Patent ID: 7484483

Claim:
A system for actuating an engine valve in an internal combustion engine to produce an engine valve event, said system comprising: means for imparting valve actuation motion; a housing disposed intermediate said motion imparting means and the engine valve; a bore extending through said housing in an axial direction; an outer piston slidably disposed in the bore formed in said housing, said outer piston having a cavity formed therein and an internal passage extending from the cavity to an outer surface of the outer piston; an inner piston slidably disposed in the outer piston cavity; a first hydraulic passage extending through a check valve and the housing to a first port on said bore; a second hydraulic passage extending through the housing to a second port on said bore, wherein the second hydraulic passage is axially spaced from the first hydraulic passage along said bore, and wherein the outer piston internal passage registers with only one of the first port and the second port at any one time; and a valve in communication with the outer piston cavity through the internal passage and the second hydraulic passage, said valve having more than one position, wherein the position of said valve determines the timing of the engine valve event, and wherein the first passage is a supply passage adapted to supply hydraulic fluid to the outer piston cavity, and the second passage is a reset passage adapted to release hydraulic fluid from the outer piston cavity.