Cam 1 rotates about fixed axis E and has two symmetrical spiral contours a and b, arranged one behind the other. Follower 2 is designed as yoke d and reciprocates in fixed guides F-F. Yoke d has four lugs A, B, C and D. Contour a slides over lugs B and C; contour b over lugs A and D. Contours a and b contact the lugs consecutively, thereby providing for positive motion. The spiral profiles are designed to obtain follower travel at uniform velocity.
$3000$SmC,3L$