Machine for manufacturing frustoconical containers made of sheet material, and more specifically yoghurt pots

Claim 1

IN A MACHINE FOR FABRICATING FRUSTO-CONICAL CONTAINERS WITH A SEALED LATERAL LAP-JOINT FROM SHEET MATERIAL SUCH AS CARDBOARD COVERED ON ONE SIDE WITH A FILM OF PLASTIC RESIN, OF THE KIND COMPRISING, IN SUCCESSION, A MAGAZINE FOR STORING SHEET MATERIAL BLANKS SHAPED AS ANNULAR SECTORS AND DISPOSED WITH THEIR COATED FACE UPPERMOST AND THEIR CIRCULAR EDGE OF SMALLER RADIUS DIRECTED REARWARDLY, A DEVICE FOR LINEARLY TRANSFERRING THESE BLANKS ONE BY ONE FROM THE BOTTOM OF SAID MAGAZINE TO BENEATH ONE OF THE MANDRELS OF A VERTICAL-AXIS REVOLVER-HEAD WHICH IS EQUIPPED WITH FOUR HORIZONTAL-AXIS FRUSTO-CONICAL MANDRELS SECURED RADIALLY THERETO BY THEIR LARGER BASES AND WHICH IS DRIVEN IN SUCCESSIVE NINETY-DEGREE STEPS ABOUT ITS AXIS, A SET OF JAWS AND PRESSERS FOR WRAPPING AND LATERALLY SEALING EACH BLANK ON THE CORRESPONDING MATERIAL WITH ITS COATED FACE IN CONTACT THEREWITH WHEREBY TO FORM A FRUSTO-CONICAL SLEEVE, A SECOND DEVICE FOR LINEARLY TRANSFERRING EACH FRUSTO-CONICAL SLEEVE TO A CONTAINER-FINISHING STATION WHEREBY TO MOUNT SAID SLEEVE WITH ITS LARGER BASE DIRECTED TOWARD SAID SECOND TRANSFER DEVICE IN A SOCKET OF A HORIZONTAL-AXIS REVOLVER-PLATE HAVING SIX FRUSTOCONICAL SOCKETS THEREON AND ROTATED IN SUCCESSIVE SIXTYDEGREE STEPS ABOUT ITS AXIS, SAID SLEEVE DURING THE STEPWISE MOVEMENT OF SAID REVOLVER-PLATE BEING OPERATED UPON BY A DEVICE FOR POSITIONING THEREON A BOTTOM WHICH A THIRD TRANSFER DEVICE CONVEYS FROM MEANS FOR CUTTING AND SWAGING CONTAINER BOTTOMS, OUT OF A STRIP OF SAID COATED SHEET MATERIAL, TO FORM A BOWL-SHAPE WITH A FLARED FRUSTO-CONICAL FLANGE HAVING ITS COATED SURFACE OUTWARDS, BY A DEVICE FOR FOLDING THE CORRESPONDING END OF SAID SLEEVE OVER SAID BOTTOM-FLANGE, BY A DEVICE FOR HOT-CRIMPING THE FOLD OBTAINED THEREBY, BY A DEVICE FOR FORMING A ROLLED EDGE ON THE OTHER END OF SAID SLEEVE AND BY A DEVICE FOR EJECTING THE CONTAINER CONSTITUTED BY SAID SLEEVE PROVIDED WITH SAID BOTTOM AND SAID ROLLED EDGE, CONTROL MEANS FOR DRIVING IN SEQUENTIAL RELATIONSHIP THE REVOLVER-HEAD WITH ITS JAWS AND ITS PRESSERS, THE REVOLVER-PLATE, THE MEANS FOR CUTTING AND SWAGING THE BOTTOMS, AND THE ENTIRETY OF SAID DEVICES, AND MEANS RESPONSIVE TO THE ABSENCE OF A SLEEVE ON A FRUSTO-CONICAL MANDREL FOR RENDERING THE BOTTOM-CUTTING AND SWAGING MEANS TEMPORARILY INOPERATIVE; THE IMPROVEMENT WHICH COMPRISES, ABOVE SAID FIRST TRANSFER DEVICE, MEANS FOR CUTTING A BEVEL THROUGH THE THICKNESS OF THE SHEET MATERIAL ALONE ALONG THAT STRAIGHT EDGE OF THE BLANK WHICH IS TO