Here it is stated that due to recent rule changes at the USPTO, patents may now be revived even after a two year period:
George - just for edification, they recently changed the rule to get rid of the two-year limit. See Patent Law Treaties Implementation Act of 2012, Pub. L. No. 112-211, 126 Stat. 1527; see also 35 U.S.C. § 41(c)(1). 35 U.S.C. § 27; and 37 C.F.R. 1.137. There's a good summary of this at clm.com/publication.cfm?ID=489. – HTH Aug 12 '14 at 17:22
They link to this summary: http://www.clm.com/publication.cfm?ID=489
"Recent changes to Title 35 of the U.S. Code effected by the Patent Law Treaties Implementation Act of 2012, Pub. L. No. 112-211, 126 Stat. 1527, eliminate the unavoidable standard and remove the 24-month time limit to reinstate an unintentionally abandoned patent. Now, any patent which has expired for failure to pay a maintenance fee can be revived, at any time, upon a statement that the delay in paying the maintenance fee was unintentional. 35 U.S.C. § 41(c)(1). Similarly, any patent application that has gone abandoned for an unintentional failure to file a timely response can be revived at any time. 35 U.S.C. § 27; 37 C.F.R. 1.137."
Thoughts? Ideas? Is there any case law regarding this?