The U.S. Court of Appeals for the Federal Circuit vacated and remanded a claim construction determination, finding that the district court improperly imported limitations from the specifications into the claims of two similar patents. Judge Lourie concurred in part and dissented in part, finding that the district court improperly imported a limitation from the specification into the claims of only one of the two patents at issue. Arlington Indus., Inc. v. Bridgeport Fittings, Inc., Case No. 10-1025 (Fed. Cir., Jan. 20, 2011) (Rader, C. J.) (Lourie, J., concurring in part and dissenting in part).

The appeal arose out of a lawsuit between Arlington Industries and Bridgeport Fittings in which the district court construed the terms “spring metal adaptor” in one of Arlington’s patent and “spring steel adaptor” in another of Arlington’s patent as both requiring a longitude “split” in the claimed electrical cable calorie, i.e., allowing the collar to expand and contract. Both patents are directed to a metal collar, or “adaptor,” that surrounds the end of an electrical cable and permits the cable to be snapped into an electrical junction box. The district court held that a split in the metal collar was necessary to allow the diameter of the collar to easily expand or contract as required by the “spring” language.

Writing for the majority, Chief Judge Rader disagreed with the district court’s result and the “failure” of the district court to adapt its construction from one of Arlington’s patent for terms used in others. The majority opinion held that the term “spring” in the term “spring metal adaptor”) was not a functional limitation to the extent it required the metal adaptor to spring—i.e., expand or contract. Rather, the term “spring” referred to the type of “metal” or “steel” to be used. Upon further review of the intrinsic claim construction evidence specifically for the specific patents in which the claim terms in issue were found, the Court construed the terms “spring metal adaptor” and “spring steel adaptor” as not requiring a collar that has a “split.”

Judge Lourie, in dissent, criticized the majority’s construction of “spring metal adaptor” in light of the specification of the first Arlington patent (claiming the “spring metal adaptor”). He argued that the specification is “the heart of the patent” and discloses what the inventors actually contemplated as their invention at the time of filing their patent. Rather than “follow our muddy, conflicting and over formulistic rules,” Judge Lourie would simply use the specification to determine “what the inventors intended when they used the language they did.” Furthermore, Judge Lourie suggested that the majority’s under-appreciation of the specification permits the patent to be “used as a business weapon” in an “attempt to fit … into the claim language what the inventors never contemplated as part of their invention.” Therefore, the “claims should not mean more than what the specification indicates.”

Applying this rationale, Judge Lourie’s concluded that the “spring metal adaptor” required a “split” in the collar.