Patent ID: 7204434

Claim:
A fuel injector comprising: an injection valve having an injection nozzle and a pin, the pin being movable to regulate fuel flow through the injection valve, wherein the pin terminates with a shutter head that engages a valve seat of the injection valve; an electromagnetic actuator for moving the pin between a closed position and an open position respectively closing and opening the injection valve, the electromagnetic actuator having a main spring exerting a force for keeping the pin in the closed position, at least one coil, at least one fixed magnetic armature, and at least one movable armature, wherein the at least one movable armature is attracted magnetically by the at least one fixed magnetic armature in opposition to the force of the main spring and is connected mechanically to the pin; a tubular supporting body having a feed channel housing the pin; and a sealing body, in which the valve seat of the injection valve is defined, and which seals the bottom of the feed channel; wherein the pin comprises a stop member, which is integral with the pin and comes to rest on a top surface of the sealing body when the pin is in the open position opening the injection valve so as to limit a travel of the pin, wherein the at least one movable armature and the at least one fixed magnetic armature define an air gap therebetween between that has an axial size that is always greater than the travel of the pin to ensure the travel is determined by the stop member contacting a guide member and not by the at least one movable armature contacting the at least one fixed magnetic armature and, wherein the main spring has one end that rests on the at least one movable armature; and a calibrating spring having one end resting on the at least one movable armature, on the opposite side to the main spring.