| 摘要 |
A telescopic column pipe (10, 11) to be located in the ground, wherein an upper pipe element (11) is provided with a top covering (14, 15) to be disposed substantially at ground level, and is displaceably received at a smooth portion thereof in a lower pipe element. The upper pipe element has an outside screw thread (17) extending over at least part of the circumference of said pipe element. By rotating the upper pipe element this element can be moved up and down in relation to the lower pipe element solely by the cooperation of the screw thread with the surrounding ground material. |
