Thermal barrier for frame structures

Claim 1

A composite structure which extends, transversely of its length, from a cold region to a warm region and has an integral heat conduction barrier therein; comprising two elongated structural members each extending from one temperature region to a point between said regions, each of said members having at said point an upstanding leg having two surfaces and extending in the same direction and spaced from each other whereby one surface of each leg faces the other, said surface of each of said leg facing each other having a dovetailed slot extending in the same plane as said structural member, said surface of each leg opposite to each of the facing surfaces having an elongated projection extending in the same plane as said structural member near substantially the junction of said structural member and said leg, a U-shaped member having two upstanding portions and a relatively flat apex portion, said upstanding portions adapted and constructed to embrace said surfaces of said legs opposite to each of the said facing surfaces, each of said upstanding portions having extending inwardly an elongated projection adapted and constructed to be positioned between the said projections of each of said legs and said structural members, said base portion of said U-shaped member adapted and constructed to connect the ends of said extending legs, said base portion having two inwardly extending upstanding spaced elongated elements substantially parallel with respect to said extending legs, said elements adapted and constructed to define a dovetailed slot therebetween, said facing surfaces of said legs and a portion of said base portion defining a U-shaped channel, said U-shaped channel being filled with a thermal barrier material.