Patent ID: 7040069

Claim:
An elongate, long-span transmission beam employable between columns in a building frame structure comprising an elongate central portion having a uniform first depth occupying the majority of the overall length of the beam, and having a common cross-section along its length, a pair of elongate end portions each having a uniform second depth which is less than said first depth, and each also having a common cross-section along its length, a pair of elongate depth transitional regions each integrally interposed an end of said central portion and an end of an end portion, possessing a graded depth which transitions in size from said first depth where the transitional region is integral with an end of said central portion to said second depth where the transitional region is integral with an end of an end portion, said central portion, end portions and transitional regions each being characterized by material continuity along lines extending within them which are transverse to the lengths of the portions and regions, and intermediate the opposite ends of each uniform-depth end portion, a laterally reduced beam-section region.