Abstract: A door latch mechanism mounts on a door for selectively engaging a door strike. A latch bolt moves along a line of action to disengage the strike and allow the door to be opened. A dead lock prevents unwanted opening of the door and includes a blocking element to prevent movement of the latch bolt along its line of action. A release enables the latch bolt to move along its line of action and includes a bell crank for displacing the blocking element whereby the latch bolt can disengage the strike.

Abstract: A key retaining multiple lock mechanism, suitable for parcel lockers and other structures and capable of being mounted on doors for such structures, has a first lock with a first key trapping tumbler mechanism. The first lock has a strike-engaging tongue and a spring loaded bolt cooperating with a second lock dead bolt structure. The dead bolt is operated by a second key to extend and retract the dead bolt. When extended, the dead bolt compresses the spring-loaded bolt when the mechanism is in a locked condition and acts as a stop when the mechanism is in the unlocked condition, preventing relocking of the structure without first retracting the dead bolt with the second key.

Abstract: A door locking structure forming a panic exit device consisting of an elongated housing recessed within the leading edge of a door structure, an operating rod including latch bolts disposed in said housing, an astragal seated within a channel formed in the leading edge of said housing, link members connecting said rod and said astragal and operating means carried by said housing operating said rod to move said astragal inwardly and outwardly of said channel, a plurality of cam headed lug members carried by said rod, a plurality of studs corresponding to said cam members extending rearwardly of said astragal whereby latching movement of said rods moves said cam members to engage their corresponding studs to hold said astragal in an outward or extended dead locked position.