Abstract: A vertical landing apparatus comprises a body, at least three legs, and at least three leg locks coupled to the body. The body comprises a body lower end and at least three leg housings. Each leg housing comprises a passage extending longitudinally upwardly from a leg housing lower opening. Each leg is translatable within the passage of a respective leg housing between deployed and leg locking positions. Each leg comprises a leg lower end that is longitudinally outboard of the body lower end. Each leg comprises a longitudinally outboard extent from the body lower end to the lower leg end that is longer when in the deployed position than the leg locking position. Each leg lock is associated with a respective leg and configured to move between a locked position in which translation of the leg is prevented and a disengaged position in which translation of the leg is allowed.

Abstract: A hydraulic lock for a hydraulic system includes a flow control valve and a second check valve. The flow control valve having a first inlet, a first outlet, a first check valve and a flow restrictor, each of the first check valve and the flow restrictor being communicably coupled to the first inlet and the first outlet and being arranged in parallel between the first inlet and the first outlet. The second check valve having a second inlet and a second outlet, the second inlet being communicably coupled to the first outlet, the second check valve further having a ball seating surface having an aperture there through, a ball, and a resilient member biasing the ball towards the ball seating surface to seal the aperture, the aperture being communicably coupled to the second inlet and the second outlet.

Abstract: An assembly is used with a remote source of hydraulic power to control flow of wellbore fluid in a drilling system. At least one choke is operable to control the flow of the fluid to other portions of the system. At least one hydraulic actuator disposed with the choke actuates operation of the choke in response to the hydraulic power. At least one control valve disposed with the choke controls supply of the hydraulic power to and controls return of the hydraulic power from the actuator. An accumulator can be disposed with the choke and coupled to the supply upstream of the control valve. The control valve can couple to the actuator with a pair of pilot-operated check valves disposed in fluid communication between the control valve and the actuator. A stage tank and stage pump can be disposed with the choke. The tank receives the return from the control valve, and the stage pump can pump the return from the stage tank to the source.

Abstract: A camera crane mobile base has a chassis including a front and rear wheel frames joined to a frame body via front and rear frame arms. Axle assemblies are pivotally attached at opposite ends of the wheel frames. A wheel is mounted onto each axle assembly. Front and rear steering systems have linkages pivotally attached to the axle assemblies and to upper and lower steering arms. A post frame is pivotally attached to a frame body with a center post pivotally attached to the post frame.

Abstract: A system, including a magnetorheological (MR) fluid locking system, including a housing, a piston disposed in the housing, wherein the piston is configured to move axially within the housing, an MR fluid disposed in the housing, an MR fluid pump fluidly coupled to the housing, wherein the MR fluid pump is configured to pump the MR fluid into the housing, and an electromagnet configured to magnetize the MR fluid to control axial movement of the piston.

Abstract: A blade pitch-controlled wind turbine system for achieving maximum wind efficiency with variable speed and blade pitch control. The blade pitch-controlled wind turbine system includes a support assembly including a tower; a turbine rotor assembly being supported upon the support assembly; and a blade pitch control assembly being supported upon the support assembly and being in communication with the said turbine rotor assembly.

Abstract: An actuator includes a cylinder and a piston disposed in the cylinder. The piston has a head and a rod. The actuator further includes a collapsible locking member disposed in the head of the piston, and a gas-filled capsule disposed in the cylinder. The gas-filled capsule is in an expanded position when fluid in the cylinder is below a threshold pressure, and the gas-filled capsule is in a collapsed position when fluid in the cylinder is above the threshold pressure. The actuator also includes a lock piston operably connected to the gas-filled capsule. The lock piston engages the collapsible locking member and biases the collapsible locking member radially outward to a locked position when the gas-filled capsule is in the expanded position.

