of these pathways in fluid communication with a supply port while another of the pathways is in fluid communication with a return port to selectively move an actuation member along a range of travel. A brake valve may also be included to provide pressurized fluid to the actuation member when the actuation device is in an on condition and divert at least a portion of the pressurized fluid away from the actuation member through another pathway when the actuation device is in an off condition. A fluid-powered brake is coupled to this further pathway to selectively apply braking force to the actuation member in response to the diverted pressurized fluid.

Abstract: A control system of a hydraulic type for a thrust reversal device with which a jet engine nacelle is equipped, and associated with a nozzle variation device, is provided by the present disclosure. The control system includes at least one additional control unit hydraulically connecting actuators together, wherein hydraulic supply lines from the control unit in a nozzle mode and from the control unit in a reverser mode are then able to communicate hydraulically with each other. A plurality of control valves are laid out so that when the unit for driving the actuators in a nozzle mode is active, a corresponding hydraulic signal controls the valves of the control unit in a position such that the hydraulic supply lines of the actuators from the driving unit according to a reverser mode are cut off.

Abstract: A locking piston assembly (100) is provided according to the invention. The locking piston assembly (100) includes a piston chamber (107), a piston rod (106) configured to be substantially extended from and substantially retracted into the piston chamber (107), and a piston head (108) coupled to the piston rod (106) and configured to move reciprocally in the piston chamber (107). The locking piston assembly (100) further includes at least one lock (120) configured to mechanically lock the piston head (108) and the piston rod (106) in at least a substantially fully extended position. The lock (120) is configured to unlock the piston head (108) and the piston rod (106) in a presence of a pressurized fluid provided to retract the piston rod ( 106). The pressurized fluid is introduced into the piston chamber (107) and the piston rod (106) is retracted only after the lock (120) is unlocked.

Abstract: A piston type pneumatic engine, including a cylinder block, a piston, a cylinder, a crankshaft, a connecting rod, a camshaft, and a device for controlling the opening or closing of a gas valve. A cylinder cover arranged on the cylinder block is provided with an inwardly-opened type compressed-gas intake valve and an exhaust valve. An intake cam and an exhaust cam are arranged on the camshaft. The opening or closing of the intake and the exhaust valves is controlled by a rocker arm which is driven by the camshaft. The camshaft is driven by the rotated crankshaft via a timing chain or belt.

Abstract: A hydraulic lock system includes a spring pack defined between a female spring support and a male spring support, the spring pack includes a multiple of serrated washers, each of which defines an inner diameter which is greater than a diameter of the actuator rod and an outer diameter greater than an inner diameter of the cylinder.

Abstract: An apparatus may have a cylinder including a piston rod and a chamber in which a working fluid is received to resist movement of the piston rod into the chamber, and an accumulator having a first chamber in communication with the cylinder chamber to receive fluid from the cylinder chamber upon movement of the piston rod into the cylinder chamber. The apparatus may also have a pressure controller having a fluid chamber where some of the working fluid may be received and an actuator operable to increase the volume of the fluid chamber when the piston rod is retracted into the cylinder chamber to increase the total volume in which the working fluid may be received, wherein the increased volume of the fluid chamber may accommodate fluid movement in the assembly not caused by movement of the piston rod.

Abstract: A valve device and method for the activation of an actuating drive, which can be acted upon with a pressure medium by a position controller. The position controller can be acted upon by a working connection of the actuating drive with a pressure medium which can be delivered to the position controller via a feed pressure connection. The valve device includes means for blocking the actuating drive in the event of a failure of the feed pressure. The blocking means includes a pilot-controlled shut-off valve which is arranged in the region of the working connection of the position controller, and a pilot control valve arrangement connected to the feed pressure connection of the position controller to control pressure of the feed pressure connection and cause the pilot-controlled shut-off valve to assume a shut-off position when the feed pressure falls below a defined first limit value.

