Print PDF

No Structural Equivalence

November 30, 2004

Decision icon Decision

Last Month at the Federal Circuit - November/December 2004

Judges: Rader (author), Friedman, and Dyk

In Frank’s Casing Crew & Rental Tools, Inc. v. Weatherford International, Inc., No. 03-1519 (Fed. Cir. Nov. 30, 2004), the Federal Circuit affirmed a district court’s decision of no infringement of U.S. Patent No. 5,049,020 (“the ‘020 patent”). The ‘020 patent concerns a system for handling sections of well casing suspended within a derrick during oil-field operations. Specifically, the ‘020 patent claims a system for making up a vertically extending string of interconnected casing sections comprising a derrick, bracket subassembly, and a boom and jaw subassembly. The boom and jaw subassembly includes a means for pivoting and elevating the boom.

The district court ruled that the structure corresponding to this claimed means included lift and boom plates disclosed in the specification. Plaintiff argued instead that the relevant corresponding structure is a piston and cylinder subassembly disclosed in the specification. According to the Federal Circuit, the only structure identified in the ‘020 patent for performing the pivoting function is the lift plate under the boom. Although the ‘020 patent also discloses a piston and cylinder subassembly, that subassembly, in connection with the lifting function, includes a connection to the lift plate. Moreover, according to the Federal Circuit, during prosecution history, the applicants had stated that the lifting cylinder could not be used when directly connected to the boom, underscoring the essentiality of the lift plate to the claimed function.

On the issue of infringement, the Federal Circuit concluded that although the accused product performed the same function recited in the claims, its structure for doing so was not insubstantially different from that in the ‘020 patent. Thus, the structure did not infringe under 35 U.S.C. § 112, ¶ 6. Moreover, because the lifting mechanism without a lift plate was in use before the filing of the patent, the Court did not find it necessary to conduct a separate analysis under the DOE.

The Court affirmed the district court’s decision denying attorney fees.