| 摘要 |
PROBLEM TO BE SOLVED: To easily form a mechanism for preventing backflow of ink by forming axial recess-like deformed parts by plastic deformation on an outer periphery of a barrel at a rear end of a tip press-bonded to an ink containing tube. SOLUTION: The ballpoint pen comprises a tip 3 of the pen at a front end and an ink containing tube 2 at a rear part. In this case, two axial recess-like deformed parts 5, 7 are formed by plastic deformation on an outer periphery of a barrel 4 of a rear end of the tip press-bonded to the tube 2. The part 5 is partly deformed to form a partial protruding strip 6 on its inner periphery, and the part 7 is formed on its inner periphery with an entire peripheral ball seat 8 by entire peripheral deformation, and a ball valve 11 is loosely engaged with a valve chamber 9 formed between the strip 6 and the seat 8. In the state that the tip 3 is directed upward, the valve 22 is disposed at the seat 8 of the chamber 9 to seal a guide hole 10. |
