US Patent 7854195 Needle with air duct

A baler has a bale chamber and a needle movable through the bale chamber to pass a strand of twine from one side of the bale chamber to a knotter located on the opposite side, the twine being engaged by a tip of the needle. In the invention, pressurized air is directed at the needle tip. The supply of pressurized air may be discontinuous and timed to coincide only with certain phases of the needle operating cycle. The air stream avoids crop material being caught up in the knots formed by the knotter.