Perimeter security system with improved Z-bar lock for maximum degree of mechanical and electronic protection

摘要

A Z-bar security system, one which is provided with a key and a secured latch, is combined with an electronic alarm and monitoring system. This combination provides the maximum degree of both mechanical and electronic security. In a preferred embodiment, a Z-bar latch assembly has a three-position rotatable cylinder which is operable by a key from outside of the door. These three positions correspond, respectively, to "open", "viewing" and "closed" positions of the door.