(a) PATENT APPLICANT.-An applicant for a patent, any of whose claims has been twice rejected, may appeal from the decision of the primary examiner to the Patent Trial and Appeal Board, having once paid the fee for such appeal. (b) PATENT OWNER.-A patent owner in a reexamination may appeal from the final rejection of any claim by the primary examiner to the Patent Trial and Appeal Board, having once paid the fee for such appeal. 35 U.S.C. § 134 July 19, 1952, ch. 950, 66 Stat. 801; Pub. L. 98-622
The time for taking any action by a patent owner in an inter partes reexamination proceeding will be extended only for sufficient cause and for a reasonable time specified. Any request for such extension must be filed on or before the day on which action by the patent owner is due, but in no case will the mere filing of a request effect any extension. Any request for such extension must be accompanied by the petition fee set forth in § 1.17(g) . See § 1.304(a) for extensions of time for filing a