| 摘要 |
The invention refers to a movable supporting frame for supporting the roof in underground cavities, in particular for securing the excavating edge when recovering the pillars in coal mining, comprising a cap (5) supported against a base frame (1) by means of hydraulically extendable props (3) and a lemniscate drive means (4), the props (3) being pivotally connected with the base frame (1) and with the cap (5). The props (3) are essentially perpendicularly oriented relative to stratification and are linked to the base frame (1) and to the cap (5) in a universally pivotably manner, noting that preferably four props are arranged at the corners of a rectangle as seen in a plan view. The lemniscate drive means (4) is connected with the base frame (1) for swivelling movement in transverse direction relative to the plane defined by the lemniscate guides (8, 9) and is adjustably supported against any swivelling movement and is connected with the cap (5) for universal swivelling movement. The cap (5) can be lowered into a transport position (5'') located below the lowest working position. One lemniscate guide (8) is pivotally linked to a length-adjustable directing strut (12) having its other end pivotally linked to a linking point (13) connected with the base frame (1), the length (b) of said directing strut being maintained unchanged within the operating range (a) of the supporting frame and being increased in transport position (5''). This allows to select a very low transport position without obstructing the operating positions defined by the lemniscate drive means (FIG. 1). |
