Patent ID: 7628139

Claim:
A fuel injection assembly comprising: an injection body with a fuel supply passage and a main high pressure fuel supply cavity; a plunger disposed within said injector body for displacing fuel from said fuel supply cavity; a first outlet passage leading from said cavity and in selective fluid communication to a low pressure return; a first actuator valve in said first outlet passage to control the fluid communication of said first outlet passage to said low pressure return; a second passage leading from said cavity to a nozzle valve, which opens to allow fuel to be injected therefrom; said nozzle valve constructed to be opened by fluid pressure exerted in said second passage onto said nozzle valve; a continuously open restrictive passage continuously open from said second passage to a chamber at the backside of said nozzle valve for exerting closing fluid pressure from said second passage onto said nozzle valve to close said nozzle valve against the opening fluid pressure exerted on said nozzle valve; a third passage leading from said chamber to said lower pressure return; said third passage being less restrictive than said continuously open restrictive passageway when said actuator valve is in an open position; and a second actuator valve to control fluid communication between said chamber and said low pressure return via said third passage to relieve pressure from said chamber and to prevent closing fluid pressure from building up in said chamber when said second acturation valve is actuated to open communication between said continuously open restrictive passageway and said third passage via the chamber and said low pressure return.