The Missing Inventor Problem

by Dennis Crouch

Fortress Iron has asked the Supreme Court to review the Federal Circuit's decision invalidating two of its cable-railing patents because an omitted coinventor could not be found. Fortress Iron, LP v. Digger Specialties, Inc., No. 26-362 (petition filed Sept. 3, 2026). Judge Lourie wrote the opinion below for a unanimous panel, 171 F.4th 1310 (Fed. Cir. 2026), and the full court denied rehearing in June. I previously wrote about the holding, and then followed up with a second post asking where the invalidity rule comes from now that the AIA has repealed Section 102(f). This post centers on the cert petition, and I also pull in the Supreme Court's 1868 inventorship decision in Agawam v. Jordan.

The invention is a vertical cable rail barrier, a railing whose infill is a set of tensioned vertical cables, of the kind used on a deck, balcony, or stairway. Fortress's owner had the idea and an employee sketched the design, adding some detailed features. But prototypes built in China had a problem: the cables rotated as they were being tensioned. Hua-Ping Huang suggested square openings and square swage fittings to stop the rotation, and a coworker, Shih-Te Lin, suggested changes to strengthen the rail. Both ideas went into the final product, but the patents named only the two Fortress employees. During litigation, the parties discovered that Huang and Lin should be added as inventors. Lin was located and added by the USPTO. But there was difficulty finding Huang.

So the basic setup here is that everyone agrees that Hua-Ping Huang contributed to the invention and should be named on the patents. Fortress wanted to add him. But Huang left the contractor in 2016 without leaving contact information, and Fortress could not locate him. Fortress argued that it owned rights regardless because the contribution was a "service invention-creation" immediately owned by the contractor who assigned rights to Fortress. No assignment from Huang appears in the USPTO records. The recorded chain runs from Quan Zhou Yoddex to Fortress Iron, and even after finding him Fortress took his consent to be named, not an assignment.

In the litigation, Fortress conceded that Huang and Lin were coinventors and turned to 35 U.S.C. § 256 to fix the patents. The statute offers two routes. Under subsection (a), the USPTO Director may issue a certificate of correction "on application of all the parties and assignees." Fortress used that route for Lin, but admitted it was unavailable for Huang, who could not be found to sign.

Section 256(b) is the courtroom route. It provides that the error of omitting an inventor can be corrected by the court "on notice and hearing of all parties concerned." Fortress argued that Huang is not a party concerned because he holds no ownership interest, would lack standing to bring his own Section 256 claim, and could only benefit from being named. The district court disagreed, and the Federal Circuit affirmed.

Judge Lourie wrote that inventors remain central to the patent system even after they assign their rights, and that a coinventor is a party concerned whether or not he owns anything. Limiting the phrase to those whose economic interests might be harmed would rewrite the statute, and in any event nobody knows whether Huang would be helped or hurt by being named. Notice and a hearing are "a prerequisite to relief, not a mere formality." Because Fortress could not give notice, the error could not be corrected, and the court ultimately concluded that an inventorship error that cannot be corrected invalidates the patent.

Huang has now been found. He signed a Statement of Inventor under 37 C.F.R. § 1.324(b)(1) on April 10, 2026, eight days after the panel opinion issued, and Fortress filed the papers on April 16. On July 20 a supervisory patent examiner granted the petitions and sent the files to the Certificates of Correction Branch. Nothing has issued since. But a certificate of correction does not undo a judgment of invalidity. The district court has already held the two patents invalid and the Federal Circuit has affirmed. Unless the Supreme Court intervenes or Fortress wins relief from the judgment under Rule 60(b), the corrected patents seemingly remain unenforceable against DSI. Other accused infringers could also invoke the invalidity ruling under Blonder-Tongue Laboratories, Inc. v. University of Illinois Foundation, 402 U.S. 313 (1971) (non-mutual issue preclusion applies to invalidated patents).

---

To continue reading, become a Patently-O member. Already a member? Simply log in to access the full post.