| 摘要 |
PURPOSE:To enable warning output at the time of yarn snapping and automatic take-up stop output by running yarn where luminous flux which is emitted by a projection part and reaches a photodetection part is cut off. CONSTITUTION:The projection part and photodetection part are arranged on the internal surface of an annular photoelectric switch base 4, a projection part glass bead 1 and a photodetection part glass bead 2 face each other, and luminous flux emitted by the projection part is received by the photodetection part. When the yarn is run through the ring, at least a part of the luminous flux emitted from the glass bead 1 is shut off by the yarn and does not reach the glass bead 2. If the yarn is snapped, the emitted luminous flux is not shut off by the yarn and the luminous flux reaching the glass bead 2 increases, to that is sensed as the snap of the yarn. Further, the swivel motion of the running yarn is converted into variation in electric pulse width to discriminate the running speed of the glass fiber bundle, thereby varying a yarn breaking judgement time. |
