Apparatus for zig-zag folding of paper webs and the like

Abstract

An apparatus for converting a continuous paper web with transversely extending weakened zones into successive stacks of overlapping panels in zig-zag formation has two endless foraminous belt conveyors with divergent active reaches which attract alternate panels of the running web and advance alternate weakened zones into the range of the flights of two spiral conveyors. The spiral conveyors terminate the change of orientation of oncoming panels and deposit the panels on a vertically movable support whereon the panels accumulate into a stack. When the number of panels in a stack reaches a predetermined value, a nozzle admits compressed air between the topmost panel of the stack and the next-following panel so as to open the zig-zag formation and permit insertion of a table having a slot for a reciprocable knife which severs the web along the fold line between the topmost panel of the stack and the next-following panel. One of the spiral conveyors is arrested during introduction of the table into the gap between the two neighboring panels. Stops are disposed between the discharge ends on the active reaches of the foraminous conveyors and the adjacent spiral conveyors to promote the folding of panels relative to each other as well as to prevent lateral stray movements of the panels on their way toward the support.