GB1474525A - - Google Patents

Abstract

1474525 Reciprocating pumps CAV Ltd 2 July 1974 [13 July 1973] 33562/73 Heading F1A An engine fuel pump comprises a bucket piston 24 moved on its delivery stroke by a cam acting via follower roller 18, tappet 17, spring 20 and rod 22, and on its return stroke by spring 26, a diaphragm 30, or a piston, defining a suction chamber 15 behind piston 24 into which fuel is drawn during both the delivery and return strokes, the displacement of piston 24 being greater than that of diaphragm 30. Piston 24 has a flapper valve 33 controlling piston apertures 32 through which fuel passes from suction chamber 15 during the return stroke, the fuel being delivered via passage 27 on the delivery stroke. A priming lever (34), Fig. 2 (not shown), acts on tappet 17 to effect manual operation of the pump. In Figs. 3 to 5 (not shown), check-valves are provided in the inlet and delivery connections, return movement of the tappet is limited by a pin (46), and the priming lever acts on the piston rod.