Patent ID: 8333336

Claim:
A fuel injector comprising: an injector body with a fuel passage disposed therein that is partly defined by an annular valve seat; an electronically controlled valve that includes a valve member with an annular valve surface that moves into and out contact with the annular valve seat to close and open the fuel passage; the annular valve surface defining a portion of a compound annulus defined by the valve member, and the compound annulus being a first annular void that opens into a second annular void; wherein the compound annulus is defined by a small diameter segment of a cylindrical outer surface of the valve member; and an additional annulus defined by a large diameter segment of cylindrical outer surface; wherein the electronically controlled valve is a spill valve, and the fuel passage is a spill passage; a plunger positioned to move in the injector body to displace fuel from a fuel pressurization chamber disposed in the injector body; and the spill passage being disposed in the injector body and extending between the fuel pressurization chamber and a low pressure outlet.