Reinforced aluminium hollow tubular lighting mast, comprising in plane view three variable thickness sections and three constant thickness sections

摘要

150 mm dia. tubular mast having a total circumferential length comprising at least three identical section unitary parts (L1,L2,L3). The parts have two ends (3,4) the thickness of the section between the ends regularly varies from a minimum thickness at the ends to a maximum at the section center (5). The parts (L1,L2) are separated by three constant thickness sections (P). Each part occupies an angular section of about 78.5 degrees and each (P) section occupies an angle about 41.5 degrees. The transversal section of the mast may be conic or sensibly cylindrical. The thickness ratio between the section ends (3,4) and the center (5) is about 3/5. At the bottom of the mast is an opening for a door. On the top of the mast is a crossbeam supporting lamps. On the inside of a section (L2) is a rib (14) indicating the position for the door cutting tool.