Variable camshaft assembly

Claim 1

In an internal combustion engine employing a two part cam assembly to vary valve timing, including speed sensitive means, a double function cam-camshaft-camshaft support arrangement comprising, an axially movable camshaft acting against a camshaft return spring through the intercession of a rotatable bearing, said camshaft having a plurality of fixed cam surfaces thereon, a wormed portion alongside each fixed cam surface on said camshaft, a camshaft support positioned at or near each said wormed portion of said camshaft, a circular opening through each camshaft support of a diameter larger than that of said camshaft, independent secondary cams of substantially the same outer dimensions of said fixed cam surfaces on said camshaft, each said secondary cam possessing a circular protrusion axially alongside of such diameter and width to mate with and turn rotatably in said circular opening through said camshaft support, means to prevent axial movement of said secondary cam, a centrally positioned wormed opening through said secondary cam and associated circular protrusion of such size and configuration to mesh operably with said wormed portions on said camshaft, such a combination allowing said camshaft a certain amount of twisting axial movement, said twisting axial movement being induced by the combination of weight, rotational speed, and worming of said camshaft acting against the rotatably trapped secondary cams and said camshaft return spring, thereby permitting said cam-camshaft-camshaft support arrangement to vary valve timing while simultaneously acting operably as part of the speed sensing means.