Apparatus and method for folding synthetic plastic sheet stock

Claim 1

IN THE METHOD OF FOLDING PLASTIC SHEET STOCK, THE STEPS COMPRISING PROVIDING TWO SPACED PAIRS OF FOLDING MEMBERS, SAID MEMBERS OF EACH PAIR BEING OF GENERALLY CIRCULAR CONFIGURATION AND HAVING SUBSTANTIALLY PARALLEL AXES OF ROTATION IN OPERATIVE POSITION, ONE OF SAID MEMBERS OF EACH PAIR BEING A DIE PAD MEMBER HAVING A RESILIENT RUBBER-LIKE MATERIAL EXTENDING ABOUT ITS PERIPHERY AND THE OTHER BEING A FOLDING BLADE MEMBER HAVING A BLADE EDGE EXTENDING ABOUT ITS PERIPHERY, SAID RESILIENT RUBBER-LIKE MATERIAL OF SAID DIE PAD MEMBERS HAVING OPPOSING SIDE FACES TAPERING OUTWARDLY AND OPPOSITELY TOWARDS THEIR CIRCUMFERENTIAL EDGES, SAID BLADE MEMBERS HAVING PERIPHERAL PORTIONS OF GENERALLY U-SHAPED CROSS-SECTION WITH SAID BLADE EDGES BEING AT THE INTERSECTION OF THE CIRCUMFERENTIAL FACE AND THE OUTER SIDE FACE OF SAID BLADE MEMBERS DEFINING SAID U-SHAPED CROSS-SECTION; SAID BLADE EDGES OF SAID PAIR OF BLADE MEMBERS EXTENDING INTO SAID RUBBER-LIKE MATERIAL OF THE COOPERATING DIE PAD MEMBERS AT SAID TAPERING SIDE FACES THEREOF IN OPERATIVE POSITION; ROTATING SAID MEMBERS AT SUBSTANTIALLY EQUAL TANGENTIAL SPEEDS AT THEIR AREA OF ENGAGEMENT WITH THE FOLDING BLADE AND DIE PAD MEMBERS ROTATING IN OPPOSITE DIRECTIONS; AND PASSING A LENGTH OF SYNTHETIC PLASTIC SHEET STOCK BETWEEN SAID PAIRS OF MEMBERS, THE BLADE EDGES OF SAID ROTATING FOLDING BLADE MEMBERS DEPRESSING SAID STOCK INTO SAID TAPERING SIDE FACES OF SAID RESILIENT RUBBER-LIKE MATERIAL OF THE COOPERATING ROTATING DIE PAD MEMBERS SUFFICIENTLY TO CAUSE SAID RUBBER-LIKE MATERIAL TO FLOW AND FOLD SAID STOCK AGAINST SAID OUTER SIDE FACE AND ALONG SAID CIRCUMFERENTIAL FACE OF SAID BLADE EDGES, SAID PLASTIC SHEET STOCK EXTENDING RELATIVELY TAUTLY BETWEEN SAID TWO PAIRS OF FOLDING MEMBERS.