The Federal Circuit’s March 11, 2026 decision in Gramm v. Deere is an important correction to an approach that appears with some regularity in means-plus-function disputes: courts and litigants import unclaimed capabilities from the specification into the corresponding-structure analysis and then use that expanded analysis to manufacture indefiniteness. The Federal Circuit rejected that move.
Background and Claim Dispute
Gramm’s patent claimed a header-height control system for a crop harvesting machine. The disputed claim term was “control means,” and the parties agreed that it was a means-plus-function limitation reciting the function of “raising and lowering the header… a designated height above the soil.” The parties also agreed that the specification identified corresponding structure in the form of a controller interface 18, a head controller 20, and a hydraulic control system 38 working in combination. The key issue was this: although the claims recited only control of header height, the specification described head controller 20 as controlling both header height and lateral position. Should the function be defined by the claim language alone, or should the district court fold the specification’s additional function into the analysis? More broadly, when a means-plus-function claim recites function X, and the specification describes corresponding structure that performs function X but also performs function Y, how should the court characterize the relevant function?
District Court’s Analysis
The issue was complicated by the fact that the specification did not directly identify the concrete structure of head controller 20. Instead, it stated that “[i]n a specific embodiment of the present invention, head controller 20 is as incorporated in a Deere combine.” At the patent’s 1997 filing date, three Deere combine controllers were commercially available. The district court accepted Deere’s argument that the relevant disclosure pointed to Deere’s Dial-A-Matic Versions #2 or #3, rather than Version #1, because Versions #2 and #3 could control not only header height but also lateral position—the latter being a function described in the specification, but not recited in the claim. This distinction is important because Versions #2 and #3 were found to be microprocessor-based. Once the district court framed the issue that way, the familiar algorithm rule for computer-implemented means-plus-function limitations came into play. Because the patent specification did not disclose an adequate algorithm, the district court held the claim indefinite.
Federal Circuit’s Reversal
The Federal Circuit reversed. It did not retreat from the longstanding rule that if the corresponding structure is a general-purpose computer or microprocessor programmed to perform the claimed function, the specification must disclose the algorithm. It also left intact the district court’s finding that Dial-A-Matic Versions #2 and #3 were microprocessor-based and therefore would require an algorithm if they were the relevant corresponding structures. The Federal Circuit likewise left intact the district court’s conclusion that the patent did not disclose an adequate prose algorithm for those versions.
Key Holding on Corresponding Structure
What the Federal Circuit rejected was the district court’s threshold decision to exclude Dial-A-Matic Version #1 from the corresponding-structure analysis merely because Version #1 lacked an additional capability—controlling lateral position—that was mentioned in the specification but was not part of the claimed function. The claimed function was header-height control. The court held that structure should not be disqualified simply because it does not also perform some extra, unclaimed function disclosed elsewhere in the specification.
Clarification of Means-Plus-Function Analysis
That holding is important because it reinforces the proper sequence of a means-plus-function analysis. The court must first identify the function actually recited in the claim, and then identify the structure clearly linked to that function. The corresponding-structure inquiry must remain tied to the function the claim actually recites—nothing more. The specification is not a grab bag from which an accused infringer may pull additional features and then insist that the corresponding structure must satisfy all of them.
Application of the Correct Standard
Once the court corrected that error, the rest followed fairly quickly. Deere had conceded that Dial-A-Matic Version #1 used logic circuitry—diodes, switches, and integrated circuits—rather than a microprocessor to raise and lower the header. Under existing Federal Circuit law, circuitry-based implementation does not trigger the WMS Gaming algorithm requirement in the same way as a general-purpose computer or microprocessor. Because Version #1 qualified as valid corresponding structure, the indefiniteness ruling could not stand. The Federal Circuit held that the district court erred in excluding Version #1 and reversed the indefiniteness judgment.
Why the Claim Survived
Gramm prevailed because there was at least one adequately disclosed embodiment that corresponded to the claimed function, and one is enough. The court expressly relied on the principle that a claim can survive if even a single embodiment provides sufficient corresponding structure. That point is a useful reminder: in some cases, the fight is not about showing that every possible embodiment works for § 112(f) purposes, but about preserving one defensible structural path through the claim.
Practical Takeaways for Counsel
So what should counsel take away from Gramm v. Deere?
Drafting Strategy: Preserve Alternative Structural Embodiments
First, if you are prosecuting means-plus-function claims, revisit any term for which the corresponding structure could be characterized in more than one way. If the specification includes both a circuitry-based embodiment and a software- or microprocessor-based embodiment, the distinction may be outcome-determinative on indefiniteness. Gramm shows that one adequately linked non-microprocessor embodiment can save the claim even if other embodiments would trigger an algorithm problem.
Algorithm Disclosure: Do Not Rely on Commercial Products Alone
Second, if you are using functional claiming around software, processors, controllers, or configurable logic, you still want explicit algorithmic disclosure in prose, flowcharts, decision logic, or other concrete form. That remains true even if the specification references a commercially available product, because that product—like Dial-A-Matic Version #3 here—may later be characterized as a microprocessor-based device requiring disclosure of a corresponding algorithm in the specification. Gramm survived because there was a circuitry-based structural route available. Many patents will not have that safety net. When possible, draft the specification so that such a safety net exists.
Claim Construction: Keep the Function Narrow and Grounded in the Claim Language
And third, be disciplined about defining the claimed function narrowly and accurately. Do not allow the other side to inflate the function by borrowing extra verbs, capabilities, or objectives from surrounding specification text. The Federal Circuit’s reasoning in Gramm is a direct rebuke against that kind of slippage. If a capability appears in the specification but not in the claimed function, it should not be used to exclude otherwise qualifying structure.
Key Takeaway
Gramm v. Deere reminds us that in the means-plus-function context, corresponding structure must be identified by reference to the function actually claimed, not by importing extra features from the specification. For litigators handling valuable but aging patent assets, and for prosecutors drafting means-plus-function claims today, that clarification may prove quite important.
For companies relying on functional claiming, a disciplined approach to defining claimed functions and corresponding structure can reduce indefiniteness risk and strengthen enforcement positions. Contact Conley Rose to discuss how your organization can refine its patent strategy in light of recent Federal Circuit decisions.