apparatus for pumping fuel exempt

摘要

A fuel pumping apparatus for supplying fuel to an internal combustion engine includes an angularly movable cam, the setting of which is determined by a piston housing a servo-valve. The servo-valve is subjected to a control pressure and moves to admit or release fluid from the cylinder containing the piston. For this purpose, a port is provided which is controlled by a land on the servo-valve. The land is shaped so that on angular movement of the servo-valve, a variation in the setting of the piston will occur and thereby a variation in the setting of the cam.