| 摘要 |
<P>PROBLEM TO BE SOLVED: To enable easy and smooth insertion into a chip even when there is a burr in the front end of a shank part of a spring, to make a fore-end ball rotate smoothly on the occasion of writing and to enable exhibition of an excellent writing performance free from a writing scratch, regarding a ballpoint pen using ink of low viscosity. <P>SOLUTION: This ballpoint pen has the ballpoint pen chip in front of a joint and has an ink holding tube in the rear. A lengthwise outer peripheral part of the pipe-shaped tip having a supporting seat formed of inward projections in a plurality of places is fitted in the fore end of the joint so that a holder is provided, and the fore-end ball is held rotatably in the fore end of the tip, contacting the supporting seat. The fore-end ball is so provided that it is pressed by the shank part in front of the winding part of the spring and brought into close contact with the inner edge of the ball holding part of the chip, so that outflow of the ink be obstructed. In this constitution, an expanded hole having a concave or convex curved surface is formed in the rear-end opening of a hole communicating with the rear end of the chip of the holder. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
