GB454772A - Thread-controlling mechanism for sewing machines - Google Patents

Abstract

454,772. Sewing-machines. FAIRWEATHER, W. C., 65, Chancery Lane, London.-(Singer Manufacturing Co. ; Elizabeth, New Jersey, U.S.A.) April 6, 1936, No. 10064. [Class 112] An overedge stitching-machine with a straight eyed-needle and two threaded loopers, as described in Specification 14799/07, [Class 112], is provided with a needle-thread controller consisting of a member with a pair of stationary arms with thread eyes, between which a camshaped finger is operated by the needle-bar actuating mechanism to engage the thread. The needle-bar 7 and its bearings 6 are inclined to the vertical. The needle-bar 7 is operated by an inclined link 11 and lever 12, pivoted at 13. The lever 12 has a rearward arm 15 with a ball-connection 16 to a pitman 18 operated by the ball-crank 3 on the main shaft 2. Thread controller. A plate 24 is fixed to the frame 4 below the usual tension device 25 This plate has two arms 27, 28 between which a cam-finger 31, adjustably fixed to the needlebar operating lever 12 by screws 29, and slots 30, works. As the machine is operated, the needle descends and the cam-surface 32 of the finger 31 engages the needle-thread A between the eyes 271, 28<1> of the arms 27, 28, the edge 32 being shaped to keep the thread under control at all times. When the needle reaches its lowest position, the thread is engaged by the portion Z of the cam edge. This allows sufficient slack thread to permit formation of a needle loop for seizure by the primary looper 20. On the ascent of the needle, the loop is drawn snugly about the blade of the looper 20, so that when this is withdrawn, the loop is too small to be accidentally seized in the succeeding looper stroke. The stitch is set on the upstroke of the needle and the cam-edge gradually pulls thread from supply through the tension 25, permitting a minimum tension to be used.