Emergency door opening mechanism for use with a locking mechanism for a pneumatic differential engine

摘要

Disclosed is an emergency door opening mechanism enabling manual opening of doors in case of an emergency. The door opening mechanism is for use with a locking mechanism (100), the locking mechanism being for use with a pneumatic cylinder/differential engine for a power-operated door. The mechanism includes a locking rod (20), a plunger (24) associated with the locking rod to cause extension and retraction of the locking rod with respect to a door opening/closing gear (46). A spring member (34) is associated with the plunger for maintaining the plunger and the locking rod in an extended position during a door closed position. An aperture is located through a sidewall portion of the gear hub which is capable of receiving an end of the locking rod when the locking rod is in an extended position to lock the door in a door closed position.