| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ball point pen which exhibits successful writing performance using a low-viscosity ink and also can allow easy fitting of a spring inside a tip and in a stable position, even in case burrs are generated consequently by cutting at the forward end of a bar shaft part for the spring and also has an apex ball which is set in close contact with the inner surface of a ball embracing part of the tip and smoothly rotates without a writing thin spot during writing. <P>SOLUTION: A pipe-like tip with a receiving seat formed by an internal protrusion found in a plurality of spots, is fitted to the head of a joint. The apex ball is rotatably embraced by the apex part of the tip, while the back surface of the former is brought into contact with the receiving seat. Further, a contact ball which can be freely inserted into a hole formed in the center of the receiving seat, is arranged in the state that the contact ball is set in contact with the back surface of the apex ball. Besides, the forward end of the bar shaft part forward of the spring comes into contact with the back surface of the contact ball, then forward end of the bar shaft part presses the back surface of the apex ball through the contact ball, and an ink is prevented from flowing out by the consequent action to bring the apex ball into close contact with the inner edge of the ball embracing part. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
