Thermoplastic strips for sliding clasp fasteners

Abstract

A strip for a stringer of a sliding fastener which is constituted by a row of successive discrete transverse strip elements which are interconnected at their opposite ends by two longitudinally extending cords, each element having an enlarged central portion and opposed leg portions with enlargements at their ends through which the cords pass and are embedded. The strip is bent to a U-shape and stitched to a mounting tape.

What we claim is: 
     
       1. A strip for use in the production of a stringer of a sliding fastener, comprising a row of transversely extending discrete strip-like thermoplastic elements, each element including an enlarged central portion, and opposed leg portions extending transversely from said central portion and defining respective sides of the strip; and two cords extending longitudinally along opposite sides of the strips, each transverse element including enlargements on the ends of the leg portions, the cords extending through the .[.enlargement.]. .Iadd.respective enlargements .Iaddend.and being embedded therein, said enlargements extending from the leg portion longitudinally along the .[.cord.]. .Iadd.respective cords .Iaddend.such that the enlargements of adjacent strips are spaced from one another, whereby said cords provide the sole interconnection between the elements.Iadd., the cords being offset from the center of the respective enlargements so that when the strip is folded in U-shape, the cords are disposed close to the confronting surfaces of the respective enlargements. .Iaddend. 
     
     
       2. A strip as claimed in claim 1, wherein said enlargements have a substantially rectangular shape.  .[.3. A strip as claimed in claim 2, wherein each cord extends through the row of transverse elements offset 
     
     
        from the major axis of the rectangular enlargements. .]. 4. A strip as claimed in claim .[.3,.]. .Iadd.1, .Iaddend.wherein the rectangular enlargements have a longer dimension which extends in the direction of the 
     
     
        cord. 5. A strip as claimed in claim 1, wherein said leg portions have narrow stem portions connecting the central portion of a transverse element with the two ends of the transverse element, and an intermediate 
     
     
        enlargement on each of said stems. 6. A strip for use in the production of a stringer of a sliding clasp fastener, comprising a row of discrete strip-like thermoplastic elements, each element including an enlarged central portion, and opposed leg portions extending transversely from said central portion and defining respective sides of the strip; two cords extending longitudinally along opposite sides of the strips, each cord being secured to the respective legs portion of each element, each leg portion including a substantially rectangular enlargement on the outer end of such leg portion, the cords extending through the enlargements and being embedded therein, said enlargements extending from the leg portions longitudinally along the cord such that the enlargements of adjacent strips are spaced from one another, whereby said cords provide the sole interconnection between the elements, a narrow stem joining each central portion with each end enlargement, and an intermediate enlargement on each of said stems, the strip being longitudinally folded into U-shape so that the two cords are in confronting relation and said enlarged central portions protrude laterally along one longitudinal edge of the folded 
     
     
        strip. 7. A stringer for a sliding clasp fastener comprising a row of transverse, discrete strip-like thermoplastic elements, each element including an enlarged central portion, and opposed leg portions extending transversely from said central portion and defining respectively sides of the strip; two cords extending longitudinally along opposite sides of the strips, each cord being secured to the respective leg portion of each element, each leg portion including a substantially rectangular enlargement on the outer end of such leg portion, the cords extending through the enlargements and being embedded therein, said enlargements extending from the leg portions longitudinally along the cord such that the enlargements of adjacent strips are spaced from one another, whereby said cords provide the sole interconnection between the elements, a narrow stem joining each central portion with each end enlargement, and an intermediate enlargement on each of said stems, each stem being bent substantially at right angles to produce a U-shaped longitudinal fold along the row of transverse elements, a mounting tape having one longitudinal edge portion located within the fold, and a line of stitching extending longitudinally along said edge portion of the tape with individual stitches passing around respective stems between the intermediate enlargements and their adjacent rectangular end enlargements. 
     
     
        . A stringer for a sliding clasp fastener comprising a row of transverse, discrete strip-like thermoplastic elements, each element including an enlarged central portion, and opposed leg portions extending from said central portion and defining respective sides of the strip; two cords extending longitudinally along opposite sides of the strips, each cord being secured to the respective leg portion of each element, each leg portion including a substantially rectangular enlargement on the outer end of such leg portion, the cords extending through the enlargements and being embedded therein, said enlargements extending from the leg portions longitudinally along the cord such that the enlargements of adjacent strips are spaced from one another, whereby said cords provide the sole interconnection between the elements, a narrow stem joining each central portion with each end enlargement, and an intermediate enlargement on each of said stems, each stem being bent substantially at right angles to produce a longitudinal fold along the row of transverse elements, a mounting tape having one longitudinal edge portion located to one side of the fold, and a line of stitching extending longitudinally along said edge portion of the tape with individual stitches passing around respective stems between the intermediate enlargements and their adjacent rectangular and enlargements.