| 摘要 |
The mast has a base on which movable upper section is installed, with devices for its fixation in vertical direction, and device for its lifting and lowering. The device for lifting and lowering the upper part of the mast is arranged as installed on the base at diametrically opposite sides a movable upper section of the mast, two props and hoist shaft of which is connected with cable to respective ends of the props and to the movable upper section with possibility of its inclination and fixation of position. The device for its fixation in vertical position is arranged as a cross-piece that is rigidly fixed between two props with possibility of rest of the movable upper part of the mast there. |
