## Facts

- Edward H. Phillips invented and obtained U.S. Patent No. 4,677,798 for modular, steel-shell panels that could be welded together to form vandalism-resistant, load-bearing, impact-resistant walls.
- The panels included internal steel “baffles” that formed compartments (often for concrete) and, as described in the specification, could affect how projectiles behaved after penetrating the exterior shell.
- After receiving the patent, Phillips entered into an agreement with AWH Corporation and two other companies to market and sell the panels.
- The relationship ended. The following year, Phillips received an AWH sales brochure that led him to believe AWH continued using the patented technology without permission.
- Phillips sued AWH Corporation in the U.S. District Court for the District of Colorado for patent infringement.
- Claim 1 recited, in part: “further means disposed inside the shell for increasing its load bearing capacity comprising internal steel baffles extending inwardly from the steel shell walls.”
- The district court treated the “means” language as invoking 35 U.S.C. § 112, ¶ 6 (means-plus-function), and limited the claim to the corresponding structures described in the specification and their equivalents.
- After reviewing the specification, the district court construed “baffles” to require structures extending inward from the shell walls at an oblique or acute angle (not perpendicular) and granted summary judgment of non-infringement because the accused product did not include baffles so oriented.
- A divided Federal Circuit panel affirmed. The Federal Circuit then vacated the panel decision and reheard the case en banc to address claim-construction methodology, including how courts should use the specification, prosecution history, and extrinsic sources such as dictionaries.

## Issues

1. In construing patent claims, what is the proper relationship between intrinsic evidence (claims, specification, prosecution history) and extrinsic evidence (including dictionaries and testimony)?
2. Did the “means ... comprising internal steel baffles” language invoke 35 U.S.C. § 112, ¶ 6, or did the claim recite sufficient structure to avoid means-plus-function treatment?
3. Does the term “baffles” in the ’798 patent exclude perpendicular (90-degree) internal structures based on the specification’s discussion and embodiments?

## Decision

- The en banc Federal Circuit reaffirmed that claim terms generally take their ordinary and customary meaning to a person of ordinary skill in the art at the time of the invention, read in the context of the patent’s intrinsic record.
- The court held that intrinsic evidence is the main source for claim construction; extrinsic materials (including dictionaries) may assist but are less significant and cannot override the meaning supported by the intrinsic record.
- The court rejected dictionary-first claim construction approaches to the extent they treat the specification as merely a check against dictionary-derived meanings.
- The court concluded that the claim’s reference to “internal steel baffles” recited structure and therefore did not invoke § 112, ¶ 6, despite the presence of the word “means.”
- On the merits of the disputed term, the court held that “baffles” was not limited to non-perpendicular, projectile-deflecting structures because the intrinsic record did not contain a clear definition or clear disclaimer narrowing the term that far.
- Disposition: affirmed in part, reversed in part, dismissed in part, and remanded for further proceedings consistent with the corrected claim construction.

## Legal Principles

- “It is a bedrock principle of patent law that the claims of a patent define the invention” and the scope of the patentee’s right to exclude.
- Claim terms are given their ordinary and customary meaning as understood by a person of ordinary skill in the art at the relevant time, in the context of the entire patent.
- The intrinsic record controls claim construction: the claim language is read in view of the specification and prosecution history.
- The specification is highly relevant and often the single best guide to a disputed term’s meaning, but courts generally may not import limitations from described embodiments into the claims absent clear lexicography (the patentee defining a term) or a clear and unmistakable disclaimer of broader scope.
- Prosecution history can inform claim meaning and disclaimer, but it may be less clear than the claims and specification because it reflects negotiation with the PTO.
- Extrinsic evidence (including dictionaries, treatises, and testimony) can help explain terms and the relevant art, but it is less significant than intrinsic evidence and cannot contradict the meaning shown by the patent record.
- For § 112, ¶ 6, use of the word “means” creates a rebuttable presumption that the limitation is means-plus-function, but the presumption is overcome when the claim itself recites sufficient structure for performing the stated function; a structural term like “baffles,” as used in the claim, can provide that structure.

## Conclusion

Phillips v. AWH Corporation set the modern Federal Circuit approach to claim construction by placing primary weight on the intrinsic record and treating dictionaries and other extrinsic sources as secondary tools, while also holding that the “means ... comprising internal steel baffles” language did not trigger § 112, ¶ 6 and that “baffles” was not limited to angled, projectile-deflecting structures absent a clear definition or disclaimer in the patent record.


Phillips v. AWH Corporation, 415 F.3d 1303 (2005) (en banc)