| 摘要 |
<p>A method of monitoring continuously advancing string material (1) of the kind comprising a continuous alternating succession of string sections, for example a cigarette filter string, of different material and/or structural configuration with regard to cutting the string (1) into identical plugs (7) for checking and correcting the position of each cut. Prior to being cut the string (1) is scanned by a sensor unit (4) which detects the beginning and end of each string section. A device associated with the cutting device (5) generates an output signal to indicate the moment when the string (1) is cut. Between this output signal and the moment at which the sensor unit (4) issues a signal corresponding to the end of the string section to be cut, a measured value is obtained which is independent of the feed into of the string (1) and which is proportioned to the length of the string section between the two signals. This measured value is then compared with a reference value and the operative stroke of the cutting device (5) is adjusted when a certain number of successive measured values deviate in the same direction from the reference value.</p> |
