| 摘要 |
PROBLEM TO BE SOLVED: To facilitate an operation of a dual type writing instrument by simplifying a constitution of the instrument. SOLUTION: The dual type writing instrument comprises a pair of slide dwells 12a, 12b combined in an opposed state, and engaging grooves 22 formed on other surfaces of the dwells 12a, 12b. An operating cam 3 has a cam surface and a locking protrusion 13. When the cam 3 is rotated to move either the dwell 12a or 12b, the protrusion 13 is engaged with the groove 22 of the other dwell to prevent the movement of the other dwell. |
