A patent was issued for a method of cooking bacon, where the cooked bacon was sold to consumers. Plaintiffs sued defendant infringer for patent infringement. Defendants counterclaimed that the patent was indefinite. The claims language that was indefinite was in the preamble to claims 1 and 3 which recites “[a] process … to produce a pre-cooked sliced bacon product resembling a pan-fried bacon product.” (as distinguished from microwaved bacon) The issued patent did not define or identify specific criteria for measuring or determining the texture, mouth feel, bite, appearance, or color of pan-fried bacon. The district therefore ruled that the bacon patent is invalidated due to indefiniteness.
Two interesting points, first, the method of cooking bacon would have been patentable, if the patent specification defined or identified specific criteria for measuring or determining the texture, mouth feel, bite, appearance, or color of pan-fried bacon. Second, the preamble to the claims, were considered limiting on the rest of the claim. Many attorneys have been taught that preambles are not limiting. The case is HIP Inc. v. Hormel Foods Corporation et al., case number 1:18-cv-00615 (D. Del.), and can be found here.