GB270174A - Chain-stitch sewing machine - Google Patents

Abstract

270,174. Fairweather, W., (Singer Manufacturing Co.). Nov. 26, 1926. Chain-stitching and double-loop stitching; governing needle-thread. - In a machine forming stitches by a threaded looper co-operating with the needle, the needle loop is held for penetration by the looper by a slender rotary loop-taker which is passed completely through the needleloop and the loop-taking movement, of which takes place in the same direction as the feed, the loop penetrating movement of the looper being opposite to the direction of feed. The needle-loop is not materiallv drawn out until the needle has risen above the work. The looptaker 20 is supported in a raceway in a head 18 mounted on the undershaft 13 and is driven by arms 24. 25 engaging shoulders on the looptaker. The raceway is made slightly eccentric to the shaft, so that the driving arms 24, 25 are slightly parted from their respective shoulders at the time when they pass the engaged threadloop. The looper 30 is carried by a bracket mounted on a hub 26 rotatably mounted on a sleeve 11. and is oscillated by an eccentric 34 on the shaft 18 and mechanism comprising a pit man 35, levers 36, 38 connected by a shaft 37, and a link 39. The under-thread is passed through a guide 32 and the eye 31 of the looper so that a. triangle is formed for penetration by the needle. The needle-thread is controlled by a constant tension 50, rotary take-up discs 45, and an intermittent tension 49 actuated by a cam on the shaft 10, so that increased tension is applied during the tightening of the stitch. The take-up has a rise 53 for drawing up the loop already formed as the needle rises and a rise 54 for partly drawing up a new loop as soon as it is released by the loop-taker, just before which is a depression to allow the thread to slip off the loop-taker without any snapping action. In a modified looper-actuating mechanism. Fig. 14, the looper 53<1> is mounted on a shaft 54<1> parallel with the shaft 13 and actuated by an eccentric 57 and a follower block 56 in which slides a pin 55 projecting from the shaft. Specifications 29901/96 and 8718/97 are referred to.