PURPOSE: To stabilize the electrifying from a power source to a wire, and to reduce the frequency of the maintenance by providing two non-contact connectors, which are electrically connected to a wire reel, and a non-contact connector, which is fixed to a non-rotary part with a predetermined distance.

CONSTITUTION: A wire reel 11 is fitted to one end surface of a rotary shaft 32, and a non-contact connector 35 is fitted to the other end surface thereof. Furthermore, a non-contact connector 37 is fitted to the non-contact connector 35 with a predetermined distance, and one end of a power source 38 is connected to the non-contact connector 37. The non-contact connector 35 and the non- contact connector 37 are magnetically connected to each other, and the electrifying from one to the other in the non-contact condition is enable. Electrifying from the power source 38 to wire reels 11, 12 through the non-contact connector 37, the non-contact connector 35 and a relay cable 34 is enabled. Consequently, electrifying from the power source 38 to a wire 13 is stabilized, and the frequency of the maintenance is reduced.