| 摘要 |
1. Extended construction element of variable length with an inner tube (13) and an outer tube (12), one of the tubes being telescopically displaceable in or on the other tube, with bearings to guide the axial movement of the displaceable tube and to absorb the transversal forces applied on this tube, rail with linear roller bearings (16) between the bearing surfaces of the inner and the outer tube and with at least one expansion element (19, 20, 21) providing for abutment of the roller bearings (16) against the bearing surfaces of the inner and the outer tube, characterized in that railguiding rails (14) are arranged on two opposite sides of one tube (12) extending in the longitudinal direction of said tube while the other tube (13) is provided with guiding slots (15) matched for said guiding rails (14), rail that the linear roller bearings (16) are arranged between the guiding rails and the walls of the guiding slots, and rail that ans the walls of the guiding slots, and rail that said at least one expansion element (19, 20, 21) is arranged such as to cause, through expansion of the inner tube (13) the abutment of the roller bearing (16) on the bearing surfaces of the inner and the outer tube. |
