Mechanism for selectively locking and unlocking a translatable shaft

摘要

A mechanism for locking and unlocking a reciprocating shaft includes a plate fixed to the shaft having an inclined surface. A housing surrounds the shaft and plate having a wall surrounding the inclined surface. A set of balls is located between the inclined surface and the housing wall. An assembly is translatable relative to the shaft and is biased by a spring to jam the balls between the inclined surface and the housing wall to lock the shaft against reciprocation. The assembly is movable against the force of the spring by a fluid pressure actuated cylinder to move the balls away from the inclined surface to unlock the shaft.