| 摘要 |
PURPOSE: To select the position of a grip part by a simple operation and to fix it surely by changing the condition of engagement between the screw part of the surface of a shaft cylinder and the inward protruding parts of the inner surface of the grip part at any position. CONSTITUTION: A screw part 6 is formed on the surface of a shaft cylinder 1, and more than one inward protruding part 8 is formed on the inner surface of a cylindrical grip part 7. The protruding parts 8 are engaged with the screw part 6, and the grip part 7 is made possible to turn on the outer surface of the cylinder 1 and also to move in the longitudinal direction. In this operation, irrespective of the position of the grip part 7, the condition of engagement between one of the protruding parts 8 and the screw part 6 of the cylinder 1 is made different from that between one of the other protruding parts 8 and the screw part 6 of the cylinder 1. In this way, the position of the grip part 7 is moved in the longitudinal direction by a simple operation, selected, and fixed surely so that the holding part 7 is not moved by the writing pressure during writing. |
