The US Patent & Trademark Office (PTO) terminated a pending
ex parte reexamination after finding that the challenger
was estopped because the prior art references could have been
raised in a prior inter partes review (IPR). In re
Tyler, Reexam. No. 90/014,950 (PTO Nov. 15, 2022).
In 2017, GITS Manufacturing filed two IPR petitions against a
patent owned by G.W. Lisk after Lisk asserted the patent against
GITS in district court. In 2018, the Patent Trial & Appeal
Board issued final written decisions in each IPR, finding some
claims unpatentable and maintaining the patentability of other
claims. The Federal Circuit affirmed both IPR decisions in
2021.
In February 2022, the PTO initiated an ex parte
reexamination of one of the patents based on a request filed by
GITS. The reexamination proposed multiple grounds of
unpatentability based on four prior art references that were not
involved in the IPRs. GITS included a lengthy discussion and an
expert declaration
