US Patent 7159550 Variable valve train of internal combustion engine

This variable valve train has a camshaft, a rocker shaft, and a rocker arm mechanism for transmitting a motion of a cam formed on the camshaft to a valve. The rocker arm mechanism includes a first arm which drives the valve, a second arm, a third arm, and a variable mechanism which rocks the rocker shaft. The first arm is rockably supported on the rocker shaft. The second arm is driven by the cam and rocks around a universal joint as a pivot on the side of the rocker shaft. The third arm is displaced to drive the first arm as the second arm rocks.