| 摘要 |
There is measured the length of a thread withdrawn overhead from a spinning cop or from a yarn bobbin. In order to circumvent the fault sources caused by slip and/or thread elongation there is generated a signal which periodically varies in accordance with the movement of the thread release or detachment point at the spinning cop or at the yarn bobbin, as the case may be, and there are counted the number of cycles of the fundamental frequency of this signal. The thread length is obtained by multiplication of the counted number of cycles by the constant thread length of two successive winding layers for spinning cops or yarn bobbins of the same origin and the same thread. The periodic signal can be derived from the thread withdrawal force or from the number of revolutions of the detachment point. The method is particularly suitable when rewinding a number of spinning cops on to a cross-wound bobbin. |
