| 摘要 |
PURPOSE:To suppress a fall of ink when a pen point is left in a state of being turned up by a method wherein a valve seat is positioned to a further tip side of a ball point pen tip than a valve body, and a specific gravity of the valve body is made less than a specific gravity of ink in an ink tank. CONSTITUTION:A valve body 6 inside a ball point pen tip 2 is a sphere made of synthetic resin having a space in its inside and less in a specific gravity than ink. A central hole 8 is provided as an ink passage in an inward projected part 4. An ink-flowing groove 10 is provided in a ball bearing seat part 9 in contact with a ball 1. Further, a surface on a valve chamber 7 side of the inward projected part 4 is a valve seat part connected liquid-tightly to the valve body 6. An opening end part 11 on the opposite side to the ball 1 of the ball point pen tip A is so deformed as to project inward partially at a plurality of positions, and the deformed inward projected part 12 is an engaging part of the valve body 6. The deformed inward projected part 12 is partially formed not on the whole periphery. |
