Federal Circuit Invalidates Fortress Iron Patents Under § 256

Fortress Iron LP’s patent infringement dispute over pre-assembled vertical cable railing panels ultimately turned on a threshold patent-law requirement: correct inventorship. In affirming summary judgment of invalidity, the Federal Circuit concluded that two asserted patents could not be salvaged because a concededly omitted coinventor could not be located, notified, and given an opportunity to be heard. The decision emphasizes that the statutory mechanism for correcting inventorship protects the interests of all “parties concerned,” including missing inventors, and that an uncorrectable inventorship defect can be dispositive even where the error is later acknowledged.

Development of the Invention and the Omitted Coinventors

The patents at issue, U.S. Patent Nos. 9,790,707 and 10,883,290, cover vertical cable railing systems marketed as pre-assembled panels. According to court filings, Fortress’s owner conceived of the concept in 2013 and engaged Chinese manufacturing partners to develop a working prototype. During that process, the design encountered a functional problem: the cables could rotate during tensioning, undermining performance and installation.

Two employees of the Chinese partner, Hua-Ping Huang and Alfonso Lin, proposed modifications that addressed the cable-rotation issue and were incorporated into the final product design reflected in the asserted patents. Despite those contributions, the patents initially issued naming only Fortress-associated personnel as inventors. The omission became more difficult to remedy over time because Huang left the Chinese company in 2016 without leaving forwarding contact information, complicating any later effort to secure his participation in a correction process.

Inventorship Correction Efforts Under 35 U.S.C. § 256

After Fortress sued Digger Specialties Inc. for infringement, the parties’ positions converged on a key point: Fortress acknowledged that Lin and Huang should have been named as coinventors. Fortress was able to locate Lin and pursue an administrative correction under 35 U.S.C. § 256(a), a process that contemplates agreement from relevant parties and assignees to amend inventorship. That approach, however, depended on being able to identify and engage each omitted inventor.

With Huang unlocatable, Fortress sought relief under § 256(b), which allows a district court to order correction in certain circumstances. The defense is represented by Parsons Behle & Latimer, according to court filings. The district court declined to order correction, concluding that statutory prerequisites were not satisfied in the absence of notice to Huang and an opportunity for him to be heard, and it entered summary judgment that the patents were invalid due to the uncorrected inventorship defect.

Federal Circuit’s Affirmance and the Consequence of an Uncorrectable Error

On appeal, the Federal Circuit agreed that Huang qualified as a “party concerned” under § 256(b). The court rejected the argument that an omitted inventor should be excluded from that category because correction would purportedly benefit him. Instead, it treated inventorship as carrying legal, financial, and ownership consequences that can affect a person’s rights and interests, including the potential to dispute inventorship status or related implications.

Because § 256(b) requires notice and a hearing for parties concerned, Fortress’s inability to locate Huang prevented compliance with the statute’s procedural safeguards. The Federal Circuit also affirmed the invalidity ruling based on the statute’s text regarding the effect of inventorship error. Under § 256, an inventorship defect “shall not invalidate” a patent only if the error “can be corrected,” and the court treated that conditional language as decisive: where correction is not possible, the safe harbor does not apply. The decision, therefore, links patent enforceability to practical ability to complete the correction process, underscoring the litigation risk when an omitted inventor cannot be found.