Festo On Remand
On remand from the Supreme Court on the issue of whether Festo can rebut the presumption of having surrendered all subject matter between the original claim limitations and the amended claim limitations by filing narrowing amendments for the two patents in suit, the federal circuit in Festo Corp. v. Shokestsu Kinzoku Kogyo Kabushiki Co., 344 F.3d 1359 (Fed. Cir. 2003), concluded that Festo had failed to demonstrate two of the three rebuttal criteria, namely that the rationale underlying the narrowing “magnetizable” and “sealing ring” amendments “bore no more than a tangential relation to the equivalent in question,” and that the amendments were made for “some other reason such that the patentee could not reasonably have been expected to have described the alleged equivalent.” The federal circuit, however, remanded to the district court the remaining rebuttal criterion of whether “the alleged equivalent would have been foreseeable at the time of the narrowing amendment.” The court also concluded that the rebuttal of presumption of surrender was a question of law to be determined by the court, not a jury, since prosecution history estoppel is a matter of law and questions relating to the application and scope of prosecution history estoppel should therefore also be determined by the court.
In applying the three rebuttal criteria to the patents in suit, the federal circuit refused to provide a list of factors encompassed by each of the rebuttal criterion, stating instead that the factors should be addressed as they arise on a case-by-case basis. The federal circuit nevertheless provided some general guidance. The federal circuit stated that a court must, in general, limit its determination of the rebuttal criteria to the prosecution history record. A court may, however, consider extrinsic evidence, including expert testimony, in addressing the first rebuttal criterion--foreseeability of the alleged equivalent-- and may hear expert testimony interpreting the record in order to evaluate the second criterion-- tangential relatedness to the equivalent. Emphasizing that the third criterion of “some other reason” must be interpreted narrowly and its determination, when possible, should be limited to the record, the federal circuit nonetheless chose not to decide what extrinsic evidence may be considered in evaluating the third rebuttal criterion.
Applying these guidelines to the patents in suit, the federal circuit remanded the first rebuttal criterion to the district court noting that factual issues existed as to whether a person of ordinary skill in the art would have considered an aluminum sleeve to be an unforeseeable equivalent to a “magnetizable” sleeve or a two-way sealing rings to be an unforeseeable equivalent of the accused pair of sealing rings. As to the second criterion, the federal circuit concluded that by not providing a reason for the amendment Festo had failed to show that “magnetizable” amendment was only tangentially related to aluminum sleeve. The federal circuit also determined that Festo could not establish the tangential relatedness of the “sealing ring” amendments to the accused pair of sealing rings since it made the “sealing ring” amendments to distinguish prior art. Regarding the third criterion, the federal circuit determined that there was no linguistic or “other” limitation to describing an aluminum sleeve or a pair of sealing rings. According to the federal circuit, aluminum could have been described as “aluminum” or even “metal” and a pair of sealing rings would be encompassed by a description of “at least one sealing ring.” Concurring with the majority decision, Judge Rader nevertheless cautioned that bringing more certainty to the doctrine of equivalents may cause more uncertainty in the form of unintended consequences, particularly given the rapidity of doctrinal changes. Judge Rader, nonetheless, strongly endorsed the foreseeability principle stating that such a principle is likely to ease the “pace and uncertainties inherent in transition to new rules.”
Dissenting Judges Newman and Mayer questioned the majority’s adjudication of the second and third rebuttal criterion as questions of law, stating that all three rebuttal criteria raise factual questions and as matters of first impression require “full and fair exploration of issues with the benefit of the procedures of trial.”