US Patent 7992530 Continuous variable valve lift device

A continuous variable valve lift (CVVL) device opens and closes a valve by pressing a rocker arm through a rotational force transmitted from a drive cam. The CVVL device includes a drive arm, which is pivotably mounted such that one side thereof presses a rocker arm, a variable arm, which is pivotably mounted, and pushes and pivots the drive arm when pivoted, and a transmission arm, which is coupled with a transmission roller, which is located between the drive cam and the variable arm, at one end thereof, and is pivoted such that a position where the transmission roller comes into contact with both the drive cam and the variable arm is changed.