US Patent 7350484 Controlled leakage valve for piston cooling nozzle

Device to feed cooling and lubricating fluid to cooling and lubricating nozzles for the pistons of an internal combustion engine, having at least one valve with an upstream channel and a downstream channel, said valve having a blocking element able to move in a compartment to block an opening of a seat. The valve responds to the pressure of the cooling fluid by opening when the upstream pressure is greater than a threshold pressure and closing when the upstream pressure is less than the threshold pressure. A means of calibrated leakage connects the upstream channel to the downstream channel in parallel with the zone of closure of the valve.