| 摘要 |
PURPOSE:To reliably detect a longitudinal crack a conveyer belt by burying a plurality of resonance circuits extending over the whole width of the belt in the conveyer belt, and disposing a plurality of resonance detectors at a position adjacent to the belt. CONSTITUTION:A resonance circuit X comprises a set of a resonance circuit 1 for detection, which is extended in the lateral direction of a conveyer belt 7 and formed by a coil portion 4, a condenser portion 5 and a lead wire 6 for connecting the portions, and a resonance circuit 9 for a mark. A plurality of thus constructed resonance circuits X are buried in the endless conveyer belt 7 extending over the whole width (h) of the belt longitudinally. The respective resonance circits 1, 9 are set at equal resonance frequency and buried at a designated interval lbetween the circuits in the running direction of the belt. Two resonance detectors 10a, 10b for detecting a resonance phenomenon and disposed below passages for the above coil portion 4 and the resonance circuit 9 for a mark. When the detectors 10a, 10b do not detect any resonance phenomenon, it is judged that a longitudinal crack is caused in the belt 7. |
