Simpleair, Inc. v. Google LLC, 884 F.3d 1160

SimpleAir sued Google multiple times (SimpleAir I–IV) over a family of continuation patents derived from U.S. Patent No. 6,021,433 (the ’433 patent) covering push-notification technology; several child patents were terminally-disclaimed to the ’433 patent.
Earlier litigation resulted in judgments of noninfringement against SimpleAir on various continuation patents (including the ’914 and ’279 patents); SimpleAir IV asserted two later-issued continuations (’838 and ’048).
The district court dismissed SimpleAir IV under Rule 12(b)(6) as barred by claim preclusion and the Kessler doctrine, reasoning that a common specification and terminal disclaimers made the patents patentably indistinct.
On appeal, the Federal Circuit held the district court erred by presuming that terminally-disclaimed continuations are patentably indistinct from parent patents without comparing claim scope.
The panel explained terminal disclaimers are a strong clue (because they overcome obviousness-type double patenting rejections) but are not admissions of lack of patentable distinctness; therefore claim comparison is required to determine preclusion.
The Court vacated and remanded for further proceedings, instructing the district court to analyze whether the asserted claims are “essentially the same” (i.e., patentably indistinct) as those previously adjudicated; it also rejected Google’s broad Kessler argument but noted Kessler could apply if claims are found indistinct.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether claim preclusion bars SimpleAir IV	Different continuation patents create distinct causes of action; common spec/terminal disclaimer insufficient	Substantial transactional overlap (same accused service, common spec, terminal disclaimers) makes suits the same cause of action	Vacated dismissal — court must compare claim scope; terminal disclaimer alone insufficient to presume preclusion
Whether a terminal disclaimer conclusively shows patents are patentably indistinct	Terminal disclaimer is not an admission of lack of distinctness	Terminal disclaimer and examiner rejection are strong evidence of indistinctness	Terminal disclaimer is a strong clue but not conclusive; claim-by-claim comparison required
Whether Kessler doctrine bars SimpleAir’s suit (including post-judgment activity)	Kessler cannot bar assertions of different continuation patents not previously adjudicated	Kessler bars re‑litigation of essentially the same accused activity even post‑judgment	Rejected Google’s expansive Kessler argument; Kessler may apply only if claims are patentably indistinct and accused activity is essentially the same post‑judgment
Whether issue preclusion applies	(SimpleAir) Not raised below	(Google) Issue preclusion prevents relitigation	Waived — Google did not raise issue preclusion in district court, so appellate court declined to consider it

Lawlor v. Nat’l Screen Serv. Corp., [citation="349 U.S. 322"] (establishes claim preclusion principle)
Senju Pharm. Co. v. Apotex Inc., [citation="746 F.3d 1344"] (reexamination claims do not automatically create new causes of action)
Acumed LLC v. Stryker Corp., [citation="525 F.3d 1319"] (transactional test for same cause of action in patent cases)
Kearns v. Gen. Motors Corp., [citation="94 F.3d 1553"] (different patents ordinarily raise different causes of action)
Aspex Eyewear Inc. v. Marchon Eyewear, Inc., [citation="672 F.3d 1335"] (new claims from reexamination can be claim‑precluded)
Brain Life, LLC v. Elekta Inc., [citation="746 F.3d 1045"] (distinguishes role of Kessler doctrine to protect post‑judgment accused activity)
Motionless Keyboard Co. v. Microsoft Corp., [citation="486 F.3d 1376"] (terminal disclaimer is not an admission of obviousness)
Quad Envtl. Techs. Corp. v. Union Sanitary Dist., [citation="946 F.2d 870"] (filing of terminal disclaimer does not raise a merits estoppel)