Patent ID: 7748644

Claim:
A fuel injector for an internal-combustion engine, comprising: an injector body including a substantially cylindrical side wall having a longitudinal axis and an inner surface forming a first shoulder; an injection-control valve including a valve body fixedly positioned in said injector body and delimiting an annular chamber configured to receive a fuel under pressure, said valve body forming a fuel chamber configured to communicate fuel in a first direction away from the valve body toward a servo-valve, said valve body having a head, a duct in fluid communication with the annular chamber and the fuel chamber to communicate fuel therebetween, the head sealingly positioned against the first shoulder, introduction of fuel to the annular chamber and through the duct and fuel chamber subjecting the valve body to a first thrust along the first direction; a support surface formed in, or fixedly attached to, an outer surface of the valve body facing the inner surface of the injector body, the support surface being spaced from the annular chamber in a second direction, opposite the first direction; and a seal member positioned between said inner surface of the injector body and said outer surface of the valve body, said seal member being supported by said support surface against movement in the second direction, said seal member being subjected to a pressure of the fuel reaching the seal member from the annular chamber between the outer surface of the valve body and inner surface of the injector body during operation, the support surface being subjected to a second thrust resulting from the fuel pressure on the seal member, the support surface transferring the second thrust to the valve body in the second direction, preventing one-sided thrust loading of the valve body.