| 摘要 |
<P>PROBLEM TO BE SOLVED: To protect an air-tight sealing part from damages and ink stains by avoiding nib from touching the air-tight sealing part of the cap when a cap is attached, and to fully avoid air pressurization inside the cap even when the cap is attached abruptly, and also to fully avoid air decompression inside the cap even when the cap is detached abruptly. <P>SOLUTION: The external surface of the inner cap 3 is adhered to the internal surface of the outer cap 4. The rear-end tube section 31 is formed projecting backward at the opening end of the inner cap 3. Annular outward sealing part is formed in the outer periphery of the rear-end tube section 31. The front-end tube section 61 is formed projecting forward at the front opening end of the shaft tube 6. Annular inward sealing part is formed in the inner periphery of the front-end tube section 61. When the cap 2 is attached onto the nib 8 side of the shaft tube 6, the outward sealing part and the inward sealing part adhere closely to each other in radial direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
