PURPOSE: To eliminate accident and failure that will be a cause of line stop, and to eliminate danger in maintenance work.

CONSTITUTION: A strip looper is provided with a base 1 and a carriage 2, the distance between them can be changed, and the carriage 2 is energized in the direction separated from the base 1, while rollers 3 for winding a strip 5 are also provided on the base 1 and the carriage 2. A position detection means 7 for detecting the position of the carriage 2 relative to the base 1 and for outputting a signal for adjusting the feeding speed of the strip according to the detected position is also provided. The position detection means 7 is formed out of a noncontact type detection means for detecting the motion of a support system member of the carriage 2 or for directly detecting the position of the carriage 2.