Cam 1 reciprocates along fixed guides a-a and has a profiled ridge. Follower 2 reciprocates in fixed guides B-B and carries two rollers, 3 and 4, which roll along the side surfaces, b and c, of the ridge on cam 1. Roll- ers 3 and 4 are mounted on a crosspiece which is pivoted on follower 2. Positive motion is achieved because the distance between the theoretical, or pitch, curves of surfaces b and c is constant and equal to D͞E, the distance between the centres of rollers 3 and 4. Line DE makes the angle α with axis d-d of follower motion.
$3024$SmC,3L$