Check valves

Claim 1

A liquid fuel injection pumping apparatus for supplying fuel to an internal combustion engine and comprising a check valve, the check valve including a body part in which is defined a bore, an annular member located at one end of the bore, a seating defined by said annular member, a closure member in the form of a ball for cooperation with said seating, a plug member serving to close the other end of said bore, a cylindrical flanged member held by the plug against an edge defined within the bore, a cylinder defined in said member, a piston mounted in said cylinder, and first, second and third passages communicating with said one end, said other end and the intermediate portion of the bore respectively, the apparatus further comprising an injection pump having a pumping chamber in communication with said third passage, a feed pump having an outlet in communication with said second passage, a metering device through which the outlet of the feed pump communicates with said first passage, the arrangement being that during a filling stroke of the injection pump the ball is lifted from its seating by the flow of fuel through said first passage and when the flow of such fuel ceases the ball is urged onto the seating by the piston before the start of the injection stroke of the injection pump.