Structure of lightweight bars and connector means therefore

A structure comprising:

• a. a first hollow, elongated member having a plurality of faces, composed of a single piece of sheet metal having its longitudinal edges joined together to close the cross-section of said member, each of said faces having a longitudinally extending channel, at least one of said channels comprising a base and a pair of substantially planar sides, said sides being mutually inclined as viewed in transverse cross-section such that the width of the channel increases in a direction extending outwardly of said member from the base of said channel;
• b. a second hollow, elongated member having faces and channels as in said first member;
• and
• c. a connector connecting together said first and second members, said connector comprising a base of substantially the same width as the base of said one of said channels and a pair of substantially planar sides which are mutually inclined at a slightly different angle than the sides of said channel, said connector's planar sides frictionally engaging at least one channel in each of said first and second members.