Blank feeder for packaging machine

Abstract

A blank feeder for a packaging machine for use with folded flat blanks unfoldable into tubes of square to rectangular cross section and having different lengths to form containers of different capacities. The feeder includes a magazine for containing a stack of flat container blanks. The magazine comprises an inclined frame defining a downward delivery opening and having opposite side members, an upper member and a lower member, a pair of blank unfolding pawls provided at the bottom surfaces of the upper and lower frame members and partly projecting into the opening, and a pair of movable blank supports reciprocatingly movable between an upper position above the frame and a lower position below the frame through the opening. The upper frame member is movable by a hydraulic cylinder longitudinally of the frame to adjust the distance between the unfolding pawls to the length of the blank. Blanks are supplied by an elevator to the movable blank supports in the upper position and then placed on fixed blank supports at the frame bottom by lowering the movable supports. When the movable supports are raised to the upper position to remove the remaining blanks from the magazine after packaging, the blanks are transferred from the movable supports onto movable guide rods brought to a fallen position from an upright position on the lower frame member.