The Federal Circuit Court of Appeals’ recent decision in Focus Products Group International, LLC v. Kartri Sales Co., Inc., No. 2023-1446 (Fed. Cir. Sept. 30, 2025) reversed summary judgment of infringement on two patents and vacated on a third. The Court held the district court erred in both claim construction and application of its infringement analysis by failing to properly find the patent file history disavowed subject matter relied upon to find infringement. The disavowal was critical because the claim language broadly covered the product’s configuration found to be infringing by the district court.
A patent’s claim scope can be narrowed only if the file history contains a “clean and unmistakable” disavowal that overcomes the heavy presumption that claim terms carry their full and ordinary meaning. In practice, that standard has been difficult to meet even when applicant’s arguments overcame prior art and examiner rejections. The accused device in Focus Products was a shower curtain ring with a flat upper edge (shown here). The Federal Circuit relied on several statements by the examiner that the application’s claims covered different species—one for a ring with projections and another for a ring with a “flat upper edge.” The patentee elected to withdraw claims covering a ring with a flat upper edge without objecting to the examiner’s definition. And in the Notice of Allowance, the examiner again stated that a “flat upper edge” fell outside the scope of the applicant’s election and invited the applicant to challenge that designation.
Related Attorneys
Related Articles
Related Capabilities
© 2026 Jenner & Block LLP. Attorney Advertising. Jenner & Block LLP is an Illinois Limited Liability Partnership including professional corporations. This publication, presentation, or event is not intended to provide legal advice but to provide information on legal matters and/or firm news of interest to our clients and colleagues. Readers or attendees should seek specific legal advice before taking any action with respect to matters mentioned in this publication or at this event. The attorney responsible for this communication is Brent E. Kidwell, Jenner & Block LLP, 353 N. Clark Street, Chicago, IL 60654-3456. Prior results do not guarantee a similar outcome. Jenner & Block London LLP, an affiliate of Jenner & Block LLP, is a limited liability partnership established under the laws of the State of Delaware, USA and is authorised and regulated by the Solicitors Regulation Authority with SRA number 615729. Information regarding the data we collect and the rights you have over your data can be found in our Privacy Notice. For further inquiries, please contact dataprotection@jenner.com.