Flap laminating mechanism for carton blanks

A mechanism for laminating pre-cut flaps on planar carton blanks as the carton blanks move to a carton forming station, wherein each carton blank is rectangular in configuration with transverse forward and rearward end edges joining opposed logitudinal side edges, and wherein a laminating flap is located at each corner of the blank, the laminating flaps being transversely foldable about longitudinal laminating fold lines substantially parallel to the side edges of the carton blank, the transverse width of the carton blank area between transversely aligned laminating fold lines being at least twice as great as the transverse width of each laminating flap from its laminating fold line to the side edge of the blank, said mechanism comprising:

• a stationary framework;
• a longitudinal, upwardly-facing, powered conveyor flight extending along the framework for elevationally supporting individual carton blanks and for continuously moving the carton blanks in succession along a longitudinal path extending the length of the conveyor flight from an infeed end to a discharge end;
• carton blank delivery means for directing individual carton blanks onto the conveyor flight adjacent its infeed end, with the longitudinal side edges and laminating fold lines of the carton blanks arranged parallel to the longitudinal path of the conveyor flight with respect to the framework;
• a pair of pivot arms mounted to said framework at opposite sides of the conveyor flight, said pivot arms being movable about longitudinal axes parallel to the conveyor path, each pivot arm being movable between a lowered position wherein it is clear of carton blanks moving along the conveyor flight, and a raised position where it engages a laminating flap folded upwardly thereby along its laminating fold line;
• stationary folding irons extending downstream along the length of the conveyor flight at each side thereof from locations adjacent the respective pivot arms, said folding irons having inwardly-facing surfaces for engagement by the raised laminating flaps folded by the raised pivot arm adjacent thereto and for folding the raised flaps inwardly over their laminating fold lines and against the adjacent areas of the carton blanks in response to the continuous movement imparted to the carton blank by the conveyor flight;
• the distance between each pivot arm and the stationary folding iron associated therewith being less than the laminating flap length measured parallel to the longitudinal path of the conveyor flight, whereby each laminating flap can momentarily overlap both the pivot arm and stationary folding iron adjacent thereto while moving continuously along the longitudinal path of the conveyor flight.