GB984207A - Thread tension device - Google Patents

Abstract

984,207. Sewing machines. SINGER CO. Feb. 14, 1964 [March 7, 1963], No. 6293/64. Heading D1G. A sewing machine thread tensioner comprises an arbor or spindle, a plurality of thread-tensioning discs, a guard plate engaging at least one disc, a compression spring, means for compressing the spring for pressing the guard plate against one of the discs, an anchor plate having a stop finger for limiting the degree of compression, and a C-clamp received in a circumferential groove in the arbor for positioning the anchor plate thereon. The thread tensioner arbor has an end portion 42 received in an opening 37 in the front wall 33 of the sewing machine. An enlarged adjacent portion 44 is formed with longitudinal slots for selectively anchoring the end 46 of the coiled portion 47 of a check spring mounted thereon. Thread-tensioning discs 66, 67, 68 are slidably mounted on a portion 41 adjacent portion 44, and disc 66 abuts the latter. A guard disc 69 abuts disc 68 and has an axially-extending finger 71 slidably received in an aperture 72 in a fixed plate 73. A cylindrical member 82, slidable on the arbor, abuts three equally-spaced dimples 81 on plate 73. A diametral rib 91 on member 82 passes through a diametral longitudinal slot 49 in the arbor. A compression spring 92 is interposed between member 82 and a cylindrical member 95 which screws on tothe end 48 of the arbor. Member 95 is secured within a knob 98 by a grub screw 99. Thread tension is thereby varied by turning knob 98. An anchor disc 84 is mounted slidably on the arbor between plate 69 and member 82, and is formed with opposed lugs engaged in slot 49. Disc 84 is held in position by a C-spring 52 engaged in a circumferential slot 51 in the arbor. An arm 86 projecting radially from disc 84 and aligned with a notch 89 in member 82, carries an axially-extending stop finger 88 adapted to engage an axial rib 102 on knob 88 for limiting the rotation of the latter and thereby the spring tension. A rod 58, slidable in the arbor, is displaced by a lever 22, on raising of the presser bar, to displace member 82 for relieving the thread tension.