Rigidly attached cams 2 and 3 rotate about fixed axis A. Constant-breadth cam 3 is confined between flat parallel faces c of yoke 1 on follower 4. Constant-breadth cam 2 is confined between flat parallel guide faces d of follower 4. Follower 4 has slot e sliding along pin B of link 5 which can be turned about fixed axis E. When cams 2 and 3 rotate, claws a are inserted into perforations of the film, advance the film and are withdrawn from the peiforations. The paths of claws a can be changed by turning link 5 and clamping it in the required position with locking pin D.
$3206$CmL,OC$