| 摘要 |
There is provided a sewing-machine bobbin thread tension controller capable of elaborately, accurately controlling bobbin thread tension without depending on frictional force. A bobbin thread tension controller includes an outer shuttle 110, a middle shuttle presser 130, a middle shuttle 150, a bobbin thread tension control mechanism 200, a shuttle actuation unit 250, and a bobbin 300. The middle shuttle 150 has a magnet 190. A magnet 270 is disposed, in close proximity to the magnet 190, on an arm 260 attached to a rotary shaft of a shuttle actuation motor 252 provided in the shuttle actuation unit 250. The middle shuttle 150 is rotated by rotating the magnet 270 by means of the motor 252. Further, a rotary disc 210 is provided, in close proximity to the middle shuttle 150, on a rotary shaft of a bobbin thread tension control motor 202 of the bobbin thread tension control mechanism 200 and is provided with a magnet 214. A magnet is disposed on a part of the bobbin 300 facing the rotary disc 210. The motor 202 rotates the bobbin 300. |