Abstract: An adjustable length cylinder assembly includes a housing and a piston reciprocably mounted within the housing for movement between an extended position and a retracted position. The piston defines first and second hydraulic fluid chambers of differing cross-sectional area on opposite sides of the piston. An accumulator is housed within one of the housing and the piston. Channels communicate hydraulic fluid the first and second chambers and the accumulator during the movement of the piston. A valve member is concentric with the piston and accumulator and rotatable between a first rotary position in which the channels are open so that fluid can be transferred between the chambers to allow retracting and extending movement of the piston and a second rotary position in which the channels are closed so that fluid cannot be transferred and the piston is locked against retracting and extending movement.

Abstract: A locking actuator may be locked in an extended position. A piston with a first and a second end defines a recess that originates proximate to the first end. A strut is adapted to at least partially nest within the recess and the strut is adapted to hold at least one locking mechanism proximate to a tip of the strut. The at least one locking mechanism is held by the strut. The at least one locking mechanism is adapted to move into a first position engaging the piston when the actuator is locked, and is adapted to move to a second position not engaging the piston when the actuator is unlocked.

Abstract: A lock mechanism of a cylinder includes a lock member for locking or unlocking a piston rod by actions of air pressure and a spring force, a third pressure chamber for causing air pressure to act on the lock member, and a third port. In a pneumatic circuit, a check valve and a throttle valve are connected in parallel in each of first and second pipes connecting first and second ports of the cylinder and a solenoid valve and a check valve and a throttle valve are connected in parallel in a third pipe connecting the third port and the first pipe or the second pipe.

Abstract: A pneumatic or hydraulic cylinder (10) having a bore (12) cooperating with a piston (18). Extending from the piston (18) is a piston rod (37). There is further provided a pawl (26) which is engageable with the piston (18) to retain the piston (18) at a desired location. The pawl (26) is moved from engagement with the piston (18) upon fluid under pressure being delivered to one end of the cylinder (10).

Abstract: A valve for controlling flow of cryogenic liquid propellant in a rocket engine comprises a double acting piston-cylinder unit having a first position in which the valve is closed and a second position in which the valve is open, a locking device being engageable with the double acting piston-cylinder unit to lock the unit in the closed position of the valve is closed while being free from the valve in its open position. The locking device has a control piston connected to a locking member to selectively lock and unlock the piston-cylinder unit against the force of a spring acting to lock the piston-cylinder unit, and a control chamber capable of receiving a pressure medium to move the piston and to unlock the piston-cylinder unit. A two-way control valve controls flow of the pressure to the control chamber and to valve closing and opening operation chambers of the piston-cylinder unit.

Abstract: The present invention provides an actuator controlled by an electro-hydraulic servovalve with a failfixed operation upon the loss of electrical power to the servovalve. A lock valve has apertures therethrough with friction pads therein for locking the actuator in position upon loss of the electrical power.

Abstract: A pneumatic piston-cylinder unit has a cylinder (1) in which an air piston (4) with a tubular piston rod (5) is reciprocably actuated by compressed air from two main air channels (18, 19). The air cylinder (1) includes an integrated hydraulic control system (6) having an actuation device (8) which is fixedly mounted in the air cylinder (1) for creating a flow of hydraulic fluid through hydraulic control system (6) when compressed air is present in the main air channels (18, 19) and for stopping the flow of hydraulic fluid and thereby preventing the air piston from moving when there is no compressed air in the main channels (18, 19). A piston (34) and a cylinder (28) of the hydraulic control system (6) are displaceable an adjustably long distance in relation to each other to make it possible to open and close, respectively, a larger or smaller hydraulic fluid passageway thereby controlling the moving speed of the air piston (4) while maintaining the air pressure.

Abstract: The invention relates to a safety arrangement on hydraulic piston-cylinder units. In particular for monitoring locking cylinders, e.g., of operating tools mounted on a grab bucket boom. A sensor for monitoring the piston position is provided on the piston-cylinder unit and is coupled electrically to a monitoring circuit for triggering an alarm arrangement if the piston is incorrectly positioned. The sensor (3) is coupled to an electrically actuatable locking valve (2) coupled in the monitoring circuit (9) for controlling the hydraulic piston-cylinder unit (1).

