GB598891A - Improvements in or relating to valve assemblies, and pump assemblies including the improved valve assemblies - Google Patents

Abstract

598,891. Relief valves. THOMPSON PRODUCTS, Inc. Feb. 11, 1944, No. 2565. Convention date, March 26, 1943. [Class 135] A combined relief and byepass valve assembly particularly for pumps, comprises relatively inverted nested cups of, e.g. sheet metal or moulded plastic material, the outer cup having an internal abutment for the byepass valve seat which is held against the abutment by the inner inverted cup ; a closure member for said seat being located in said outer cup and urged into contact with the seat, and the outer cup having a relief valve closure surface formed on its outside surface. As shown in Fig. 2, the valve comprises a casing member 11 for an aircraft fuel pump 21 having an inlet chamber 16 and a discharge chamber 18, a casing member 12 housing a valve assembly which serves to establish communication between the chambers 16, 18 when the pressure in the chamber 18 is excessive or the pump becomes inoperative and another pump in series therewith supplies the chamber 16, and a casing member 13 for valveloading means. The valve assembly, shown also in Fig. 5, comprises a slidable cup 50 formed with a shoulder 50d, the exterior constituting a valve member adapted to seat on the seat 26, an inverted cup 52 adapted to hold a seat ring 51 on the shoulder 50d, and a valve disc 53 urged against the seat ring 51 by a spring 54. The cups are ported at 52e, 50h and 50i, and the cup 52 has tangs 52d which straddle one of the legs of the cup 50 to hold the ports 52e and 50h in alignment. The loading spring 46 is held between members 39, 44, the upper of which is adjustable by a threaded member 36, the lower having a dimple 44a seated in a depression 45a of a washer 45 overlying a diaphragm 34 which closes the bottom of the casing member 13, the interior of which communicates through a boss 42 with the atmosphere or an engine manifold.