PNEUMATIC DOOR OPERATOR HAVING NOVEL PNEUMATIC ACTUATOR AND LOCK

摘要

PNEUMATIC DOOR OPERATOR HAVING NOVEL PNEUMATIC ACTUATOR AND LOCK A power door operator for transit vehicles utilizing a rodless pneumatic cylinder (10) to open and close doors (2,3) in the sidewall of a vehicle. Door movement having a controlled door edge force is achieved through coupling an external piston (11) of the cylinder and vehicle doors through belt (16). Magnetic coupling between internal and external pistons of the cylinder provide force having breakaway value applied to the operated door. A novel lock (30, 31, 32, 33) operated by admission of air to the cylinder (10) latches or unlatches the door in its closed position subsequent or prior to door closing or opening. Control of door motion at the ends of its travel is achieved through the use of a novel differential area (10a) in the cylinder. Piston force is modified for positions approaching either end of the cylinder using a sliding rod (40) contained by the piston (10a). Movement of the rod modifies available force.