Written by Collin Rose.
Two years ago, I wrote about the Federal Circuit’s decision in Celanese International Corp. v. International Trade Commission. Around the same time, the Court decided Sanho Corp. v. Kaijet Technology International Ltd., a decision that provides important background for understanding NCS Multistage. Celanese confirmed that pre-AIA on-sale bar precedent applies with full force to AIA patents. Sanho held that a private transaction did not “publicly disclose” an invention under § 102(b)(2)(B). Together, the decisions sharpened the still-evolving boundary between the on-sale bar and the AIA grace period.
Recently, the Court wrote the next chapter. In NCS Multistage Inc. v. Nine Energy Service, Inc., No. 2025-1000 (Fed. Cir. Sept. 14, 2026), the Federal Circuit extended Sanho’s reasoning from § 102(b)(2)(B) to § 102(b)(1)(B), the provision inventors actually rely on to shield their own prior commercial activity from intervening third-party prior art. And it did so on facts that go further than Sanho: not a single sample by courier, but a completed commercial sale and delivery of finished goods. The holding is the same. A private sale, even with delivery, is not a public disclosure.
The ’445 Patent and the AirLock
NCS Multistage owns U.S. Patent No. 10,465,445 (the ’445 patent), which covers a float tool used in oil and gas wellbore casing operations, specifically, a rupture disc technology for casing flotation devices. NCS sued Nine Energy Service in the Western District of Texas, alleging that Nine Energy’s BreakThru Casing Flotation Device infringed the ’445 patent. A jury found for NCS on infringement and no invalidity.
The timeline matters. In July 2012, NCS sold its first AirLock device, which incorporated the claimed invention, to a customer called Tundra. One month later, in August 2012, a third party called TCO sold its own TDP-PO tool to Apache, with subsequent use by January 2013. NCS filed a provisional patent application on February 5, 2013, and a non-provisional application on June 28, 2013.
Here’s where it gets complicated. The PTAB determined, in denying institution of post-grant review (TCO AS v. NCS Multistage Inc., PGR2020-00077), that the provisional was inadequate to support the eventual claims. Because the AIA became effective on March 16, 2013, claims that could only rely on the June 28, 2013 non-provisional filing date were post-AIA claims. Under AIA § 3(n)(1), a single post-AIA claim puts the entire patent under the new § 102.
That left NCS in a bind. TCO’s August 2012 sale to Apache was potential prior art under § 102(a). NCS needed a way to knock it out. It turned to the § 102(b)(1)(B) grace period, arguing that its own July 2012 sale of the AirLock to Tundra was a “public disclosure” that antedated TCO’s sale and therefore prevented TCO’s activity from qualifying as prior art.
What the Court Held
The Federal Circuit rejected NCS’s argument and vacated the judgment below. Writing for a panel that included Judges Reyna and Hughes, Judge Cunningham held that the sale of the AirLock to Tundra was not a “public disclosure” under § 102(b)(1)(B).
The analytical move is significant. Section 102(b)(1)(B) and § 102(b)(2)(B) use identical language—both require that the subject matter was “publicly disclosed” by the inventor. Sanho had interpreted that phrase in the context of § 102(b)(2)(B), which deals with patent-application prior art in inter partes review. The Court in NCS Multistage recognized that the same language should carry the same meaning across both provisions and expressly applied Sanho’s framework to § 102(b)(1)(B): “publicly disclosed by the inventor” means “it is reasonable to conclude that the invention was made available to the public.”
The Court then applied that standard to the facts. NCS had delivered finished AirLock devices to Tundra in sealed black tubes that would have to be cut open to access the device. There was no evidence that receipt of the sealed black tubes would reveal the invention’s key features—the rupture disc configuration and internal diameter relationships that the patent claims cover. Technical documents exchanged between NCS and Tundra were marked confidential. And there was no evidence of any teaching of the relevant aspects of the invention to anyone beyond Tundra.
The Court’s conclusion was blunt: “We need not go further than Sanho to determine that no reasonable jury could have found that the sale of the AirLock to Tundra was a public disclosure.”
Beyond Sanho’s Facts, Same Result
It is worth pausing on why this case matters beyond Sanho. In Sanho, the inventor had sent a single HyperDrive device via private courier to the company’s owner. A 15,000-unit order had been placed, but there was no evidence the order was ever fulfilled. On those spare facts, the Court said that it was not a “close question.”
NCS Multistage presented a stronger factual case for public disclosure. NCS actually delivered finished, commercial-ready AirLock devices to Tundra. This was not a pre-production sample hand-carried by a courier; it was a completed sale with product delivery. If any private transaction were going to cross the line into “public disclosure,” you would think it would be one that involves actual delivery of the finished article.
Yet the Court held it was not enough. The critical question is not whether product changed hands, but whether the public was taught the relevant aspects of the invention. The AirLock devices arrived in sealed black tubes. The internal features were not apparent from the outside. Without evidence that Tundra or anyone else could learn the invention’s details from the delivered product, there was no public disclosure.
This tells us something important about what “publicly disclosed” means in the context of a sale: the transaction must do more than transfer possession. It must make the invention available to the public in a way that teaches or reveals its relevant aspects. Delivery of a sealed, opaque product to a single commercial customer, without more, does not clear that bar.
