Federal Circuit Expands Reach of Doctrine of Equivalents

In a recent decision, the Federal Circuit expanded the scope of protection of existing patents. The courts have long held that patent claims cover not only their literal scope of protection but future unforeseeable developments as well, provided the future developments are considered equivalent. On Wednesday, the Federal Circuit confirmed that the Doctrine of Equivalents can also cover technology that was foreseeable at the time the patent was filed, even if the foreseeable technology was not mentioned in the patent application. Ring & Pinion Service Inc. v. ARB Corp. Ltd., No. 2013-1238 (Fed. Cir. Feb. 19, 2014).

Patent owners should be aware, however, of continuing limitations on the Doctrine of Equivalents. For example, a patent owner's claim amendments during patent prosecution may create an absolute bar to equivalent infringement for foreseeable substitutes. In addition, foreseeable substitutes that are disclosed in the specification, but not claimed, may be dedicated to the public.

Because of the complexity of the issues surrounding the Doctrine of Equivalents, it is important for both patent owners and accused infringers to contact knowledgeable patent counsel when making strategic decisions about patent coverage and freedom-to-operate. We are available to assist with these issues.