Method of producing zip fasteners

Claim 1

AN IMPROVED METHOD OF WEAVING A SLIDE FASTENER COMPRISING TWO FASTENER ELEMENTS, EACH OF SAID ELEMENTS COMPRISING A FLATTENED INCORPORATED AS A WEFT INTO ONE OF THE HOOKING ELEMENTS INCORPORATED AS A WEFT INTO ONE OF THE EDGES OF A FABRIC TAPE SUPPORTING SAID ROW, SAID METHOD COMPRISING THE FOLLOWING STEPS: WINDING ON A SPOOL A WEFT FILAMENT OF CONSTANT CROSS-SECTIONAL SHAPE HAVING IN ITS PLANE TWO-AND ONLY TWO-AXES OF SYMMETRY OF UNEQUAL LENGTHS, SAID WINDING BEING EFFECTED WITHOUT TWISTING THE FILAMENT, DISPOSING SAID SPOOL IN A FIRST SHUTTLE HAVING A GENERALLY LONGITUDINAL DIRECTION SO THAT THE FILAMENT IS UNWOUND FROM THE SPOOL IN A DIRECTION PERPENDICULAR TO SAID LONGITUDINAL DIRECTION, THE SHUTTLE NORMALLY MOVING IN SAID LONGITUDINAL DIRECTION IN A LOOM, DISPOSING IN A LOOM SAID FIRST SHUTTLE AND A SECOND SHUTTLE CONTAINING A WEFT FOR FORMING SAID FABRIC, SAID LOOM FURTHER COMPRISING WARP THREADS FORMING SHEDS, A REED HAVING TEETH SPACED A SUITABLE DISTANCE APART, CAUSING THE TWO SHUTTLES TO MOVE IN A TO-AND-FRO MANNER IN THE SHEDS AND THEREBY CREATING FOR EACH MOVEMENT IN EACH DIRECTION OF SAID FIRST SHUTTLE A TWIST THROUGH 180* OF THE FILAMENT, THE SHEDS BEING SO FORMED THAT THE WEFT OF THE SECOND SHUTTLE IS INTERWOVEN WITH THE WARP THREADS TO FORM SAID FABRIC, WHEREAS SAID FILAMENT IS INTERWOVEN WITH CERTAIN THREADS OF THE EDGE OF THE WARP AND PASSES ROUND A CATCH THREAD SO AS TO FORM LOOPS CONSTITUTING THE HOOKING ELEMENTS, AND FEEDING THE THUS WOVEN FASTENER ELEMENTS FORWARDLY SO AS TO WITHDRAW THE CATCH THREAD FROM THE THUS FORMED HOOKING ELEMENTS; SAID METHOD FURTHER COMPRISING THE STEP OF REGULATING THE RESPECTIVE MOVEMENTS OF THE FIRST SHUTTLE AND THE REED IN SUCH MANNER THAT THE LOOPS CONSTITUTING THE HOOKING ELEMENTS ARE FORMED IN FOUR STAGES IN THE FOLLOWING MANNER, WITH THE FIRST SHUTTLE MOVING TOWARDS THE RIGHT, THE FILAMENT PASSES ROUND THE CATCH THREAD FLAT AGAINST THE LATTER AND UNDERGOES A TWIST TOWARDS THE RIGHT FROM SAID CATCH THREAD, THE REED BEING IN ITS TRAVEL POSITION; AS THE FIRST SHUTTLE REACHES THE END OF ITS TRAVEL TOWARDS THE RIGHT THE REED IS CAUSED TO MOVE TO ITS FORWARD POSITION AND ONE OF THE TEETH THEREOF EXERTS A PRESSURE ON THE FILAMENT WHICH IS PRESENTED EDGEWISE, AND THUS RENDERS THE DEGREE OF TWIST OF THE FILAMENT CONSTANT AND CONTRIBUTES TO THE DIMENSIONAL REGULARITY OF THE HOOKING ELEMENT LOOP; THE FIRST SHUTTLE RETURNS TOWARDS THE LEFT AND DRAWS THE FILAMENT UNDER THE CATCH THREAD, THE REED HAVING RETURNED TO ITS REAR POSITION; THE FIRST SHUTTLE REACHES THE END OF ITS TRAVEL TOWARD THE LEFT AND THE REED IS MADE TO RETURN TO ITS FORWARD POSITION IN CONTROLLING THE TWISTING OF THE FILAMENT AND THE DIMENSIONAL REGULARITY OF THE HOOKING ELEMENT LOOP.