Slip size at yarn reel wound by friction roller

摘要

A method for producing a reel by means of a textile machine's winding apparatus entails switching a motor, for the friction roller driving the reel, on and off at intervals in such a way that acceleration phases during which there is slip between roller and reel and free-wheeling phases follow one another, the rotational period lengths for roller and reel being continuously detected and processed. The magnitude of slip parallel to the reel arising during acceleration phases is found by: (a) calculating the true trend of increase for the reel radius from the reel and roller periods during the free-running phase; (b) predicting the trend in a subsequent acceleration phase from one or more preceding free-running phases; (c) calculating the trend falsified by slip from the roller and reel periods and; (d) comparing this falsified trend with the predicted trend to obtain the magnitude of slip. Also claimed is the apparatus used in the method. This apparatus includes the sensors (23, 24) for detecting the rotation speeds and hence the rotational periods of roller and reel, the connected analytical equipment (25) comprising: (i) means (33) for calculating the increasing trend for the reel radius (rsp); (ii) means (34) for evaluating the trend in free-running phases and predicting the trend in the subsequent acceleration phase and; (iii) means (35) for comparing the prediction derived from the periods of roller (10) and reel (17, 17') with the trend derived in the acceleration phase and falsified by slip.