Automatic sheet metal defect display - for cold rolled sheets using electro-magnetic appts is sensitive to longitudinal defects

摘要

Appts. includes means for magnetising the sheet arranged at one side of it and sensors arranged at the other side parallel to the sheet surface and transforming the continuous flux fields into electrical signal. Each sensor is connected to the inputs of a signal formation module for controlling the routing and testing of the sheets during mfr. Turning plates covering the width of the sheet are mounted above and parallel to its surface and the sensors are associated in groups whose number equals that of the plates, the sensors of each group being placed on the corresponding plate. The sheet is magnetised by polar electromagnets disposed below each plate so that the sheet is magnetised transversely of its direction of travel and rolling.