PURPOSE: To prevent a wound yarn from being loosened by a braking device even in a state that the direction of a nipple is changed and the yarn is easily loosened by attaching the braking device between a winding bobbin and a hole for yarn route to be arranged near a needle tip.

CONSTITUTION: In a braking device 31, the root part of a screw shaft 33 equipped with a screw 34 in the tip part is fixed to a supporting member 32 which root part is fixed to a supporting cylinder 17. This screw shaft 33 supports a drum 35 for coil spring, a pair of thread condition trays 36 and 37 and adjusting screw 38 to apply soft pressure to the yarn conditioning trays successively in a state these parts are inserted. By turning an adjusting screw 39, the adjusting screw 38 is compressed and extended and pressure between the yarn conditioning trays 36 and 37 is changed. Then, the passage resistance of the wound yarn 26 to pass this interval is enlarged or reduced. The generation of loosening is prevented by the existence of the braking device 31 and in a bulky yarn 27, the wound yarn 26 is always fixedly and beautifully wound around a core thread 14.