Engine valve control mechanism

A rocker arm including a rigid link (34) adapted to be pivotally supported at one end (34a) and to operate a device (16) at the other end (34b) in response to rotation of a cam lobe (24c) projecting radially outward of a base circle surface (24b) of a camshaft (24) effecting pivotal movement of the link (34) by engaging a cam follower (38) operative to transmit displacement of the cam lobe (24c) to the link (34), the cam follower (38) being mounted (40) on the link between the ends (34a, 34b) and being selectively movable relative to the link between a first position wherein the cam lobe displacement is transmitted to the link and a second position wherein the cam lobe displacement is not transmitted to the link, the improvement comprising:

• roller follower means (36) mounted on the link (34) at a position axially adjacent the cam follower (38) relative to the axis of the camshaft, said roller follower having an outer cylindrical surface adapted to engage the base circle surface (24b) of the camshaft (24) and to maintain a clearance between the cam follower (38) and the base circle surface (24b).