GB1449492A - Control of yarn tensions - Google Patents

Abstract

1449492 1449492 Yarn tensioning K BOUS 11 Sept 1973 [19 Sept 1972] 42704/73 Heading D1D In a yarn tensioner yarn is wound around two spaced rolling elements, and an adjustably loaded braking pin, movably arranged between the elements, abuts the windings, the engagement between the braking pin and yarn being such that the angle over which the yarn contacts the pin decreases to counteract increasing yarn tension and increases to counteract decreasing yarn tension to maintain contact yarn tension. As shown in Fig. 1, yarn runs about rollers 2, 3 and interchangeable yarn-engaging pin 7 is moved between optical fixed yarnengaging pins 15, 16 by levers 8, 9 bearing movable weights. Rollers 3 may be fixed on pin 4, or may be replaced by a smooth or multi-grooved roller. The distance between the yarn windings may be adjusted by inclining the guide pin or rollers. The pin 7 may be biased by tension or compression springs, by movable permanent magnets or by centrally adjustable electromagnets. If tension becomes very high or low, the movement of pin 7 causes the temporary stopping of yarn withdrawal. As shown in Fig. 2, pin 23 is pivoted by tension sensing arm 21 and biased by a spring 25 which may be replaced by weights, magnets or centrally adjustable electromagnets. The yarn tension or yarn speed device of an associated machine may act on lever 20 or the spring via rods, or by using electrical, electromagnetic, pneumatic or hydraulic means. As shown in Fig. 3 yarn is looped around driven rollers 27, 28, and lever 22 pivots about spindle 31 to urge yarn-engaging pin 33 between fixed yarn-engaging members 29, 30. Lever 32 is pivoted by lever 38 with varying yarn tension, is biased by spring 34, and is damped by permanent magnet 41 and pivotable segment 40. As shown in Fig. 5, yarn loops about rollers 68, 69 and lever 60 pivots with varying yarn tension to pivot both 61 bearing movable weight 62 and lever 63 bearing yarn-engaging pin 64. Levers 72, 73, 75 form a similar tensioning system. The levers may be counterbalanced by springs or permanent magnets.