US Patent 7527035 Fuel supply system, especially for an internal combustion engine

A fuel supply system comprises a piston pump having a working chamber and an adjustable throttle device, arranged upstream of the working chamber and adapted to modify the flow of fuel supplied to the working chamber. The invention is characterized in that the throttle device, in the closed position, allows a leakage volume to arrive at the working chamber. The piston pump comprises a leakage pump device which supplies at least a part of the leakage volume from the working chamber to a low-pressure zone located upstream of the throttle device.