High security push-to-exit pedestrian door control

Abstract

A combination lock/deadbolt is connected to a push-to-open panic-bar device to operate in response to push-bar operation, thereby withdrawing both the push-bar latchbolt and the deadbolt permitting instantaneous and unrestricted egress from a secured area. To maintain the security of the area from unauthorized entry from outside the secured area, a connection between the push-to-open device and the combination lock/deadbolt assembly is implemented with a lost motion connection. The lost motion device, preferably is a flexible cable transmitting force only in tension, assures that any operation of the combination lock/deadbolt will not effect the security provided by the push-to-open device. Further, the push-to-open device may be provided both with a conventional key cylinder lock and a knob, ever, or thumb lever release on the door exterior. Opening action initiated from outside the door through the knob lever or thumb lever release is mechanically segregated from the cable connection to the combination lock/deadbolt, preventing operation of the push-to-open device from the outside causing operation of the combination lock/deadbolt assembly. Accordingly, an authorized individual must have both a key for the key cylinder lock and the authorized combination for the combination lock in order to gain entry to the secured area, yet anyone may exit the secured area without any restrictions or delay merely by pushing the push-to-open bar.