In re Richman, 563 F.2d 1026, 195 U.S.P.Q. (BNA) 340 (C.C.P.A. 1977) (full-text).
Factual Background Edit
The patent claim in issue was method of calculating an airborne radar boresight correction angle aboard the aircraft, which utilized an arithmetical formula and included new and unobvious steps for acquiring the data used in the formula, was held to be nonstatutory subject matter.
Trial Court Proceedings Edit
The court held that if a claim was directed essentially to an arithmetic formula, substituting "words which mean the same thing" as the formula in the claim would not render the method patentable. This would be true even if the formula (or substituted words) were limited to a "specific purpose."