Patent ID: 10244828

Abstract:
A wide top narrow bottom type double-layer zipper that the width of the interlocked bottom interlocking coils is smaller than the width of the interlocked top interlocking coils; the top interlocking coils and the bottom interlocking coils have the same spiral pitch; the top and bottom layers of the wide top narrow bottom type double-layer zipper are vertically aligned and sewed; the diameter of the polyester coils extend spirally around the respective filler cords of the respective bottom interlocking coils monofilament is about 0.02 mm˜0.1 mm smaller than the diameter of the polyester coils monofilament that extend spirally around the respective filler cords of the respective top interlocking coils; the engaged tooth line of the top interlocking coils at the top cover panel of the zipper slider and the engaged tooth line of the bottom interlocking coils at the bottom cover panel of the zipper slider exhibit a non-superimposed relationship.