The US Court of Appeals for the Federal Circuit affirmed a district court’s decision to correct inventorship in a post-issuance inventorship dispute, finding that the alleged joint inventors’ contributions were significant even though they were mostly unclaimed. Tube-Mac Indus., Inc. v. Campbell, Case No. 22-2170 (Fed. Cir. Mar. 15, 2024) (Lourie, Hughes, Stark, JJ.) (nonprecedential).

Steve Campbell was the original sole inventor named on a utility patent application directed to a container for transporting gaseous fluids. Before Campbell filed the patent application, Campbell’s prototypes had a “major problem” with the container’s liner. Campbell enlisted the help of Tube-Mac Industries’ Gary Mackay and Dan Hewson to solve the problem. Campbell, Mackay and Hewson exchanged plans regarding the problem over the course of several months. Campbell’s patent issued, naming himself as the sole inventor. Mackay, Hewson and Tube-Mac filed suit seeking to be named as co-inventors. The district court agreed and ordered correction of the patent under 35 U.S.C. § 256. Campbell appealed.

A court may order a correction of inventorship when it determines that an inventor has been erroneously omitted from a patent. In any inventorship challenge, the inventors listed in an issued patent are presumed to be the correct inventor(s). Thus, a party challenging inventorship must prove incorrect inventorship by clear and convincing evidence. A joint inventor must contribute significantly to the invention’s conception or reduction to practice when that contribution is measured against the scope of the full invention.

The Federal Circuit found that prior to the involvement of Mackay and Hewson, Campbell did not have a viable invention that could be reduced to practice without extensive experimentation. The Court also found that Mackay’s and Hewson’s contributions solved the problem that precluded the prototype from being successful, even though their contributions were “mostly unclaimed.” The Court noted, however, that their contributions were included in the application’s figures, specifications and dependent claims. Accordingly, the Court found that Mackay and Hewson contributed significantly to the conception of the invention and should be included as co-inventors.

The Federal Circuit also dismissed Campbell’s arguments that the district court did not properly construe the claims to determine their scope and erred by misidentifying the subject matter of the claims.