Fortress Iron, LP v. Digger Specialties, Inc., Appeal No. 2024-2313 (Fed. Cir. Apr. 2, 2026) 

In the Federal Circuit’s only precedential patent case this week, the Court affirmed an invalidity finding as to a patent that failed to name one of the inventors.  The issue was one of first impression, and the Court’s decision sounds a cautionary note to patent applicants to ensure they get inventorship correct.

Fortress designs railing and fencing products used in the construction of outdoor living spaces.  It works with two Chinese companies to manufacture those products.  In 2013, the owner of Fortress had an idea for a particular type of railing.  He and one of his employees worked with one of Fortress’ Chinese suppliers to bring the idea to fruition.  Two employees of that supplier, Lin and Huang, suggested changes, which were eventually incorporated into the final design.  Fortress filed patent applications naming its own owner and employee as inventors, but failed to name Lin or Huang.

In 2021, Fortress sued Digger for patent infringement.  During discovery, Digger learned that Lin and Huang had contributed to the invention, and Fortress acknowledged that they were co-inventors.  Fortress located Lin and successfully added him as a coinventor following the procedure outlined in 35 U.S.C. § 256(a).  But Huang had departed employment from the Chinese manufacturer in 2016 and did not leave forwarding contact information.

The parties cross-moved for summary judgment.  Digger moved for invalidity based on failure to name a co-inventor, and Fortress moved to add Huang as a coinventor pursuant to 35 U.S.C. § 256(b).  The district court granted Digger’s motion and denied Fortress’.  The appeal followed.

The Federal Circuit began by noting the requirements of § 256(b).  Specifically, it has been described as a “savings provision” and is only applicable if its requirements can be satisfied.  Among the requirements is “notice and hearing of all parties concerned.”  Fortress argued that Huang was not a “party concerned.”  The Court considered this issue as one of first impression and held that an inventor is a “party concerned” for purposes of § 256(b).  They “occupy the central role in the patent process,” and it is irrelevant if they have an economic stake in the outcome.  Being named an inventor on a patent “carries legal, financial, and ownership consequences that an inventor has a right to contest.”  Because Huang was not given notice, the Court held the requirements of § 256(b) were not satisfied, and inventorship could not be fixed.

The Court then affirmed the patent was invalid under Section 101.  Based on the language of § 256(b), stating that “the error of omitting inventors . . . who are not inventors shall not invalidate the patent . . . if it can be corrected,” the Court held that invariably, failing to name an inventor could render the patent invalid:  “we hold that a patent which incorrectly lists its inventor(s) and cannot be corrected according to law is invalid.”

The opinion can be found here.

By Nika Aldrich

This article summarizes aspects of the law and does not constitute legal advice. For legal advice with regard to your situation, you should contact an attorney.