Abstract: A linear actuator assembly (30) having an inner sleeve (100) which moves in a first direction or in an opposite second direction relative to a fixed outer sleeve (90) between a fully extended position and a fully retracted position. The linear actuator assembly (30) includes a stop mechanism (99, 112) limiting the movement of the inner sleeve (100) relative to the outer sleeve (90) in the extended position, the stop mechanism (99, 112) having a first portion (99) associated with said outer sleeve (90) and a second portion (112) associated with said inner sleeve (100) with the first (99) and second (112) portions abutting each other when said inner sleeve (100) is in the extended position to define a hard stop.

Abstract: An actuator includes a cylinder and a piston disposed in the cylinder. The piston has a head and a rod. The actuator further includes a collapsible locking member disposed in the head of the piston, and a gas-filled capsule disposed in the cylinder. The gas-filled capsule is in an expanded position when fluid in the cylinder is below a threshold pressure, and the gas-filled capsule is in a collapsed position when fluid in the cylinder is above the threshold pressure. The actuator also includes a lock piston operably connected to the gas-filled capsule. The lock piston engages the collapsible locking member and biases the collapsible locking member radially outward to a locked position when the gas-filled capsule is in the expanded position.

Abstract: A lock valve includes a lock valve body having a bore with a valve spool reciprocatingly received therein. There is a check valve adjacent each end of the bore. Each of the check valves has a check valve member facing the bore and resiliently biased towards a valve seat at each end of the bore. A pressure relief port communicates with the bore near the center thereof and between lands of the valve spool. A pair of spaced-apart grooves are disposed within the spool valve bore. Each groove permits fluid communication past a land of the valve spool when the valve spool is displaced towards one end of the bore by fluid pressure applied to other end of the bore so as to unseat the check valve member adjacent to the one end to the bore and allow pressurized fluid to pass from the one end of the bore, through the groove, and into the relief port.

Abstract: Providing a hydraulic control apparatus for a vehicular automatic transmission, which makes it possible to design an oil pump with a reduced delivery capacity, thereby permitting an improvement of fuel economy of a vehicle. The hydraulic control apparatus includes a supply passage connecting/disconnecting valve 114A which is operated, in synchronization with a switching operation of a lock-up relay valve 114, to apply a modulator pressure PM via an orifice 118 to a lock-up clutch 18, for placing the lock-up clutch 18 in the lock-up on state, and to inhibit the application of the modulator pressure PM to the lock-up clutch 18, for placing the lock-up clutch 18 in its lock-up off state.

Abstract: An operator cab for a work vehicle is releaseably mounted to a frame of the vehicle via a cab support pin and a flexible mount during vehicle work operations and rotationally attached via the cab support pin for servicing working parts of the work vehicle. A locking cylinder having an end pivotally connected to the cab allows movement of the pivotal connection relative to the cylinder, i.e., allows the cab to move relative to the frame as the flexible mount allows, during work operations. When the cylinder lifts the cab for servicing, movement of the pivotal connection relative to the cylinder is restricted.

Abstract: An actuator comprises an actuator output shaft, a rotatable lock formation associated with the output shaft so as to be axially fixed relative thereto, the lock formation defining an entry passage, a lock pocket and an exit passage, a pin positioned for movement relative to the lock formation such that, as the actuator approaches a fully extended position, a part of the pin is received within and passes along the entry passage, and resilient detent means operable such that, once the pin has moved beyond a predetermined position within the entry passage, the resilient detent means prevents return movement of the pin along the entry passage.

Abstract: A gas cylinder actuator with a safety device for controlled ejection of the piston stem, which has, on the side of the region for fixing the head portion to the jacket, a region in low relief on the inner face of the jacket, designed to interrupt the seal provided selectively either by the gasket elements associated with the piston or by the gasket elements associated with the head portion, and normally operating against the inner face of the jacket, in case of separation of the head portion with an outward movement of the piston.

