GB539452A - Improvements in or relating to sewing machines and to seams produced thereby - Google Patents

Abstract

539,452. Sewing - machines. ARMSTRONG, J. J. V. (Union Special Machine Co.). Dec. 28, 1939, No. 32926. [Class 112] A compound seam comprises a fabric uniting seam set in from the fabric edge and an overedge seam. The stitches of each seam are complete in themselves but are further inter-looped with the stitches of the other seam so that either seam can be separately unpicked. Fig. 5 shows an example in which each seam is a line of single thread loop stitches and the thread loops of the overedge seam are carried through the loops of the plain seam. In another example both seams are double loop seams and the needle-thread loops of the overedge stitches are passed through the under thread loops of the plain seam. Fig. 4 shows the stitch-forming mechanism. The plain seam needle 4 co-operates with a looper 19 and, in place of a needleavoiding movement of the looper, the looperthread is spread for the needle by a hook 18. The overedge seam needle 5 co-operates with a looper 21 and a hook or looper 23 which carries the thread loops over the fabric edge. This looper has a horn 24 which engages the plain seam needle thread above the work and thereby tightens seam stitches. The needles 4, 5 are on one bar and the loopers 19, 21 one one shaft.