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 d moving along slider 4 which turns about fixed axis C. Link 3 slides in fixed guides E and is displaced by slot d in the horizontal direction. Link 3 is displaced in the vertical direction by means of slot e of slotted link 2 which actuates pin F of link 3. When crank 1 rotates about axis A, slotted link 2 displaces link 3 with operating claw a in the vertical direction. Pin F of link 3, moving along the left half of slot e in link 2, inserts claw a into a perforation of the film. Then the film is advanced by horizontal motion of link 3 from the action of slot d. Finally, claw a is withdrawn from the perforation as pin F slides along the right half of slot e.
$1391$LG,OC$