In the case of Westinghouse Electric & Manufacturing Company v. Formica Insulation Company, the Supreme Court ruled in favor of Formica Insulation Company in 1924. The dispute centered around a patent for an electrical insulation material known as "formica." Westinghouse claimed that it had exclusive rights to manufacture and sell formica under its own patents, while Formica argued that their product was different and did not infringe on any existing patents held by Westinghouse. The court found that although both products were similar, they were not identical; therefore, no infringement occurred. This ruling established a precedent for determining whether or not a product violates an existing patent based on its similarities or differences with patented items rather than just considering if it performs the same function.

The dissenting opinion in the case of Westinghouse Electric & Manufacturing Company v. Formica Insulation Company argued that the majority's decision to uphold Formica's patent was incorrect due to a lack of novelty and non-obviousness, key requirements for patentability. The dissent pointed out that there were prior patents and publications which disclosed similar inventions before Formica filed its application, thus negating any claim to originality or innovation. Furthermore, it was suggested that even if these earlier works did not explicitly describe every detail of Formica’s invention, they provided enough information for someone skilled in the field to deduce it without requiring inventive skill - another reason why the patent should be invalidated. The dissent also criticized the majority for failing to properly apply legal standards regarding anticipation and obviousness during their evaluation of evidence.