PURPOSE: To suppress heat transmission from a segment to the internal mechanism by supplying coolant from a flow passage system equipped in a hollow shaft between the periphery of the hollow shaft and the inner periphery of the segment and in a space around a slide rod.

CONSTITUTION: The space between the outer periphery of the hollow shaft 2 and the inner periphery of the segment 5 is filled with coolant from the hollow shaft 2 and it is supplied so that nearly the whole tip side of the slide rod 6 is dipped. Therefore, the inner peripheral surface of the segment 5, the hollow shaft 2 itself and the slide rod 6 can be cooled and most of the heat transmitted from the hot strip to the segment 5 is robbed by the coolant. When the hot strip of high temperature is wound round the segment 5 and the coolant is supplied with it, only the outer peripheral side of the segment 5 is heated, the inner peripheral part can restrain the rise of temperature by the coolant. Consequently, the transmissions of heat between the slide rod 6 and the wedge shaft 4 and of heat between the slide rod 6 and the intermediate shaft 2 are suppressed.