Internal combustion engine valve actuation system

Claim 1

A valve actuation system for an internal combustion engine comprising: (a) means coupled to a cam on the camshaft on the engine for controlling the position of an associated intake valve, (b) means for dynamically varying said position independently of any other valve in a predetermined manner depending on a selectable lift and duration pattern, comprised of a linkage having a variable stroke betwen said cam and said intake valve, the linkage being comprised of a master cylinder containing a master piston coupled as a lifter to said cam, a slave cylinder containing slave piston coupled to said valve for controlling its position, a hydraulic line coupling said cylinders, a control cylinder coupled to the hydraulic line containing a control piston, a stop for the control piston, means for controlling the position of said stop, the position of the control piston being variable up to the stop depending on the retraction position of said master piston, following which the position of the slave piston is varible depending on further retraction of the master piston whereby the displacement of the intake valve is varied with displacement of the master piston, (c) the intake valve including a valve closure spring, (d) a control piston spring which is weaker than the valve closure spring interfacing between the control piston and the stop, and (e) a check valve coupled to the control cylinder for introducing fluid to said hydraulic line, and being coupled to an oiling system of the engine, and an oil spill port in said master cylinder coupled to said oiling system and being uncovered when the master piston is in its fully extended position, whereby fresh oil can be cyclically recirculated from said oil system through the check valve, the hydraulic line and the oil spill port for return to the oiling system.