| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a chuck 1 for mechanical pencil, which facilitates processing, and with which a lead 5 can be securely held without decreasing lead holding force even in long-period use. <P>SOLUTION: There is provided the chuck 1 for mechanical pencil in which a lead holding part 1A is halved and the lead 5 is held by wedge operation. Two kinds of screw grooves which differ in pitches are formed on the inner surface of the lead holding part 1A of the chuck 1. Further, the two kinds of screw grooves differing in pitches are so formed that the first screw groove 1B which has the large pitch has a deeper screw depth than the second screw groove 1C having the small pitch. <P>COPYRIGHT: (C)2013,JPO&INPIT |
