ABSTRACT
Cams are used in a very wide variety of mechanisms ranging from the valve mechanism in an automotive engine to sash locks in traditional double-hung windows. The most common type of cam is the radial cam, or plate cam. One of the most widespread applications of cams is in automotive engines where they are used as part of the valve-lifting mechanism. A simple schematic of a pushrod-type valve lifting mechanism. As the cam rotates, the follower is constrained to rise up and down, "following" the surface of the cam. It is much more expensive and time-consuming to manufacture a precision cam than it is to fabricate ordinary links, so their use is mostly restricted to situations where linkages cannot achieve the required motion. The contact force between the cam and follower is directed along the surface normal u, but the desired motion of the follower is purely horizontal.
