Zoltek Corporation v. United States

Addressing written description and obviousness issues, the US Court of Appeals for the Federal Circuit reversed the US Court of Federal Claims (CFC), holding that the CFC erred in finding the claims invalid under 35 USC § 112 and § 103. Zoltek Corporation v. United States, Case No. 14-5082 (Fed. Cir., Feb. 19, 2016) (Newman, J).

This is the third appeal in this case, which began in 1996 when Zoltek filed suit against the United States in the CFC alleging that the process used to produce carbon fiber sheet materials for the B-2 Bomber and the F-22 Fighter Plane infringed Zoltek’s patent. In the first appeal, the Federal Circuit held that, pursuant to § 271(g), a patentee has no cause of action against the United States when any step of a patented method is practiced outside of the United States. Acting en banc, the Federal Circuit reversed its Zoltek I ruling, holding that § 1498(a) establishes liability of the United States for infringement resulting from acts that are performed with its authorization and consent(IP Update, Vol. 15, No. 4). On remand, the CFC found the patent at issue invalid for lack of written description under § 112 and obvious under § 103, resulting in the current appeal.

The patent at issue is a reissue patent directed to a method of manufacturing carbon fiber sheet products whose electrical resistivity is pre-selected and value-controlled by the described method. During the reissue proceedings, Zoltek removed one step of the claimed method directed to the preparation of the starting material. This broadening of claim scope, together with a purported lack of support for the broader claim in the original specification, formed the basis for the CFC’s finding that the patent at issue was invalid for lack of written description.

The Federal Circuit reversed, explaining that a broadening amendment is not improper when a reissue applicant “substitutes a preparatory step known to those skilled in the art at the time of the invention with a requirement to start with the product of that known preparatory step.” This rule is of course subject to the requirement that a broadening reissue be filed within two years of issuance.

With respect to obviousness, the patentee relied on a graph created by the inventor demonstrating the electrical resistivity properties of the carbon fiber sheets. In reaching its conclusion that the patent claims were obvious, the CFC relied heavily on the government’s expert witness, who recreated the inventor’s graph using a mathematical formula that he developed based on the teaching of a number of prior art references. The Federal Circuit explained that the government’s expert witness reached his conclusions based on data and resources that were not available at the time the patent was filed. According to the Federal Circuit, this “[h]indsight reconstruction for litigation ends is not of probative value.” The Federal Circuit then remanded the case back to the CFC to address infringement issues, which were bifurcated from the case based on the government’s invocation of state secret privilege. Thus the Zoltek saga continues.