| 摘要 |
PROBLEM TO BE SOLVED: To provide a ball point pen tip, by which no writing blurring develops in the change of a writing direction, the discharge of ink is smooth and, in addition, neither ink dripping phenomenon nor irruption of foreign matter through a writing tip part develops. SOLUTION: By forming a ball receiving seat 13a1 and a side face seat part 13b on the lines of the surface of a transfer ball 20 by setting the ratio of the maximum diameter of the ball receiving seat 13a1 to the inner diameter of a ball house 13 in the range of about 70 to 90% between the site on the end side hinderer than the midway site in the inner side surface of the ball house 13 and the surface of the transfer ball 20 and between the bottom surface 13a of the ball house 13 and the surface of the transfer ball 20, an ink well space part 16 for temporarily storing a proper amount of ink therein is ensured. |
