Apparatus and method for forming and debowing cartons with pinching

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. Pinching wheels rotatably secured adjacent the forming guides include a pinching notch with a leading edge projecting inwardly into the forming head path. The pinching notch engages the descending carton bottom and side panels to capture and pinch the fold lines and overbreak the side panels at the fold lines between the carton side and bottom panels. An inclined surface with a sharp creasing edge abutting the inside of the fold line assists the pinching notch in creasing the fold lines. An extension edge formed adjacent a trailing edge of the pinching notch completes the overbreaking action. A release edge formed adjacent the leading edge gently releases the carton side panels from the overbreaking position upon counter rotation of the wheel. The height of the cutout opening allows each carton side panel to clear the upper periphery of the openings to prevent buckling. After debowing the side panels, a stripping edge of the pinching wheel engages the upper edge of the carton side panel to strip the erected cartons from the forming head during the ascending return stroke. Clearance notches provided in the forming head side walls serve to prevent interference contact between the pinching wheels and the forming head and also improve pinching engagement.