| 摘要 |
<p>A catch thread device for monitoring quilt stitch and chain stitch grippers. During normal operation of the sewing machine, the thread on the bobbin (3) is used as a reflecting surface. The diffused light rays reflected at the thread enter the light receiver (10) of the catch thread device (8). If the supporting surfaces are not covered by the thread, no light rays enter the photodetector (10), whereupon a warning signal is emitted by a control circuit (12) connected to the photodetector (10).</p> |
