Rigidly attached cams 2 and 3 rotate about fixed axis A. Constant-breadth cam 2 is confined between the parallel flat faces of the yoke in follower 4 which has slot d sliding along fixed pin 8. Follower 4 is connected by turning pair B to slide 5 which reciprocates in fixed guide f. The working surface of cam 3 slides along flat face e of follower 7 which reciprocates in guides c-c of follower 4. Link 1 is connected by turning pairs C and D to follower 7 and to bellcrank 1 ever 6 which, in turn, is connected by turning pair B to slide 5 and has claw a. When cams 2 and 3 rotate, claw a is inserted into a perforation of the film, advances the film and is withdrawn from the perforation.
$3209$CmL,OC$