Broadest Reasonable Interpretation is NOT Broadest Possible InterpretationSeptember 30, 2017

In a decision by the Federal Circuit Court of Appeals last week, In re Smith International, Inc., the Federal Circuit reversed the Patent Trial and Appeal Board (“the Board”) decision affirming the Examiner’s rejections of some claims in an ex parte reexamination. The invention is directed to a downhole drilling tool for oil and gas operation. The involved claims recite the word “body”  without further limiting features in the claims and a definition in the specification. The Examiner interpreted the word “body” to encompass other components such as “mandrel” and “can sleeve” that the specification also discussed. Under such interpretation, the Examiner rejected the claims as being anticipated by and obvious over a prior art. 

The Board affirmed the Examiner’s rejection, reasoning that the word “body” is a generic term without structural specificity and that the specification does not define the word and preclude the Examiner’s interpretation. Furthermore, The Board rejected the argument that the person of ordinary skill in the art would understand the term as a distinct element from other components, because the patent owner “has not shown that the parts identified in the prior art as bodies are so similar to create a specific identity of a body is.” The Board reasoned that it was perfectly reasonable to understand the term to include one or more other elements, given its broadest reasonable interpretation.

The Federal Circuit concluded that the Board’s construction of “body” was unreasonably broad, holding “[t]he correct inquiry in giving a claim term its broadest reasonable interpretation in light of the specification is not whether the specification proscribes or precludes some broad reading of the claim term adopted by the examiner.” The Federal Circuit held that the correct inquiry is “an interpretation that corresponds with what and how the inventor describes his invention in the specification,i.e., an interpretation that is consistent with the specification.” 

Specifically, The Federal Circuit held that following the Board’s logic, “any description short of an express definition or disclaimer in the specification would result in an adoption of a broadest possible interpretation of a claim term, irrespective of repeated and consistent descriptions in the specification that indicate otherwise.” And “PTO fails to point out to any description of the body that would support its strained construction of “body.”” Thus, the Borad’s interpretation is unsupported and improper. A broadest reasonable interpretation cannot be a broadest possible interpretation.

Xiaohong Liu, Ph.D., is an Intellectual Property Attorney in the Biotechnology/Chemical Patent Practice Group at McKee, Voorhees & Sease, PLC. He is a native Chinese speaker and would be happy to discuss this topic with you in further detail. For additional information please visit or contact Xiaohong directly via email at

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