| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress entanglement of a plurality of coil springs, suppress the inclination of the linear part of the coil spring, and suppress such failures that it is impossible to write with a ballpoint pen due to ink-drying in the ballpoint pen tip and the ink leaks from a gap between a ball and a ball holder when not in use. <P>SOLUTION: The coil spring for a ballpoint pen tip, including a coil part functioning as a spring part and the extending linear part provided at the leading end thereof, is configured such that the length of the linear part is made shorter less than a value obtained by subtracting the wire diameter of the coil spring from the outer diameter of the coil part of the coil spring. <P>COPYRIGHT: (C)2013,JPO&INPIT |
