Intellectual Property Law

Estoppel applies to all added limitations in claims, including when present in unamended claims

By McKee, Voorhees & Sease, P.L.C.

In a decision Friday, the Federal Circuit affirmed a district court's grant of summary of no literal infringement and that prosecution history estoppel barred application of the doctrine of equivalents.  During prosecution of the patent, a total of three limitations from two different dependent claims were added to the asserted claim in separate amendments, although only two of the limitations were addressed by the applicant and examiner.  The district court held the third element was not literally present in the accused product, and, based on the amendment, could not be present under the doctrine of equivalents.

The Federal Circuit agreed.  The court held it was immaterial that the first amendment (with the "extra" limitation at issue) did not result in allowance; the estoppel applied to each of the added limitations.  Importantly, the court also observed that this presumption of estoppel applied to all claims of the patent containing the limitation, whether or not they were amended:

Thus, in this case, the cancellation of original independent claim 1 coupled with the rewriting of original dependent claim 7 as independent claim 14 gave rise to a presumption of surrender applicable to all limitations, found in any of the claims of the '625 patent, that correspond to the limitations of claim 7.

The court also held that even though the third limitation was not specifically argued, its addition was not tangential to the rationale underlying the amendment, thereby preventing application of prosecution history estoppel.  Specifically, the amendment stated one of the two limitations was not present in the prior art, but added the limitation was not present "in combination with the other structure" of the claims.  This additional language brought the additional limitation into the argument, making it not tangential.  Further, the court held the absence of explanation why the additional limitation was added meant it could not be tangential, because whether an amendment is tangential must be determined from the prosecution record.  Accordingly, the court affirmed the district court's grant of summary judgment of noninfringement.

More detail of Felix v. Am. Honda Motor Co. after the jump.

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Full post as published by FileWrapper on April 15, 2009 (boomark / email).