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: A tensioning apparatus for a circulating element, such as a belt or a band, has a basic body in which a first chamber is formed. A piston is positioned in the first chamber and carries a piston rod. The piston can be displaced in the first chamber by the use of a pressure fluid. Either the piston rod or the base body is attached to the carrier for the belt or band. Either the piston rod or the basic body carries a head piece which can be moved in contact with the circulating element. A locking mechanism for the piston rod can be engaged and disengaged by the use of fluid pressure.

Abstract: A tensioning apparatus for a circulating element, such as a belt or a band, has a basic body in which a first chamber is formed. A piston is positioned in the first chamber and carries a piston rod. The piston can be displaced in the first chamber by the use of a pressure fluid. Either the piston rod or the base body is attached to the carrier for the belt or band. Either the piston rod or the basic body carries a head piece which can be moved in contact with the circulating element. A locking mechanism for the piston rod can be engaged and disengaged by the use of fluid pressure.

Abstract: A system is used with a boom pivoted on a frame about a horizontal pivot axis between raised and lowered positions by a first fluid ram joining the frame and the boom. A releasable locking mechanism locks the boom relative to the frame to prevent pivotal movement of the boom about its horizontal pivot axis. A second fluid ram is disposed between the frame and the boom, the second fluid ram compressed between the frame and the boom when the boom is adjacent the raised position, but prior to the boom achieving a latched position substantially coinciding with the raised position. A fluid circuit of the second fluid ram has two selectable pressure levels. The first level substantially prevents the boom from achieving the latched position, the second level permits the boom to achieve the latched position while providing fluid cushioning to dissipate impact forces between the boom and frame.

Abstract: A rod brake includes a housing containing a pressure vessel and a piston intensifier. The pressure vessel has a bearing tube with a bore sized to receive a movable rod. A cavity is provided between an inner wall of the pressure vessel and the bearing tube for a pressure medium carried therein. Access is provided for surface-to-surface contact with a portion of the piston intensifier and the pressure medium. The piston intensifier includes a piston movable by an external force such as a compression spring or air pressure. The piston has an inner face having an annular ring attached or integrally formed with the piston. Alternatively, the piston has a plurality of dowels extending from the inner face.

Abstract: A fluid pressure cylinder has a piston rod 18 fixed to a piston 26 and projecting outside a cylinder body 23. A lock surface 43 inclining to a radial direction of the piston rod 18 is formed in an engagement member 31 provided in the piston rod 18. A lock rod 35 reciprocating in an about right-angle direction to the piston rod 18 is built into a lock cylinder 33 provided in the cylinder body 23. The lock rod 35 is provided with: a large-diameter section 35a fitted into a guide hole 36 formed in the lock cylinder 33; and a slide contact section 37 provided in the large-diameter section 35a via a constriction section 35b. The slide contact section 37 contacts with a radial-inner portion of the lock surface 43 when the lock rod 35 comes nearest to the piston rod 18.

Abstract: A device for clamping a rod to stop axial and/or rotative movement between the rod and the device. The device includes pressure and clamp units, the clamp unit having a bushing fixed therein and provided with a radially resilient center section normally sized to permit movement of the rod therein. The pressure unit has an actuating piston normally held under fluid pressure in one position but movable under spring pressure toward a second position should the fluid pressure be lost or released. Such movement results in the application of pressure to the bushing to radially deflect its center section inwardly into clamping engagement with the rod to stop its movement. The center section remains clamped on the rod until sufficient fluid pressure is applied to the actuating piston to move it back to its first position thus permitting radial expansion of the center section to release the rod for movement.

Abstract: A pneumatic device for pivoting a pivotal component is articulated to a structural element by means of a joint. Hoses produced from a material of low ductility, to which compressed air can be admitted, are inserted between the pivotal component and the structural element. The hoses contain an airtight bag. When these bags are inflated via valves, compressive forces act both on the structural element and on the pivotal component, causing the latter to swivel out. In order that the hoses cannot migrate, webs run from the joint to the hoses. In order to relieve the hoses in a specific limit position of the pivotal component and to prevent oscillatory movements of the pivotal component, a locking device is provided. The locking device includes a rod, which runs through a brake device fixed to an arm.

