Relying on Phillips methodology and an open transitional phrase, the U.S. Court of Appeals for the Federal Circuit vacated a summary judgment grant of non-infringement and set aside a finding of equivalents barring prosecution history estoppel. Free Motions Fitness, Inc. v. Cybex International, Inc. Case No. 05-1006 (Fed. Cir. Sept. 16, 2005) (Dyk, J.; Prost, J. dissenting).
Free Motions sued both Cybex and Nautilus for infringing its exercise machine patents. The exercise machine in issue included cables and pulleys that lift a weight stack. The claimed invention required that specified cables and extension arms pivot or swivel about a certain point. In the accused device, the arm and pivot assembly operated in a manner different from that as literally claimed. Based on this difference and a finding of prosecution history estoppel that barred the patent owner from relying on the doctrine of equivalents, the district court granted summary judgment of no infringement. Free Motions appealed.
In reversing the district court, the Federal Circuit relied on several canons of construction to modify the district court’s claim construction. First, the Federal Circuit held the district court erred in construing the claimed "first" and "second" pivot points as requiring specific spatial locations relative to the extension arms. Instead, the Federal Circuit ruled that "first" and "second" are merely used to distinguish between repeated recitations of an element.
Next the Court took issue with the interpretation of the claim term "adjacent." After concluding that the intrinsic evidence did not suggest a special definition for "adjacent" and that the term does not have a specialized meaning in the relevant art, the Court resorted to a dictionary definition. Under Phillips, where reference to a dictionary is necessary, the "task is to scrutinize the intrinsic evidence in order to determine the most appropriate definition," not its broadest dictionary definition or its aggregate of multiple dictionary definitions. Nonetheless, the Court here construed "adjacent" broadly to simply mean "not distant," rather than adopt the narrow and more common usage of "relatively near and having nothing of the same kind intervening."
Also, the defendant argued the claimed phrase "a cable" should be limited to "a single cable" because that was the only embodiment described in the specification. However, the Federal Circuit rejected this argument, noting that "a" or "an" conventionally means "one or more" in claims containing an open-ended transitional phrase such as "comprising" and explained this convention is only overcome by evidence of "a clear intent by the patentee to limit the article to the singular."
Relying in part on claims differentiation, the Federal Circuit found the references to a single cable were only a description of the preferred embodiment and did not "evince a clear intent to limit the article [cable] to the singular."
The Federal Circuit also set aside the district court’s finding of prosecution history estoppel. During prosecution, the patentee amended a claim to define over prior art by reciting a relationship between an axis of rotation and another axis and argued the claimed assembly "provides for virtually no variation in cable tension," whereas the prior art contained cables with tension variations. The district court concluded that Free Motion was estopped from asserting equivalence against an infringing device that also had the undesirable cable tension variation. Despite that record, the Court found no estoppel:
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