| 摘要 |
PURPOSE:To detect thread breakage reliably by detecting thread breakage from a signal fed from a beam switch for passing a beam through a slit made in a pulley to be driven through motion of thread or a barrier board to be rotated by said pulley. CONSTITUTION:Upon normal feed of yarn 6, a pulley 1 is driven by said yarn 6 and rotates thus to rotate a barrier board 5 coupled through a spindle 2 with same speed thereby the beam from beam switch 7 will pass at the position of slit 5a but blocked therebetween. Consequently, the output signal from the switch 7 will be a continual waveform as shown in zone A. Upon stoppage of feeding of yarn 6, rotation of barrier board 5 will also stop to produce signal of zone B if the beam of switch 7 is at the position of slit 5a, while signal of zone B' at the position separated from the slit 5a and signal of zone C if it is at the edge of slit and since they are continuous signals, it is detected that the yarn is not fed. Consequently, thread breakage can be detected irrespective of vibration of thread. |
