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The Doctrine Of Equivalents And Claiming The Future After Festo, Joshua Sarnoff

College of Law Faculty

In two recent cases, Warner-Jenkinson Co. v. Hilton Davis Chemical Co., 520 U.S. 17 (1997), and Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 535 U.S. 722 (2002), the Supreme Court unanimously approved of the modern doctrine of equivalents articulated in Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605 (1950). The Court also extended equivalents protection to later-arising technologies and imperfectly reconciled the modern doctrine with the doctrine of prosecution history estoppel for amended claims. The Court's new doctrine conflicts with historic implied-disclaimer standards. The U.S. Court of Appeals for the Federal Circuit has further …