US Patent 7603973 Variable mechanical valve control for an internal combustion engine

A variable mechanical valve control for an internal combustion engine is provided having an underhead camshaft for adjusting a valve stroke and an opening and closing time, making it possible to achieve a very compact transmission gear between the push rod drive and the intake and exhaust valves, to reduce the number of components required for the transmission gear, and to obtain a mechanical, completely variable valve train with an underhead camshaft.