GB212300A - Improvements in thread controlling devices for sewing machines - Google Patents

Abstract

212,300. Thompson, W. P., (Union Special Machine Co.). Dec. 6, 1922. Chain-stitching and double loop stitching; multiple - needle machines, - A rotary device for controlling looper thread is arranged to take up slack after the point of the loop has entered the needlethread loop the slack being held and gradually given up as the looper moves to the end of its stroke. The control comprises a guide-wire 17, spring nippers 18 and guide-eyes 19, 21 in wires 20, 22 which direct the thread across a pair of discs 23, 24 mounted on a sleeve 25 on the main shaft 15. As the part a, b of the coin-discs engages the thread a stripper finger 27 raises the thread over the nose b and it is then detained on the surface b, c by a finger 29 till the point c is reached the looper meanwhile entering well into the needle-loop. At the point c the thread falls below the finger 29 and rests on the radially-diminishing part d a which gradually gives up slack. At the point a the looper starts back and slack is taken up by the rise a, b. The form of the cam at c allows reverse movement without fracture of the thread. The sleeve 25 is secured by a screw located between the cam-discs and covered by a spring member 30 held against rotation by a post 32 between its arms. The take-up is described in connection with a machine having two needles and two loopers 9, 10 making similar stitches and actuated in known manner by a rocker 13 and link 16.