Abstract: A hydraulic system comprises a mechanical brake assembly having a brake piston engageable with an output rotation shaft of a hydraulic motor, a cylindrical casing having the brake piston slidably received therein and a brake spring resiliently urging the brake piston to engage with the output rotation shaft of the hydraulic motor. The brake piston and the cylindrical casing collectively define a main hydraulic chamber held in fluid communication with a release fluid passageway which is communicable with a hydraulic pump and a reservoir tank through a shuttle valve and a directional control valve. The brake piston and the cylindrical casing further collectively define a secondary hydraulic chamber held in fluid communication with the release fluid passageway through a fluid feed/return passageway on which a brake resistance restrictor provided for restricting flow of the working fluid in the fluid feed/return passageway.

Abstract: Disclosed is a a time delay valve, which has a reduced number of components so that the manufacture thereof is easy and the number of manufacturing processes is reduced, and by which the delay time thereof is easily reset and changed. The time delay valve is disposed incorporated in a casted-housing of the hydraulic motor to be prevented from being damaged. The time delay valve has a spool movably disposed therein in such a manner to be elastically supported by a spring and be moved by a signal pressure applied to a signal pressure port, and an orifice spool movably disposed therein with being elastically supported by another spring. The constant pressure port and the pressure receiving chamber is interconnected with each other through an oil flowing path in the course of an alternating stroke of the spool. The orifice spool is moved by the elastic force of the spring and the pressure difference between a spring chamber of the orifice spool and an oil flowing path.

Abstract: An actuator for a thrust reverser is disclosed which will prevent retraction of the thrust reverser door from its open, reverse thrust position should there be a malfunction in the locking system which locks the thrust reverser door in its closed forward thrust position. Upon deployment of the thrust reverser during a normal aircraft landing, should there be a malfunction in the thrust reverser door locking system, the actuator holds the thrust reverser doors in their opened positions so as to provide a positive, visual indication of such a system malfunction. The actuator has an internal device in the actuator head which, in cooperation with the control rod of the secondary mechanical locking system prevents hydraulic fluid from retracting the actuating piston and rod assembly from their extended positions and thereby prevents retraction of the thrust reverser door from the reverse thrust positions.

Abstract: A method for locking a hydraulic actuator in a predetermined position and a locking hydraulic actuator are provided. The method includes the steps of supplying hydraulic fluid to a forward chamber in the hydraulic actuator, transferring the hydraulic fluid from the forward chamber into a forward moiety of the rearward chamber in the hydraulic actuator, and sealing the hydraulic fluid in the forward moiety of the rearward chamber to accomplish the locking function. Conversely, the actuator lock is released by the application of fluid supply pressure to the rearward variable chamber.

Abstract: In a position independent locking of a hydraulic cylinder/piston mechanism, a pressure limiting member is provided in the supply pipe for the hydraulic medium, with the pressure limiting member being open during the hydraulic displacement of the piston and is closed during lack of hydraulic pressure. The pressure limiting member opens starting from a specific pressurization of the hydraulic medium as a result of a force generated by means of the piston and is located in a related working chamber.

Abstract: This invention relates to an assembly of a hydraulic motor and a combined device for immobilization, comprising: a reaction cam; a cylinder-block mounted to rotate with respect to the reaction cam; a first immobilization member fast with the cylinder-block; a second immobilization member fast with the reaction cam and capable of being disposed in a first position, in which the first and second immobilization means are fast with one another, and a second position, in which these first and second immobilization members do not cooperate for their mutual immobilization. The device for adjusting the relative position of the first and second immobilization members comprising a jack comprising a chamber.

