| 摘要 |
PURPOSE:To make it possible to obtain a platen roller having excellent degree of concentricity of shaft parts and capable of obtaining an accurate degree of roundness, without requiring after-working, by disposing a cylindrical rod at the centers of both ends of a metallic blank pipe having excellent degree of roundness along the longitudinal direction of the blank pipe, and forming both end opening parts of the blank pipe by rotational forming in conformity with the cylindrical rod to provide shaft parts. CONSTITUTION:While rotating a blank pipe 10 and a cylindrical rod 12, squeezing heads are pressed against both ends of the pipe 10 to roughly shaping both end parts 10a of the pipe 10 by bending them inward in a first step. In a second step, the end parts 10a are bent to a right angle so that tip parts thereof come close to the cylindrical rod 12, and finally the tips 10b to be shaft parts are brought into close contact with the rod 12, thereby completing the working. Thereafter, the rod 12 is drown out, and a rotary shaft separately prepared is fitted to the worked pipe. |
