The Crom Corporation, Cross-Appellant v. John M. Crom, Jr., and Crom Prestressing, Inc., Cross-Appellees

Two brothers who had once worked together in a family corporation in Florida came to a parting of the ways, and their separate ways brought them into hot litigation in the United States District Court for the District of Nevada over patent rights. In a jury trial, the old Florida corporation prevailed, obtaining a declaratory judgment that the defendants may not assert the disputed patent against the plaintiff corporation.

The Crom Corporation was engaged in the business of constructing large water tanks made of interlocking, vertically arranged steel panels, upon either side of which a cement covering was applied. A sealing material was placed by hand in the interlocking joints before application of the cement surfaces, but leaking at the joints was a substantial problem. In 1961 the two brothers together developed a concept of so shaping the interlocking edges of the steel plates as to form an interior channel into which a sealant might be pumped. The first attempt to practice the concept proved a failure, however, for during the application of the cement, some of the cement entered the channels at places and blocked them.

Before the first attempt to practice the concept, John…