A ring encircles produce placed on a work table. Tie ribbon is fed by pressure rollers around the inner periphery of the ring to form a complete loop. A first gripper clamps and retains the free end of the ribbon against a second gripper. The pressure rollers operate in reverse retracting excess ribbon...http://www.google.com/patents/US4655264?utm_source=gb-gplus-sharePatent US4655264 - Twist tying machine
