A private sale can be a sword against a patent owner but not a shield.

In NCS Multistage v. Nine Energy Service, a precedential Sept. 14 Federal Circuit opinion vacated a jury verdict for patent owner NCS against Nine on a casing float tool patent and ordered a new trial.

Prior Sale and the AIA Grace Period

Competitor TCO sold a similar tool to a customer in August 2012, less than a year before NCS filed. TCO's sale counts as prior art. Within one year before filing, the America Invents Act grace period removes the sale as prior art if the inventor publicly disclosed the invention first. NCS offered a July 2012 sale of one AirLock as such an earlier disclosure.

However, extending Sanho v. Kaijet (2024), the court found the AirLock sale was private: the device shipped in a sealed black tube with confidential documents, although without a nondisclosure agreement. The private sale left NCS unshielded from TCO's later sale, and the retrial must decide whether the TCO tool invalidates NCS's claims.

Claim Construction

NCS asked the court to define the claim term “casing string” to mean pipe at least 4.5 inches in outer diameter, then used the definition to argue the TCO tool was tubing rather than casing. The specification called 4.5 inches a common casing size “although other dimensions . . . are possible.” The patent's words controlled over extrinsic evidence from industry catalogs, and the size limit “put a thumb on the scale” when the jury rejected Nine's invalidity challenge based on the TCO tool.

On infringement, the claims use the term “internal diameter” for both the casing's fluid passageway and the surface where the rupture disc attaches. The district court defined the term to mean both a measured width and an inner surface. Applying the presumption that a claim term keeps one meaning unless the specification and prosecution history clearly show otherwise, the court held “internal diameter” means a measured diameter across the casing.

Patent Practice Points

  • A quiet sale cuts one way. Under Helsinn v. Teva (2019), a confidential sale can start the one-year clock against the seller's patent. After NCS, the sale also leaves the seller’s patent rights exposed to competitor sales.
  • Breadth language binds the patentee. The specification's “other dimensions . . . are possible” defeated NCS's own narrowing argument to avoid the prior art.
  • Give each structure a separate claim term. One term defining both a dimension and a structure invites a construction fight. AI claims share similar risks when terms like “model” or “layer” do double duty.

Publishing first shields U.S. rights but destroys novelty in Europe and China. Filing a provisional first protects both.

Read more from Eileen M. at IPWatchdog, Inc.

Sources

  1. 𝘕𝘊𝘚 𝘔𝘶𝘭𝘵𝘪𝘴𝘵𝘢𝘨𝘦 𝘐𝘯𝘤. 𝘷. 𝘕𝘪𝘯𝘦 𝘌𝘯𝘦𝘳𝘨𝘺 𝘚𝘦𝘳𝘷𝘪𝘤𝘦, 𝘐𝘯𝘤., No. 2025-1000 (Fed. Cir. Sept. 14, 2026) (precedential): https://www.cafc.uscourts.gov/opinions-orders/25-1000.OPINION.9-14-2026_2754720.pdf
  2. Eileen McDermott, "Federal Circuit Vacates Win for Patent Owner Due to Bad Claim Construction," IPWatchdog (Sept. 15, 2026): https://ipwatchdog.com/2026/09/15/federal-circuit-vacates-win-for-patent-owner-due-to-bad-claim-construction/
  3. Dennis Crouch, "The Federal Circuit Extends Sanho to the Section 102(b)(1)(B) Grace Period," Patently-O (Sept. 16, 2026): https://patentlyo.com/patent/2026/09/the-federal-circuit-extends-sanho-to-the-section-102b1b-grace-period.html
  4. 𝘚𝘢𝘯𝘩𝘰 𝘊𝘰𝘳𝘱. 𝘷. 𝘒𝘢𝘪𝘫𝘦𝘵 Tech. Int'l 𝘓𝘵𝘥., 108 F.4th 1376 (Fed. Cir. 2024)
  5. 𝘏𝘦𝘭𝘴𝘪𝘯𝘯 𝘏𝘦𝘢𝘭𝘵𝘩𝘤𝘢𝘳𝘦 𝘚.𝘈. 𝘷. 𝘛𝘦𝘷𝘢 𝘗𝘩𝘢𝘳𝘮𝘴. 𝘜𝘚𝘈, 𝘐𝘯𝘤., 586 U.S. 123 (2019)
  6. 𝘛𝘊𝘖 𝘈𝘚 𝘷. 𝘕𝘊𝘚 𝘔𝘶𝘭𝘵𝘪𝘴𝘵𝘢𝘨𝘦 𝘐𝘯𝘤., PGR2020-00077 (P.T.A.B. Feb. 18, 2021)
  7. 35 U.S.C. § 102(b)(1)(B); AIA § 3(n)(1), 125 Stat. 284, 293