Crank 1 rotates about fixed axis A. Connecting rod 4 is connected by turning pairs B and D to crank 1 and to rocker arm 5 which turns about axis C and has pin b. P in b slides along slot c of bellcrank lever (follower) 3 which oscillates about fixed axis E and carries pin f. Cylinder cam 2 is rigidly attached to crank 1 and has groove e along which pin f slides. When crank 1 rotates, claw a of connecting rod 4 describes a complex connecting-rod curve, modified by the oscillation of lever 3 leading to displacement of axis C, in which claw a is inserted into a perforation of the film, advances the film and is withdrawn from the perforation.
$3215$CmL,OC$