The Helsinn Trap
The NCS Multistage decision throws into sharper relief a tension that has been building since the Supreme Court’s 2019 decision in Helsinn Healthcare S.A. v. Teva Pharmaceuticals USA, Inc., 586 U.S. 123. In Helsinn, the Court held that a private commercial sale triggers the § 102(a)(1) on-sale bar even when the details of the invention are not publicly disclosed. Under the AIA, “on sale” carries the same meaning as it did pre-AIA, encompassing secret and private sales.
Now combine Helsinn with Sanho and NCS Multistage. A private sale starts the inventor’s clock under § 102(a)(1) by triggering the on-sale bar, and the inventor has one year to file. But that same private sale does not constitute a “public disclosure” under § 102(b)(1)(B), which means it cannot stop the clock by shielding the inventor against intervening third-party prior art that appears during the grace period.
This creates the Helsinn trap. An inventor who makes a private sale has started a one-year countdown to file. If a third party independently develops and discloses the same invention during that year, the inventor cannot invoke § 102(b)(1)(B) to neutralize the third party’s disclosure because the inventor’s own sale was not “public” enough. The private sale started the clock but cannot stop it. The inventor is exposed to prior art that appears in the gap between the sale and the filing, with no grace-period remedy.
For inventors and patent practitioners, this asymmetry is a practical hazard. The lesson is clear: if you are going to sell before you file, you need to think carefully about whether that sale will qualify as a public disclosure, because if it does not, you are running unprotected.
Unresolved Questions
As in Sanho, the Court in NCS Multistage reserved the question of what is sufficient for a sale to constitute a public disclosure. The Court found it unnecessary to define the exact standard because the facts before it fell so clearly on the “not public” side of the line.
That leaves practitioners with a set of open questions that the Federal Circuit will eventually have to answer:
Would a public offer on a website suffice? If an inventor lists a product for sale on a publicly accessible website with a product description and images, does that “teach the relevant aspects of the invention” to the public? The answer likely depends on whether the listing reveals the inventive features, but the Court has not addressed it.
What about products with non-apparent internal features sold on the open market? The AirLock’s key features were hidden inside sealed black tubes. But many patented inventions involve internal mechanisms or compositions that are not visible from the outside. If such a product is sold at retail, on the open market, to dozens or hundreds of customers, is that a public disclosure? The fact that anyone could buy the product and reverse-engineer it might matter, but the Court has not said so.
Does the number of buyers matter? Both Sanho and NCS Multistage involved sales to a single customer. Would the analysis change if the inventor sold to fifty customers? Five hundred? The Court’s framework focuses on whether the public was “taught” the invention, not on the volume of sales, but volume could be relevant to whether the information became available to the public.
Until the Court draws a clearer line, these questions will persist, and patent owners should plan their commercialization strategy with the risk of ambiguity in mind.
The Remand: Claim Construction and New Trial
The public-disclosure holding was not the only ground for reversal. The Federal Circuit also vacated the judgment of infringement based on new claim constructions. The Court held that “internal diameter” means only a measured diameter across the width of the casing string, not both a measured diameter and an inner surface, as the District Court had construed it. The Court also rejected a size limitation on the term “casing string,” finding that the specification’s permissive language (“may be 4.5 inches”) was insufficient to support either lexicography or disavowal of claim scope.
Both the judgment of infringement and the judgment of no invalidity were vacated, and the case was remanded for a new trial. Practitioners watching this case should keep an eye on the remand proceedings, which will test NCS’s infringement theory under the narrower constructions and may force NCS to develop a new argument for neutralizing TCO’s prior art.
Practical Takeaways
- File before you sell. The safest path remains the simplest: file a patent application before any commercial activity. A provisional application is relatively inexpensive and, if properly drafted with adequate written description support, secures a pre-AIA effective filing date that avoids the entire § 102 analysis.
- If you sell first, make the disclosure public. If commercial pressures require selling before filing, inventors should consider whether the manner of sale will qualify as a public disclosure. A private delivery in sealed packaging to a single customer is unlikely to suffice. Public marketing materials, trade show demonstrations, or published specifications that reveal the inventive features may be necessary to trigger § 102(b)(1)(B)’s protective shield.
- Understand the asymmetry. Under current law, a private sale triggers the on-sale bar (Helsinn) but does not constitute a public disclosure (Sanho, NCS Multistage). This means the one-year grace period clock starts, but the inventor has no shield against intervening third-party prior art. Counsel should advise clients of this gap explicitly.
- Ensure your provisional is robust. NCS’s predicament arose in part because its provisional application did not adequately support the issued claims, pushing the effective filing date to the non-provisional and placing the patent under the AIA. A well-drafted provisional with comprehensive written description support is an insurance policy against exactly this kind of scenario.
- Watch for the next case. The Federal Circuit has now twice declined to define what is sufficient for a sale to constitute a public disclosure. The standard is being built case by case, and the next decision could reshape the landscape. This area of the law is not settled.
Collin Rose is a partner at Munck Wilson in Houston, where he represents clients in patent litigation and counsels companies in the oil and gas, energy, and technology sectors on patent strategy and IP risk management. He can be reached at [email protected].
