Abstract: Apparatus for stacking paperboard blanks including a timed conveyor utilizing vacuum pressure to hold the blanks by their leading edges beneath the conveyor and serially advance them against a backstop whereupon they are released by the vacuum to settle upon an elevator which lowers incrementally as a stack of blanks is formed thereon. When the stack is completed, interrupter tines move over the stack and under the conveyor to store oncoming blanks while the stack is discharged from the elevator after which is rises. As the tines withdraw, the stored blanks settle on the elevator and subsequent blanks form another stack. A counter is used to energize operation of the tines to form stacks of a predetermined number of blanks on the elevator. An inclined conveyor utilizing vacuum belts is used to feed the blanks into engagement with the timed conveyor.

Abstract: A belt type box blank folding machine including bar folder assemblies on a downstream end thereof for engaging partially folded substantially upstanding outer panels on the blanks and folding them downward against inner panels of the blanks. The bar folders are arranged to pivot from an upright position, in engagement with the upstanding panels, to a horizontal position and to simultaneously reciprocate along the path of blank travel to provide maximum engagement with the outer panels during folding thereof. The bar folders are parallel with the fold line of the outer panels during folding thereby preventing twisting of the panels and locking of the leading flaps of the outer panels against the inner panels.