PURPOSE:To increase the controllable range of the rolling pressure of a rolling blade, to facilitate the control of the pressure, and to enable the control of the gap between the rolling face and the rolling blade, by attaching a linking lever between a sliding piece and a rolling blade, and pressing the sliding piece with a helical spring. CONSTITUTION:A rolling blade 13 is attached to the lower end of the rolling arm 12, and a sliding piece 16 is attached slidably to the arm 12 and is pressed by the force f1 of the helical spring 15. The gap between the rolling blade 13 and the rolling face 14 can be adjusted by shifting the nut 21, and the rolling pressure F can be controlled by displacing the linking point P of the linking arm 18 and the rolling blade 13.
