GB212616A - Improvements in sewing machines - Google Patents

Abstract

212,616. Thompson, W. P., (Union Special Machine Co.). Dec. 8, 1922. Sewing-machine needles, vibrating laterally; chain-stitching; loop-stitching. - In a sewing- machine in which the needle and the looper vibrate laterally in unison to form zig-zag stitching the lateral vibrations for both parts are divided from one member which can be connected to a constantly oscillating lever or be locked against movement. The needle-bar 2 is reciprocated by a needle-lever 4 from an eccentric 7 on the main shaft 8. The pivotally-mounted needle-bar gate 3 is vibrated laterally from a rock-shaft 13 on which is mounted an arm 14 connected to the usual arms 15 constantly-oscillating through variable amplitude. The arms 14, 15 are connected by a latch 20, 22 slidingly mounted in the lever 14 which is normally pressed down by a spring to hold the V-shaped under edge in a fixed groove and which can be raised to engage a square edged slot in the lever 15 by means of a treadle-operated table 23 which when raised bears upon a roller 24 on the latch 20, 22. A looper 36 is oscillated by a link-connection with a lever 43 fulcrummed at 49 on a link 50 and actuated by a lever 45 which is pivoted at 46 to the frame and linkconnected to an extension 48 of the needle-lever 4. The looper is given needle-avoiding movements from an eccentric on the main-shaft 8. The link 50, Fig. 6, is pivoted to an arm 51 of a shaft 52. A second arm 55 on the shaft 52 is adjustably connected by a link 58 to an arm of the shaft 13. When the arms 14. 15 are connected, the shaft 13 is rocked to vibrate the needle laterally and to shift the pivot 49 of the looper-oscillating means, thereby shifting the working position of the looper.