| 摘要 |
PURPOSE: A mechanical pencil controlling the length of a lead is provided to prevent breaking lead by accurately adjusting the lead for mechanical pencil. CONSTITUTION: A mechanical pencil controlling the length of a lead comprises a mechanical pencil lead ball and a control cap(20). In the control cap, which is attached to the mechanical pencil lead ball, a sub-control cap screw thread(12) is placed. The control cap interlocks with the sub control cap. A control cap screw thread(21) is an apparatus for interlocking the control cap and the sub control cap. The control cap screw thread and the sub control cap screw thread are interlocked for screw-combining, thereby freely controlling the length of the lead. |
