Patent ID: 8708249

Claim:
A fuel injector for a compression ignition internal combustion engine comprising a fuel injection valve having an injection valve member moveable, in use, under the influence of fuel pressure within an injection valve member control chamber acting upon it, between a closed position and an open position, a high pressure fuel supply passage to the injection valve member control chamber, and an actuator operable to open and close a discharge valve connected between the injection valve member control chamber and a fuel outlet passage to a low pressure reservoir or drain, wherein a shut-off valve is provided in the high pressure fuel supply passage, the shut-off valve having a shut-off valve member moveable, in use, under the influence of fuel pressure within a shut-off valve member control chamber acting upon it, between a closed position and an open position, wherein the shut-off valve member control chamber is connectable to the low pressure reservoir or drain via the discharge valve, and wherein a fuel transfer passage is provided between the injection valve member control chamber and the low pressure reservoir or drain, characterized in that the shut-off valve controls a flow of fuel from the high pressure fuel supply passage to the injection valve control chamber, and the discharge valve controls a flow of fuel from the injection valve control chamber to the low pressure reservoir or drain.