Lock e.g. for fire door has door frame detector that releases bolt when door is in closed position

摘要

The lock, incorporating a bolt (24) that can be set in retracted or deployed positions by an actuator (26), has a keeper (30) to hold the bolt in its retracted position and a feeler (70) that detects the presence of the door frame and releases the keeper only when the door is closed. The keeper is in the form of a lever (52) with a lug (64) that engages with a recess (50) in the edge of the bolt and prevents the bolt being deployed when the door is not shut.