Link 1 of slotted-link mechanism ABC rotates about fixed axis A. Slotted link 2 is connected by turning pair B to link 1 and has slot b sliding along fixed pin C. The axis of slot b does not pass through point B. Mounted on slotted link 2 is toothed segment d. When crank 1 rotates about axis A, the tips of claws a of segment d describe connecting- rod curves in which claws a are inserted into perforations of the film, advance the film and are withdrawn from the perforations.
$1387$LG,OC$