Abstract: A device for operation of a sliding door member, the device being movable between an open position in which the door member is open and a closed position in which the door member is closed. The device includes a pneumatic cylinder having an actuating piston and a rod assembly. A slidable cage sealingly sleeved between the cylinder and the piston reduces the force applied to the piston rod when approaching the open position. When moving towards the first position force is provided initially by conjoined movement of the piston and said cage, and finally by the piston only. A latch for locking the device in the closed position is provided by a spear secured to the piston and rod assembly and a pin to lock the spear disposed in the cylinder. A manual delatching can be achieved by a cable operated spool which moves the pin to unlock the spear.

Abstract: A hydraulic lock cylinder in which a cross bore is provided in an end structure of the cylinder housing which intersects the hydraulic fluid inlet passage to the central bore of the cylinder; a control piston is reciprocally mounted in the control bore; and pressurized fluid is admitted to the opposite ends of the control bore to shuttle the control piston within the control bore between a closed position in which the inlet passage is blocked and an open position in which the passage is open. The control piston includes a flat surface and a control port opening in the flat surface and an annular fitting screws into the inlet passage housing and includes a seal on its lower end for sealing coaction with the flat surface on the control piston to seal the inlet passsage.

Abstract: A hydraulic cylinder that locks into position has a housing (1) with at least one pressure connection (7) and a piston (3) and rod (6) that travel tight in an out of the housing. The locking mechanism comprises a piston (11) that rests against a spring (35) and a barrier mechanism (23) with a cage of balls (25) that roll radially into a locking position in a locking groove (26) and back into an unlocking position in an unlocking groove (22). The primary piston communicates with a hollow space (18) and acts on a primary participating surface (19) and the locking piston communicates with an unlocking space (13) and acts on an unlocking surface (14) by way of the pressure connection. There is a variable choke (17), which disengages after a while, beween the pressure connection and the primary space (18) in the primary piston (3).

Abstract: A hydraulic actuator including an actuator cylinder and a ram slidable therein from a retracted position to an extended position. This ram has an axially extending chamber positioned in an end section and a number of ball passageways extend between this chamber and the outer surface of the ram. A locking ball is positioned in each passageway. A ring is slidably mounted on the ram and is positioned at its forwardmost point of travel to hold the balls so that they do not project from the passageways. A spring biases the ring towards its forwardmost position. A ball moving spool is slidably mounted in the chamber and has an annular ball receiving recess. A stop is located in an end section of the cylinder for preventing further forward movement of the ring and this stop causes the ring to slide rearwardly relative to the ram upon further extension of the latter.

Abstract: The invention is directed to a penumatic or hydraulic drive for opening and closing of doors, in which the linear motion of a double-acting piston 5 driven by a pressure medium is converted into a rotary motion of a spindle 2 through a piston rod 6 and a helical gear box 3. Herein a blocking lever 10 supported in a stationary manner is provided, which in the closed position of the door engages under the action of a spring 18 at a part 11 connected with a piston 5, wherein said blocking lever secures the piston in its end position and is held in its open position counter to the force of an additional spring 15 by a power cylinder 14 acted upon by the pressure means.

Abstract: Power cylinder comprising a housing having a throughbore capped by end plates defining therein a longitudinally extending chamber. A piston including a longitudinally extending body portion mounts for reciprocal movement in and in bearing relation to the portion of the wall surface which bounds the length of said chamber. The piston has a longitudinally extended through passage and brake means immediately of its outer peripheral surface. A valve device associated with the piston body includes a portion thereof in communication with the through passage. The housing has ports respectively communicating with respective end portions of the chamber for selective delivery thereto and discharge therefrom of fluid under pressure and the selective application of such fluid under pressure to one or both ends of the piston.

