Door locking system

A modular lock unit including a carrier frame and a heavy base plate and framework is positioned in a steel door jamb. A lock solenoid and an unlock solenoid are connected to opposite ends of a bolt cam slide extending through a vertical slot in a horizontally reciprocal bolt so that vertical movement of the slide effects camming movement of the bolt between an extended locking position and a retracted unlocking position. The slide includes a central slot oriented at approximately 45.degree. and having vertical deadlock end portions. A lock pin in the bolt extends through the central slot of the slide and enters the deadlock portion of the bolt when in either its extended or retracted position. Camming movement of the bolt is effected by the front and rear edges of the slide engageable with front and rear follower surfaces in the slot in the bolt. A control circuit includes a central main control switch for the locking system positioned in a guard station and also includes electric key switches for giving the inmate the permissive ability to unlock his door under the control of the guard. The circuit also provides for automatically locking the door when it is closed and for automatically retracting the bolt in the event that any obstruction is provided in the strike in the door so as to preclude damage to the solenoid employed for extending the bolt. A time delay relay terminates power to the lock solenoid after it has been actuated for 1.5 seconds so as to preclude solenoid damage. The slide for moving the bolt to its extended position is supported by heavy slide bearing surfaces in the support framework so that any force applied to the bolt is not conveyed to the solenoid but is absorbed by the framework and the slide member.