Tray former

Abstract

An improvement in a carton forming mechanism of the type wherein a mandrel is reciprocated through a die assembly to fold the side walls and tabs of an upwardly open carton assembly having perpendicular pairs of side walls. It is designed specifically for carton blanks having protruding tabs at the ends of both pairs of side walls, so that each side wall is overlapped by a bent tab when the carton is completed. The folding mechanism includes two opposed pairs of folding irons mounted about parallel spaced pivot axes. Each folding iron has an arcuate surface to fold a first carton wall relative to the bottom carton wall. It also includes a radial extension at the outermost edge of the arcuate surface for folding a first tab relative to the first wall. Radial spacing is provided on each folding iron between the arcuate surface and the shaft mounting it. This spacing is sufficient to permit second tabs at the ends of second side walls of the carton perpendicular to the folded first side walls to pass between the pivot shafts without interference. A pair of pressure rollers are rotatably mounted about parallel axes perpendicular to the pivot axes and at an elevation below that of the folding irons, whereby the second carton side walls are folded along their score lines common to the bottom carton wall as each blank is forced between the rollers by reciprocation of the mandrel. In the resulting partially-folded carton condition, the second tabs remain extended for subsequent completion of the carton.