Abstract: A pneumatically movable device with a safety lock means having a movable member, a pneumatic actuator connected to the movable member and adapted to move the movable member and a direction control valve connected to the actuator. A cylinder for locking is connected between one of the ports of the cylinder and the direction control valve. A spring is disposed in the cylinder for locking. Openings provided at a chamber at a side of the spring are connected to the actuator and the directional control valve respectively through a check valve disposed for preventing the air from flowing into the cylinder for locking. Openings provided at a chamber at a side remote from the spring are connected to on one hand to the actuator through a check valve disposed for preventing the air from flowing into the cylinder for locking and on the other hand to the directional valve through the check valve with a restrictor disposed for preventing the air from flowing into the direction control valve.

Abstract: The apparatus comprise a generally tubular outer element, a generally cylindrical inner element disposed therewithin and sized relative thereto to provide a generally annular operating space therebetween. An intermediate element is disposed in said operating space and is dimensioned relative thereto to create interference fits with said outer and inner elements and prevent relative movement therebetween. Means are provided to introduce pressurized fluid to the respective element interfaces to expand the outer element within the elastic limit thereof to an extent sufficient to release the interference fits and enable relative outer-inner element movement. Re-locking of the outer and inner elements occurs automatically upon depressurization of the fluid and attendant return of the outer element to its unexpanded configuration. Actuating means to effect relative outer and inner element movement upon apparatus unlocking are also provided, and include means to pressurize the fluid.

Abstract: A road vehicle has steerable front and rear wheels, the rear wheels being steered by an electro-hydraulic system responsive to the manual control input to the front wheels. The hydraulic actuator of the system is biased to the straight-ahead steering position by springs, so that the rear wheels are centered in the event of electric or hydraulic failure, and an hydraulically restrained latch element is spring biased to then latch the actuator piston in its centered position.

Abstract: A hydraulic adjustment motor containing a piston-and-cylinder unit is provided at the roll surface of a roll to be moved to position the roll surface relative to another roll surface of a further roll. Each adjustment motor is arranged between the related roll surface to be moved and its related roll stand. A regulation device is arranged between a pressure source, the pressure chamber of the adjustment motor and a hydraulic medium vessel. This regulation device regulates impingement of the pressure chamber with different pressures up to the maximum pressure of the pressure source and regulates the outflow of a selected volume of the hydraulic medium out of the pressure chamber, correlated to the desired lowering of each roll surface, during lowering of the roll surface and for maintaining a residual volume of the hydraulic medium. Consequently, there is provided a defined relative position between the roll surfaces.

Abstract: A control system (70, 70A) is provided that is particularly advantageous for controlling an automatic vehicular clutch. Linkage (23, 23A) for operating the clutch preferably includes a control arm (18, 18A) that is engageable by a latch member (20, 20A) that is driven by either a force actuator (37, 37A) and/or a speed signal (48, 48A) and is operable to hold the clutch in either the engaged or disengaged condition in the event of fluid pressure loss below or rise above a predetermined amount according to the type of clutch and other parameters.

Abstract: The servomotor arrangement has a moving system comprising a piston movable in a cylinder. A latching or retaining member movable transversely of the direction of movement of the system is provided to retain or latch the moving system. The latching member is in operative connection with a pressure chamber, and the pressure chamber is in communication by way of a stop member with a pressure medium source and with a pressure medium sink. The latching member is controllable, a feature which has advantages for the operating behavior of the servomotor arrangement.

Abstract: A method and arrangement for reciprocating a piston in a cylinder of a fluid actuated actuator between one and another alternate positions, and using the piston fluid actuator fluid to move a lock member from a first position to a second position to lock the cylinder when it is moved from one position to its other alternate position. Actuator fluid is communicated to unlock the lock member and to move the piston back to its one position. In another form, the lock member is moved to its first position by the actuator pressure fluid which actuates a valve to communicate actuator fluid pressure from the lock member to the cylinder to move the piston back to its said other position.

