The US Court of Appeals for the Federal Circuit affirmed a final written decision from the Patent Trial and Appeal Board (PTAB) finding patent claims directed to aircraft lavatories obvious based on prior art because a skilled artisan would have used common sense to incorporate a missing limitation into the prior art. B/E Aerospace, Inc. v. C&D Zodiac, Inc., Case Nos. 19-1935, -1936 (Fed. Cir. June 26, 2020) (Reyna, J.).

C&D Zodiac sought inter partes review of two patents owned by B/E Aerospace relating to space-saving technologies for aircraft lavatory enclosures. The challenged claims recited a “first recess” and a “second recess” associated with a lavatory unit. The PTAB found that the challenged claims were obvious over several prior art patents under separate “traditional” and “common sense” approaches. The PTAB based its traditional approach on Zodiac’s arguments and expert testimony. The PTAB’s common sense approach relied on the prior art in combination with common sense and the knowledge of a person of ordinary skill in the art. In particular, the PTAB found that the prior art taught the claimed first recess, and that it would have been a matter of common sense to add the claimed second recess.

During the proceeding, B/E also moved to exclude design drawings Zodiac attached to its petition showing a second recess, because Zodiac had not shown that the drawings were “patents” or “printed publications” as required by 35 USC § 311(b). The PTAB denied the motion, explaining that the drawings were not required to be printed publication prior art because they were considered only for the purpose of identifying the knowledge of an ordinary skilled artisan rather than canceling claims as unpatentable.

B/E requested a rehearing. B/E challenged as improper the PTAB’s reliance on “common sense” in finding obviousness and the PTAB’s consideration of the design drawings. The PTAB denied the rehearing request, and B/E appealed.

The Federal Circuit affirmed the PTAB’s obviousness determination under both the traditional and common sense approaches. The Court found that modifying the prior art to include a second recess was the predictable application of known technology. The Court also agreed that it would have been a matter of common sense to incorporate a second recess in the prior art. The Court rejected B/E’s assertion that the PTAB relied on an unsupported assertion of common sense to supply a missing limitation in the prior art. Obviousness determinations may rely on common sense when accompanied by sufficient reasoning. The Court found that the PTAB’s reliance on common sense was proper because it was accompanied by reasoned analysis and supported by detailed expert testimony. The simplicity of the technology also supported the use of common sense.

The Federal Circuit determined that it did not need to reach the issue of the design drawings because the PTAB’s final obviousness determination was correct and did not rely on those drawings. The PTAB independently supported its obviousness conclusion based on Zodiac’s argument and evidence, including expert testimony.

Practice Note: Common sense accompanied by appropriate reasoning can play a role in determining obviousness, particularly when the technology is simple. Parties seeking to rely on or challenge the use of common sense in an obviousness analysis should consider the strength of the arguments and evidentiary support, including expert testimony, for an assertion of common sense.