Abstract: An elongated cylinder housing has a piston therein molded from a resinous plastic material. The piston has an angularly extending slot receiving a metal clutch roller operated by a clutch control bar slidable relative to the piston. The clutch control bar is secured to a secondary piston member, and springs are disposed between the piston and the secondary piston member for normally causing the control bar to pull the clutch roller into an engaged position. The clutch roller is disposed in such engaged position to prevent travel of the piston in one direction except when actuating fluid in the cylinder operates on the secondary piston member against the force of the springs to cause the clutch roller to move the clutch control bar into a released position. The bottom of the slot that receives the clutch roller is covered by metal plates to permit free rolling engagement of the clutch roller thereon and at the same time to prevent indentation of the clutch roller into the plastic.

Abstract: A brake cylinder device including a brake piston operable by a spring force to an application position and to a release position in response to an opposing fluid pressure force, and a fluid pressure operable locking device operable responsively to release pressure for locking the piston in the release position and for delaying such locking of the piston in the release position during normal operations to prevent untimely locking-up of the piston.

Abstract: A new and improved ram lock for blowout preventer rams which permits locking of the ram at multiple and adjustable positions to compensate for wear on sealing elements of blowout preventer rams and increase sealing action of the ram without requiring separate special control lines. Automatic locking of the ram at a desired position, such as in adjustable sealing positions to compensate for ram elastomer wear, is obtained.

Abstract: A hydraulically or pneumatically controlled device for locking a piston in he bore of its cylinder at any point of its stroke, comprises, mounted on the piston, fluid-tight seals, a series of wedges, and annular jacks incorporated in the piston. The wedges are arranged to move in translation parallel to the axis of the cylinder under the effect of the annular jacks so as to absorb the increase in the radial plays between the piston and the bore of the cylinder on its pressurization. This peripheral extension which is produced between the bottom of the cylinder on its intake side and the fluid-tight end seal of the piston spaced furthest from it, is followed, after the release of the lateral walls of the cylinder, by a retraction of the lateral walls of the cylinder acting on the outer surface of the wedges. The latter exert a grip on the piston thus effecting positive locking by binding of the cylinder and of the piston.

Abstract: A new and improved ram lock for blowout preventer rams which permits locking of the ram at multiple and adjustable positions to compensate for wear on sealing elements of blowout preventer rams and increase sealing action of the ram without requiring separate special control lines. Automatic locking of the ram at a desired position, such as in sealing position, is obtained.

Abstract: A boom stop having a elongated tubular body portion is mounted on the rod end of one of the hydraulic lift cylinders of a skid steer loader. When the boom of the skid steer loader is lifted, the boom stop is carried outwardly with the rod end of the cylinder, the opposite end of the boom stop dropping into a plane adjacent the rod end of the cylinder when the hydraulic cylinder is almost fully extended. Thus the boom stop is interposed between the outer end of the cylinder body and the rod end of the cylinder to retain such lift cylinder in an extended position under loading conditions.

Abstract: Structure for locking a cylinder piston or the like in one limiting position thereof including a housing, a wedge member secured to the piston for reciprocation therewith mounted within the housing and having a cam surface thereon, and a locking piston positioned within the housing for reciprocal movement transversely of the wedge member also having a cam surface thereon engageable with the cam surface of the wedge member in one position thereof to secure the cylinder piston in the one limiting position. The camming surfaces have a surface area and a locking angle with respect to the cylinder piston to provide improved locking force on the cylinder piston and prevent backup of the cylinder piston on pressure drop or failure to the locking piston.

Abstract: An actuating and bracing jack comprising a cylinder and a rod which are pivotably connected at their free ends to a fixed member and to a moveable member respectively. The cylinder has at least at one of its extremities, an internal resilient catch member, and the rod carries a projection capable of coming into engagement behind the catch member. The cylinder has an enlarged cylindrical chamber housing a displaceable locking device capable of being driven by the rod upon retraction movement thereof, to a first position to which the catch member is firmly applied against the projection. The locking device is displaceable in the opposite direction in the cylinder under the action of an actuating fluid to a second position to which the catch member is freed. The rod is provided with a device for taking up play between the rod and cylinder, such device including a displaceable draw member which acts upon a member urging a slotted portion of the rod outwardly into close proximity to the cylinder.

Abstract: A safety arrester for arresting a hydraulically operated lifting ram of a hydraulic elevator comprises an arrester body within which a plurality of brake shoes are located. The brake shoes are segments of a ring around a passage through the arrester body for receiving the ram, are spring biassed into frictional engagement with the ram, and are displaceable out of engagement with the ram by hydraulic actuator means.

Abstract: A hydraulic hand brake for a fluid pressure actuated brake on a railway vehicle has a cylinder and piston assembly extending coaxially from the brake cylinder. A threaded rod having a non-locking thread extends from the piston and has threaded thereon a traveling nut with a coupling surface on a side away from the brake piston engageable with a second coupling surface on a ring attached to the cylinder. A spring urges the nut in the direction to engage the coupling surfaces and a control piston engages the nut to disengage the coupling surfaces when the control piston is subjected to a hydraulic pressure. Subjecting the piston of the cylinder and piston assembly to a hydraulic pressure will cause the threaded rod to engage the brake piston and to move the brake piston in the braking direction.

Abstract: A rotary actuator, suitable for use with rotors having flow-varying blading, for effecting adjustment of the blading, including two relatively-rotatable and co-axially-disposed main actuator components. Each of the components carries a respective abutment means, one of which is axially-displaceable with respect to its component between an inoperative position and an operative position, and both of which are so disposed with respect to their components that during operation of the actuator with said one abutment means in its operative position, the two abutment means co-operate to arrest relative rotational movement of said components only upon said components reaching a pre-determined relative rotational position.

Abstract: A rotary actuator includes two relatively-rotatable main actuator components, abutment means being carried by the first component and displaceable axially with respect thereto, and further abutment means being carried by the second component. Holding means is operable for holding the displaceable abutment means out of engagement with respect to the further abutment means whereby relative rotational movement between the components occurs when one of them moves in either one of its two directions of rotation. Controlling means is operative, with the holding means inoperative, for urging the displaceable abutment means into engagement with the further abutment means at any relative rotational position of the components.

Abstract: A hydraulic brake actuating and locking device is provided for applying brakes of a vehicle comprising an elongated brake cylinder having a tubular push rod axially operable therein for actuating the brakes and a hydraulically controlled locking device disposed within the tubular push rod and operable when rendered effective for acting on the inner periphery of the push rod to restrain the push rod against axial movement relative to the brake cylinder. The locking device is selectively actuated in accordance with the movement of a locking wedge within the push rod by a hydraulically operated locking piston.

Abstract: A work locating apparatus having a tension member actuated by an actuating member, particularly an actuating piston, via a starting stroke and a working stroke in which a pneumatic cylinder constitutes a control means and a mechanical step-up mechanism is operable between the control means and the tension member with the actuating member abutting directly the tension member by the starting stroke and the step-up mechanism by the working stroke of the tension member.