| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ballpoint pen tip that can obtain stable ball rotation and amount of ink outflow by separately forming a ball seat at a different position in an axial direction. <P>SOLUTION: The ballpoint pen tip has, in a tip body an ink circulation hole which communicates to a rear hole of tip body, and an ink circulation groove extending in the shape of a radiation from the ink circulation hole at a center of a bottom wall of ball holding chamber, holds rotatably part of the ball by projecting it from a tip leading edge by inserting the ball to the bottom wall, and caulking the tip end inside. The ballpoint pen tip is characterized in that the ball holding chamber has a first ball holding chamber, and a second ball holding chamber of diameter smaller than the first ball holding chamber at a rear part of the first ball holding chamber, and inserts the ball to the bottom walls of the first ball holding chamber and the second ball holding chamber, and forms the ball seat of substantially the same shape with the ball to bottom walls of the first ball holding chamber of the bottom wall of the second ball holding chamber, while holding the ball rotatably. <P>COPYRIGHT: (C)2012,JPO&INPIT |
