| 摘要 |
PROBLEM TO BE SOLVED: To manufacture writing utensils of different lengths without changing a die for molding by constituting the shaft cylinder of a linear pipe having a uniform diameter. SOLUTION: A shaft cylinder 1 is constituted of a linear pipe of a uniform diameter which is molded by extrusion-molding. Therefore, when the length of the shaft cylinder 1 is changed when necessary, the pipe by the extrusion- molding is cut by a desired length, and at the same time, female threads 1a, 1b are respectively formed on the inner peripheries of the rear end part and the tip end part of the shaft cylinder 1, and the shaft cylinder 1 is formed. In addition, in response to the length of the shaft cylinder 1, the length of an intermediate cylinder 10 comprising a linear pipe having a uniform diameter is changed in the same manner. By this method, by cutting the pipe having the uniform diameter by the extrusion-molding by a desired length, the overall length dimension can be easily changed, and writing utensils of different lengths can be manufactured without changing a die for molding. |
