A variable valve lift device includes an outer cam; an inner cam having a base circle and a nose smaller than the base circle and the nose of the outer cam; at least one of an intake and exhaust valve opened and closed by being moved in the axial direction thereof, the valve being biased in the closing...http://www.google.fr/patents/US5603294?utm_source=gb-gplus-shareBrevet US5603294 - Variable valve lift device
