Gator Tail, LLC v. Mud Buddy LLC, 618 F. App'x 992

Gator Tail owns U.S. Patents 7,052,340 and 7,297,035 claiming a belt-driven short-tail mud motor with a horizontally mounted engine and timing-belt drive, mountable like an outboard.
Prior art: the Torrey patent disclosed long-tail motors with horizontal engines; the Saito patent disclosed short-tail motors using a vertical engine (no timing belt).
Defendants (Mud Buddy, Go-Devil) alleged infringement; defendants sought ex parte PTO reexamination, which initially rejected the claims but ultimately the PTO confirmed the patents after applicant submissions.
District court held asserted claims invalid for obviousness (primary ground), and alternatively for lack of written description and indefiniteness; court focused on combining Saito and Torrey as predictable design choices.
On appeal, Gator Tail challenged obviousness (and auxiliary rulings), arguing the district court erred in (1) discounting PTO reexamination, (2) misreading Saito as teaching away from a horizontal engine, and (3) improperly assessing commercial-success evidence.
Federal Circuit reviewed obviousness de novo with factual findings for clear error and affirmed the district court: claims invalid under 35 U.S.C. § 103.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Obviousness of asserted claims	Claims non-obvious; PTO confirmation supports validity	Claims are predictable combination of Saito and Torrey; prima facie obvious	Affirmed obviousness — district court findings not clearly erroneous
Weight due to PTO reexamination	District court undervalued PTO confirmation and interim rejections	Trial evidence undermined PTO rationale; district court may weigh reexam evidence	District court properly considered PTO but reasonably gave it less weight based on trial testimony
Whether Saito teaches away from horizontal engine	Saito discourages horizontal engine in short-tail motors (teaches away)	Saito does not criticize or render horizontal engines inoperative; it compares prior horizontal long-tail motors favorably to Saito’s vertical design	Saito does not teach away; district court correct to find it does not discourage combination
Commercial success nexus to non-obviousness	Sales show commercial success of the patented product; court should presume nexus	Sales figures alone are weak; defendants rebut presumed nexus or show lack of market context	No persuasive commercial-success nexus; any error in nexus analysis was harmless

Fromson v. Advance Offset Plate, Inc., 755 F.2d 1549 (Fed. Cir. 1985) (PTO reexamination decisions are evidence but not controlling)
Scanner Techs. Corp. v. ICOS Vision Sys. Corp. N.V., 528 F.3d 1365 (Fed. Cir. 2008) (obviousness review: law de novo, facts for clear error)
KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398 (2007) (framework for obviousness and motivation to combine)
In re Gurley, 27 F.3d 551 (Fed. Cir. 1994) (definition of "teaching away")
McGinley v. Franklin Sports, Inc., 262 F.3d 1339 (Fed. Cir. 2001) (teaching away and "seemingly inoperative" combinations)
DePuy Spine, Inc. v. Medtronic Sofamor Danek, Inc., 567 F.3d 1314 (Fed. Cir. 2009) (when a reference does not teach away despite preference)
United States v. Adams, 383 U.S. 39 (1966) (evidence showing departure from long-accepted practice is relevant to non-obviousness)
Ormco Corp. v. Align Tech., Inc., 463 F.3d 1299 (Fed. Cir. 2006) (nexus requirement for commercial success evidence)
Brown & Williamson Tobacco Corp. v. Philip Morris Inc., 229 F.3d 1120 (Fed. Cir. 2000) (presumption of nexus when product is coextensive with claims)
In re Huang, 100 F.3d 135 (Fed. Cir. 1996) (unit-sales evidence alone is a weak showing of commercial success)
Cable Elec. Prods., Inc. v. Genmark, Inc., 770 F.2d 1015 (Fed. Cir. 1985) (discussing commercial success evidence)