Box beam

Claim 1

A FABRICATED BEAM CONSTRUCTION COMPRISING, IN COMBINATION, A PAIR OF PARALLEL, SPACED, GENERALLY PLANAR, ELONGATED ALUMINUM FLANGES, A PLANAR LACING ABUTTING SURFACE DEFINED ON EACH OF SAID FLANGES IN OPPOSED RELATION, SAID LACING ABUTTING SURFACE EXTENDING SUBSTANTIALLY THE LENGTH OF AND PARALLEL TO THE ASSOCIATED FLANGE, A PLURALITY OF ALUMINUM LACING MEMBERS INTERPOSED BETWEEN SAID FLANGES AND HAVING ENDS AFFIXED TO SAID FLANGES MAINTAINING THE SPACING BETWEEN SAID FLANGES, SAID LACING ENDS INCLUDING A PLANAR SURFACE PARALLEL TO AND ABUTTINGLY ENGAGING A FLANGE LACING ABUTTING SURFACE, A LONGITUDINAL SHOULDER SURFACE DEFINED ON EACH OF SAID FLANGES ADJACENT AND PERPENDICULARLY INTERSECTING THE LACING ABUTTING SURFACE THEREOF DEFINING A RIGHT ANGLE INTERSECTION UPON SAID FLANGES, SAID LACING ENDS BEING OF A TRANSVERSE WIDTH LESS THAN THE TRANSVERSE WIDTH OF SAID LACING ABUTTING SURFACES AND COPLANARLY ENGAGING SAID ABUTTING SURFACES WHEREBY A LACING LATERAL SIDE ENGAGES SAID SHOULDER SURFACE, A WELD FILLET WELDING SAID LACING ENDS TO SAID FLANGES AT THE INTERSECTION OF THE LACING AND LACING ABUTTING SURFACES ON THE OPPOSITE LATERAL SIDE OF SAID LACING WITH RESPECT TO SAID SHOULDER SURFACE AND AN ELONGATED FLANGE PORTION OF SUBSTANTIALLY ENLARGED CROSS SECTION ADJACENT SAID SHOULDER SURFACE AND LACING ABUTTING SURFACE INTERSECTION ADAPTED TO CARRY AWAY WELDING HEAT DURING WELDING OF SAID LACING TO SAID FLANGES.