In Ring & Pinion Service Inc. v. ARB Corp., Appeal 13-1238, the Federal Circuit reversed summary judgment of non-infringement and remanded with instructions to grant summary judgment of infringement.

R&P sued for a declaratory judgment of non-infringement of a patent owned by ARB. The parties stipulated that the accused product literally met every limitation of the representative claim except for a “cylinder” limitation. The parties further stipulated that the accused product included an “equivalent” cylinder. The parties cross-moved for summary judgment and stipulated that the outcome of the case would be determined by the resolution of a single legal issue: whether an equivalent is barred under the doctrine of equivalents because it was foreseeable at the time of the patent application. The district court held that, while foreseeability does not preclude the application of the doctrine of equivalents, a finding of infringement under the doctrine of equivalents would vitiate the “cylinder” limitation. The district court granted summary judgment of non-infringement to R&P. ARB appealed.

The Federal Circuit reversed, holding that the district court committed legal error because claim vitiation is not an exception to the doctrine of equivalents. Further, the parties’ stipulation precluded a finding of claim vitiation because it states that the accused product includes an equivalent to the “cylinder” limitation. The Federal Circuit agreed with the district court that foreseeability does not bar the doctrine of equivalents and held that this conclusion should have resulted in a judgment of infringement pursuant to the stipulation.