Box girder type telescopic cantilever arm - has pressure chord and stem wall ribs and angled edge reinforcing planes

摘要

The box type girder or support structure, esp, in a telescopic cantilevered arm, is of polygonal cross-section, with walling pieces of monolithic material. The pressure chord (1) incorporates a full-length rib, or more than one, of any desired shape (2), and the stem walls (3) likewise have full-length ribs (4). Each edge forming a corner has a shaped reinforcemtn with planes at any desired angle, and these reinforcing sections also run along the whole length of the unit. The shaped reinforcements on the pressure edges may be in a wide variety of forms. The planes serve as sliding tracks for complex double-planed sliding shoes with aligned pressure forces.