Cam 1 rotates about fixed axis D and has a contour composed of three circular arcs of radius R described from points A, B and C. Follower (slide) 2 reciprocates in fixed guides b-b and has a yoke with the distance (breadth) R between flat faces a which confine cam 1. Positive motion is achieved because all the diameters of cam 1 equal R. If axis D is located in the middle of arc BC, slide 2 has a stroke equal to 2R. Slide 2 has harmonic motion with instantaneous dwells at the extreme positions.
$2994$SmC,3L$