| 摘要 |
899,246. Sewing; sewing machines. HEILMANN, W. E. July 2, 1958 [July 2, 1957], No. 21212/58. Class 112 [Also in Group XXV] A helical slide fastener element 1 is secured to a cord 2 by a pair of side-by-side helicallyarranged threads 3. Two elements 1 are then enmeshed by means of a sliding clasp, and finally the associated cords 2 are simultaneously sewn to respective tapes 4 in a twin-needle doublethread chain stitching machine, with the tapes 4 being positioned uppermost. The threads 3, the lower looped thread 5 and the lower portion of the upper thread 6 combine to form a guide for the sliding clasp. One of the threads 3 is of cotton and its companion thread 3 is of wear-resistant material such as polyamide or polyurethane. |
