Patent ID: 7866286

Claim:
A method for operating an electro-hydraulic actuation mechanism operative to urge a moveable engine valve to a lift, comprising: commanding the engine valve to a desired lift; activating a first spool valve to permit flow of pressurized hydraulic fluid through a second spool valve to a main hydraulic chamber, the main hydraulic chamber configured to urge the engine valve to the desired lift; monitoring lift of the engine valve; and commanding an on/off valve to a closed position when the monitored lift of the engine valve approaches the desired lift to effect flow of pressurized hydraulic fluid from one of a second and a third hydraulic chamber to a fluid chamber of the second spool valve, the second spool valve configured to terminate the flow of pressurized hydraulic flow from the first spool valve to the main hydraulic chamber to stop opening of the engine valve at the desired lift.