Methods and devices for making cups and similar vessels of a thermoplastic material

Claim 1

APPARATUS FOR MAKING A CUP FROM A SHEET OF TERMOPLASTIC MATERIAL PREVIOUSLY SOFTENED BY HEATING, COMPRISING A MOULD DEFINING A RECESS HAVING A VERTICAL AXIS AND OPEN AT BOTH ENDS, A HOLLOW INVERTED BOX SHAPED ELEMENT DISPOSED ABOVE THE MOULD, THE LOWER MARGIN OF THE BOX SHAPED ELEMENT AND THE UPPER MARGIN OF THE MOULD HAVING COACTING SURFACES FOR HOLDING S SHEET OF MATERIAL DURING MOULDING, SAID MOULD HAVING AN INWARDLY DOWNWARDLY TAPERED INNER WALL TERMINATING AT ITS LOWER END IN AN ANNULAR INWARDLY DIRECTED PROJECTION HAVING AN UPPER SURFACE EXTENDING IN A HORIZONTAL PLANE AND HAVING AN OUTWARDLY DOWNWARDLY EXTENDING ANNULAR LOWER SURFACE, A PUNCH POSITIONED WITHIN SAID BOX SHAPED ELEMENT ABOVE A SHEET OF MATERIAL AND MOVABLE ALONG SAID VERTICAL AXIS WITH RESPECT TO THE MOULD TO INITIATE FORMATION OF A CUP, MEANS FOR INTRODUCING FLUID UNDER PRESSURE TO THE INTERIOR OF THE BOX SHAPED ELEMENT FOR FORMATION OF A CUP, A COUNTER PUNCH INCLUDING AN ANNULAR PERIPHERAL OUTWARDLY DOWNWARDLY TAPERED SURFACE COMPLEMENTARY TO AND OVERLAPPING THE LOWER SURFACE OF THE INWARD PROJECTION OF THE MOULD, SAID COUNTER PUNCH BEING MOVABLE ALONG SAID VERTICAL AXIS WITH RESPECT TO THE MOULD FOR FOLDING BACK A DOUBLE THICKNESS OF SAID MATERIAL AT THE BOTTOM OF A CUP AND PRESSING SAID DOUBLE THICKNESS OF MATERIAL AGAINST THE LOWER SURFACE OF THE INWARD PROJECTION TO PROVIDE A CUP HAVING A DOWNWARDLY OUTWARDLY TAPERED ANNULAR SUPPORT.