Patent ID: 8249739

Claim:
A yarn feeding device for a knitting machine, having a motor for driving a roller from which a yarn is fed out on the basis of knitting data inputted into the knitting machine, and a rotatable buffer for intermediately storing the yarn fed out from the roller and supplying the yarn to the knitting machine, the yarn feeding device further comprising: a torque generator for applying a variable torque to the buffer; a yarn speed calculator for obtaining yarn speeds at plural sections in a knitting course from a loop length of a stitch for each knitting needle and a knitting speed calculated base on the knitting data; conversion means for converting, at the plural sections in the knitting course, the yarn speeds into a plurality of torques to be applied to the buffer so as to correct yarn tension fluctuation caused by the changes in the yarn speeds; and a torque controller controlling the torque generator at the plural sections in the knitting course so that the torque to be applied to the buffer becomes the torque obtained by the conversion unit.