Constant tension device for yarn feed - with yarn reserve which is decreased before stopping yarn feed, on over tension conditions

摘要

Yarn fed to a textile machine passes through a constant tension device comprising a feeler over which the yarn passes and a yarn reserve forming device which forms the yarn into a reserve. On over-tension condition of the yarn the feeler operates pref. a micro-switch to actuate a control device to switch of the yarn reserve forming device and if the required tension is achieved within a minimum time delay (e.g. 3/10th sec.) the yarn reserve forming device is re-started. If the minimum time delay is exceeded the yarn supply to the machine is arrested whilst the yarn reserve forming device builds up the required reserve of yarn, and if a max. time delay (pref. 25-30 secs) is exceeded the machine is switched off for adjustment by an operative. The device is used particularly in feeding yarns to a circular knitting machine. The whole machine is not switched off unless severe over tensioning of the yarn occurs.