| 摘要 |
874,041. Moulding sliding-clasp fasteners. LIGHTNING FASTENERS Ltd. Jan. 1, 1960 [Dec. 3, 1958], No. 38924/58. Class 87(2). A toothed strip for a sliding-clasp fastener is produced by injecting heated thermoplastic material such as nylon into registering interconnected pocketed rebates or grooves 8 formed in and around the peripheries of the adjacent faces of a pair of ratating dies, 1, 2, which rotate about relatively inclined axes, and removing the strip 16 from the dies. Nylon is injected from cylinder 13 having a heater 15 through orifice 12 into the co-operating grooves 8 and their spaced pockets 9. Dies 1, 2 rotate synchronously in the direction of arrow 7 and their peripheries converge at the injection station 5 and diverge at the stripping station 6. The injection nozzle is curved and is provided with a rib 11 engaging the grooves which prevents injection into the pockets before they reach the orifice 12. The strips may be formed with shoulders and webs, Fig. 4, (not shown) by using the dies slightly out of phase one way and then out of phase to an equal and opposite degree.
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