| 摘要 |
PROBLEM TO BE SOLVED: To provide a ballpoint pen of a low cost for effectively maintaining preventive performance of dry-up, ink leakage, ink backflow or the like and to be easily manufactured. SOLUTION: In the ballpoint pen comprising a spring 5 contained in a tip 1 to press a tip ball 4, and a ball valve 6 contained to be openable or closable with a guide hole opened at a rear end of the tip, the spring has a straight part 5a provided at its end, a wire wound part 5b provided to give a pressing force toward rearward from a rear end of the straight part, further a close wire wound part 5c provided area of the wound part 5b and a bar shaft part 5d protruding from the rear end of the close wound part. The tip has a resin tip joint 7 and a metal holder 3 fixed to the end of the joint. The close wound part of the spring is fixed to an inner hole wall of the joint and the straight part urges a back surface of the ball so that the ball is liquidtightly brought into close contact with an inner surface of a ball embracing part of the holder. A neck part 2b of an overall circumference is formed on a rear outer periphery of the shaft of the joint press bonded to an ink containing tube. |
