US Patent 7096806 Yarn feed system for tufting machines

A yarn feed system, enabling the control of individual yarns to the needles of a tufting machine, and which system can be manufactured as a substantially standardized unit or attachment that can be removably mounted to a tufting machine. The yarn feed unit includes a series of yarn feed devices for feeding each of the yarns to the needles of the tufting machine, and a series of yarn feed controllers that monitor and control the operation of the yarn feed devices to control the feeding of the yarns to the needles according to programmed pattern instructions.