GB1476377A - Needle thread tensioning module in a lockstitch sewing machine - Google Patents

Abstract

1476377 Sewing machines: thread tensioning SINGER CO 1 July 1974 [23 July 1973] 29062/74 Heading D1G A needle-thread tensioner with adjustable pressure on its discs is assembled on a bracket 50 which is then mounted as a module in a sewing machine with an adjusting wheel 82 projecting beneath the arm. The discs 58, 59, 60 are mounted between two partitions 95, 110 the former having a groove 99 in which the hook 102 of the check spring can move. The discs are pressed together by a pin 61 with an enlarged head 62 at one end, and attached to a lever 71 at its other end. The other end of the lever is pressed by a coil spring 77, and the fulcrum 88 (Fig. 4) is movable to regulate the thread tension. The fulcrum comprises fingers 88 on a member 78 which can be moved lengthwise by rotating the wheel 82, a notch 80 on the member embracing a crank pin 81 on the wheel. Two threads may be tensioned by placing one each side of the central disc. Tension is relieved when the presser foot is raised by the presser foot lifting lever 120 raising a lever 124 which, through a wire 126, rotates a bell crank lever 127 to press on the lever 71.