FILM INTERMITTENT FEED DEVICE FOR BAG MAKING MACHINE AND THE LIKE

PURPOSE:To control a feed roller so accurately in an inexpensive manner, by connecting rotational motion of a turning shaft to be driven by a driving gear of a machine to a servomotor via a pulse encoder and a generator, and thereby constituting it to drive the feed roller of the machine. CONSTITUTION:When a turning shaft 2 is driven, an input shaft of a pulse encoder 4 rotates, and this encoder 4 outputs a pulse train and a zero pulse, namely, Z pulse signal. This pulse train is inputted into a generator 6, whereby the generator 6 outputs such a trigonometric functional electric signal that an optional zero position is set. This electric signal is fed to a servomotor 14 by way of an amplifier 8. This servomotor 14 is intermittently driven by the trigonometric functional electric signal to be inputted in, having a feed roller 18 rotated intermittently. Thus, since a crank mechanism is no longer used, manufacturing cost becomes inexpensive and, what is more, the setting of film feed per stroke is so easy and the feed roller is controllable in a highly accurate manner.