Abolishing the Doctrine of Equivalents and Claiming the Future after Festo

51 Pages Posted: 6 Sep 2004


This article argues that the Supreme Court or Congress should abolish from patent law the modern doctrine of equivalents articulated in Graver Tank & Manufacturing Co. v. Linde Air Products Co., 339 U.S. 605 (1950), and extended to later-arising technological equivalents in 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 modern doctrine of equivalents lacks theoretical justification, imposes high costs on society and likely impedes innovation, and needlessly conflicts with other patent law doctrines and complicates patent law procedures. These adverse effects are cumulatively imposed over time in regard to every issued and litigated patent for its entire term. The doctrine of equivalents should be restored to its historic form, limiting patent protection to the scope of application of the construed language of patent claims. Any residual fairness concerns would be addressed better by non-literally interpreting claim language than by applying the modern doctrine. The Supreme Court or Congress also may need to impose additional limits on the ability to claim later-arising technologies, in order for patent law to serve its Constitutional purpose of promoting progress.

This article is the third in a series of articles relating to the doctrine of equivalents. These articles seek to encourage and to set the context for future discussions of abolishing the modern doctrine of equivalents and of claiming later-arising technologies. The first article, to be published in the Federal Circuit Bar Journal, describes conflicts among the modern doctrine and prosecution history estoppel and additional implied disclaimer and claim scope doctrines. It explains how the modern doctrine improperly extends patent protection to equivalents that could not validly be claimed. The second article, to be published in two parts in the Journal of the Patent and Trademark Office Society, discusses the historic doctrine of equivalents, the Supreme Court's radical reshaping of the doctrine in Graver Tank, and historic limits on claiming later-arising technologies. The second article explains how the modern doctrine of equivalents conflicts with the requirement for distinct claims adopted in the 1870 Patent Act, was adopted by the Supreme Court without statutory support, and was neither codified nor impliedly ratified by Congress in the 1952 Patent Act.

Keywords: Patents, doctrine of equivalents, claim scope, later-arising technology, fairness and efficiency

JEL Classification: K39, K41, L43, O31, O34

Suggested Citation

Sarnoff, Joshua D., Abolishing the Doctrine of Equivalents and Claiming the Future after Festo. Available at SSRN: https://ssrn.com/abstract=586101

Joshua D. Sarnoff (Contact Author)

DePaul University College of Law ( email )

25 E. Jackson Blvd.
Chicago, IL Cook County 60604-2287
United States
312-362-6326 (Phone)

Do you have a job opening that you would like to promote on SSRN?

Paper statistics

Abstract Views
PlumX Metrics