| 摘要 |
PROBLEM TO BE SOLVED: To provide a ballpoint pen for a ball face character with an ink direct flow and ink reverse flow prevention of a low cost using a low viscosity ink. SOLUTION: In the ballpoint pen 1 comprising a tip 3 of the pen made of a resin at a front end and an ink containing tube 2 at a rear part, a ball receiving seat 7 brought into contact with a back surface of a tip ball 14 at the time of applying a writing pressure and a spring set for pressing the back surface of the ball 14 to bring the ball 14 into close contact with an inner edge of a ball embracing part, an overall circumferential neck part 5 is formed rear of a tip barrel 4 press bonded to the tube 2 so that its inner surface is formed as a guide hole 11 with a tapered part 8 on a longitudinal inner surface. Its front tapered part 8 is formed as the seat 7, and a rib 9 of a predetermined position is formed on its forward inner surface to form a valve chamber between the seat 7 and the rib 9. A ball valve 12 is elastically deformed at the part 5 in an enlarging direction by pressing a rear tapered part 8 from a rear end of the barrel 4 so that the valve 12 is movably engaged with the chamber. At the time of upward directing the tip 3, the valve 12 is brought into close contact with the seat 7 to liquidtightly block the hole 11. |
