PURPOSE: To conduct straightening with a single machine by aligning a working plane from a horizontal position to positive inclined position, to a vertical position and to a negative inclined position and, in such a case, downward moving the pivot axis of the working table when the working plane is aligned from the vertical position to the negative inclined position.
CONSTITUTION: The alignment of the working plane B is started with each working plane pivoting means as follows. It is executed from a 1st approximately horizontal position (β=90°) to the 2nd positive inclined position (0<β<90°) where the working plane B is frontally faced and elevated, to the 3rd vertical position (β=0°) where the working plane B is frontally faced and to the 4th negative inclined position (0<-β<90°) where the working plane B is frontally faced and lowered. In such a case, when the working plane is aligned from this vertical position to the negative inclined position, each pivot axis X-X of the working table B is downward moved with respect to an advancing path Y-Y of a longitudinal direction of a stock material (b). In this way, a piece having a large dimension is shaped.
Del, Fabro Giorgio