Apparatus for forming a plastic article

Abstract

Abstract A METHOD AND APPARATUS FOR MAKING CONTINUOUS COUPLING ELEMENTS FOR SLIDE FASTENERS. A SYNTHETIC THREAD OF A THERMOSETTING MATERIAL IS ADVANCED AXIALLY TOWARD RADIALLY OUTWARDLY EXTENDING GUIDE PINS OR TEETH ON THE PERIPHERY OF A CYLINDRICAL DISC MOUNTED FOR STEP-BY-STEP ROTATION. THE SYNTHETIC THREAD IS ADVANCED A LENGTH SUFFICIENT TO FORM A LOOP OF A HELICAL COIL, AFTER WHICH THE CYLINDRICAL DISC IS ADVANCED ONE STEP, OR ONE GUIDE PIN. THE SYNTHETIC THREAD IS ADVANCED BY MEANS OF A PAIR OF ROLLERS WHICH HAVE MEANS ON THEIR PERIPHERY OR WHICH COACT WITH STAMPING TOOLS TO DEFORM THE SYNTHETIC THREAD AT CERTAIN POINTS AND GIVE IT A PROPER SHAPE. THE SHAPED THREAD WILL PROVIDE A LOOP HAVING A DEFORMED COUPLING SURFACE AT ITS APEX AND DEFORMED ENGAGING SURFACES FOR THE COUPLING SURFACES OF A MATCHING COUPLING ELEMENT AT THE LOOP BASE. AFTER A LOOP HAS BEEN FORMED AND ADVANCED IT IS STAMPED FLAT BY A RECIPROCATING STAMPING DEVICE AND IS THEN HEATED SO AS TO BECOME SET. THE CYLINDRICAL DISC MIAY ALSO BE PROVIDED WITH AN ADDITIONAL SET OF GUIDE PINS ON ITS PERIPHERY, OFFSET FROM THE FIRST SET OF GUIDE PINS, SO THAT TWO CONTINUOUS COUPLING ELEMENTS MAY BE FORMED IN ENGAGING RELATIONSHIP SIMULTANEOUSLY.

Inventors

• 👤 Bernd Porepp

Bibliographic Details