Abstract: A fluid-pressure-operated, double-acting working cylinder which dampens the final braking of the work piston, includes a cylinder housing with a movable work piston disposed therein, the work piston dividing the cylinder into two work chambers. A piston rod, on which the work piston is mounted, extends through the housing. At least one auxiliary braking member is disposed on at least one side of the work piston in an offset slidable relation to the work piston. A braking arrangement disposed on the auxiliary braking member is controlled by fluid pressure to brake the auxiliary braking member to a desired position within the cylinder. A dampening chamber, a dampening spring configuration is disposed between the auxiliary braking member work piston such that, following braking of the auxiliary braking member, continued movement of the work piston is effectively dampened.

Abstract: A piston-controlled locking mechanism including an external cylinder having annular retaining means, a first elongated piston located adjacent the cylinder and having ball lock positioning apertures in the extension, a second coaxially located piston positioned inside of the skirt of the first piston and having indentations capable of mating with the ball positioning portions of the first piston, and positioning elements for first moving the inner piston to release the balls and thereafter moving the outer piston to either release or lock the cylinder.

Abstract: A hydraulic piloted pressure reducing and regulating valve which is fail safe for holding the valve at the last selected operating pressure in the event of the loss of control signals. A pressure regulating valve having a body and a control piston therein is provided with a pilot piston in the body which is adapted to be connected to a hydraulic pilot pressure. A spring is provided between the pilot piston and the control piston whereby the control piston can move in response to flow demands in the valve. A rod is connected to the pilot piston with a locking sleeve engaging the rod and releasably locking the rod and pilot piston against movement. A hydraulic pressure port is in communication with the space between the rod and the sleeve for releasing the rod upon application of pressure to the port. The port and the pilot piston are separately connected to a hydraulic fluid supply and a control system whereby upon failure the valve will maintain the last selected operating pressure.

Abstract: A spring applied and hydraulically released motor shaft brake apparatus for a hydraulic motor which is compact in size. The brake apparatus includes a piston slidably mounted in a cylinder defining a brake chamber and a drain chamber. The piston is slidably and rotatably mounted on the motor shaft and a spring is disposed in the drain chamber for biasing the piston towards the brake chamber to thereby lock the motor shaft against rotation. The brake chamber is selectively connectible with a pressurized fluid source while the drain chamber is connected with a drain. The piston has formed therein a passage with a restrictor disposed therein for restricting flow of fluid in the passage.

Abstract: In an indexing system for a member such as a turret head of a lathe, in which the member after undergoing an indexing movement is locked by a locking bolt thrust by spring force into a bolt hole in a plate coaxially fixed to the member, a hydraulic cylinder is used to exert a great force for holding the locking bolt positively and unmovably in each bolt hole against any reactive counter force from the side of the member due to a great load. The hydraulic cylinder is controllably actuated by a single hydraulic system containing also a hydraulic motor for driving the member in its indexing movement and a solenoid valve.

Abstract: A hydraulic circuit for selectively extending and retracting a mobile telescoping boom assembly and for independently extending and retracting an articulated pipe service line mounted on the boom assembly. The circuit can be used with a hydraulic ram to extend and retract the boom assembly or a winch and cable arrangement can be used. A pair of winches are used to extend and retract the articulated service line.

Abstract: The invention is an integrated hydraulic control circuit for actuating the thrust reversers and variable exhaust nozzle on high preformance gas turbine engine powered aircraft. The hydraulic circuits for both systems are integrated into a single housing and are served by common elements. The circuit for the deployment and stowage of the thrust reverser buckets is hydraulically sequenced inhibiting the application of hydraulic power to the actuators prior to withdrawal of the locking pin. In a like manner, the thrust reversers must be fully retracted before the locking pin is deployed. The hydraulic circuit for the thrust reversers also includes a pressure compensating circuit which reduces the pressure applied to thrust reverser actuators with the thrust reversers in the stowed position.

Abstract: An actuator system characterized by parallel connected flow regulator valves for controlling the flow of fluid to and from the extend ends of a corresponding number of fluid actuators. Retract orifices in the fluid lines leading to the retract ends of the actuators prevent cavitation of the extend ends of the actuators under an aiding air load pulling the actuators out during extension thereof.