GB537051A - Improvements relating to pressure regulating valves - Google Patents

Abstract

537,051. Reciprocating pumps for liquids. TRICO PRODUCTS CORPORATION. Jan. 4, 1940, No. 253. Convention date, Aug. 2, 1939. [Class 102 (i)] [Also in Groups XXIX and XXVI] A relief valve, which is especially applicable to the fuel feed lubricating system of motors, is constructed so that the opening of the valve is resisted by a spring or like yielding means and the effective force tending to open the valve is increased as the valve opens so as to counteract the increasing resistance of the yielding means. As applied to a pump system, Figs. 2 and 3 in which a rotating eccentric piston 16 co-acts with chambers 17, 18 to pump oil through passages and ports 29, 30, 31, 32, a relief valve 51 is arranged in the pressure port 30 and is normally closed by the action of a spring 53 arranged in an axial bore 52 of the pump shaft. Normally the pressure fluid acts on the rim of valve 51, but as soon as the valve opens, fluid passes through a bore 72 in a fixed head 63 secured to a rod 52<SP>1</SP> provided also with a collar 68 for controlling the spring 52. The pressure is then exerted or a supplementary part 65 of the valve which normally seats on the head 63 and is not subject to fluid pressure. As the valve opens further, the supplementary resistance increases as the fluid which passes the groove 72 can drain away past a groove formed by a flat part 76 of the rod 52<SP>1</SP> but as the valve opens this outlet becomes restricted so that fluid enters faster than it leaves and so increases the pressure on the valve part 65. The eccentric 16 also oscillates a valve-like piston 14 which oscillates in air chambers 12, 13 in the housing 11 of the oil pump, and draws air through valved passages and discharges air under pressure through passages 38, 39. In a modification the interior of the piston 51 tapers between its forward rim and the supplementary valve 65, so that the greater the movement of the piston the larger is the opening for the passage of fluid to act upon the supplementary part of the valve. The Specification as open to inspection under Sect. 91 comprises also a modified form of valve 51, Fig. 8 (Cancelled), in which the valve opens against the action of spring pressure and also of fluid pressure due to the tight fitting of the valve in the chamber 88 containing the spring 87. A relief valve 91 opens to relieve the fluid pressure and so compensates for the increasing pressure on the valve due to the compression of the spring 87. This subject-matter does not appear in the Specification as accepted.