The U.S. Court of
Appeals for the Federal Circuit recently reiterated the rule of Warner-Jenkinson,
that the doctrine of equivalents will not be applied so broadly as to wholly
eliminate a limitation recited in a claim. Cooper Cameron Corp. v. Kvaerner
Oilfield Products Corp., Nos. D1-1383, -1408 (Fed. Cir. May 14, 2002).
Cooper owns patents
related to subsea wellheads that protect the well during maintenance and
repair. The claim at issue recites, "[a] wellhead comprising Ö a workover
port extending laterally through the wall of the spool tree from between the
two plugs" (emphasis added). The accused device had a workover port
placed above the two plugs. Cooper claimed infringement of its patent
under the doctrine of equivalents.
The Federal Circuit
affirmed the district court's grant of summary judgment, holding that the
defendant's workover port enters the wellhead assembly "above" the
two plugs, which "cannot be equivalent to a connection 'between the two
plugs.'" The Court rejected Cooper's argument that the location of the
workover port was irrelevant to its operation and thus was not an essential
element to the claim, reasoning that to ignore Cooper's decision to include
"between" as a limitation in...