US Patent 7387076 Locking system for a door of an enclosure

A locking system for a door of an enclosure has a handle, lock, and locking bolts mounted to the door, door jams mounted to the enclosure, dead bolts coupled to the locking bolts, and a blocking bolt coupled to the lock. When door is closed and handle is closed, then locking bolts are moved to locked position, such that door jams block path of locking bolts and thereby prevent door from being opened. When lock is unlocked, dead bolts can move toward each other allowing door to be opened. However, when lock is locked, door cannot be opened because blocking bolt, between dead bolts, prevents dead bolts from moving toward each other.