GB599680A - Improvements in or relating to fluid transfer mechanisms - Google Patents

Abstract

599,680. Fluid-actuated valves. THOMPSON PRODUCTS, Inc. May 3, 1944, No. 8360. Convention date, June 12, 1941. [Class 135] [Also in Group XXVI] A valve aggregate for a pump comprises a valve housing having coaxial cylindrical bores and an intermediate annular partition providing a valve seat, a relief valve for said seat having guiding portions at all times in contact with said bores and having an axial passage closed at one end, means providing a byepass valve seat in said passage, a byepass valve for said seat, and resilient means held under compression between said closed end of said passage and said byepass valve to hold said byepass valve closed. A rotary pump of the outwardly-sliding vane type has an annular relief valve 70, Figs. 5 and 6, within which is housed a byepass valve 83 and a seat 82 therefor. The relief valve 70 is held on to its seat by a spring 110 which may be assisted by supercharger pressure acting on the upper side of a resilient diaphragm 103 through a port 123. The spring 110 acts upon the diaphragm 103 through a ball seating 106, and its force is adjustable by a screw 113 engaging a disc 111, rotation of the latter being prevented by a finger 121 engaging a groove 120. The lower part 71 of the relief valve 70 acts as a dashpot to suppress bouncing. Under excessive delivery pressure the relief valve 70 lifts to establish communication between the delivery port 61 and the inlet port 60 by way of passages 86, 85. When the pump is out of action, it can be supplanted by external means, such as an emergency pump, the byepass valve 83 opening to allow passage of fluid from inlet to outlet by way of passages 85, 89, 100 and 86. To enable the pump to be rotated in the opposite direction it is, preferably, capable of being assembled with the valve housing 12 at 180 degrees to the position shown. The diaphragm 103 may be replaced by a bellows. In a modification, Fig. 7, the relief valve and the byepass valve seat are integrally formed by a single member 130, the end of which is closed by a separate disc 137 held against an annular seat 136 by a spring 138.