GB428821A - Control system for doors or the like - Google Patents

Abstract

428,821. Door-operating appliances. COMPAGNIE INTERNATIONALE DES FREINS AUTOMATIQUES SOC. ANON., 70, Rue Louvrex, Liege, Belgium. Nov. 12, 1934, No. 32599. Convention date, Nov. 10, 1933. [Class 65 (i)] A power-operated door is locked hydraulically, against manual operation, at one end of its movement by a piston in a locking cylinder controlled by a valve which is operated by the taking-up or opening of play provided in the connection between the operating means and the door. In the arrangement shown, the door is operated by a rod 5 attached to a piston 6 having arms 5<a> to provide a lostmotion connection with the rod 2<a> of a piston 2 which is moved to the left, to open the door, by connection to a source of vacuum through pipe 3 and is returned by a spring 4, to close the door, when the connection 3 is cut off. The cylinder in which the piston 6 works is filled with liquid, any loss being made up from a reservoir 12 ; the piston is consequently prevented from moving to the left unless a valve 11 in it is opened to allow the passage of liquid. This valve is opened by the movement of rod 2<a> taking up the play in the connection with arms 5<a> at the commencement of the opening stroke of the mechanism, but cannot be opened by pushing the rod 5, so that the door is locked closed except against opening by the piston 2; the valve 11 opens automatically during the closing movement against a spring 7, which normally maintains the parts 2<a>, 5 in the relative positions shown. In a modification, the valve 11 is dispensed with, the spring 7 being arranged in an equivalent manner connecting the parts 2<a>, 6, and the reservoir 12 is connected to the cylinder to the left of the piston 6, so that during the opening of the door the piston forces liquid into the reservoir and compresses air therein to provide the power for the closing movement, the spring 4 not being required. The pistonrod 2<a> carries a piston valve which closes the passage to the reservoir when the door is closed and this locks the door until the pistonrod moves in taking up the play between it and piston 6. A non-return valve is provided to allow passage of liquid under pressure from the reservoir to the cylinder when the pistonvalve is closed, in order to complete the closing movement of the door.