| 摘要 |
<p>A center presser foot of a sewing machine is provided to prevent over-load on a main shaft of the sewing machine by adjusting a height location of the center presser foot from height of a need plate. A center presser foot of a sewing machine includes a control unit(55). The control unit is performed by the following steps of: dropping the center presser foot(6) according to an initial output value; pressing a sewn material strongly; comparing the initial output value with a real output value; modifying an output value of a height controlling motor(52); and adjusting a height location of the center presser foot by dropping the foot based on the modified output value.</p> |
