Last week, the U.S. Court of Appeals for the Federal Circuit issued an opinion in Grace Instrument Industries, LLC v. Chandler Instruments Company, LLC, Ametek, Inc., No. 2021-2370 (Jan. 12, 2023).
Grace sued Chandler alleging Chandler’s viscometer infringed Grace’s U.S. Patent No. 7,412,877. During claim construction, the district court held the claim term “enlarged chamber” is indefinite because “enlarged” is a “term of degree” that “necessarily calls for some comparison against some baseline” and because the ’877 patent fails to disclose objective boundaries for a skilled artisan to know what the claimed “enlarged chamber” must be larger than. In so ruling, the district court rejected Grace’s argument that “enlarged chamber” could be defined by its purpose and that the baseline for “enlarged” is the prior art. The district court also construed the term “means for driving said rotor to rotate located in at least one bottom section,” adopting Chandler’s proposed construction. The parties’ stipulated that all asserted claims are either invalid or not infringed based on the district court’s construction of those two terms. Grace appealed.
The Federal Circuit affirmed-in-part, vacated-in-part, and remanded. First, the Court considered the “enlarged chamber” term. The Court held that although “enlarged chamber” is not a term of art, the intrinsic record informs a skilled artisan of its meaning. The Court explained that “[e]ven when guidance is not provided in explicit definitional format, the specification may define claim terms by implication such that the meaning may be found in or ascertained by a reading of the patent documents.” In the context of the ’877 patent, “enlarged chamber” does not require a chamber that is larger than some baseline object; rather it describes a chamber large enough to accomplish a particular function. The Court construed “enlarged chamber” consistent with that determination and vacated the district court’s invalidity determination. Next, the Court considered the district court’s construction of the means-plus-function term. The Court held the district court correctly applied grammatical principles and correctly interpreted the intrinsic evidence to arrive at the proper construction of that term. Accordingly, the Court affirmed the portion of the district court’s judgment based thereon. The Court remanded the case for further proceedings.