Tangential Equivalents: Recent Case Confirms There Is Life After Festo

On Oct. 4, 2004, the Federal Circuit rendered its opinion in <i>Insituform Techs., Inc. v. Cat Contracting, Inc.</i> ("<i>Insituform IV</i>"), 385 F.3d 1360 (Fed. Cir. 2004). This opinion is the first post-<i>Festo</i> Federal Circuit opinion that finds a successful rebuttal of the <i>Festo</i> presumption (<i>eg</i>, the presumption of the surrender of infringement under the doctrine of equivalents due to prosecution history estoppel) based on the "tangential relationship" prong of <i>Festo</i>. This case seems to set a fairly low bar for the rebuttal of the presumption. This is a significant development given the Federal Circuit's apparent desire to restrict the doctrine of equivalents (as reflected in its initial <i>Festo</i> ruling that was reversed by the Supreme Court, as well as by the tenor of the post-reversal <i>Festo</i> opinion).

25 minute readNovember 30, 2004 at 01:54 PM
By
Hope Melville
Donald E. Daybell
Tangential Equivalents: Recent Case Confirms There Is Life After Festo

On Oct. 4, 2004, the Federal Circuit rendered its opinion in Insituform Techs., Inc. v. Cat Contracting, Inc. (“Insituform IV“), 385 F.3d 1360 (Fed. Cir. 2004).

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