Filament track profile for sliding clasp fastener - combining good head support with extended anchorage loops

摘要

Complementary track patterns are made from continuous thermoplastic filaments. The interlocking heads are formed by bends in the filament profile normal to the plane of the track. One supporting leg of each bead is extended to provide an elongated loop which can be secured by an array of threads for holding the track to a support tape. The other supporting leg of each bend is part of a short loop linked to the next head. Appts. is described for winding pair os tracks alternately about a common coaxial mandrel and outboard mandrels for the extended loops of each individual track. When two tracks are engaged, each of the interlocking heads is in effect supported by three short profile loops, one being its integral support and the other being the short legs supporting each of the adjacent heads. The fastening is thus inhibited from twisting and disengaging. The extended loops provide adequate anchorage area.