| 摘要 |
PROBLEM TO BE SOLVED: To prevent the inside of the barrel cylinder of a ballpoint pen, hands and apparels from being contaminated by preventing the reverse flow of ink which is generated due to writing facing upward or impacts from occurring; and also, prevent air bubbles from being generated in the ink by a centrifugal process, a temperature change, and deterioration with time; and prevent problems due to the generation of air bubbles from occurring even after a long period of time has passed. SOLUTION: The tip of a ballpoint pen is fixed to the distal end of a joint, and an ink storage tube is fixed to the rear end of the joint. Then, a valve chest is provided at the rear side of the inner hole of the core section of the joint in a manner to communicate with the rear end of the tip. Also, a tapered shape or spherical surface shape ball-receiving seat is provided at the rear section of the valve chest. In this case, a ball valve which can be closely joined to the ball-receiving seat is loosely fitted in the valve chest. In addition, a core is fixed in the inner hole of the core section of the joint, in a space between the front side of the ball valve and the rear end of the tip for this ballpoint pen. In such a ballpoint pen, a low viscosity ink is filled in the ink storage tube, and a grease-form follower, which can move following the ink, is filled at the rear end of the ink. Then, a groove of a proper depth, which penetrates the front and rear ends of the core, is formed at a specified location on the outer peripheral section of the core. |
