Steuben Foods, Inc. v. Shibuya Hoppman Corp., Appeal No. 2023-1790 (Fed. Cir. Jan. 24, 2025)

In its only precedential patent decision this week, the Federal Circuit addressed an “anachronistic exception, long mentioned but rarely applied” in the field of patents: the “reverse doctrine of equivalents.” This marks the first time the doctrine has appeared in Federal Circuit precedent in more than 15 years. As the Court noted, it had “never affirmed a decision finding noninfringement based on the reverse doctrine of equivalents.” This case provided no exception.

The patents at issue concerned systems for aseptic packaging of food products. An improvement over the prior art concerned a “second sterile region positioned proximate” to a “first sterile region,” which surrounded a region where the food product exited a valve. This “second sterile region” allegedly solved a problem with potential contamination.

Steuben filed suit against Shibuya, alleging its aseptic bottling line infringed three of Steuben’s patents. At summary judgment, Shibuya argued that its system did not have a “second sterile region,” and that there were material factual disputes concerning application of the reverse doctrine of equivalents.  The district court found literal infringement, but also found that trial was warranted on Shibuya’s reverse doctrine of equivalents theory. At trial, the jury found Shibuya had infringed, but the district court granted JMOL of no infringement. The district court found that Shibuya had presented a prima facie case of establishing it had not infringed under the reverse doctrine of equivalents, and that the rebuttal testimony of Steuben’s expert was wrong as a matter of law and entitled to no weight. Steuben appealed, arguing that the reverse doctrine of equivalents is not a viable defense to infringement, and that the district court had otherwise erred in overturning the jury’s verdict of infringement.

The Federal Circuit started by discussing the background of the reverse doctrine of equivalents. The doctrine derives from a case from the late 1800s, Boyden Power-Brake Co. v. Westinghouse, 170 U.S. 537, 568 (1898), in which the Supreme Court had stated:

We have repeatedly held that a charge of infringement is sometimes made out, though the letter of the claims be avoided. The converse is equally true. The patentee may bring the defendant within the letter of his claims, but if the latter has so far changed the principle of the device that the claims of the patent, literally construed, have ceased to represent his actual invention, he is as little subject to be adjudged an infringer as one who has violated the letter of a statute has to be convicted, when he has done nothing in conflict with its spirit and intent.

The Supreme Court made a similar statement in Graver Tank & Mfg. Co., Inc. v. Linde Air Products Co., 339 U.S. 605, 608–9 (1950), in which they commented:

[The doctrine of equivalents] is not always applied in favor of a patentee but is sometimes used against him. Thus, where a device is so far changed in principle from a patented article that it performs the same or a similar function in a substantially different way, but nevertheless falls within the literal words of the claim, the doctrine of equivalents may be used to restrict the claim and defeat the patentee’s action for infringement.

However, the doctrine had rarely surfaced in the ensuing years, and the Federal Circuit has never affirmed a decision that found infringement based on it. Steuben argued that the reverse doctrine of equivalents had been preempted by the Patent Act of 1952, contending that it conflicts with 35 U.S.C. § 271(a) and had been subsumed in 35 U.S.C. § 112 when Congress enacted the 1952 act.

The Federal Circuit found these arguments “compelling,” but ultimately concluded that it “need not decide” the issue, because the jury had substantial evidence to find infringement notwithstanding the doctrine. The Court instead held that the district court erred by overturning the jury verdict because the testimony of Steuben’s expert had provided sufficient evidence for the jury to resolve the issue of infringement in Steuben’s favor. A determination of whether the reverse doctrine of infringement survives will have to wait for another day.

The Court also affirmed findings with respect to two other patents. With respect to one, the Court applied the doctrine of vitiation to a claim term construed under Section 112(f), and ruled that a patent requiring a sterilant to be added “intermittently” could not be satisfied by a system that adds the sterilant “continuously.”

The Federal Circuit remanded the case to the district court with respect to JMOL decisions on validity and damages that were insufficiently reasoned. The opinion can be found here.

By Nika Aldrich

This article summarizes aspects of the law. This article does not constitute legal advice. For legal advice regarding your situation, you should contact an attorney.