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Claims to Turbine Engine Blade Superalloy Found to Be Obvious

May 25, 2005

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Last Month at the Federal Circuit - June 2005

Judges: Rader (author), Clevenger, and Friedman

In In re Harris, No. 04-1370 (Fed. Cir. May 25, 2005), the Federal Circuit affirmed the Board's conclusion of obviousness for an application claiming a nickel-based superalloy for turbine engine blades. U.S. Patent Application No. 09/797,326 ("the '326 application") discloses an embodiment of the claimed alloy CMSX®-486. The PTO rejected the claims as being prima facie obvious in view of U.S. Patent No. 5,069,873 ("the '873 patent") or U.S. Patent No. 5,611,670 ("the '670 patent"). The PTO made a prima facie case of obviousness because the ranges of the claimed composition overlapped the ranges disclosed in the prior art.

The Federal Circuit noted that claimed ranges must produce a new and unexpected result that is different in kind and not merely in degree from results of the prior art. Concluding that an increase in stress-rupture life did not represent any difference in kind sufficient to show unexpected results, the Federal Circuit affirmed the Board's finding of a prima facie case of obviousness.