| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ballpoint pen distal end section which can properly press an extremely fine ball forward. <P>SOLUTION: This ballpoint pen distal end section 1 is equipped with a ballpoint pen chip 2 which rotatably embraces a ball 23 on the distal end section, and a spring 4 which urges the ball 23 forward. The spring 4 consists of a straight section 41, and a coil section 42 which is integrally connected with the rear end of the straight section 41. The outer diameter of the ball 23 is set to be less than 0.3 mm. A pin-form movable body 3 is loosely inserted in the ball pen chip 2 in a space between the ball 23 and the spring 4. The movable body 3 consists of a smaller-diameter section 32, and a larger-diameter section 31 which is connected with the rear side of the smaller-diameter section 32. The smaller-diameter section 32 is passed through the central hole 21a of a ball receiving seat 22. The distal end of the smaller-diameter section 32 is brought into contact with the rear surface of the ball 23. The distal end of the straight section 41 of the spring 4 is brought into contact with the rear end of the larger-diameter section 31. The outer diameter A of the wire of the spring 4 is set to be larger than the inner diameter D of the central hole 22a of the ball receiving seat 22. <P>COPYRIGHT: (C)2008,JPO&INPIT |
