Process and apparatus for molding zipper fasteners

Claim 1

A PROCESS FOR MAKING A CONTINUOUS ZIPPER STRINGER WITH A SERIES OF FLEXIBLY CONNECTED INDIVIDUAL ZIPPER ELEMENTS, EACH ELEMENT HAVING A BODY PORTION AND A SUBSTANTIALLY NARROWER HOOK-LIKE SECTION PROJECTING BEYOND SAID BODY PORTION TOWARD AN ADJACENT FASTENER ELEMENT, WHICH PROCESS CONSISTS OF (A) ROTATING A WHEEL HAVING A SOLID PERIPHERY WITH MOLD CAVITIES OPENING THROUGH THE PERIPHERY OF THE WHEEL, EACH MOLD CAVITY CONFORMING IN SHAPE TO ONE OF SAID ZIPPER ELEMENTS, SAID MOLD CAVITIES BEING CONNECTED BY A GROOVE WITH A STATIONARY NOZZLE FITTING TIGHTLY AGAINST THE WHEEL PERIPHERY ON OPPOSITE SIDES OF SAID GROOVE; (B) INJECTING PLASTIC MATERIAL INTO THE MOLD CAVITIES THROUGH SAID NOZZLE AS THE WHEEL ROTATES IN LINE WITH A STATIONARY CORE WHICH FITS IN THE BOTTOM PORTION OF SAID GROOVE; (C) SIMULTANEOUSLY WITH SUCH INJECTION, INTRODUCING A CONTINUOUS FLEXIBLE CORD WITHIN SAID GROOVE BETWEEN SAID CORE AND SAID NOZZLE; AND, (D) WITHDRAWING SUCH FLEXIBLY CONNECTED FASTENER ELEMENTS FROM THE PERIPHERY OF SAID WHEEL WITHOUT OPENING SAID MOLD CAVITIES IN A LATERAL DIRECTION.