GB761492A - Improvements in or relating to yarn-tensioning devices - Google Patents

Abstract

761,492. Yarn tensioning arrangement. LERMONT, B. June 25, 1954, No. 18781/54. Class 120 (2). [Also in Group VIII] Spring strip is wound into two coils of opposite hand which have an inherent tendency to press against each other by their outermost convolutions, so that the interconnecting part is substantially straightened, and yarn is tensioned by being guided and cupped between the said convolutions. The yarn may travel either parallel to the coil axes (e.g. yarn 33 of Fig. 3) or, in either sense, in a direction perpendicular to those axes (e.g. yarn 67 of Fig. 5). The coil 28, Fig. 3, is wound on a mandrel 24 which slightly expands and is thus gripped by the innermost convolution and each increment of each coil is bent to the same radius so that the coils 28, 30 are " self-winding " and the pair are in equilibrium. Alternatively, coil 52, Fig. 5, may be given a tendency to unwind coil 49, by reason of, say, a gradual decrease in the radius of curvature from end 47 to end 50, or by gradual increase in thickness. of the spring strip ; and a mandrel 46 is rotatable by knob 56, to vary yarn tension, the device being held adjusted by pawl and ratchet 58, 57, Fig. 7. Shaft 53, carrying mandrel 51, is mounted in slots 54 so that the coils may always be in contact. An arm 76, secured to shaft 53, carries a yarn guide eyelet 75, Fig. 10, and the device may then be used. purely to open contacts 80 and stop the machine in the event of excess yarn tension, or may combine this function with tension control, Fig. 11. When the yarn path is at right angles to the coil axes, a slot is provided in the straight coilconnecting portion of the spring, for passage of the yarn.