Brief Fact Summary. Wilson (Plaintiff) won an infringement suit regarding the design patent on its golf balls, and Dunlop (Defendant) and David Geoffrey & Associates (Defendant) appealed.
Synopsis of Rule of Law. There can be no infringement if the scope of equivalency necessary to find infringement would cover prior art.
Issue. Can there be infringement if the scope of equivalency necessary to find infringement would cover prior art?
Held. (Rich, J.)Â No.Â There can be no infringement if the scope of equivalency necessary to find infringement would cover prior art.Â Prior art limits what an inventor could have claimed, and therefore it limits the possible range of allowed equivalents of a claim.Â To simplify analysis, imagine a hypothetical patent that literally covers the accused product.Â The question then becomes whether the Patent and Trademark Office would have permitted the hypothetical patent over the prior art.Â The patent owner, or Plaintiff, bears the burden of proving the range of equivalents it seeks would not capture the prior art.Â Given the Uniroyal prior art, the hypothetical claim, similar to Plaintiff’s Claim 1 but enough to cover the Dunlop (Defendant) balls, would not have been patentable.Â Though the dependent claims must be examined separately, neither are they infringed.Â Reversed.
Discussion. As a result of Wilson, the burden was clearly put on both patentees to create and prove the validity of the hypothetical claim.Â This resulted in widespread criticism, and the Federal Circuit in Key Manufacturing Group, Inc. v. Microdot, Inc., 925 F.2d 1444, 17 U.S.P.Q.2d 1806 (Fed. Cir. 1991), pointed out the hypothetical claim analysis was not “obligatory” in the determination of every doctrine of equivalents.Â The Wilson court had actually only characterized the hypothetical claim analysis as “helpful,” not necessary