Cam 1 is rigidly attached to crank 3 which rotates about fixed axis D. Cam 1 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. The stroke of slide 2 equals 2D͞B-R. Slide 2 has harmonic motion with instantaneous dwells at the extreme positions.
$2995$SmC,3L$