PURPOSE: To early detect the winding of a fiber bundle round a roller and to remove the same by storing in memory the position of the sheetlike fiber bundle under the normal transfer, comparing this with the current position in operation and giving a warning indication or stopping the operation when there is any trouble.

CONSTITUTION: When a sheetlike fiber bundle is transferred under the normal condition, a set switch 201 is turned on, while by operating a traverse device, the position of the full range of the width of traverse is detected by a sensor 7, and a counter 108 is advanced step by step by the pulse train of a pulse generator 13, making an RAM105 store the address by indicating the same. When the actual operation is performed, the traverse is conducted under the condition that the switch 201 is turned off, and in case any unusual state is found by comparison of the actual position with the stored position, a signal is given from a preset counter 113 on condition that the pulse from the pulse generator 13 is counted by a given number. By this, a warning device 203 is operated or the machine is stopped, and the winding of the fiber bundle round a roller is found early, thus this being removed in an early stage.