PURPOSE: To release engagement, disengage the roll moving device and facilitate roll exchange by providing an engaging part to the roll bearing of the roll moving device.

CONSTITUTION: When the cylinder 7 provided to the slider 5 of the roll moving device is operated, the operating end of a hook 6 is pushed and the engagement of the hook 6 with the engaging part 2B of the roll bearing part 2A is released. Since this causes the shaft 2 of the roll 2 to be disconnected from the roll moving device, the roll shaft end is pulled off from the coupling and the roll is exchanged. The axial movement adjustment of the roll 2 is accomplished by holding the hook 6 engaged, operating a cylinder 4 and moving the roll 2 together with the roll bearing 2A in the roll axis direction. Then, the bearing part 10 provided to a spindle 8 is held coupled to a slider 5 by means of an arm 11 and pin 12 and therefore the spindle 8 moves together with the roll moving device and its movement quantity is absorbed in the spline joint.