Patent ID: 7308888

Claim:
A fuel pump arrangement for delivering high pressure fuel to an associated engine, the fuel pump arrangement including three or more pumping plungers; each pumping plunger having: an associated pump chamber; return biasing means for effecting a return stroke of the plunger; and an associated cam for driving the plunger to perform a pumping stroke against the return biasing means, during which pumping stroke fuel within the pump chamber is pressurised; wherein each cam is oriented relative to each other cam; wherein each cam has a surface shaped such that the return stroke of its associated plunger is intermittently interrupted to define a plurality of steps that are each characterized by an interval of discontinued plunger movement, during which interval the pumping plunger is substantially stationary; and wherein each such step of discontinued plunger movement is substantially coincident with a pumping a stroke of at least one of the other plungers, thereby to reduce negative torque loading of the camshaft.