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IP Alert: Federal Circuit Affirms Reissue Claims Invalid for Omitting Important Element of Invention

June 18, 2019

The Federal Circuit’s recent decision in Forum US, Inc. v. Flow Valve, LLC serves as a reminder that the ability to expand the scope of patents through reissue may be limited even where subject matter was not surrendered during prosecution of the original patent. On June 17, the court held that new claims that did not include a limitation found in all of the claims of the original patent and present in each of the specific embodiments discussed in the specification were invalid under 35 U.S.C. § 251 for failing to meet the “original patent” requirement.

Although the court confirmed that a reissue application should not be rejected based on the absence of an “intent to claim” certain subject matter, it held that “the original patent must do more than merely suggest or indicate the invention recited in reissue claims” and that it “must appear from the face of the instrument that what is covered by the reissue was intended to have been covered and secured by the original.” While this does not make entirely clear exactly what is required to meet the original patent requirement, it is a signal that a patentee should be wary of expecting to obtain claims through reissue that lack limitations that appear to be important to the embodiments described in the specification, even if omitting such limitations would not have posed a problem during prosecution of the original patent.

Flow Valve’s patent related to supporting assemblies for holding workpieces during machining. All workpieces disclosed in the patent are machined pipe fittings that attach to other pipe sections through threaded connections where one or more ends of the fitting require machining on a turning machine. The written description and drawings only disclose embodiments with arbors, and all of the claims of the original patent required arbors. When Flow Valve filed a reissue application, it presented claims that did not recite arbors, but made no changes to the specification or drawings. Forum US filed a declaratory judgment action seeking a declaration of invalidity of Flow Valve’s reissue patent. Forum US contended that the added reissue claims were invalid because they did not comply with the original patent requirement under 35 U.S.C. § 251. The district court granted summary judgment in its favor.

On appeal, the Federal Circuit observed that 35 U.S.C. § 251 allows for a reissue patent “for the invention disclosed in the original patent.” The court held that although there were some passages in the specification that refer generally to “machining” without reference to arbors and some boilerplate language indicating that the invention was not limited, all of the references to a “turning machine” described arbors and the specification does not “clearly and unequivocally” disclose an arbor-less embodiment of the invention. As a result, the court affirmed summary judgment of invalidity of the reissue claims and held the reissue claims were not directed to the invention disclosed in the original patent within the meaning of § 251.

This case shows that while there are some similarities between the original patent requirement of 35 U.S.C. § 251 and the written description requirements under 35 U.S.C. § 112, the requirement under § 251 is stricter and requires clear and unequivocal disclosure of the claimed subject matter. It does not appear to be enough that each element of the reissue claim finds support in the specification, and claims can be held invalid for failing to include elements that are described in the specification as important to the invention.

For more information on this case, please contact Fitch Even partner Mark A. Borsos, author of this alert.

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