Constant-breadth cam 2 rotates about fixed axis A and is rigidly attached to gear 3 which meshes with gear 5, rotating about fixed axis D and rigidly attached to constant-breadth cam 4. Cam 2 is confined between the flat faces of yoke 1 of link 7 which carries claw a. Cam 4 is confined between the flat faces of slot g of link 7 which has slot f sliding along fixed pin K. When cam 2 rotates, claw a of link 7 is inserted into a perforation of the film, advances the film and is withdrawn from the perforation. Cam 4 is made up of two segments, b and c, which can be turned with respect to each other about axis D and clamped. This regulates the times in the cycle when the claw is inserted into and withdrawn from the perforation.
$3331$GrC,OC$