| 摘要 |
PCT No. PCT/SE82/00216 Sec. 371 Date Feb. 7, 1983 Sec. 102(e) Date Feb. 7, 1983 PCT Filed Jun. 15, 1982 PCT Pub. No. WO82/04447 PCT Pub. Date Dec. 23, 1982.A signal arrangement for supplying a signal as a prewarning to the operator of a sewing machine, when the bobbin thread is about to run out. The bobbin has a reflective center, and a radiation source and detectors are mounted in the loop-taker. A friction clutch may be provided between the bobbin and the loop-taker, so that the bobbin rotates in one direction when thread is wound thereon, and the other direction when all of the thread has unwound therefrom. |
