Constant-breadth cam 1 rotates about fixed axis A and is rigidly attached to gear 3 which meshes with gear 5, rotating about fixed axis B and rigidly attached to plate cam 4. Cam 1 is confined between the flat faces of yoke 2 of link 7 which is connected by turning pair D to follower 8. Follower 8 turns about fixed axis C and carries roller 9 which rolls along the contour of cam 4. Link 7 carries claws a. When cam 1 rotates, claws a are inserted into perforations of the film, advance the film and are withdrawn from the perforations.
$3332$GrC,OC$