| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ball-point pen tip for oil-base ink without a hollow-line phenomenon, in which ink breaks off during writing, and a dripping phenomenon, and by which excellent writing can be acquired. <P>SOLUTION: The maximum value of the cross sectional area of a gap, which is formed of the inner wall of a ball holding chamber and a ball as an ink passage in the ball holding chamber, is made as A. The sum total of projected areas at the opening part to the ball holding chamber of a radial groove, when the ball is retreated to the utmost, is made as B. And when the sum total of the projected areas at the opening part to the central hole of the radial groove is made as C, it is set as 0.279A≤B≤0.424A and 1.718B≥C. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
