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Importation of Limitations from the Specification into Claims Is Improper

February 01, 2006

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Last Month at the Federal Circuit - March 2006

Judges: Clevenger, Rader (author), Dyk

In Varco, L.P. v. Pason Systems USA Corp., No. 05-1136 (Fed. Cir. Feb. 1, 2006), the Federal Circuit held that the district court abused its discretion in denying Varco, L.P.’s (“Varco”) motion for a preliminary injunction because it construed disputed claim terms too narrowly.

The only claim at issue, independent method claim 14 of Varco’s U.S. Patent No. 5,474,142 (“the ’142 patent”), claims the automatic regulation of the release of a drill string of a drilling rig. The ’142 patent describes using signals from up to four parameters to automatically control the release of the drill string. Before the automatic regulation begins, an operator manually sets a desired threshold value for each of the chosen parameters. When two parameters are selected to control the drilling operation, one parameter primarily controls, and the other controls only if the signal crosses the manually preset undesirable threshold to prevent conflicts in control.

In deciding Varco’s motion for a preliminary injunction, the district court construed two disputed claim terms. The district court relied on the specification and the applicant’s arguments in prosecution to construe the first disputed term, “selecting,” to require two manual steps by the operator of the drilling rig, and it relied on the preferred embodiment to construe the second disputed term, “relaying,” to require pneumatically operated valves. Because an operator of Pason Systems USA Corporation’s (“Pason”) accused device selects the controlling parameters via a computer screen interface and the device does not use pneumatic valves, the district court held that Varco had not shown a likelihood of success in proving infringement and denied Varco’s motion for a preliminary injunction.

On appeal, the Federal Circuit held that the district court erred in construing both disputed claim terms too narrowly. With regard to the district court’s construction that the “selecting” step is limited to manual operation, the Federal Circuit highlighted that the preamble indicates the opposite, stating that the method is for “automatically regulating” the drill release. The Court explained that the manual steps described in the specification, and relied upon by the district court, are precursors to, not a part of, the selected regulator’s automatic regulation. The Federal Circuit also relied on claim differentiation to demonstrate theerror in the district court’s construction. Moreover, the prosecution history confirms that the claimed “selecting” step is not directed to the manual setup or calibration. Thus, the district court erred in reading this limitation into the claim.

With regard to the district court’s construction of “relaying,” the Federal Circuit held that the district court erred in limiting the claim to the method in the preferred embodiment. While the preferred embodiment uses pneumatic valves to relay the signal, there is no such limitation in the claim. Moreover, the disclosure of valves that “operate as relays” implies that other things could also operate to relay the signal. The Federal Circuit also considered extrinsic evidence to support thebreadth of the term “relaying,” quoting Pason’s expert and counsel in admitting that the term is not limited to pneumatic valves.

Because the district court’s construction was unduly narrow, the Federal Circuit vacated and remanded for further proceedings, and instructed the district court to further consider whether DOE applied, particularly in view of after-arising technology.