Constant-breadth cam 2 and round eccentric 3 are keyed to shaft 1 and rotate about fixed axis A. Link 6 oscillates about fixed axis D and is connected by turning pair E to follower 5. Fork f of link 6 slides along pin k of link 7 which reciprocates in fixed guides B-B. Link 8 oscillates about axis D and is connected by turning pair F to follower 4. Eccentric 3 is confined between the flat faces of square yoke d of follower 4 which carries claw a. Cam 2 is confined between the flat faces of square yoke c of follower 5 whose slot e slides along fixed pin H. The motion of follower 5 is transmitted by link 6 to link 7 which carries claw b. When shaft 1 rotates, claw a describes a complex curve in which it is inserted into a perforation of the film, advances the film and is withdrawn from the perforation. Claw b is inserted into a perforation to restrain the film from movement at the moment that claw a is being withdrawn.
$3213$CmL,OC$