Gear 1 rotates about fixed axis B and meshes with gears 2 and 3 which rotate about fixed axes K and C. Links 4 and 5 are connected by turning pairs F and D to gears 2 and 3, and to each other by turning pair E. When driving gear 1 rotates, the tip of claw A of link 4 describes a complex connecting-rod curve of which a portion is used to insert claw A into a perforation of the film, to advance the film and to withdraw claw A from the perforation.
$2520$LrG,OC$