Cam 1 rotates about fixed axis A and its contour a is along an involute of a circle. Follower 3 oscillates about fixed axis B and carries strip 2 which slides along contour a. After cam 1 rotates 360°, strip 2 slides off contour a and spring 4 returns follower 3 with an impact to its initial position.
$3011$SmC,3L$