Method and apparatus for gapping slide fastener chain

Abstract

Continuous or other lengths of flat back plastic filament coil slide fastener chain is gapped in such a manner that the tape ends produced by the gapping are scrap-free and undamaged. The slide fastener chain to be gapped is held in a laterally taut state in a die and anvil apparatus while the interengaged coil elements are forced upwardly into engagement with blades which cleanly sever the outer leg portions of the coil elements, which leg portions are conveyed upwardly by suction. During the outer leg severing operation, the slide fastener chain is further stretched laterally and caused to spread apart slightly at its center line. The center portion of the chain between the removed coil outer leg portions is received in a control and stabilizing channel between the severing blades while an ascending punch acts on the remaining interior coupling portions of the coil elements and removes them cleanly from the tapes without damaging the tapes. The removed interior coupling portions of the coil elements are also conveyed upwardly by suction away from the gapping zone. Filament coil fragments remaining near one or both ends of the gap are removed by projections on each end of the punch.