Biagro v. Grow More (Fed. Cir. 2005).
Claim Construction: In a step-back from recent claim construction holdings, the Court of Appeals for the Federal Circuit held that an “attorney’s statements” made during prosecution “do not alter the ordinary meaning of the claim language.”
Biagro’s patents relate to a phosphorus-based fertilizer for plants. Representative claim 1 requires a “phosphorous-containing acid or salt . . . in an amount of about 30 to about 40 weight percent.”
Grow More’s product contains phosphorous, but the final product does not contain any phosphorous acid (although it is created using phosphorous acids). Biagro argued that the claims should be interpreted as requiring the “chemical equivalent” rather than actually requiring an acid in the final product. Biagro also pointed to the prosecution history where the attorney had pointed to the phosphorous acid in two examples — when in fact those examples only included chemical equivalent amounts of phosphorous acid. The CAFC found Biagro’s arguments unappealing and affirmed the district court’s construction and dismissal.
Doctrine of Equivalents: Biagro had amended the claims during prosecution to include the “phosphorous acid,” but contended that Festo should not apply. The CAFC disagreed:
Burden: Even at summary judgment, the patentee has the burden of showing that it can overcome the Festo presumption associated with a narrowing amendment.
Reason for the Amendment Merely Tangential: A narrowing amendment made when were claims were rejected but done without any discernible reason is presumed to be made for a patentable reason, and not for a reason merely tangential to the equivalent.
The prosecution history revealed no reason for the amendment, and therefore Festo could not show that the rationale underlying the amendment was only tangential to the accused nonmagnetizable equivalent. Similarly, in this case, since the prosecution history shows no reason for adding an upper limit to the concentration range, Biagro cannot claim that the rationale for the amendment is merely tangential.
Other Reason: The court rejected the Biagro’s reasoning that the patentee had believed the claims meant “chemical equivalent” when, in fact, they did not.
Summary judgment of noninfringement affirmed.