According to the United State Court of Appeals for the Federal Circuit (CAFC) precedential opinion decided on March 26, 2019, ARCTIC CAT INC. v. GEP POWER PRODUCTS, INC., the claim preamble terms, such as “A power distribution module for a personal recreational vehicle comprising” or “A personal recreational vehicle comprising”, are not limiting.

Two patents by Arctic Cat Inc. were found to be invalid in inter partes reviews (IPR) before Patent Trial and Appeal Board (PTAB or “Board”) and Arctic Cat appealed. The patents describe an assertedly inventive electrical-connection box having an array of receptacle openings that allow wires to be arranged and secured in various positions for distributing power to various electrical components, including components of a personal recreational vehicle. The Board rejected (and CAFC affirmed) part of Arctic Cat’s argument that certain language in the claim preambles is limiting, i.e., defines the inventions to be assessed for patentability, because “the claim bodies . . . describe structurally complete inventions that do not include personal recreational vehicles and that the preambles recite[] only an intended use for the otherwise complete claimed apparatus”.

CAFC holds that “a preamble is not limiting where a patentee defines a structurally complete invention in the claim body and uses the preamble only to state a purpose or intended use for the invention”. Furthermore, “not every preamble reference to additional structure is limiting, even when the structure is noted in the specification—even, indeed, when the structure is underscored as important by the specification”. “What is missing in the specification is any identification of a feature of the vehicle that is asserted to be an improvement other than the “power distribution module” as described in the various claims. The vehicle in the preamble is entirely conventional apart from the improvement in the body of the claims”, therefore not limiting as well. Finally, CAFC confirms “that preamble language is limiting when the claim recites a combination in the way specified in the one PTO regulation on preambles, i.e., by describing the “conventional or known” elements in a “preamble,” followed by a transition phrase “such as ‘wherein the improvement comprises,’” and then an identification of elements that “the applicant considers as the new or improved portion”, as in a Jepson form.

Obviously, both extra caution and right format are required when one uses claim preambles as an intended limitation or drafts a claim in general, especially when one expands the scope of claims.