Patent ID: 7159799

Claim:
A fuel injector for an internal combustion engine, the injector comprising: a nozzle body provided with a nozzle bore, an inner valve which is engageable with an inner valve seating to control fuel delivery through one or more first nozzle outlet, an outer valve which is received within the nozzle bore and engageable with an outer valve seating to control fuel delivery through one or more second nozzle outlet, an arrangement for controlling movement of the inner and outer valves, including a control chamber for fuel and an actuator for facilitating transmission of an actuation force to the inner and outer valves so as to permit movement of either the inner valve only to provide a first injection state in which fuel is delivered through only said first outlet, or movement of the outer valve only to provide a second injection state in which fuel is delivered through only said second outlet, and a coupling arrangement for coupling movement of the outer valve to the inner valve in circumstances in which the outer valve is moved away from the outer valve seating through an amount exceeding a predetermined threshold amount, thereby to cause the inner valve to lift away from the inner valve seating to provide a third injection state in which fuel is delivered through both the first and the second nozzle outlets together, wherein a first surface associated with the inner valve is exposed to fuel pressure within the control chamber and a second surface associated with the outer valve is exposed to fuel pressure within the control chamber.