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Atlas Powder Co. v. IRECO Inc. - 190 F.3d 1342 (Fed. Cir. 1999)


To invalidate a patent by anticipation, a prior art reference normally needs to disclose each and every limitation of the claim. However, a prior art reference may anticipate when the claim limitation or limitations not expressly found in that reference are nonetheless inherent in it. Under the principles of inherency, if the prior art necessarily functions in accordance with, or includes, the claimed limitations, it anticipates. Inherency is not necessarily coterminous with the knowledge of those of ordinary skill in the art.


Plaintiff Atlas Powder Company, the holder of the Clay patent, sued defendant IRECO Incorporated for alleged infringement of the Clay patent. During the course of litigation, Dr. Robert Clay, the inventor filed a reissue petition with the United States Patent and trademark Office (PTO). Altas moved to stay the litigation pending resolution of the reissue application. The district court denied the motion and conducted a first bench trial on the issues of validity and infringement of the Clay patent in October 1986. Dr. Clay then requested suspension of prosecution of the reissue application by the PTO in February 1987. In 1992, the district court found that the Clay patent was invalid as anticipated by either one of two prior art references, Egly or Butterworth. The Clay patent and its reissue both claimed composite explosives made from the combination of a particular blasting composition and an unsensitized water-in-oil emulsion. Egly and Butterworth also contained the same composition. The only element, which was arguably not present in the prior art compositions, was the requirement that "sufficient aeration be entrapped to enhance sensitivity to a substantial degree." Appellant Hanex Products, as successor patent licensee, challenged the determination of invalidity of original and reissue patents as anticipated by two other patents.


Was the Clay patent invalid for containing identical compositions of prior art issued to two other companies?




The United States Court of Appeals for the Federal Circuit affirmed the district court's finding of invalidity with respect to claims 1, 2, 3, 10, 12, 13, and 14 of the Clay patent and the Clay reissue patent. According to the Court, when a patent claimed a chemical composition in terms of ranges of elements, any single prior art reference that fell within each of the ranges anticipated the claim. The Court also noted that elementary principle of patent law, i.e., that when, as by a recitation of ranges or otherwise, a claim covered several compositions, the claim was "anticipated" if one of them was in the prior art. In chemical compounds, a single prior art species within the patent's claimed genus read on the generic claim and was anticipated. In the case at bar, the Court determined that the district court correctly interpreted the claims and applied the law of anticipation. There was also no clear error in factual determination that prior art inherently possessed sufficient aeration to enhance sensitivity to substantial degree within the overlapping ranges.

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