DOE Not Limited By The Foreseeability Of Equivalents

In Ring & Pinion Service Inc. v. ARB Corp., No. 13-1238 (Fed. Cir. Feb. 19, 2014), the Federal Circuit held that application of the DOE is not limited by the foreseeability of equivalents, reversed the district court's grant of SJ of noninfringement based on claim vitiation, and remanded for the entry of judgment of infringement.

Ring & Pinion Service Inc. ("R&P") sought a DJ that its automotive locking differential product did not infringe ARB Corporation Ltd.'s ("ARB") U.S. Patent No. 5,591,098 ("the '098 patent"). After claim construction, the parties filed a joint stipulation regarding infringement. The parties agreed that R&P's product literally met all but one limitation of the asserted claims, the "cylinder means formed in . . ." limitation, but that the accused product contained an equivalent cylinder that would have been foreseeable to a person having ordinary skill in the art at the time the '098 patent was filed. Thus, according to the parties' stipulation, there were no issues of material fact regarding infringement under the DOE, and infringement depended solely on whether an equivalent is barred under the DOE because it was foreseeable at the time of the patent application.

The district court entered an order approving the parties' joint stipulation. And after requesting additional briefing to address the all-limitations rule, the district court held that foreseeability did not preclude application of the DOE, but that application of the DOE would vitiate the "cylinder means formed in . . ." limitation. Accordingly, the district court granted SJ of noninfringement for R&P. ARB appealed.

"There is not, nor has there ever been, a foreseeability limitation on the application of the doctrine of equivalents." Slip op. at 4. The Federal Circuit held that "[t]here is not, nor has there ever been, a foreseeability limitation on the application of the doctrine of equivalents." Slip op. at 4. Rather, the Court explained that excluding equivalents that were foreseeable at the time of patenting would conflict with long-established holdings that "known interchangeability weighs in favor of finding infringement under the doctrine of equivalents." Id.

The Court addressed the primary cases relied on by R&P to support a foreseeability bar to application of the DOE. The Court first rejected as misplaced R&P's reliance on Sage Products, Inc. v. Devon Industries, Inc., 126 F.3d 1420 (Fed. Cir. 1997), which, according to the Court, held that...