Improvements in safety cut off devices for hydraulic pressure systems such as fluid-operated brakes

摘要

787,339. Hydraulic brakes. DARQUIER, J. J. Dec. 8, 1954, No. 35539/54. Class 103 (1). [Also in Group XXIX] A safety cut-off device for hydraulic brake systems comprises a valve body 1 with an inlet 2 for connection to a supply pipe, outlets 4 for connection to branch pipes to the brake cylinders, and branch ducts 3 connecting the inlet to each of the outlets, and one or more valve members 5 normally positioned intermediate the openings of the ducts 3 into the outlets 4 and longitudinally displaceable upon a loss of pressure in any one of the outlets to close the duct opening into the said outlet, the valve member or members each being normally retained in its intermediate position by retaining means comprising a spring-loaded stem 6 movable transversely to the valve member in a cavity 10 open to the outlet 4 via a duct 11. Fig. 1 shows a single valve member in the form of two opposed truncated cones joined at their narrow ends to form a throat 51 which is engaged by a metal ball 8 in contact with the stem 6. This stem is guided in a cavity 10 connected to the outlets 4 by passages 11. When the valve member 5 is displaced in either direction, the stem 6 rises and completes an alarm circuit A through a springy contact 12 supported by an insulated member 7. In a modification, two valve members both of truncated conical form are provided and the inlet 2 is permanently connected to the space between them. The valve member or each of them may be locked in position by the longer portion 16 of a screw 15, Fig. 3, having long and short portions separated by a fixed head. The short portion 161 of the screw is used to block the aperture 18 in the valve body when the device is operative. The valve member may engage sharp edged seat members 21, Fig. 5, mounted in plugs 19 screwed into the outlets 4.