Abstract: The invention relates to a device for displacing and locking movable switch parts (1), comprising a hydraulic piston, which is formed by a rod (6) and cooperates, via coupling or locking members (8), with an axially displaceable sleeve (5) intended to receive the radially displaceable coupling or locking members (8), The displaceable sleeve (5) is coupled with the movable switch parts (1) and an externally arranged tube (4), at least partly overlapping the sleeve (5) and the rod (6). A hydraulic duct (11) is connected to the externally arranged tube (4), on a front face of the sleeve (5), facing away from the coupling site for the movable switch parts (1).

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 fastening tool assembly that employs an engine having a sliding sleeve arrangement to control the supply of air to and exhaust from the pneumatic engine. The sliding sleeve arrangement eliminates the need for a conventional main valve and thereby reduces the overall weight and length of the pneumatic fastening tool relative to those tools that employ a conventional engine configuration.

Abstract: A wind-driven electric generator of the downwind type has a wind turbine rotor with oppositely disposed flexible blades attached to the hub of a drive shaft by a flexible spar extending from the hub into hollow portions of the blades. The ends of the spar are attached to intermediate regions of the blades by respective ball joints. Each blade has a root-rib with a stub shaft that is slidably supported in a ball joint mounted on the hub. The blades are pitched to a stall position by a collective pitch mechanism in the absence of proper operating conditions. A nacelle cover of the wind turbine defines an airflow path through the head, and an airflow responsive device inside the nacelle cover controls the collective pitch mechanism to place the blades in a stall position or run position depending upon predetermined airflow conditions. A reverse-cone prevention device limits the ability of the blades to cone reversely.

Abstract: The invention relates to an arrangement for a fluid-driven lock cylinder for the actuation of moving parts such as slides, cores and corresponding units on press tools and injection moulding tools for metal or plastic materials. A piston is accommodated in a displaceable fashion in a piston cylinder. A divided ring forms an end stop for the piston. The stop ring exhibits a maximum diameter which exceeds the diameter of the piston. An inclined external axial part of the stop ring forms a stop for making contact with a counter-pressure part of the piston cylinder. The counter-pressure part is inclined to a degree corresponding to the inclination of the end stop on the stop ring.

Abstract: A rod clamp device having a rod clamp sleeve with a frusto-conical outer surface and an annular cam with a frusto-conical inner surface and an annular ball guide cage arranged to equalize movement of the bearing balls in circumferentially spaced paths along the clamp sleeve so that the annular cam applies pressure through the bearing balls uniformly around the rod clamp sleeve when the cam is moved axially in one direction to a rod clamp position, and the annular cam uniformly releases pressure on the bearing balls when the cam is moved axially in an opposite direction to a release position. The rod clamp sleeve has slots and the ball guide cage is keyed to the clamp sleeve to maintain a preset angular relation therebetween while allowing relative axial movement.

Abstract: A method and apparatus for operating a fluid actuated actuator between one and another alternate positions provides different forces for locking and unlocking the actuator. The actuator may use the same fluid pressure to operate a primary piston within a cylinder and to operate the locking mechanism. Actuator fluid is communicated to unlock the lock member and to move the piston back to its open or unactuated position. A sequencing valve determines the proper sequence of actuating the primary piston before the locking mechanism is driven in place, and clearing the locking mechanism prior to reciprocating the piston back to its unactuated position. Different forces for locking and unlocking the locking mechanism is provided by a free-floating piston mounted on a guide rod. The invention may also be applied to a BOP or the like where different opening and closing forces are desired.

