| 摘要 |
<p>PURPOSE: To previously inform that the under thread is going to run out by providing a marked conductive matter near the end of under thread, and detecting it with a current application sensor. CONSTITUTION: When winding under thread 22 on a bobbin, a marking of conductive material is provided at the place about 1.5m from the commencement of winding. This bobbin is charged in a bobbin case 23, and sewing is made. When the under thread 22 is consumed, and the marked section of the conductive material becomes tangled with the upper thread 21 and makes perforations and it contacts with the sensor terminal 9 of a needle plate 1, a current application sensor (composed of a current application sensor body 29 and the sensor terminal part 8), and issues an alarm. By doing like this, a worker presses a reset push button switch 26, and interrupts the sewing in proper work process before the under thread 22 runs out, and replaces the under thread. This way, the continuation of the wasteful sewing work can be prevented, and the loss of work time can be prevented.</p> |
