Dynamic valve mechanism of internal combustion engine

Claim 1

A dynamic valve mechanism in an internal combustion engine including a rocker shaft mounted on a cylinder head, a cam shaft rotatably mounted on the cylinder head and disposed in generally parallel relationship to the rocker shaft, the cam shaft having a cam thereon, a rocker arm swingably supported on the rocker shaft and having a first arm projecting radially therefrom for engagement with the cam and a second arm projecting radially therefrom for engagement with the stem of a valve projecting through the cylinder head, the improvement comprising a positioning portion fixedly and integrally joined to one arm of said rocker arm and projecting sidewardly thereof along a direction which is generally parallel with the axial direction of said rocker shaft, said positioning portion terminating in an axial free end defined by an axially facing abutment surface, and a holding portion fixed to said cylinder head and projecting axially toward said positioning portion and terminating in an axial free end which defines thereon a contact surface which is abutted against said abutment surface.