Building frame of channel sections - has two parallel longitudinal internal ribs in each section arm

摘要

The frame structure is built up of channel sections with internal longitudinal ribs joining two edge strips bent over inwards. These support fixing devices such as nuts inserted in the section and securing angle-pieces joining it to others. Each arm (3) of the channel section has a pair of parallel lengthwise ribs (6, 6'), joined to each other by an internal groove base (7). The joins between the various portions can be radiused, and the external dimensions of the base (2) and arms can be the same.