Abstract: A positioning drive having a hydraulic motor with a cam disc which is rotatable with a motor shaft and has a cam, a control valve which, with the hydraulic motor forms a unit with a housing and has a valve piston which is displaceable between several positions, a control element via which the valve piston can be supported on the cam disc, and an adjustment element which is operatively disposed between the control element and the valve piston and coaxial to the latter. The relative position between the valve piston and control element is variable by relative adjustment of the adjustment element with respect to the valve piston. The position of the adjustment element relative to the valve piston is securable by a releasable locking element. The outer of the two parts, valve piston and adjustment element, is guided outwards through the housing, and the locking element is accessible externally of the housing.

Abstract: A fluid pressure operated braking device for a piston rod. The braking device includes a clamp sleeve and a cam member spring biased axially in a direction to actuate the clamp sleeve to a clamp condition, and a fluid pressure operator that provides a hydraulically amplified force for moving the cam member in opposition to the spring to release the clamp sleeve. The fluid pressure operator includes a first piston operated in response to fluid pressure applied thereto to produce a force correlative with fluid pressure and the first piston is connected to a second piston that pressurizes a non-compressible fluid in a closed pressure chamber communicating with a third piston, and a third piston actuates the cam ring in opposition to the spring to release the clamp ring.

Abstract: A thrust reverser synchronization shaft lock system that includes a sync lock control valve (50) and two hydraulically controlled sync locks (60) attached to the synchronization shafts (5) of a jet engine thrust reverser system, is disclosed. The thrust reverser system further comprises an isolation valve (45), a directional control valve (47), a plurality of actuators (19), and synchronization shafts (5). The sync locks (60) are capable via the synchronization shafts (5) of preventing the actuators (19) from deploying the thrust reversers of the jet engines. The sync locks (60) remain in a locked state until an independent control signal sent from the flight deck positively instructs the sync lock control valve (50) to unlock the sync locks (60), ensuring that the unlocking of the sync locks (60) corresponds to a valid thrust reverser deploy signal.

Abstract: A device for clamping an axially movable rod comprising a housing having a cylindrical inner wall and end walls that slidably support the rod. A pair of annular rod clamp rings in the housing having inner clamping surfaces for engaging the rod and frusto-conical outer surfaces, and a pair of annular pistons in the cylinder having an inner surface engaging the outer surface on the annular rod clamp rings and an outer surface slidable in the cylindrical inner wall of the housing. The pistons have spring receiving cavities radially intermediate the inner and outer surfaces thereof and the springs disposed in the cavities for moving the pistons axially in a direction to clamp the rod. A fluid pressure chamber is provided in the cylinder for actuating the pistons in a direction to release the rod.

Abstract: A linear drive is disclosed comprising a single-acting pneumatic piston cylinder unit, at least one spring which acts against the pneumatic force and loads the piston rod in the direction of one end position, and one form-locking pneumatic locking mechanism respectively for each of the two end positions of the piston rod.

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: A lock cylinder for a backhoe slide frame which provides for a positive lock of the slide frame in selected positions is described. The slide frame is supported on two generally horizontal rails that are vertically spaced, and the lock cylinders mount between the vertically spaced rails. The lock cylinders each have a piston that acts to hold the slide frame seated against the upper one of the rails. The piston also provides a wedging action on at least one rail to hold the slide frame from fore and aft movement relative to the rail.

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 pneumatic operated fastener driving device having an improved piston, which together with the cylinder form an elastic interference fit connection so that the piston is held from movement until a sufficient air pressure is applied to the piston. The piston has little or no frictional resistance with the inner surface of the cylinder during the driving or return stroke.

Abstract: A piston sealing arrangement for pressure-fluid-operated systems is disposed in an annular recess of a piston (5) or an associated housing (4) and is composed of a sealing ring element (1A, 1B) as well as an elastic element (2, 3) acting on one side in opposition to the direction of the pressure force (A). Herein the elastic element is dimensioned such that the sealing ring element (1) moves against its elastic element (2, 3) at a pressure smaller than the force against which the piston (6) is moving and by which it is kept on its stop, a pressure-fluid film being formed as a result which safeguards a uniform initial movement of the piston to a largest possible degree.

