WG Patents Pre-Stressed Hollow Tile Beam

During the effort to create new business, DD invented a pre-stressed hollow tile beam known ad “Kalex,” resulting in US patent number 2,101,447. DD assigned the patent jointly to WG, Whitacre Engineering and Balast Rock, a California company. During this period, DD worked for Whitacre Engineering Company for some years. By pre-stressing the bottom of the tile beam, it could span wide areas and the floors would hold greatly increased loads. The invention attracted the attention of the cement and concrete interests, which hired Professor Vander Heyden at the University of Wisconsin to develop and patent such a system using concrete blocks rather than clay tile. Vader Heyden’s work resulted in US patent number 2,696,729, which was assigned to the concrete block sponsors of the research. The Whitacre interests successfully sued the concrete interests in federal court in Indiana. The court essentially ruled that Vander Heyden et al. had “stolen” the intellectual property of the basic DD invention and the court awarded ownership of the Vander Heyden patent to the Whitacre interests. For the next 25 years, our companies collected substantial royalties from manufacturers whom we licensed to make “Dox” block beams out of cement block. We will revisit this subject in 25 years.