Federal Circuit Reverses Indefiniteness Ruling on Means-Plus-Function Claim

In Gramm v. Deere & Co., No. 2024-1598 (Fed. Cir. Mar. 11, 2026), the Federal Circuit reversed a district court’s determination that the means-plus-function limitation “control means” was indefinite. The parties agreed on the claimed function and corresponding structure of the term but disagreed as to whether the specification’s “head controller 20” feature of the corresponding structure was sufficiently definite. Gramm submitted expert testimony that a skilled artisan would have understood that, as of the patent’s filing date, there were three commercially available head controllers. The district court, however, excluded one of those controllers as a corresponding structure because it lacked lateral positioning capability and determined that the remaining structures required an algorithm not disclosed in the specification. Gramm appealed.

The Federal Circuit reversed the district court’s indefiniteness determination, holding that the district court erred by requiring the structure to perform unclaimed functions. The court emphasized that the specification’s reference to controlling header height was sufficient to support the claimed function. Additionally, because one of the commercially available head controllers used logic circuitry—not a microprocessor—it did not trigger the algorithm disclosure requirement under § 112(f). The court thus concluded that the structure was adequately disclosed and reversed the indefiniteness determination and remanded for further proceedings.