Abstract: A hydraulic actuator comprising a cylinder formed with an axial cylinder chamber, a main piston provided in the cylinder chamber and dividing the chamber into a first chamber and a second chamber and further formed with a locking chamber, an annular locking groove formed in the cylinder, a locking member cooperating with the annular locking groove to lock the main piston in a predetermined position, the locking member movable between an unlocking position and a locking position, a locking-unlocking piston for moving the locking member into the locking and unlocking positions, and a pressure introducing passageway for selecting the first or second chamber that is higher in pressure and introducing the higher pressure in the selected chamber into the locking chamber of the main piston. The locking-unlocking piston is moved by the pressure introduced by the pressure introducing passageway to move the locking member into the locking and unlocking positions.

Abstract: A hydraulic system for use in a resistance welding machine with a stationary electrode and a variable electrode to provide adjustment of the stationary electrode to ensure proper positioning to maintain weld quality. The hydraulic system comprising an actuated piston attached to the stationary electrode, a motive piston to control the flow of hydraulic fluid in the hydraulic system, a hydraulic locking device to lock the stationary electrode in a stationary position to resist forces during the welding operation and a pneumatic control system to operate the hydraulic system.

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: Spring-loaded cylinder with a tension piston (7) which can be pressurized by a pressure medium. Between the tension piston (7) and a piston rod (3) movable thereby, a cylinder-piston arrangement (19, 20, 21) is installed, whose cylinder chamber (21) can be pressurized from the pressurization chamber (10) of the tension piston (7) via a sealing ring (18), constituting a reflux valve. A first axial friction coupling (17, 18) is provided between the tension piston (7) and the piston rod (3) and a second friction coupling (13, 14) between a housing section (1) and the piston rod (3). The second friction coupling (13, 14) has a buffer clearance A, corresponding to the nominal application stroke. The friction force of the first friction coupling (17, 16) is greater than the expansion force of the cylinder-piston arrangement (19, 20, 21), and the friction force of the second friction coupling (13, 14) is greater than the friction force of the first friction coupling (17, 16) reduced by the expansion force.

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 wherein 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 occur 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: The control valve for an hydraulic actuator is provided with a particular operating state for venting the hydraulic system, which state is attainable positively whenever the hydraulic pressure is inadequate, e.g., in the case of venting or presence of air bubbles; a pressure-monitoring element permits positively the slide element of the control valve to be placed into the venting disposition, in that a particular stop on the slide rod cooperates with a plunger extending from the monitoring cylinder and being subject to the differential force between a spring and system pressure.

Abstract: A system for damping abrupt movement of a punch press ram at the moment of cut-breakthrough with the use of at least two damping pistons disposed within cylinders and arranged to engage the press ram before and during cut-breakthrough. The cylinders within which the damping pistons are carried are connected to a hydraulic control system which permits the pistons to yield with the ram until the instant of cut-breakthrough, whereupon the damping pistons act as rigid bodies and prevent abrupt breakthrough movement of the ram.

Abstract: A piston braking device for a hydraulic or pneumatic cylinder, employing an annular braking plate loosely fitted on the piston rod of the cylinder and rockable into a tilted position relative to the piston rod upon actuation by a plate drive means, and a brake control mechanism operative to apply a counter pressure on the braking plate to maintain or reset the braking plate in a normal right angle position, the braking plate having braking portions on its inner periphery which braking portions are pressed against the circumference of the piston rod to apply friction brakes thereto in a manner which increases the braking force in proportion to the propelling force of the piston rod.

Abstract: A hydraulic control system for use with a vehicle having an earthworking implement and having a plurality of components operated by hydraulic motor means having hydraulic release type brakes associated therewith and including means responsive to actuation of the brake for precluding operation of the motor associated therewith and responsive to release of the brake for permitting operation of the motor.