Modular system for space grid structures

Claim 1

A modular system for use in fabricating space grid structures comprising a plurality of girders and a joint, each of said girders comprising a substantially spherical member fixedly mounted to an end thereof by a substantially cylindrical connecting portion of a given diameter, said joint comprising first and second substantially hemispherical hollow parts being adapted to be assembled to define a cavity into which one or more of said end members are substantially completely received, each of said parts having four substantially orthogonal substantially semi-circular openings and four substantially orthogonal elongated openings, said parts, when assembled, forming four substantially orthogonal substantially circular openings, each having a diameter substantially equal to said diameter and four substantially orthogonal elongated openings, each having a width substantially equal to said diameter and extending in a direction substantially parallel to the axis of said joint, said openings being adapted to accept said connecting portions therein, means extending through said cavity for connecting said part, said connecting means extending along said axis of said joint and structural rigidity enhancing members extending outwardly from said parts in a direction substantially coplanar with said axis.