Patent ID: 7510127

Claim:
A fuel injector comprising: an injector body defining an unrestricted path and a restricted rate shaping path that includes a guide bore and a planar valve seat; a moveable intensifier piston, when in a retracted position, including a first hydraulic surface and a second hydraulic surface, and the first hydraulic surface being exposed to hydraulic pressure in the unrestricted path and the second hydraulic surface being exposed to hydraulic pressure in the restricted rate shaping path; a variable flow rate valve member being guided to move within the guide bore between a first position and a second position, defining a first passage with a predetermined flow area and including a side surface separating a closing hydraulic surface from an opening hydraulic surface, and the side surface including a plurality of guide surfaces separating second passages; the variable flow rate valve member separates the restricted rate shaping path into a first portion that extends between a flow control valve and the variable flow rate valve member and a second portion that extends between the variable flow rate valve member and the second hydraulic surface of the intensifier piston; and the first portion of the restricted rate shaping path includes at least four peripheral equalizer passages that fluidly connect an equalizer chamber to the first passage and the second passages of the variable flow rate valve member.