The US Court of Appeals for the Federal Circuit remanded a district court’s claim construction and grant of a defendant’s summary judgment motion of non-infringement under the doctrine of equivalents, finding that a reasonable juror could find that the accused products performed substantially the same function in substantially the same way to achieve substantially the same result as the claimed invention. Edgewell Personal Care Brands, LLC v. Munchkin, Inc., Case No. 20-1203 (Fed. Cir. Mar. 9, 2021) (Moore, J.)

Edgewell manufactures and sells the “Diaper Genie,” a diaper pail system with a replaceable cassette placed inside the pail for soiled diaper collection, forming a wrapper around the diapers. Munchkin marketed a refill cassette as compatible with Edgewell’s pails. Edgewell’s two patents at issue relate to improvements in the cassette. After claim construction, Edgewell asserted literal infringement of one patent and infringement under the doctrine of equivalents of the other patent. The district court granted Munchkin’s summary judgment motion of non-infringement against both patents. Edgewell appealed.

Edgewell’s first patent is directed to a cassette with a clearance at its bottom portion. The claim construction dispute turned on whether the claims required a clearance space after the cassette was installed. The district court construed the claim to require a space and to require that the claimed “clearance” cannot be filled by an unclaimed interfering member. The district court granted Munchkin summary judgment because Munchkin’s refill cassette had no space after the cassette was installed. The Federal Circuit reversed, explaining that an “apparatus claim is generally to be construed according to what the apparatus is, not what the apparatus does.” The Court found that without an express limitation, “clearance” should be construed to cover all uses of the claimed cassette. The Court determined that the specification and purpose of the “clearance” supported the notion that the claim does not require a clearance after insertion.

The second patent is directed to a cassette with a cover that includes a “tear-off” section. The district court’s construction of an annular cover was of a single, ring-shaped cover. Munchkin’s cassettes each include a two-part cover, and the district court granted Munchkin’s motion for summary judgment of non-infringement. Although the Federal Circuit agreed with the claim constructions, the Court found that the district court erred in granting summary judgment to Munchkin under the doctrine of equivalents for claim element vitiation on the basis that “annular cover” and “tear-off” limitations §§would be rendered meaningless.

The vitiation doctrine ensures that applying the doctrine of equivalents “does not effectively eliminate a claim element in its entirety.” The Federal Circuit found that the district court erred in evaluating this element as a binary choice—single-component structure versus a multi-component structure. Instead, the Court explained that the district court should have evaluated the evidence to determine whether a reasonable juror could find that the accused products perform substantially the same function, in substantially the same way, achieving substantially the same result as the corresponding claim elements. Edgewell’s expert opined that Munchkin’s products performed the same function in the same way to achieve the same result as the claimed annular cover. Edgewell also presented Munchkin employee deposition testimony to support its expert’s opinions. The Court found this sufficient to create a genuine issue of material fact for the jury to resolve.