Patent GB-431000-A (GB)
Title: Improvements in or relating to pneumatically and/or manually operated sliding or folding door gear
IPC: E05F15/56
Filed: 1934-01-15
Abstract: 431,000. Door-operating appliances. OTTAWAY, E. C., 5, Lyndhurst Avenue, Tolworth, Surrey, CHAMBERS, W. E., 58, Manor Drive, Wembley Park, and LUNGHI, P., 70, King's Road, Camden Town, both in London, and LONDON PASSENGER TRANSPORT BOARD, 55, Broadway, Westminster. Jan. 15, 1934, No. 1410. [Class 65 (i)] Fluid-pressure door-operating means, particularly for vehicles, includes a manual control member mounted on the door and arranged so that movement of the control member in either direction brings the fluid-pressure means into operation to move the door in the same direction, thus giving a servo action in both directions of travel. A master .valve is provided to overrule the setting of the control member on the door when required, and also to render the fluid-pressure means inoperative. The arrangement is preferably such that the control member remains in the opening position when so placed but must be held in the closing position, so that closing movement of the door stops as soon as the control member is released, thus avoiding the possibility of injury to any person in the doorway. The control member is preferably set automatically when the door reaches one or each extreme position to keep the door in that position by the fluid-pressure means to prevent rattle. In the arrangement shown, a sliding door 10 is operated by a piston in a cylinder 11, the ends of which are connected through a valve 14 alternatively with a source of vacuum through a pipe 13 and with the atmosphere; a blow-off valve 17 is provided to allow opening of the door if the pipe 15 is obstructed. The valve 14, which is described in detail, has two rotatable discs 27, 28 with ports and passages, the former being the master valve and the latter being operated by a handle 67 pivoted on the door at 68. The valve disc 28 is operated by a rod 58 fixed eccentrically to it and to a crank 59 having a bearing coaxial with the valve ; the rod 58 is slidably engaged by a crosshead 61 vertically slidable on the door 10 by a rod 75, so that vertical movement of the rod 75, in any position of the door, causes movement of the rod 58 and rotation of the valve disc 28. The rod 75 is connected to a crank, pivoted on the door at 71, which is engaged by a pin on the handle 67 and is provided with a toggle spring to maintain it in one or other extreme position relative to a member 77 also pivoted at 71 and biassed by a spring 81 against a stop. The handle 67 and valve disc 28 are normally maintained in midposition by the toggle spring, which snaps over when the handle is moved to the opening position to hold the members there ; in moving the handle to the closing position, the toggle spring snaps back to the neutral position and the rest of the movement carries the member 77 with the handle to extend the spring 81, which returns the parts to neutral as soon as pressure is released, except at the end of the closing movement of the door when a trip arm 89, connected to the control member by a rod 88, crank 87 and rod 76, engages a stop 90 to hold the parts in the closing position. When the door is opened by means other than the handle 67, e.g. by the master valve, the crank 87 engages the stop 90 at the end of the movement to trip the handle 67 to the opening position to keep the door open. The master valve disc 27, which has a larger arc of movement than the disc 28 so that it can overrule the setting of the latter and produce a contrary movement of the door when required, is operated by a handle 23 and is spring-biassed to the mid-position ; it also has an emergency position, in which it remains until reset, to connect all three pipes to atmosphere so that the door is free for manual operation. The master valve may be separate from the valve operated by the handle 67.