| 摘要 |
<p>696,709. Stretching yams; creels; winding bobbins. BRIGHT & BROS., Ltd., J. Feb. 4, 1952 [May 3, 1951], No. 10412/51. Classes 120(ii) and 120(iii) Relates to stretching frames for threads, of the type in which the thread passes from a let-off bobbin around a pair of grooved conical stretching rollers, upwardly to a take-up bobbin which is mounted horizontally and is rotated by contact with a driven roller on which it rests. According to the invention, a brake applies to the bottom or let-off bobbin a pressure which declines as the bobbin empties, and there is applied to the top or take-up bobbin a weight which declines as the bobbin fills, whereby the stretch of the cord is made more even. As shown, Fig. 1, a let-off bobbin is rotatrbly mounted between a cone-bearing 6 and a spring-loaded plunger 7 on a bracket 4 bolted to the machine frame. A weighter member 15, having a braking surface 16 engaging the surface of the cord on the bobbin, is pivoted at 12, 13 to supports 8, 9, fixed to bracket 4. As the bobbin empties and member 15 swings towards a vertical position the braking pressure on the bobbin decreases; when the bobbin is nearly empty, braking pressure is removed entirely by engagement of a bifurcated tail 17 on member 15 with a washer 21 bearing on :a compression spring or peg 18 projecting from bracket 4. Supports 8, 9 can be adjusted laterally of bracket 4 to vary the ;position of pivots 12, 13 relative to the bobbin axis and thus regulate the amount of braking pressure applied throughout. The take-up bobbin 27, Fig. 3, is pressed against friction roller 23 ,by a weight 25, which may be in the form of a roller, carried by the horizontal arm of a bell-crank lever 24 the vertical arm of which carries a second weight 26. As the diameter of the cord on bobbin 27 increases weight 25 is lifted and lever 24 tilts, the pressure on the bobbin decreasing until, at some stage before the bobbin is full, the moment of weight 26 about pivot .22 exceeds that of weight 25 whereat the latter is lifted completely off the bobbin. Weights 25, 26 may be adjustable or detachable.</p> |
