Container blank erecter and feeder

A blank feeder for feeding blanks to a bottom forming mandrel each blank folded flat so as to unfold to a tubular form of square cross section and so as to fit the unfolded blank around the mandrel, the feeder comprising:

• a magazine having a delivery opening at one end and accommodating flat blanks as arranged from said one end toward the other and thereof in the form of a stack,
• transport means having a path of transport extending straight from the delivery opening as a starting end to a terminal end away from the opening,
• means for unfolding each of the flat blanks to the tubular form while the blank is being transported by the transport means, the unfolding means having first and second blank unfolding claws provided at edge portions of the delivery opening so as to individually engage with opposite ends of the blank in the delivery opening and separate and open said opposite ends of the blank, the first and second unfolding claws being positioned at different distances from a reference plane orthogonal to the transport path in a direction along the path, and
• means for feeding the unfolded blank to the bottom forming mandrel to fit the unfolded blank around the mandrel.