The ruling of the U.S. Court of Appeals for the Federal Circuit in In re Yasuhito Tanaka has left no doubt that the patent reissue procedure can be used to add new dependent claims, and is not limited to only correction of claiming errors. At the time of original patenting, the preferred commercial embodiments are often not yet known or specifically claimed. U.S. patent owners now have the opportunity to modify previously issued claim sets, avoiding a loss of all rights from an invalidity challenge against potentially vulnerable broad claims, by adding more defensible narrow claims directed to the most commercially relevant embodiments.

Background

In 2000, U.S. Patent No. 6,093,991 was issued to Yasuhito Tanaka with independent claim 1 and dependent claims 2-7 directed to an alternator pulley that uses a one-way clutch to improve power generation efficiency of an automobile’s clutch. Exactly two years later, Tanaka filed a reissue patent application seeking to broaden the scope of independent claim 1. Tanaka subsequently abandoned his reissue attempt to broaden claim 1, and instead presented the originally issued claims 1-7 and a new claim 16 dependent on claim 1.

The examiner rejected those claims as presented on the basis that Tanaka had failed to specify an error that broadened or narrowed the scope of the claims in the originally issued patent. After the rejection was made final, Tanaka appealed to the Board of Patent Appeals and Interferences. The Board interpreted the language of 35 U.S.C. § 251, and affirmed the examiner’s decision, holding that the statute “disallow[s] reissue applications that simply add narrow claims to the reissue patent when no assertion of inoperativeness or invalidity for the reasons set forth in § 251 can be made by the patentee.”1 The Board noted that reissue can not be used simply to hedge against the possible invalidity of one or more of the original claims.