Gear 1 rotates about fixed axis A and meshes with gears 2 and 3 which rotate about fixed axes B and E. Gear 2 is connected by turning pair C to slotted lever 4 and gear 3 is connected by turning pair D to slider 5 which moves along slot d of lever 4. When driving gear 1 rotates, the tip of claw a of lever 4 is inserted into a perforation of the film, advances the film and is withdrawn from the perforation. The tip of claw b of slider 5 is inserted into another perforation after claw a is withdrawn and holds the film stationary until it is to be advanced again.
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