| 摘要 |
PROBLEM TO BE SOLVED: To provide a rotation operation type writing instrument which allows a user to operate the instrument continuously and smoothly without generating deformation of a cam cylinder even when rotation force exceeding the required amount is applied to the cam cylinder which forms a spiral shaped cam groove.SOLUTION: By rotating a rear shaft cylinder inner cylinder (16) by performing rotation operation to a rear shaft cylinder (3), cam groove (17a) of a cam cylinder (17) and a slit (16a) of the rear shaft cylinder inner cylinder (16) make a cam projection (18a) of a press body (18) disposed inside the rear shaft cylinder inner cylinder (16) go ahead and rotate, and the writing body (14) goes ahead via the press body (18) against energization of an elastic body (15). |
