Abstract: An apparatus and method for forming flat cut carton blanks into erected cartons with debowed carton side panels is disclosed. The apparatus includes a forming head receiving and directing a carton blank through forming guides, side walls engaging and supporting the carton side panels that bend into upright position relative to the carton bottom panel during descending movement through the forming guides. Presser fingers pivotally secured to the forming guides project inwardly into the forming head path. The presser fingers bend the side panels into cutout openings provided in the side walls to overbreak the side panels at fold lines between the carton side and bottom panels. An inclined surface with a sharp creasing edge abutting the fold lines enables the presser fingers to initially crease the fold lines and thereafter bend the carton side panels inwardly onto the inclined surface for controlled overbreaking movement.

Abstract: Apparatus for forming a hinged or clamshell type carton from a paperboard blank includes a carton forming die for receiving the paperboard blank, a movable frame for transferring the carton blank from the stack into registration over the die, and a reciprocating plunger mounted above the die for forming the carton. The blank is formed into a finished carton in one simple harmonic motion. The movable frame includes a number of vacuum assisted suction cups for lifting the carton blank from the stack and at least a pair of gathering rollers which cooperate with a pair of pivoting blades mounted adjacent the die to fold and gather the hinge of the carton blank as the blank is positioned and pressed into contact with the die. A pair of inverted "T" retaining bars, disposed on the die adjacent the carton hinge, prebreak glue tabs on the carton and capture and retain the wall panels of the carton when the blank is pressed into registration with the forming die.