PURPOSE: To assure the quality of a rolled product by providing a freely rotatable looper roller which presses a strip under coiling and supporting the looper roller by means of an arm which moves back and forth or oscillates around a fulcrum.

CONSTITUTION: The looper roller 20 which presses the strip 2 under coiling is supported via the arm 21 by a hydraulically driven rotary actuator 22. The coiling tension σ1 of the strip 2 is calculated from the detected pressing force signal at a pressing position with a pressure detector 23 by an actual tension calculator 17. Reference tension σ2 and the coiling tension σ1 are compared and a command for controlling an oil pressure is emitted to a hydraulic unit 19 so that said tensions are maintained always equal to each other thereby controlling the pressing force of the roller 20. A speed correction calculator 16 outputs the speed correction signal to maintain the pressing position of the roller 20 at approximately the center of a control range to a speed reference calculator. The specified coiling tension σ1 of the strip 2 is maintained and the product quality is assured by the above-mentioned method.