Connecting rod 2 of four-bar linkage CDEF is connected by turning pair G to link 4 which, in turn, is connected by turning pair H to link 5. Link 5 turns about fixed axis K and is connected by turning pair M to link 6 which slides along rounded fixed guide a. When crank 1 rotates about fixed axis C, claws b describe a connecting-rod curve. At a portion of this curve, claws b engage perforations of the film, move the film and are withdrawn again. Claws d are inserted into perforations of the film to restrain it from movement at the moment that claws b are being withdrawn.
$780$LW,OC$