Abstract: A fuel injector comprises an injector body having a tip portion defining a spray aperture; a pintle extending within the tip portion for axial movement between an extended position and a retracted position, the pintle having a head portion engageable with the spray aperture to close the spray aperture when the pintle is in its retracted position; biasing means being provided for biasing the pintle towards its retracted position; and solenoid means for selectively moving the pintle into said extended position; said solenoid means comprising an electromagnetic coil and a moveable armature capable of being acted upon by the coil to urge the pintle towards its extended position; wherein the pintle and armature are separable from one another whereby the armature can decouple from the pintle when the pintle moves from its extended position to its retracted position.

Abstract: A fuel injector for an internal combustion engine, the injector comprising an injector body having a tip portion defining at least one spray aperture; a pintle extending within the tip portion, the pintle having a head portion engageable with a valve seat to close the spray aperture, the pintle being axially moveable between a closed position wherein the head portion abuts the valve seat and an open position wherein the head portion is spaced from the valve seat; actuating means for selectively urging the pintle towards its open position; guide means being provided within the injector body guiding the pintle for axial movement between its closed and open positions; a fuel supply chamber being defined within the injector body between the spray aperture and the guide means, characterized in that the diameters of the guide means and valve seat are selected such that the pintle is substantially pressure balanced.

Abstract: A fuel injector for an internal combustion engine, the injector comprising an injector body having a tip portion defining at least one spray aperture; a pintle extending within the tip portion, the pintle having a head portion engageable with a valve seat to close the spray aperture, the pintle being axially moveable between a closed position wherein the head portion abuts the valve seat and an open position wherein the head portion is spaced from the valve seat; actuating means for selectively urging the pintle towards its open position; guide means being provided within the injector body guiding the pintle for axial movement between its closed and open positions; a fuel supply chamber being defined within the injector body between the spray aperture and the guide means, characterised in that the diameters of the guide means and valve seat are selected such that the pintle is substantially pressure balanced.

Abstract: A fuel injector comprises an injector body having a tip portion defining a spray aperture; a pintle extending within the tip portion for axial movement between an extended position and a retracted position, the pintle having a head portion engageable with the spray aperture to close the spray aperture when the pintle is in its retracted position; biasing means being provided for biasing the pintle towards its retracted position; and solenoid means for selectively moving the pintle into said extended position; said solenoid means comprising an electromagnetic coil and a moveable armature capable of being acted upon by the coil to urge the pintle towards its extended position; wherein the pintle and armature are separable from one another whereby the armature can decouple from the pintle when the pintle moves from its extended position to its retracted position.