| 摘要 |
<P>PROBLEM TO BE SOLVED: To deliver an eraser only at a necessary time in a writing utensil having an eraser delivery mechanism utilizing a screw pair. <P>SOLUTION: A rotary screw (5) is provided to the cap (4) of a shaft cylinder (1) in a freely rotatable manner and the screw groove (17) of the eraser (7) is locked with the screw thread part (13) provided to the inner surface of the rotary screw (5). The locking piece (19) of the rotary cylinder (6) is locked with the receiving groove (18) provided to the eraser (7). The rotation stop part (15) locking with the inner end of the rotary screw (5) is provided to the rear part of the shaft cylinder (1). Since the rotary screw (5) is rotated in such a state that the cap (4) is fitted to the leading part of the shaft cylinder, the eraser is not delivered even if the rotary screw (5) is rotated. When the cap (4) is fitted to the rear part of the shaft cylinder, the rotation of the rotary screw (5) is obstructed and, therefore, the eraser (7) can be delivered by rotating the rotary cylinder (6). <P>COPYRIGHT: (C)2004,JPO |
