Addressing an issue of breadth of claim interpretation during patent examination, the U.S. Court of Appeals for the Federal Circuit reversed the decision of the Board of Patent Appeals and Interferences (the Board), holding that appellant’s application is not anticipated by a cited reference and remand for completion of examination. In re Buszard et al., Case No 06-1489 (Fed. Cir., Sept. 27, 2007) (Newman, J.; Prost, J., dissenting).

Buszard’s claimed invention relates to a flame retardant composition that produces a flexible polyurethane foam and the flexible foamed article made from that composition. The U.S. Patent and Trademark Office (USPTO) rejected the claims as being anticipated by prior art that disclosed a rigid foam produced by chemical reaction of compounds that form a rigid foam, and a flexible foam produced by crushing the rigid foam. Buszard appealed to the Board, which in turn affirmed the examiner’s decision.

The Board interpreted claim term “flexible polyurethane foam reaction mixture” to mean “any reaction mixture which produces, at least ultimately, a flexible polyurethane foam.” Buszard argued that the prior art rigid foam product is chemically different from a flexible foam that is directly produced by polymerization without crushing and that this difference is readily understood by a person of ordinary skill in the art. While agreeing that a flexible foam and a rigid foam have different chemical structure and are produced from different chemical reactants, the USPTO argued that the rejection should be sustained because the USPTO is entitled to give claims their broadest reasonable interpretation during examination.

The Court agreed with the general proposition that in order to facilitate sharpening and clarifying the claims at the application stage, the patent claims may be given their broadest interpretation consistent with the specification. This is because during prosecution, while claims are subject to amendment, the patent examiner and the applicant—in the give and take of rejection and response—may work toward defining the proper metes and bounds of the invention.

Turning to the specific facts of this case, the Court rejected the USPTO argument that the product made from mechanical crushing of the rigid foam is the same as the flexible product of a flexible form reaction mixture, noting this theory was not mentioned by the examiner or the Board and thus gave Buszard no opportunity to refute it during examination and appeal. In addition, the Court found the theory to be without record evidence or support. The Court concluded that no matter how broadly “flexible foam reaction mixture” is construed, it is not a rigid foam reaction mixture and that it is not a reasonable claim interpretation to equate “flexible” with “rigid,” or to equate a crushed rigid polyurethane foam with a flexible polyurethane foam. Thus, the Court reversed the anticipation rejection.

In dissent, Judge Prost argued that the majority failed to follow Federal Circuit precedent, in terms of claim interpretation during prosecution. As explained by Judge Prost, in the content of an infringement suit, courts take on the difficult task of analyzing the claim terms to ascertain the meaning the terms would have to a person of ordinary skill in the art as of the filing date of the patent application. Courts thus examine the claims, the specification, the prosecution history and possibly extrinsic evidence, all in an effort “to determine what the applicant regards as his invention.” However, Judge Prost reminded us that one need not engage in a guessing game during prosecution. If a claim term is ambiguous or confusing, the applicant can clarify it. If an applicant wants a claim term to have a specific meaning, the applicant can either amend the claim to expressly convey that meaning or otherwise provide an express definition for the claim term. In light of these differences, Judge Prost would find that the claim language in issue could reasonably be interpreted to include the mixture disclosed in the prior art (which is capable of producing a flexible polyurethane foam) and that if Buszard seeks a narrower interpretation, he should simply amend his claim.