Abstract: A lock mechanism including a bolt spring biased toward an unlocked position. Bolt release means including a lever movably mounted on a lock base retaining the spring biased bolt in a locked position. Contact means carried by said lever responsive to hand motion resulting in lever movement and release of the bolt to provide for automatic door unlocking.

Abstract: An exit fixture for a door is connected with the lock on the door and includes manually operated means which when depressed retracts the bolt of the lock, thereby releasing the door. Springs act upon the manually operated means to restore the manually operated means to its original position wherein the bolt will again project from the door. A bellows or other pneumatic device when filled with pressurized air overcomes the force exerted by the springs so as to allow the manually operated means to assume the position in which the latch bolt is retracted, thus permitting the door to be opened and closed without operating the lock.