Patent attributes
A yarn tension control device controls tension in a running yarn. The tension control device includes a housing having a yarn guiding inlet for receiving running yarn at an unwinding tension from a yarn supply source, and a yarn guiding outlet for guiding running yarn exiting the housing at a delivery tension. First and second opposing yarn engaging surfaces are disposed between the inlet and the outlet, and are adapted to frictionally engage opposite sides of the running yarn along a path of yarn travel through the housing. The first and second yarn engaging surfaces define a respective plurality of sequentially spaced friction rolls. A biasing assembly resiliently urges the first and second yarn engaging surfaces together. The opposing friction rolls cooperate to form a number of sequentially spaced nip points adapted to adjust yarn delivery tension in response to stress variations in running yarn entering the housing.