A recent U.S. District Court decision has clarified a potential danger when filing terminal disclaimers that contain overly-broad language. The U.S. District Court for the Northern District of Illinois in Hagenbuch v. Sonrai Systems interpreted the terminal disclaimer language “I hereby disclaim the terminal part of any patent granted on the above-identified application or any continuation of it” as applying to any continuation application claiming priority from the application in which this terminal disclaimer was filed. Hagenbuch v. Sonrai Systems, 2015 U.S. Dist. LEXIS 39083, *4 (N.D. Ill. Mar. 27, 2015) (emphasis added).

In Hagenbuch, the court granted defendant Sonrai’s motion for summary judgment, which was based on the patents-in-suit having expired as a result of a Terminal Disclaimer filed in a parent application of the patents-in-suit. The patents-in-suit were based on a series of continuation applications stemming from Application No. 08/102,531 (the “‘531 Application”), which issued as U.S. Patent No. 5,327,347. The ‘531 Application was part of a string of file wrapper continuations, which claim priority back to Application No. 06/351,179 (the “‘179 Application”).

During prosecution of the ‘179 Application, Hagenbuch filed a Terminal Disclaimer to overcome an obviousness-type double patenting rejection. This Terminal Disclaimer disclaimed the terminal part of any patent “granted on the above-identified application.” Hagenbuch, 2015 U.S. Dist. LEXIS 39083 at *3. Although the ‘179 Application was subsequently abandoned, the obviousness-type double patenting rejection was reinstated during prosecution of the ‘531 Application (a continuation of the ‘179 Application) because the Terminal Disclaimer filed in the ‘179 Application was worded in such a way that it did not apply to any subsequently filed applications claiming the benefit of priority. As noted above, a Terminal Disclaimer was filed for the ‘531 Application, which included the following language:

I hereby disclaim the terminal part of any patent granted on the above-identified application or any continuation of it under 35 U.S.C. subsection 120, which would extend beyond the expiration date of the full statutory term of United States Patent No. 4,839,835 and hereby agree that any patent so granted on the above-identified application or continuation of it shall be enforceable only for and during such period that the legal title to the patent shall be the same as the legal title to United States Patent No. 4,839,835. I understand that this agreement runs with any patent granted on the above-identified application or continuation of it and that it is binding upon the grantor, its successors or assigns.

Id. at *4 (emphasis by court).

Hagenbuch argued that the Terminal Disclaimer filed in the ‘531 Application should not apply to any continuation application because the term “or” as used in the Terminal Disclaimer limited the scope of the Terminal Disclaimer. Specifically, Hagenbuch asserted that the Terminal Disclaimer applies to either “any patent granted on the above-identified application or any continuation of it under 35 U.S.C. subsection 120,” but not both. Id. at *5. The Court disagreed and held that “by its terms, the disclaimer applies to both the ‘347 Patent and to patents issued from continuations of the ‘531 Application.” Id. at *10 (emphasis added).

Hagenbuch also argued that applying the Terminal Disclaimer to downstream patents is inconsistent with the version of the MPEP that was effective when the disclaimer was filed unless the same disclaimer was refiled in each application. The MPEP at that time stated that “a terminal disclaimer filed to obviate a double patenting rejection is effective only with respect to the application identified in the disclaimer.” MPEP §1490, p. 1400-22 (5th Ed. Rev. 15, Aug. 1993) (emphasis added). However, the court held that this language referred only to a Terminal Disclaimer modeled on the form Terminal Disclaimer provided in the MPEP itself, which referenced only an “above-identified application” in the language of the disclaimer and did not include language referring to “any continuation.” Hagenbuch, 2015 U.S. Dist. LEXIS 39083 at *16. Hagenbuch included additional language in his disclaimer that referred to “any continuation,” which effectively “disclaimed the terminal part of any patent granted on any continuation.” Id. at *16-17. Whether the disclaimer was refiled in later applications had no effect on disclaiming terminal parts of the Patents in Suit. As the court concluded, “Hagenbuch chose to deviate from the standard form, and the language he chose controls.” Id. at *17.

Thus when filing a Terminal Disclaimer, it can be beneficial to ensure that the language of the Terminal Disclaimer only applies to the current application in which it is filed. Even though Terminal Disclaimers may be required to be filed for subsequent applications, these additional filings can act to prevent an applicant from inadvertently surrendering patent term on subsequent applications.