FORM THE INNER OVERLAPPING PORTION OF THE LAP-JOINT DOWN THE SIDE OF SAID SLEEVE, MEANS FOR FOLDING THIS BEVEL-CUT OUTWARDLY RELATIVE TO THE COATING ON THE BLANK, MEANS FOR HEATING THE OTHER STRAIGHT EDGE OF THE BLANK WHEREBY TO MELT ITS COATING WITHOUT SCORCHING THE SHEET MATERIAL; MEANS AT THE EXIT END OF SAID FIRST TRANSFER DEVICE FOR WRAPPING SAID BLANK ABOUT THE REVOLVERHEAD MANDREL WHICH IS HALTED FOLLOWING ONE OF ITS STEPWISE ROTATIONS FACING THE AXIS OF SAID FIRST MELTED COATING BY APPLYING THE STRAIGHT BLANK-EDGE WITH ITS MELTED COATING AGAINST THE OUTWARDLY FOLDED COATED BORDER OF THE OTHER STRAIGHT BLANK-EDGE, PRESSERS MADE OF ELASTIC MATERIAL FOR PRESSING TOGETHER THESE STRAIGHT OVERLAPPING EDGES ON SAID MANDREL DURING THIS AND THE NEXT TWO STEPWISE ROTATIONS OF SAID REVOLVER-HEAD; FACING THE SUCCESSIVE POSITIONS OF THE REVOLVER-PLATE SOCKET CARRYING A FRUSTO-CONICAL SLEEVE, ON THE SIDE OF THE LARGER SLEEVE BASE, ON THE ONE HAND, A DEVICE FOR POSITIONING THE BOTTOM INSIDE THE SLEEVE WHILE LEAVING A SLEEVE PORTION FREE BETWEEN THE LARGER SLEEVE BASE AND THE RIM OF THE BOTTOM-FLANGE, A DEVICE FOR HOTFOLDING SAID SLEEVE PORTION INWARDLY, AND TWO CONSECUTIVE HOT-CRIMPING DEVICES FOR SEALING THIS FOLD AGAINST THE INNER FLANGE WALL AND, ON THE SIDE OF THE SMALLER SLEEVE BASE, ON THE OTHER HAND, THRUST MEANS FOR THE BOTTOM WHEN THE SAME IS BEING POSITIONED, MEANS FOR LUBRICATING THAT PORTION OF THE INNER SLEEVE WALL WHICH IS ADJACENT THE SMALLER SLEEVE BASE AND OVER WHICH SAID ROLLED EDGE IS TO BE FORMED, MEANS FOR RESTRAINING THE SLEEVE BY ITS SMALLER BASE DURING THE FIRST HOT-CRIMPING OPERATION ON SAID FOLD, MEANS FOR FORMING SAID ROLLED EDGE AND A DEVICE FOR EJECTING THE CONTAINER FROM THIS MANDREL; DISTRIBUTOR MEANS RECEIVING THE EJECTED CONTAINER FROM SAID REVOLVER-PLATE, TERMINAL HEATING MEANS RECEIVING EACH CONTAINER FROM SAID DISTRIBUTOR MEANS WHEREBY TO HEAT ITS EXTERNAL PORTION ADJACENT ITS LARGER BASE AND SEAL TOGETHER THE MUTUALLY CONTACTING SURFACES OF SAID BOTTOM-FLANGE AND OF SAID SLEEVE WITHOUT SCORCHING THE SHEET MATERIAL, MEANS FOR EJECTING THE FINISHED CONTAINER FROM SAID TERMINAL HEATING MEANS, MEANS FOR REVERSING SAID BOTTOMS ON SAID THIRD TRANSFER DEVICE, AND MEANS FOR DISCHARGING THE WASTE MATERIAL OBTAINED FROM SAID BEVEL CUTS AND FROM CUTTING AND SWAGING SAID BOTTOM, WHEREBY THE FABRICATED FRUSTO-CONICAL CONTAINER IS OPEN OVER ITS SMALLER BASE AND THE SUBSTANCE IT IS TO CONTAIN IS ENCLOSED IN AN UNBROKEN CHAMBER OF THERMO-PLASTIC RESIN WITHOUT ANY POSSIBILITY OF CONTACT WITH SAID SHEET MATERIAL, THEREBY RESULTING IN AN ABSOLUTELY LEAKPROOF CONTAINER.