The U.S. Court of Appeals for the Federal Circuit reversed and remanded an order denying a preliminary injunction because the district court’s unduly restrictive claim interpretation led directly to the denial of the preliminary injunction. Varco, L.P. v. Pason Systems USA Corp., Case No. 05-1136 (Fed. Cir. Feb. 1, 2006) (Rader, J.).
The patent at issue was directed to the system and method for automatically regulating the release of a drill string on a drilling rig in response to a combination of four parameters. The claim construction dispute focused on a "selecting" step and a "relaying" step. The district court interpreted "selecting" to require "manual operation of valve selectors and manual calibration of regulators" and interpreted "relaying" to mean "transmitting a signal by means of pneumatically operated valves." In arriving at these constructions, the district court relied heavily on the specification and prosecution history. Varco appealed and argued the district court improperly narrowed the claims by importing limitations from the specification.
The Federal Circuit agreed and held the district court impermissibly imported limitations into the claims resulting in an unduly narrow claim construction. The Court explained that claim terms are generally given their ordinary and customary meaning, and the inquiry into how a person of ordinary skill in the art understands a claim term provides an objective baseline from which to begin claim interpretation.
Focusing on the claim language, the Court found the "selecting" step was not limited to manual operations. On the contrary, other claims expressly stated that selection was performed automatically, and the specification and prosecution history clearly indicated that manual operations related to calibration prior to automatic selection. As to the "relaying" step, the Court found that although the preferred embodiment used pneumatic valves operating as relays, it would be improper to use the preferred embodiment to limit the claim as nothing in the claim itself required the use of pneumatically operated valves to perform the "relaying" step.
On remand the Court stated the district court may consider the proper interpretation of the disputed claim, validity challenges to the disputed claim and infringement of the disputed claim by the defendant’s system. Further, because the case appears to present an instance of after-arising technology, the Court noted that the district court may find it appropriate to consider infringement under the doctrine of equivalents.
Practice Note
Although Phillips re-emphasized the importance of the specification for construing claims, noting that the specification is often the single most important claim construction tool, caution must still be taken to avoid importing limitations from the specification into the claims.
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