GB1002313A - Door actuating mechanism - Google Patents

Abstract

1,002,313. Door actuating mechanism. ELECTRO-HYDRAULICS Ltd. Aug. 8, 1963 [Aug. 13, 1962], No. 30951/62. Heading E2M. An hydraulically operated door actuating mechanism having power means for opening a door, means for returning the door to the closed position and means for permitting the door to be manually opened in a direction the same as or contrary to that in which the door is opened by the power means, comprises a box 1 within which is mounted a spigot 3 on which rotates a door driving peg 5 having a cam 10 and a pinion 9, the teeth of which mesh with those on a quadrant 12 forming part of a lever 11 which is rotatably mounted on a spigot 13. The arms of the lever are pivotally and adjustably connected by rods 16, 31 to a piston 18 within a cylinder 19 and a plunger 32 which moves against a spring 35 in a cylinder 33, the cylinders are machined in box 1 and closed by plugs 20, 34. The interior of cylinder 33 is connected by a hole 33a, almost at the end of the traverse of plunger 32, to the interior of box 1. A cam follower 43 mounted on an arm 41, which is pivotally connected to box 1 at 42 engages the cam 10. The other end of arm 41 is connected to a rod 45 which bears on a plunger 46 which moves against a spring 49 in a cylinder 47 machined in box 1 and closed by a plug 48. The cam is shaped so that the follower 43 always tends to maintain or return the door to the closed position. Fluid from a pump (not shown) is supplied, to open the door in respense to an electric signal, to cylinder 19 through an inlet port 28 in plug 20 via passages 21, 23 containing a needle valve 25 and a non return valve respectively and passage 22 into which a plunger 24 on piston 18 enters. Port 56 in plug 34 connected to cylinder 33 by passages 37, 38 containing a needle valve 40 and a non return valve 39 respectively is connected to the suction side of the pump or to a reservoir. The door is closed by springs 35, 49 when the liquid pressure is removed. Damping is provided by the needle valves which by restricting the liquid flow control the movement of the piston and plunger in the initial and final stages of both opening and closing the door. In manual operation in the normal direction the piston and plungers move in the same manner whilst when opening in the opposite direction, after an initial movement, the pinion 9 and quadrant 12 are disengaged as the teeth on the pinion cease.