ND73 Entrance lock

Lever with key cylinder outside; push button in lever inside; deadlatch
In unlocked state latch is retracted by either lever
Outside lever is made inoperative by pushing button on inside lever or by key outside
When locked by pushed button: rotating inside lever retracts latch and releases button unlocking outside lever; closing door also unlocks preventing lock-out
When locked by key: rotating inside lever retracts latch but outside lever remains fixed until unlocked by key outside
Inside lever always free for immediate egress