Patent attributes
A valve drive mechanism for actuating a valve of an internal combustion engine includes a cam member with a cam surface having a first portion and a second portion. A roller is configured to rotate and contact the first portion of the cam surface when the valve is in a closed position and the second portion of the cam surface with the valve is in an open position. The cam member and the roller are configured to reciprocally move relative to each other to open and close the valve. When the roller contacts the first portion, a gap within the valve drive mechanism exists between components of the valve drive mechanism on a downstream side of a force transmission path to the valve with respect to a contact point between the roller and the cam surface. A spring member urges the roller and the cam surface into contact with each other during motion between the cam member and the roller.
