Device for preventing yarn loop formation and for saving suctioned yarn on winding units

摘要

This invention relates to a device for preventing yarn loop formation and for saving the suctioning yarn on winding units. This device keeps the yarn under tension during the knotting and cone doffing steps. The device has a movable bar which is positioned adjacent to the upper end of a pirn during the unwinding process and which is shifted by an actuator to contact the pirn before the yarn is stopped. This is accomplished by keeping the yarn under tension from the pirn cone to a yarn-tensioning disc at the beginning ot the knotting and doffing cycles to prevent loops from forming. Additionally, this device limits the yarn consumption of the knotting cycle. By frictionally clamping the free end of the yarn with an anti-loop device, yarn is suctioned by a free yarn end feed nozzle in a shortened length thus limiting the amount of yarn removed and lost during a knotting cycle.