Patent ID: 8505514

Claim:
A fluid injector comprising: an injector body defining a high pressure inlet, a fuel supply passage, a low pressure drain, and at least one tip orifice; a check needle movable within the fluid injector between a first position at which the check needle blocks the at least one nozzle outlet and a second position at which the check needle at least partially opens the at least one nozzle outlet, the check needle including at least one opening hydraulic surface exposed to a fluid pressure of the fuel supply passage and at least one closing hydraulic surface exposed to a fluid pressure of a check needle control chamber, wherein said check needle control chamber is in selective fluid communication with the low pressure drain via a first orifice, and said check needle control chamber is in fluid communication with the fuel supply passage via a second orifice, and said check needle control chamber is in selective fluid communication with the fuel supply passage via a third orifice, which is in parallel with the second orifice; and a control valve assembly having a valve member movable between a first position at which the low pressure drain is blocked to the check needle control chamber, and a second position at which the check needle control chamber is in fluid communication with the low pressure drain.