Coupling device

A beam section made as a lattice work beam, having an upper longitudinal sub-beam member and a lower longitudinal sub-beam member, where a first end of the upper longitudinal sub-beam member is provided with a first beam end whereon is arranged first interconnection units consisting of two first parallel flange elements arranged with a mutual first distance x, wherein the flanges are arranged symmetrically on either side of a plane parallel to the elongated axis of the beam, and wherein the plane of each flange is parallel to the longitudinal direction of the beam, and that in each flange is configured a cut-out with a cross-section in the plane of the flange;

• and the opposite end of the upper longitudinal sub-beam member is provided with a second beam end whereon is arranged a second interconnection unit consisting of a second flange with the plane of the second flange in the longitudinal direction of the beam, wherein the width of the second flange across the plane of the second flange is smaller than or equal to x, and where substantially perpendicular to the plane of the second flange, a connecting element protrudes on each side of the second flange, wherein the cross-section of the connecting element in the plane of the second flange allows insertion of the connecting element into cut-outs of first flanges on a first beam end of a corresponding beam.