Method and device for folding and bonding corner portions of a heat sealable box blank

Claim 1

IN A DEVICE FOR SETTING UP A CARTON FROM A BLANK COMPRISING CORNER FLAPS WHICH IN THE SET UP CONDITION OF THE BLANK OVERLIE AND ARE BONDED TO CARTON SIDE WALL PORTIONS BY THERMOPLASTIC ADHESIVE PREAPPLIED TO THE BLANK, THE DEVICE COMPRISING, A MAIN DIE HAVING A SUBSTANTIALLY RECTANGULAR DIE APERTURE; A PLUNGER FOR DRIVING A BLANK THROUGH THE DIE TO EFFECT THE SETTING UP THEREOF; PREHOLDING ELEMENTS AT THE FOUR CORNERS OF THE DIE; AND A TRANSPORT MEANS FOR PLACING A BLANK OVER THE MOUTH OF THE DIE AND BETWEEN SAID PROFOLDING ELEMENTS TO FOLD THE CORNER FLAPS THEREAGAINST, THE CARTON SIDE WALLS REMAINING SUBSTANTIALLY FLAT, UNFOLDED BETWEEN SAID ELEMENTS, THE IMPROVEMENT WHICH COMPRISES AIR DISCHARGE APERTURES IN TWO FACES OF EACH OF THE PREFOLDING ELEMENTS, WHICH FACES LIE AT AN ANGLE TO EACH OTHER, FOR THE DISCHARGE OF TWO STREAMS OF AIR, ONE AGAINST THE PREFOLDED FLAP FOLDED THEREAGAINST, THE OTHER DOWNWARDLY SLANTED AGAINST THE AREA OF THE CARTON WALL TO WHICH SAID PREFOLDED FLAP IS TO BE BONDED, SAID TWO STREAMS BEING OF UNEQUAL LENGTH AND SUBSTANTIALLY AT RIGHT ANGLES TO EACH OTHER IN PLAN VIEW OF THE DIE; AND MEANS FOR SUPPLYING A COMMON FLOW OF HEATED AIR UNDER PRESSURE TO EACH OF SAID ELEMENTS FOR DISCHARGE THROUGH ITS SAID TWO SETS OF APERTURES.