| 摘要 |
PROBLEM TO BE SOLVED: To realize the smooth retraction and extension of a writing tip part from and to a tip hole and to see through the kind of a writing body and its reduce of ink by providing the hole tip part, which converges towards the tip of a barrel tube in the barrel tube and see-through window parts respectively opposing to ball pen writing bodies, on the side surfaces of the barrel tube. SOLUTION: When an operating body is rotated in one direction to a barrel tube 30, sliding projecting parts 26 of sliding pieces 21a and 21b slide along spiral grooves 42 so as to advance either one of the sliding pieces and retreat the remaining one of the sliding pieces, resulting in allowing to project the writing tip part of an advancing side writing body from the tip hole of the hole tip part 30a. Further, since a writing tip part displaces flexibly even when the ink housing parts of ball pen writing bodies 1a and 1b are non-deformable, a writing tip part smoothly retracts and extends from and to the tip hole without the hindrance of its actuation. Furthermore, since see-through window parts are provided in the barrel tube 30, the states of the ball pen writing body such as its kind and its ink residue or the like can be seen through. |
