PURPOSE: To prevent damage of yarn before it occurs by detecting the ballooning speed of reeled yarn, converting the detected result to electric voltage and detecting the change of yarn feed by electrical signal treatment by comparison of the converted electric voltage with a threshold value and change rate of electric voltage.
CONSTITUTION: Yarn 1 knotted between two yarn feeding materials 21 and 22 is reeled from one yarn feeding material 21 in the direction of winding axis and guided through a ring-shaped detector 3 consisting of a projector 6 and a receptor 7 opposingly arranged in an introducing hole 31 and also used as a yarn guide to a length measuring storage device 4. In the detector 3, a pulse signal proportional to the ballooning speed is generated, sent to a signal treating part 20, the pulse signal is converted to electrical voltage, compared with a threshold value corresponding to the change of yarn feeding or difference between the detected ballooning speed and that of the previous time is compared with the threshold value of amount of change to the detect change of yarn feeding.
ASAI TAKESHI
FUJITANI MUTSUO
TAMURA ZENJI
YAMADA SHIGEO
WAKAMATSU KENSUKE
