Reissue Patent Claims Not Clearly and Unequivocally Supported in Original Patent Are Invalid

FORUM US, INC. v. FLOW VALVE, LLC

Before Reyna, Schall and Hughes. Appeal from the U.S. District Court for the Western District of Oklahoma.

Summary: The original patent on which a broadening reissue patent is based must clearly and unequivocally disclose the invention claimed in the reissue patent.  

Forum filed a declaratory judgment action to invalidate a reissue patent owned by Flow Valve. The original patent claimed a fixture with “a plurality of arbors,” and the reissue patent added new claims without the arbor limitation.  Forum contended the added reissue claims violated 35 U.S.C. § 251, because the original patent did not disclose an invention without arbors.  In opposition, Flow Valve argued that a person of ordinary skill in the art would understand that the original patent disclosed multiple inventions, consisting of embodiments with and without arbors.  Flow Valve supported this argument with an expert declaration.  The district court granted summary judgment of invalidity because the original patent did not “explicitly and unequivocally” indicate the invention claimed in the reissue claims.  Flow Valve appealed.

Affirming the grant of summary judgment, the Federal Circuit stated that the original patent must “clearly and unequivocally” disclose the newly claimed invention to satisfy § 251, and found that Flow Valve’s original patent did not disclose any arbor-less embodiment.  The Federal Circuit added that even if a person of ordinary skill in the art would understand that the newly claimed, arbor-less invention would be possible, that understanding would be insufficient to comply with the standard set forth in the case law.

Editor: Paul Stewart

Written by: Nathan J. Lee & Jeremy Anapol