Link 1 of slotted-link mechanism ACE rotates about fixed axis A. Pin C of link 1 slides along straight horizontal slot b of link 2 which reciprocates along guides E. Link 3 is connected by turning pair B to link 2 and has slot d along which pin C of link 1 slides. When crank 1 rotates about axis A, operating claw a of link 3 is inserted into a perforation of the film as pin C of crank 1 slides along the left half of slot d in link 3. Then the film is advanced by the vertical motion of link 3 together with link 2 and, finally, claw a is withdrawn from the perforation as pin C slides along the right half of slot d.
$1390$LG,OC$