In a lawsuit involving the alleged infringement of an Exmark patent that described a lawn mower with improved flow-control baffles, a federal district court erroneously based its summary judgment finding of no invalidity solely on the fact that the patent claim at issue had survived multiple reexaminations, the U.S. Court of Appeals for the Federal Circuit has ruled. In addition, the district court erred in denying defendant Briggs & Stratton a new trial on damages. Because a damages expert failed to support her proposed five-percent royalty rate with an adequate explanation of how she had arrived at that rate, her testimony was inadmissible. Finally, the district court abused its discretion by limiting the evidence for damages to “commercialized” prior art, and by excluding from the willfulness trial evidence related to patent validity. The lower court’s findings on indefiniteness and laches were affirmed, however, so the judgment of the district court was affirmed in part, vacated in part, and remanded for further proceedings (Exmark Manufacturing Company, Inc. v. Briggs & Stratton Power Products Group, LLC, January 12, 2018, Stoll, K.).
A full summary of this case has been published on Kluwer IP Law.