| 摘要 |
PROBLEM TO BE SOLVED: To provide a sewing machine which mounts a mechanism capable of stably controlling deviation in timing between a needle and a shuttle occurring due to needle bar oscillation without requiring a troublesome adjustment step.SOLUTION: A sewing machine includes: an arm shaft 3 provided rotatably and for driving a needle bar 1; a lower shaft 4 provided rotatably and for driving a shuttle 2; an upper shaft pulley 3a provided at the arm shaft 3; a lower shaft pulley 4a provided at the lower shaft 4; a belt 6 for connecting the upper shaft pulley 3a and the lower shaft pulley 4a and for synchronizing the rotation; and a belt adjustment mechanism for coming into contact with the belt 6 and for changing belt length of the belt 6 on a tension side A where the belt 6 is drawn. Energization means is provided for energizing the belt 6 according to the change in the belt length on the tension side A. |
