GB275149A - Improvements in the connection of material by stitching - Google Patents

Abstract

275,149. Union Special-Maschinenfabrik Ges. July 29, 1926, [Convention date]. Stitches and seams; multiple-needle sewing-machines; blind stitching machines; trimming.-The two flat adjacent edges of material to be connected by a blind-stitch seam 4, Fig. 1, are first raised and then trimmed to the same depth before the bending seam is made., and the edges of the material are subsequently covered. The material is fed to the trimming mechanism with the edges in the position of an inverted V and may be bent, alter trimming and stitching, for the purpose of covering, in such a way chat a third horizontal face is formed between the two inclined faces. The binding seam, Fig. 10, is formed of two needle threads which are passed through the edges of the material from both sides forming two oppositely arranged single chain stitches which mutually lock one another. The thread lays, which are the same on both sides, consist of alternating loop lays of a length of one stitch and binding lays two stitches in length. The stitch passage for the covering seam lies above or below the stitch passages for the connecting seam and is adjusted relatively thereto. The seam is made in a machine, Fig. 15, having three needles oscillating in an arcuate path, two, 8, 9, for stitching together the edges and one 24 for covering purposes. The work is fed along a cylindrical work support 39 by dogs. The needles 8, 9 co-operate with threadless loopers opposite the needles, which take up the thread loops and retain them spaced open for the passage of the next needle, and a thread carrying looper co-operates with the covering needle 24 to form the covering seam. A stitch-plate 7 in the form of an inverted V and a similar shaped presser foot 1 having two inverted V-shaped side walls separated by a slot 3, Fig. 4, co-operate to raise the edges of the material for trimming which is done by a stationary blade 5, Fig. 2, and a blade 6 moving counter thereto. The needles 8, 9 move in circular paths behind the blades 5, 6 and on opposite sides of the work to stitch the two edges 4 of the material together, a slot 10 being provided in the presser foot 1 for the passage of the needles 8, 9. A channel in the presser foot receives the raised seam rib 4 and forces it into a feed guide 13 in the stitch plate by a downwardly directed member 12. The stitch plate 7 and a cloth support 16 are adjustable in height as shown in Fig. 4 to alter the height and depth of the stitch passage of the covering needle 24. A tongue 22, Fig. 2, also adjustable in height to correspond with the adjustment of the stitch-plate is mounted on the covering side of the presser foot 1 so that the apparatus continues to chain-stitch without material.