Abstract: A torque limiting system for limiting the torque transferred between a rotating member and another member in which a disc is disposed within the rotating member and a shaft is coupled to the disc for receiving a load. At least one bearing member is disposed in the disc and is urged in a radial direction into engagement with the rotating member to normally couple the rotating member to the shaft to drive the shaft. The bearing member responds to loads on the shaft exceeding a predetermined value for releasing the engagement with the rotating member and decoupling the rotating member from the shaft.

Abstract: An actuator assembly for moving a member, such as a gate valve, or the like, between a retracted and extended position, and a locking device for locking the member in its extended position. A ball screw is connected to the member to be moved and is in threaded engagement with a ball nut so that, upon rotation of the ball nut, the ball screw, and therefore the member, moves between a retracted and an extended position. A gear train is connect able between a power source and the ball nut for transferring torque therebetween to rotate the nut member. The locking device cooperates with the actuator for quickly and easily locking the ball screw in an extended position at any time without requiring it to be retracted and then extended, and includes a plunger that moves axially in a housing in response to movement of the ball screw. The plunger has a reduced dimension portion, and a stem is provided that has a reduced dimension portion and a regular dimension portion.

Abstract: An actuator shaft heat-sensitive locking apparatus is disclosed comprising a cylindrical housing having an axial bore. A shaft link is provided in the bore and is adjustable to contact gate valve actuator shafts of varying lengths. Once adjusted, the shaft link is movable axially between a first position and a second position, allowing the actuator shaft to close the gate valve. There is also provided a means movably extending through the housing for partially blocking the bore and a fusible element slidably mounted in the bore between the shaft link and the means for partially blocking the bore. The fusible element has both a solid state and a heat responsive state. In its solid state, the fusible elemnt prevents movement of the shaft link by enaging the bore blocking means; in its heat responsive state, the fusible element allows movement of the shaft link between the first position and second position.

Abstract: There is disclosed an apparatus for manually locking a pilot valve in an "in service" position independent of an actuating, or pilot fluid pressure. The apparatus may be either manually disengaged or will be automatically disengaged whenever the ambient temperature exceeds a predetermined level. The device includes a valve manipulating knob attached to the exterior end of a valving element for manually shifting the element from a normally closed position to the in service position. The knob includes an "L" shaped locking member which conforms to the contour of the knob, and is adapted to pivot towards the valve body and lock the valving element out in the "in service" position. This pivotal member includes an indicating surface visible from the front when the valving element is locked in an "in service" position. The locking member is comprised of a fusible material selected to yield at a predetermined temperature so as to return the valve to an operating mode responsive to the pilot fluid pressure.