The U.S. Supreme Court case Railroad Supply Company v. Elyria Iron & Steel Company in 1916 revolved around a patent dispute between the two companies. The plaintiff, Railroad Supply Company, alleged that Elyria Iron & Steel had infringed on their patented design for a railroad car coupler and sought an injunction to prevent further infringement as well as damages for past violations. However, the defendant argued that they were not infringing because their product was based on an expired patent and thus available for public use. The court ruled in favor of the defendant, stating that once a patent has expired anyone is free to make or use the invention without liability to its former owner under federal law.

The dissenting opinion in the case of Railroad Supply Company v. Elyria Iron & Steel Company argued that the majority's decision was inconsistent with previous rulings and failed to properly interpret patent law. The dissent contended that, under existing precedent, a company should not be able to claim infringement on a patented device if it had previously sold similar devices without asserting its patent rights. In this case, Elyria Iron & Steel had been selling railroad car couplers for years before suddenly claiming they were protected by an old and almost expired patent. This sudden assertion of patent rights seemed more like an attempt to monopolize the market than protect intellectual property. Furthermore, the dissent argued that even if Elyria did have valid patents, their claims would still fail because their patents covered only specific designs while they were trying to assert them against all types of couplers - effectively attempting to extend their monopoly beyond what was legally granted by their patents.