Abstract: This invention relates to fuel injection pumps of the type employed for supplying measured charges of fuel to the nozzles of an associated internal combustion engine. More particularly, the invention relates to such fuel pumps of the rotary distributor type having pumping plungers which are slidably mounted in radial bores of a rotary distributor and are surrounded by a generally circular cam ring having pairs of inwardly directed cam lobes which actuate pairs of pumping plungers inwardly simultaneously for pressurizing the charge of fuel between the plungers to a high pressure.The subject invention overcomes the above problems by angularly spacing a pair of pumping plungers and the cooperating cam lobes as required for the specific engine application and avoids the undesired side loading by creating a hydraulic counterbalancing force which automatically changes as the side loading created by the reaction forces between the cam lobes and the pumping plungers changes with speed and rate of delivery of fuel.

Abstract: Designs for variably controlling the maximum quantity of fuel which can be delivered by a pumping stroke of pumping plungers are disclosed. These include combinations of resilient and rigid leaf spring arrangements for controlling the maximum pumping stroke with and without speed responsive control valves or cams, to provide excess fuel for starting and for shaping the maximum fuel delivery curve according to speed.