Abstract: A control apparatus associated with a hydraulic lock that contains a piston rod and an operating pin slidably contained within piston rod. A conduit contains a proximal end connected to a push button unit and a distal end connected to a lever arm assembly. The lever arm assembly contains a platform secured to the terminal end of the piston rod and a lever arm rotatably mounted over the operating pin. A cable extends through the conduit between a rocker arm in the push button unit and the lever arm so that when the button is depressed, the operating pin is moved from an inoperative position to an operative position. A locking plate is pivotally mounted upon the distal end of the conduit and arranged to move over the top surface of the platform into locking engagement with the piston rod. A cutout is formed in the plate which engages a groove formed in the terminal end of the piston rod to lock the lever arm assembly to the rod with the lever arm in position to engage the operating shaft.