| 摘要 |
PROBLEM TO BE SOLVED: To provide a tip structure hard to be deformed or worn at a ball seat by high writing pressure at the time of writing at the seat for supporting a ball. SOLUTION: A protrusion 4 is formed on a ball house 2. A ball receiver 6 for placing a ball 10 at least at one end face and a ball seat 5 having a liquid channel 9 on an outer periphery are formed separately from a tip body 1. The seat 5 is movably engaged with the house 2 of a front end side by the protrusion 4 by bringing a rear end face into contact with the protrusion 4. The ball 10 is inserted, and placed on a ball bearer 6. And, the ball 10 is rotatably embraced between the end of the tip caulked inward and the seat 5 in the tip structure. |
