US Patent 7506624 Variable engine valve actuation system

A valve actuation system for a power system is provided. The valve actuation system has an engine valve moveable to selectively prevent or allow a flow of fluid relative to the engine valve. The valve actuation system also has a cam assembly with a first cam lobe and a second cam lobe. The valve actuation system also has a cam follower with a first tappet protrusion and a second tappet protrusion. A selective rotation of the cam follower engages either the first tappet protrusion with the first cam lobe to move the engine valve through a first valve event, or the second tappet protrusion with the second cam lobe to move the engine valve through a second valve event.