SEWING MACHINE

摘要

A sewing machine includes a sewing-machine motor that drives, through an upper shaft and a lower shaft, a thread take-up lever, a needle bar, and a shuttle in conjunction one another. In addition, the sewing machine includes a stepping motor different from the sewing-machine motor. A bobbin-thread supply member is driven by drive power from the stepping motor, and applies tension to a bobbin thread in accordance with the drive timing of the stepping motor and the drive amount of the stepping motor. The drive timing of the stepping motor is variable in accordance with a sewing condition.

主权项

1. A sewing machine forming a stitch by intertwining a needle thread and a bobbin thread with each other, the sewing machine comprising:
a first motor; an upper shaft rotated by the first motor; a lower shaft linked with the upper shaft, and rotated in conjunction with the upper shaft; a thread take-up lever receiving drive power from the first motor through the upper shaft; a needle bar receiving drive power from the first motor through the upper shaft; a shuttle receiving drive power from the first motor through the lower shaft; a second motor different from the first motor; and a bobbin-thread supply member driven by drive power from the second motor, applying and easing tension to the bobbin thread in accordance with a drive timing of the second motor and a drive amount of the second motor, wherein the bobbin-thread supply member is independently controlled from the thread take-up lever.