US Patent 7311073 Continuous variable valve lift apparatus

A continuous variable valve lift (CVVL) apparatus adjusting a valve lift, duration of valve opening and closing, and a valve timing includes a cam rotating by a cam shaft, a first shaft having a first radius, a second shaft having a second radius smaller than the first radius and coupled in the first shaft such that the first and second shafts are non-concentric, a roller moving upward and downward by a rotation of the cam and connected to the first shaft to be moved on the basis of a position of the first shaft, a first arm rotatably connected to the second shaft to be moved by the roller, and a second arm rotatably secured to a third shaft to open and close the valve by an operation of the first arm.