| 摘要 |
PURPOSE:To permit a writing instrument such as eraser to be projected and retracted by a simple structure by a method wherein a holder is axially and movably inserted into the rear end part of a writing device, the writing devices such as eraser and writing instrument are attached to the holder, a threaded groove is formed around the outer periphery of the holder and a rotary sleeve having a screw bar engageable with the threaded groove is mounted rotatably between the writing instrument and the holder. CONSTITUTION:A holder 12 is inserted into a receiving part 13 of an inner tank 9 with a long groove 15 thereof in engagement with a projection 14, an engaging edge 24 of a rotary sleeve 23 is engaged with an engaging edge 28 of the receiving part 13 and the rotary sleeve 23 is inserted rotatably into the inner tank 9. When the rotary sleeve 23 is rotated to use this writing instrument, since the holder 12 is restrained from its rotational movement, it is guided by a screw bar 2 and a threaded groove 16 into axial movement, an eraser 20 is projected beyond the rotary sleeve 23, so that it can be used. When the rotary sleeve is rotated reversely, the eraser 20 is retracted into the rotary sleeve 23. The holder 12 is restrained against movement by the contact of the projection 18 with the front end of the rotary sleeve 23. |
