Patent ID: 8056518

Claim:
An actuating apparatus, comprising: a rocker arm disposed in contact with a valve at a first location; a cam disposed in contact with said rocker arm at a second location; a pivot disposed in contact with said rocker arm at a third location; a stud attached to said pivot and configured to support said pivot relative to a structure; and a jam nut movably attached to said stud and configured to retain said pivot at a preselected distance from said structure, said jam nut comprising a first surface which is movable into contact with a second surface of said structure, said first surface being generally conical, wherein said first surface has an included angle which is selected as a function of the angle between a central axis of said stud and a force exerted by said rocker arm on said stud when said cam is at a preselected rotational angle about its axis, said included angle being generally equal to twice the magnitude of said angle between said central axis of said stud and said force exerted by said rocker arm on said stud when said cam is at said preselected rotational angle about its axis.