(under subclass 90.1) Device wherein means in the form of a groove, or its equivalent, in the outer surface of a revolving drum is provided to displace the cam follower both axially and radially of the camshaft.
(1) Note. The groove is usually in the form of two, intersecting loops, of different effective elevations, and the effect of the axial displacement of the follower from one loop to the other is to impart a valve-actuating movement to it upon every other revolution of the camshaft.
(2) Note. In a device of this nature, the crankshaft frequently serves as the camshaft.
