Before Lourie, Moore, and O’Malley. Appeal from the Patent Trial and Appeal Board.
Summary: In similar claims of two related patents, one preamble was limiting because it supplied antecedent basis for a subsequent structural claim limitation, and another preamble that supplied no antecedent basis was not limiting.
Firebug sued Stride Rite for infringing two patents related to footwear illumination systems. In response, Stride Rite petitioned for inter partes review of all asserted claims. After instituting review, the Board held the challenged claims unpatentable as obvious. Firebug appealed, arguing that the Board erred by construing the preambles of the challenged independent claims as non-limiting. Specifically, Firebug asserted that the term “textile” in the preamble phrase “internally illuminated textile footwear” limited the claims and distinguished them from the prior art.
Addressing the first patent, the Federal Circuit noted that the body of the independent claim reintroduced “a footwear” immediately after the preamble and the claim recited a structurally complete invention without the preamble. Thus, the preamble was not limiting. In contrast, the independent claim of the second patent did not reintroduce “footwear” after the preamble and instead relied on the preamble phrase “textile footwear” for antecedent basis in a subsequent structural claim limitation. Thus, the preamble in the second patent was limiting.
Although the Board erred by construing the second preamble as non-limiting, the Federal Circuit deemed the error harmless because the Board found that the prior art also disclosed the use of “textile” footwear, and that finding was supported by substantial evidence. Thus, the Federal Circuit affirmed the Board’s decisions on both patents.