Abstract: A lock including a housing having an actuator slidably mounted within the housing. A latch bolt and a door-position sensor are mounted within the housing, each extensible and retractable relative to the housing. The actuator has an intermediate position where the latch bolt and sensor are free to move into the housing, a deadlocking position with the actuator shifted in one direction from this intermediate position where the latch bolt is deadlocked in an extended position with the sensor retracted, and another position which produces retraction of the sensor and latch bolt. A pneumatic device powers movement of the actuator toward its other position and a spring biases the actuator toward its deadlocking position.

Abstract: Locking mechanism for locking and unlocking a sliding-type door. The mechanism for the most part is mounted externally of the door, and includes a pivoted, frame-mounted locking member pivotable between locking and unlocking positions. A dead latch latches the locking member in its locking position. An air cylinder is actuated, first to release the dead latch, and then to shift the locking member to its unlocking position. A door-carried locking member also is provided for locking the door at a region remote from the region locked by the frame-mounted locking member.