GB1134256A - Improvements in and relating to a hydraulically operated opening and closing device for doors or the like - Google Patents

Abstract

1,134,256. Hydraulically operated door operating device. ZENTSU DENKI KOGYO K.K. 11 Nov., 1966, No. 50667/66. Heading E2M. An hydraulically operated opening and closing device for doors as illustrated with reference to Fig. 1, comprises a cylinder 16, a pair of pistons 14, 14' interconnected by a piston rod 12 reciprocable in said cylinder, a lug 10 formed centrally of said piston rod, a bifurcated lever 11 engaging at the forked end thereof with said lug and the other end being connected to door-moving means, a pump 32 for supplying pressure fluid to the cylinder and having a pair of discharge ports 21, 31 each communicating with one of a pair of pressure fluid chambers 1, 17 formed between the opposite wall members of the cylinder and said pistons, and a motor 23 for reversibly driving said pump, wherein each of said pistons has a one-way control valve 26 operative to discharge part of the pressure fluid from one of said pressure chambers 1 into an intermediate chamber 29 formed in the cylinder by said pistons as percussive force is applied to the piston from the side of said pressure chamber, and wherein each of said pistons has another one-way control valve 5 operative to release the pressure fluid stored in the intermediate chamber into said pressure chamber when said chamber is under reduced pressure, and wherein the cylinder is formed with a longitudinal groove 13 along the inner wall member 16 thereof, said groove being operative to communicate one of said pressure chambers with said intermediate chamber as the piston is displaced in one direction or the other and to discharge part of the pressure fluid therethrough to adjust the speed of displacement of the pistons.