| 摘要 |
A rotary pencil includes a sleeve-shaped shaft having a front end and a rear end, a threaded spindle mounted to be fixed against rotation and axially movable in said shaft and having an at least single-start external thread. At least one threaded element is fixed in axial and rotating directions relative to the shaft and engages into the external thread. The front end of the external thread is adjoined by a cylindrical spindle section which extends over the entire circumference of the spindle, namely a free-running section, and has an external diameter corresponding to a core diameter of the external thread. |
