933 F.3d 1336
Fed. Cir.2019Background
- The Toro Company petitioned for inter partes review of claims 1–16 of U.S. Patent No. 8,011,458; the PTAB found the challenged claims obvious under 35 U.S.C. § 103.
- Independent claims 1 and 9 recite a "mechanical control assembly ... configured to" perform specified steering/speed functions for a zero-turn-radius vehicle.
- MTD (patent owner) argued the phrase is a means-plus-function limitation under 35 U.S.C. § 112, ¶ 6 and that the cited prior art lacks the corresponding structure; MTD submitted expert evidence that the term is a generic, non-structural label.
- Toro argued the specification’s disclosed "ZTR control assembly" supplies a structural definition and relied on prosecution history statements to rebut § 112, ¶ 6.
- The Board concluded § 112, ¶ 6 did not apply, relying chiefly on the specification and prosecution history; the Federal Circuit reviewed de novo whether the term invoked § 112, ¶ 6 and reviewed underlying factual findings for substantial evidence.
Issues
| Issue | MTD's Argument | Toro's Argument | Held |
|---|---|---|---|
| Whether the phrase "mechanical control assembly ... configured to" invokes 35 U.S.C. § 112, ¶ 6 (means-plus-function) | The term is a nonce/generic term that does not connote sufficiently definite structure to a person of ordinary skill; claim language is primarily functional; specification does not lexicographically define the term | The specification’s disclosed "ZTR control assembly" provides the structural definition; prosecution history shows MTD treated the term as structural | The term is governed by § 112, ¶ 6; the Board erred in concluding otherwise |
| Whether the specification’s disclosure of corresponding structure precludes application of § 112, ¶ 6 | Existence of corresponding structure in the spec does not mean the claim term itself connotes structure; specification did not clearly redefine the generic term | The spec’s ZTR control assembly shows the claimed term denotes structure | The Board erred by conflating existence of corresponding structure with the question whether the claim term connotes structure; specification did not clearly lexicographically redefine the term |
| Whether prosecution history statements foreclosed application of § 112, ¶ 6 | MTD’s past statements were equivocal and not made in the § 112, ¶ 6 context; they did not clearly disclaim means-plus-function treatment | Toro relied on prosecution statements where MTD emphasized the limitation connotes structural configuration | The Board gave improper dispositive weight to equivocal, out-of-context prosecution statements; they do not preclude § 112, ¶ 6 |
| Remedy given the erroneous claim construction | Apply means-plus-function framework and require identification of corresponding structure in the spec; reassess invalidity findings | Maintain Board’s obviousness ruling based on its prior (non-§ 112) construction | The court vacated the Board’s obviousness conclusion and remanded for proceedings consistent with the correct § 112, ¶ 6 analysis |
Key Cases Cited
- Williamson v. Citrix Online, LLC, 792 F.3d 1339 (en banc) (establishes framework for rebuttable presumption against means-plus-function when term lacks the word "means")
- Apex Inc. v. Raritan Computer, Inc., 325 F.3d 1364 (term "circuit" can connote structure depending on context)
- Diebold Nixdorf, Inc. v. Int’l Trade Comm’n, 899 F.3d 1291 (functional term with no established structural meaning invoked § 112, ¶ 6)
- Zeroclick, LLC v. Apple Inc., 891 F.3d 1003 (distinguishing non-nonce structural terms from generic black-box terms)
- Thorner v. Sony Comput. Entm’t Am. LLC, 669 F.3d 1362 (patentee must clearly act as lexicographer to avoid § 112, ¶ 6)
- Media Rights Techs. Inc. v. Capital One Fin. Corp., 800 F.3d 1366 (claim language read in light of the specification determines whether a limitation recites sufficient structure)