PURPOSE: To eliminate torsion and buckling in a shaft material and to eliminate the problems of whirling, defective biting and breakage of pusher head by biting the shaft material into a rotary elongator after beforehand revolving it before biting the shaft material into a rolling mill.
CONSTITUTION: In rotary elongating of the shaft material 11, plural pusher rolls 1 are arranged on the circumference of the shaft material 11 to be rotably elongated so that the axial center of roll is the same direction as the longitudinal direction of the shaft material. Driving devices 13 for revolving/driving those rolls are provided, slide chocks 3, 3' with which the plural rolls are supported are provided and also shifting devices 8, 8' with which those slide chocks are shifted in the same direction as the longitudinal direction of the shaft material are provided. In this way, the problem of torsion of the shaft material is eliminated and the shaft material can be pushed into the rolling mill by clamping the tip part of the shaft material. So, especially, in the case of a long size material, even when it is pushed into the mill by a large force, it can be pushed into the rolling mill without buckling.
ITO HIDEHIRO
UCHIYAMA EIZO
NITTETSU PLANT DESIGNING CORP