US Patent 7303215 Mortise locking device

A lock assembly includes a single switch actuated by a cam for monitoring the position of a main bolt and an auxiliary bolt. The main bolt and the auxiliary bolt engage and move the cam between an actuated position and a released position. In the actuated position the cam actuates a switch. Actuation of the switch indicates that the auxiliary bolt is retracted and that the main bolt is extended into a locked position. The main bolt includes a tail that engages a portion of the cam to drive the cam to the actuated position. The switch will remain in the actuated condition when the auxiliary bolt is retracted and the main bolt is also retracted.