| 摘要 |
<p>A sewing machine (1, 200) includes a needle thread tension control device (5) including a fixed portion (2, 3), a shaft (11) having an external thread portion (11a), a thread tension dial (19), first and second thread tension discs (12, 13), and a spiral movement member (16, 17). The spiral movement member includes an internal thread portion (16d) meshed with the external thread portion while being movable relative to the external thread portion in a spiral direction relative to an axis (P), and a scale (90) including marks (94) arranged serially and side by side in the spiral direction. The spiral movement member adjusts the needle thread tension by moving towards or away from the second thread tension disc while rotating in a circumferential direction by meshing between the external thread portion and the internal thread portion. The needle thread tension control device also includes a thread tension spring (15) applying respective biasing forces to the spiral movement member and the second thread tension disc.</p> |
