| 摘要 |
PURPOSE:To permit the smooth rotary motion of a pivoting body by a method wherein steps are provided between the inner peripheral surface and the outer peripheral surface of a cylindrical shaft while the abutting surfaces of a mold are provided on the end surfaces, whose diameter of the steps is smaller, or the end surfaces, whose diameter of the steps is larger. CONSTITUTION:Steps 6 are provided between the inner peripheral surface C and the outer peripheral surface D of the cylindrical shaft 1 while the abutting surfaces of a fixed mold and a movable mold are provided either on end surfaces P, P', whose diameter of the steps is smaller, or on the end surfaces Q, Q', whose diameter of the steps is larger, in accordance either a rotary body 5 is arranged on the outer periphery D of a shaft or on the inner periphery C of the shaft. According to this method, even when fins are generated on the end surfaces P, P' or the other end surfaces Q, Q', the inner peripheral surface or the outer peripheral surface of a pulley 5 or the like will never be contacted with the fins, therefore, the rotary motion of the pulley or the like will never he precluded. |
