In yet another visit with this now famous doctrine of equivalents case, the U.S. Court of Appeals for the Federal Circuit held that the disclosure-dedication rule, which limits the application of the doctrine so as not to cover disclosed but unclaimed subject matter, has no intent element. The Court also found the level of disclosure necessary to dedicate an unclaimed feature to the public is different from (and less than) that necessary to support a proposed claim construction. Toro Co. v. White Consol. Indust. Inc., Case No. 03-1424 (Fed. Cir. Sept. 13, 2004) (Linn, J) (Toro III).

Toro is owner of the U.S. patent No. 4,694,528 (the `528 patent) directed to a convertible vacuum-blower. The asserted claim recites a "cover including means for increasing pressure." The "means for increasing pressure" allows the claimed device to perform both vacuum and blower functions. When the "means" is in place it increases pressure and, thus, blower power. With the "means" detached, air moves freely through the impeller housing, thereby increasing vacuum strength.

In the first appeal in this saga, Toro I, the Federal Circuit construed a claim term "including means for increasing pressure" as not implicating the means-plus-function language of § 112, 6 and as being limited to a restriction ring permanently affixed to and included as part of the cover. White’s accused vacuum-blower had a restriction ring that was separate from the cover. Based on its claim construction and the undisputed facts of the case, the Toro I panel reversed the district court’s grant of summary judgment of literal infringement and remanded for further proceedings on the issue of infringement under the doctrine of equivalents.

After a second appeal and remand to the district court, the district court held that infringement under the doctrine of equivalents was precluded because a two-piece cover and restriction ring assembly was disclosed in the patent specification but not claimed. In the present appeal, Toro argued that the disclosure dedication rule did not apply because Toro did not intentionally fail to claim the unclaimed subject matter. Relying on language from Johnson & Johnson, the Federal Circuit affirmed the district court, holding intent is not an element of the disclosure-dedication rule.

Toro also argued that the disclosure of the unclaimed subject matter was insufficient to support a claim to the unclaimed feature under § 112, ¶1. On this issue, the Court reasoned that the level of disclosure necessary to narrow application of the doctrine of equivalents is different (and lower) than the level of disclosure necessary to support a claim to the same feature. In particular the Court noted that the disclosure necessary to implicate the disclosure-dedication rule could relate to any subject matter included within the specification, including the background of the invention.

Finally, Toro argued the district court’s application of the disclosure-dedication rule was in conflict with the Federal Circuit holding in Toro I illustrating the `528 patent neither illustrated nor described any structure other than a cover with an attached ring. In other words Toro argued that if White’s structure was disclosed (for purposes of the disclosure-dedication rule), the construction of the term "including…" should be broadened. The Toro III panel disagreed finding the previous claim construction did not result in any law of the case relating to the disclosure-dedication rule, as the issue was before neither the district nor the Federal Circuit in Toro I, nor was the issue of whether the disclosure needed to support a claim (under §112 ¶1) is different from that needed to trigger the disclosure-dedication rule.

Practice Note: The instant case demonstrates that even an apparently innocuous description of the advantages of the invention can have a drastic effect on the application of doctrine of equivalents. While much attention has been focused on the conduct of prosecution due to the Festo line of cases, it should be apparent from the Toro III case that a prosecutor’s diligence in safeguarding the potential scope equivalents begins at the stage of writing the patent application and being certain the claim "exhausts" the written description of the invention. As the Toro III decision makes clear, even the barest of disclosure can result in forfeiture of future equivalents.

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