Rigidly attached crank 5 and round eccentric 1 rotate about fixed axis C. One end of flat spring 4 is attached at point F to rocker arm 2 of four-bar linkage CBDE. The other end of spring 4 is attached at point G to yoke 3 whose circular slot b has a width equal to the diameter of eccentric 1. When eccentric 1 and crank 5 rotate, claw a of yoke 3 is inserted into a perforation of the film, advances the film and is withdrawn from the perforation.
$3214$CmL,OC$