부산대학교 도서관

A zigzag folding apparatus for a form printing machine has a guiding device for paper feeding disposed in the front end thereof, folding arms for holding paper form blanks in a zigzag along their respective transversely perforated lines through rightward and leftward swing movements thereof effected by crank shafts, and a plurality of rotary spirals for arranging the paper blanks folded by the folding arms in a pile through guiding along the fold lines of the same. Particularly, the crank shafts are connected via a rotating transmission mechanism of gearing to a servo motor for folding drive which is controlled with control signals. Additionally, the apparatus has a device for rightward and leftward positioning of said rotary spirals in accordance with a folding top-to-bottom length of the paper blank, a device for positioning the same in directions at right angles to the rightward and leftward directions in accordance with a lateral width of the paper blank, and motors for folding top-to-bottom length determining and lateral width determining respectively which are controlled with control signals.