Nat’l Steel Car Ltd. v. Greenbrier-Concarril LLC

Authored by: Jeremy J. Gustrowsky

In a recent decision, the Federal Circuit affirmed a district court’s ruling that Greenbrier-Concarril LLC did not infringe two patents owned by National Steel Car Ltd. (NSC) related to the design of railroad gondola cars. The patents in question, U.S. Patent Nos. 7,434,519 and 7,878,125, cover specific structural features of open-topped rail cars used for transporting bulk materials. NSC had alleged that several of Greenbrier’s railcars infringed on nineteen claims across these two patents.

The heart of the dispute centered on the meaning of the term “floor panel” in the patents. NSC argued for a broad interpretation that would include certain “side post gussets” as part of the floor panel, even though these gussets did not physically touch the main floor sheet. The district court, after extensive briefing and hearings, clarified that a “floor panel extension” must actually touch the floor panel itself—meaning that gussets separated by other structures did not count. This clarification was crucial, as the accused Greenbrier cars used gussets that did not directly contact the floor panel, leading the court to grant summary judgment of non-infringement.

On appeal, NSC claimed the court had improperly narrowed the patent claims and that it should have been allowed to present new infringement arguments under the clarified construction. The Federal Circuit disagreed, finding that the district court’s construction was correct and that NSC had been given ample opportunity to argue its case. The appellate court also emphasized that the claim construction process was thorough and fair, with no new or unexpected interpretations introduced late in the proceedings.

This decision highlights the importance of precise claim language in patent litigation and the challenges of broadening patent coverage through claim construction. For patent owners and accused infringers alike, the case underscores how technical details and careful definitions can make or break an infringement claim.