November 5, 2019

OK, Campers, Here’s How to Make Your Claim Preamble a Limitation

In In re: David Fought, Martin Clanton, [2019-1127] (November 4, 2019) the Federal Circuit reversed the PTAB decision that claims 1 and 2 in U.S. Application Serial No. 13/507,528 were anticipated.

The claims were directed to travel trailer with a movable garage wall. Claim 1 read:

Claim 1 | Intellectual Property Law Firm | Harness IP Claim 1 form U.S. Application 13/507528

Figs 1 and 2 | Intellectual Property Law Firm | Harness IP Figs. 1 and 2 of Application 13/507528

The Examiner rejected both claims 1 and 2 as anticipated. The Board affirmed the examiner’s rejection, concluding the preamble term “travel trailer” is a mere statement of intended use that does not limit the claim. The Federal Circuit rejected appellants first argument that “A travel trailer having” was not a preamble, noting though this claim does not use the typical claim language (comprising) which denotes the transition between the preamble and the body, the word “having” performs the same role.

Appellant’s next argument was that even if “travel trailer” is part of the preamble, it is limiting because limitations in the body of the claims rely on “travel trailer” for antecedent basis and for structural limitations. On this point, the Federal Circuit agreed, noting that it has repeatedly held a preamble limiting when it serves as antecedent basis for a term appearing in the body of a claim. Appellants provided extrinsic evidence to support their assertion that “travel trailer” is a specific type of recreational vehicle that includes a living quarters.

The Federal Circuit said:

Based on the extrinsic evidence, we conclude that a ‘travel trailer’ is a specific type of recreational vehicle and that this term is a structural limitation of the claims. There is no dispute that if ‘travel trailer’ is a limitation, Dietrich and McDougal, which disclose cargo trailers and shipping compartments, do not anticipate. Just as one would not confuse a house with a warehouse, no one would confuse a travel trailer with a truck trailer.

The Federal Circuit rejected appellant’s argument that the Patent Office had an obligation to identify the level of ordinary skill in the art — at least where the applicant had not put it in issue.


Whether a preamble is a limitation is a two-edged sword for applicants. On the one hand, if the preamble is a limitation, it can make the claim patentable. On the other hand, it can also make the claims harder to infringe. Where the applicant wants the preamble to be a limitation, purposely using the words in the body of the claim will achieve that goal. Idly parroting the words of the preamble in the body, however, can unintentionally limit the claims for purposes of infringement.