Prefabricated structural connector for steel-frame buildings

A prefabricated steel-frame building structural connector for interconnecting two vertical column members with each other end-to-end and with at least one horizontal beam member having a central web, said vertical column members having predetermined identical substantially square tubular cross sections, said structural connector comprising

• a central hollow tubular portion having a central axis, axially spaced flat ends perpendicular to said axis, a substantially square cross section identical to said predetermined column cross section, and four flat outer surfaces facing laterally outwardly of said axis,
• first and second hollow substantially cylindrical tubular end projections joined to said central portion and projecting from said ends of said central portion in opposite directions coaxially with said central portion,
• each said cylindrical end projection including four perpendicularly spaced outwardly facing flat surface portions disposed in diametrically opposed pairs extending throughout the length of the associated end projection and diametrically spaced from each other by a distance substantially equal to separation between opposed inner surfaces of said predetermined substantially square cross section, such that said cylindrical projections are constructed for close telescopic insertion into column members with said columns seated against said spaced ends of said central portions so as to align the column members axially and rotationally with said central portion and with each other, and
• at least one mounting bracket permanently joined to one flat outer surface of said central portion and having a flange projecting laterally outwardly from said one surface parallel to said axis, said flange being structured for connection to the web of a beam member.