| 摘要 |
The extruded beam, substantially U=shaped and symmetrical in profile(1), comprises side walls(2,3) between which an integral connecting web(4) is formed with reinforced sections(10,11) having a thickness of no more than five percent of the width of the beam. The connecting web consists of two hollow drums(16,17) joined by a transverse wall(18). A space(5), created below the connecting web, provides a member for support, guidance and drive for the load being carried. The height and width of the beam are approximately equal and thickened corners(6-9). |
