Hot on the heels of January’s Boehringer Ingelheim Int’l GmbH v. Barr Labs., Inc., 592 F.3d 1340 (Fed. Cir. 2010) decision on divisional practice, the Federal Circuit tackled another issue “of first impression,” how to make a valid priority claim through a chain of applications.

Most patent attorneys would have thought these basics were set in stone decades ago. They were not.

The patents at issue in Encyclopaedia Britannica claimed priority through a chain of four earlier patents. The second application in the series (first continuation) was filed and abandoned under circumstances that created the difficulty. But it was critical for Britannica to be accorded the priority date of the first application in the series because the first application’s foreign equivalent had been published more than a year before the actual filing date of even the first continuation.

The first continuation had been filed on the same day that its parent issued, without filing fee, declaration, claim to priority of the parent, or first page. The PTO issued a Notice of Incomplete Application, requiring receipt of the first page before according a filing date. Britannica petitioned to have a filing date accorded, but was rebuffed by the PTO because the petition was not supported by an oath or declaration from the inventors stating the first page was not needed to understand the claimed invention. The PTO invited Britannica to file a request for reconsideration along with such a supporting oath or declaration. Britannica elected instead to do nothing, buying a four-month extension only to file a third application in the chain on the very last day of the period for responding. Britannica left the problems in the second application in the chain uncorrected.

The court found that the priority chain was broken because the second application did not “contain a specific reference to the earlier filed application” required by 35 U.S.C. § 120.  Britannica had argued that only the application being asserted needed to contain a reference to the earlier applications to which priority was claimed. However, section 120 required each earlier application in turn had to be “similarly entitled to the benefit to the filing date of the first application,”  but the second application in the series had not been similarly entitled when the third application in the series attempted to claim priority through it.

Take note: the court warns that it “leave[s] for  another day whether filing a continuation on the day the parent issues results in applications that are co-pending as required by statute.” Slip op. at 13. The court also left for another day whether it is possible to claim priority to an application such as the second in the Britannica chain that had not been accorded a filing date before being abandoned, among other “infirmities.” Id.

The Britannica court noted that In re Henricksen, 399 F.2d 253 (CCPA 1968) had settled the issue that 35 U.S.C. § 120 imposed no limit on the number of applications in a chain through which the benefit of priority may be claimed.

Henricksen was not considered in Boehringer but perhaps it should have been. The Boehringer court ruled that the safe-harbor provision of 35 U.S.C. § 121 available for a divisional application (grandchild) that claimed priority through another divisional application (child) to the application (parent) in which a restriction requirement was made.  In addition, the court stated that the safe harbor provided by section 121 was not lost if distinct inventions are prosecuted together so long as separate divisional applications respect the lines drawn by the examiner in the restriction requirement. The dissent would have accorded a safe harbor only to a divisional having only a single distinct invention and only for a first-generation divisional application.

Encyclopaedia Britannica, Inc. v. Alpine Electronics of America, Inc., 2009-1544, -1545 (Fed. Cir. June 18, 2010)