| 摘要 |
The track edge parts (5) act as engagement components for corresp. engagement components (6) on the opposite ends of the two tension parts (3) of which the beam body (2) consists. The tension parts have counterpiece parts (8) in the vicinity of the engagement components, and through lever effect with their central areas (7) pressed against one another are arranged to tension tightly their engagement components (6) against the flange edge parts (5). - The tension parts have joint parts (11) in their central area (7), permitting the central areas to be pressed against one another, and fixed as to position by hooks (13-16). |
