Patent GB-415597-A (GB)
Title: Improvements in door operating mechanism
IPC: E05F15/04
Filed: 1933-09-22
Abstract: 415,597. Door-operating apparatus. NATIONAL PNEUMATIC CO., 420,Lexing- ton Avenue, New York, U.S.A. Sept. 22, 1933, No. 26228. Convention date, Nov. 15, 1932. [Class 65 (i).] A fluid-pressure engine is connected to a door through a rotatable shaft and is provided with means for holding the control valve in the dooropening position, when placed in that position, until the door is fully open, a releasing member rotated by the shaft then actuating the holding means to release the valve. The mechanism connecting the engine to the door incorporates a spring which yields when the closing of the door is obstructed, the relative movement of the parts connected by the spring serving to actuate the door-control valve to reverse the engine so that the door opens again. The control valve may be operated, to open the door, by a connection from the door handle. The device is shown applied to a swinging door 2 hinged to a door-post 1. The engine is of the differential type, the small cylinder 32 being constantly open to the air at the left-hand end and the space between the two pistons constantly supplied with pressure fluid through a pipe 63 ; the right-hand end of the large cylinder 33 is normally supplied with pressure fluid through a valve 60 to keep the door closed, but when this valve is closed, against the action of a spring 90, the cylinder is opened to the air through a valve 59 on the same stem 61 as the valve 60, and the door is then opened by the differential pressure between the pistons. The piston-rod of the engine is connected by a link 35 to a crank 36 on a vertical shaft 41 rotating in a bearing on the door frame, and the lower end of the shaft 41 has fixed to it an arm 39 carrying at its end a roller 40 engaging a channel guide 4 mounted on the door. The guide 4 is hinged to the door at 3, and its other end is pressed away from the door by a spring on a rod 7. The valve plunger 61 is depressed, to open the door, by a bell-crank 49 operated through a resilient connection 54 by a rod 46 ; this rod is connected to a crank 44 operated by a cord or chain 30 passing down through the centre of the shaft 41, which is hollow. The crank 44 has a latch part 66 which engages with a spring-pressed latch member 68 pivoted at 69. When the valve is operated, to open the door, by pulling the chain 30, the latch part 66 of the crank 44 rides over the latch 68 and is prevented from returning, the valve being thus held in the operated position ; when the door reaches its fully-open position, a face cam 72 on the shaft 41 depresses the latch member 68 to release the crank 44, and the valve and rod 46 are restored to normal by the valve spring 90, the door thus being closed. The lower end of the chain 30 is connected to a bar 23 sliding in guides on the door, the other end of this bar being connected by a cable 25 to the door handle 29, so that turning the door handle operates the valve to cause the door to open by power. If the closing movement of the door is obstructed, the force exerted by the engine will compress the spring 7 supporting the guide 4, and the movement of the guide 4 about its hinge 3 on the door is transmitted, through cranks 12, 15, link 17 and crank 19, to the sliding rod 23 so that the valve is operated to re-open the door ; the crank 19 has a forked arm embracing the rod 23 and bearing on stop nuts 24 screwed on the rod.