Patent ID: 8733671

Claim:
An intensifier type fuel injector comprising: a needle chamber; a needle in the needle chamber having a first position blocking fuel injection and a second position allowing fuel injection; an intensifier having an intensifier piston and a plurality of plunger pins for intensifying a fuel pressure responsive to an intensifier actuation fluid pressure, wherein the plunger pins are distributed around the axis of the intensifier piston and needle; first valving coupled to control intensifier actuation fluid over the intensifier piston; second valving responsive to a needle actuation fluid to controllably; maintain the needle in the first position against an intensified fuel pressure in the needle chamber, or allow the needle to move toward the second position responsive to intensified fuel pressure in the needle chamber; a needle control piston; at least one intensified fuel storage volume coupled through a port to the needle chamber; and, a check valve coupled to allow fuel flow from the plunger pin to the needle chamber and the at least one storage volume, and to block fuel flow in the opposite direction; the needle control piston, the intensifier piston and the needle being coaxial, and the intensifier piston is between the needle control piston and the needle; wherein the needle control piston controls the needle through at least one needle control pin concentric with and passing through the intensifier piston.