GB548711A - Improvements in fuel injection pumps for internal-combustion engines - Google Patents

Abstract

548,711. Fuel-injection pumps. COSTA, H. DA, and PLESSEY CO., Ltd. April 18, 1941, No. 5068. [Class 102 (i)] In a fuel-injection pump for internal combustion engines the pump chamber is formed between two interconnected parts 12, 13 of the plunger which are movable axially relatively to one another during each stroke of the plunger to vary the size of the pump chamber which communicates, or at required times is brought into communication, with an inlet port 17 and an outlet port 18 fitted with a non-return valve. The plunger parts 12, 13 are normally separated to the maximum extent by means of a spring 23 so as to provide a pump chamber of constant size when this chamber is opposite the inlet port 17. The plunger part 12 is reciprocated with a constant stroke by means of a cam 14, and movement of the plunger part 13 is limited by an adjustable stop 25 when the pump chamber is opposite the outlet port 18. The stop 25 may be replaced by a cam, and such stops or cams of a multiple unit may be interconnected for simultaneous control. A vent 27 may be provided in the cyclinder 11 beyond the outer end of the plunger port 13, and a port 28 may be provided opposite the inlet port 17 to act as a bleed for gravity-fed fuel, or to pass on fuel under pressure to another pump cylinder, or back to a supply pump. In a modification, the inlet and outlet ports are directly opposite one another and each is provided with a non- return valve.