Patent ID: 7434556

Claim:
A valve actuation system, comprising: an engine valve moveable between a first position at which the engine valve prevents a flow of fluid relative to the engine valve and a second position at which the fluid flows relative to the engine valve; a first cam adapted to move the engine valve from the first position to the second position during a first lift period in response to a rotation of the first cam; a second cam adapted to move the engine valve from the first position to the second position during a second lift period in response to a rotation of the second cam; wherein the first cam and the second cam are adapted to move the engine valve to the same second position; a cam following assembly disposed between the first and second cams and the engine valve, the cam following assembly adapted to selectively connect one of the first and second cams with the engine valve to thereby move the engine valve through one of the first and second lift periods, wherein the cam following assembly includes: a first cam roller selectively engagable with the first cam; a second cam roller selectively engagable with the second cam; a cam follower base; a first cam lever pivotally connecting the first cam roller to the cam follower base; and a second cam lever fixably connecting the second cam roller to the cam follower base; a bore disposed in the cam follower base; a piston slidably disposed in the bore, the piston adapted to move between a first piston position at which the piston is retracted relative to the cam follower base and the first cam controls the movement of the cam following assembly to move the engine valve through the first lift period, and a second piston position at which the piston extends from the bore to engage the first cam lever to cause the second cam to control the movement of the cam following assembly thereby executing the second lift period; a reservoir adapted to store a supply of fluid; a source in fluid communication with the reservoir and the bore via a fluid passageway; and a control valve disposed between the bore and the source, the control valve movable between a first control valve position at which fluid is prevented from flowing between the source and the bore and a second control valve position at which fluid flows between the source and the bore causing the piston to move from the first piston position to the second piston position.