SHOES BY FIREBUG LLC v. STRIDE RITE CHILDREN'S GROUP LLC:
CAFC Finds Preamble Limited Claims, But Claims Still Obvious
August 5, 2021
By Zhangyuan (Ellen) Ji
Stride Rite challenged certain claims in Firebug’s U.S. Patent 8,992,038 (“the ’038 patent”) and U.S. Patent 9,301,574 (“the ’574 patent”) in Stride Rite Children’s Group, LLC v. Shoes by Firebug LLC, IPR2017-01809, -01810. In its final written decisions, the Patent Trial and Appeal Board (“PTAB”) held that the identical preambles of claim 1 of the ’038 and ‘574 patents did not limit the challenged claims, and found the claims obvious. On appeal, the Court of Appeals for the Federal Circuit overturned the PTAB’s interpretation of the preamble of claim 1 of the ‘574 patent in holding that the preamble was a limitation in that claim, but nonetheless affirmed the Board’s obviousness finding. The panel concluded:
The preamble of claim 1 in the ’038 patent does not limit the claim because the body of claim 1 recites a structurally complete invention;
The identical preamble of claim 1 in the ’574 patent limits the claim because that claim uses terms from the preamble to define positive limitations in the body of the claim; and
The challenged claims in both patents are obvious.
Ellen drafts and prosecutes patent applications utilizing a wide range of technologies including computer software, hardware, web services, and networking system. She also helps in Inter Partes Review (IPR) and Post Grant Review (PGR) proceedings at the Patent Trial and Appeal Board (PTAB).
Stride Rite had petitioned for inter partes review (“IPR”) of claims 1-10 of the ’038 patent and claims 1-10 of the ’574 patent, asserting that the challenged claims were obvious. The PTAB sided with Stride Rite, concluding that the preamble of claim 1 in each patent was not a limitation, and that the challenged claims were obvious.
On appeal, Firebug argued that the preamble of claim 1 — identical in each patent, reciting“[a]n internally illuminated textile footwear comprises”— limits the scope of those claims to “textile footwear.” See Shoes by Firebug LLC v. Stride Rite Children's Grp., LLC, 962 F.3d 1362, 1366-67 (Fed. Cir. 2020).
The court disagreed with Firebug regarding claim 1 of the ‘038 patent, but agreed regarding claim 1 of the ‘574 patent.
With respect to the ‘038 patent, the court noted that the body of claim 1 of the ’038 patent recites “a footwear” without any limitation to a specific material. The court therefore concluded that the preamble of that claim was not limiting because the body recited a structurally complete article and the use of a textile material was unnecessary to the claimed invention. Id. at 1368.
But with respect to the ‘574 patent, the court noted that the body of claim 1 does not merely reintroduce “footwear,” but instead recites “the footwear,” thereby relying on the term “footwear” in the preamble for antecedent basis. Id. The court therefore concluded that the preamble of claim 1 of the ‘574 patent limits the scope of the claim to footwear with a textile upper because “use of preamble terms to define positive limitations in the body of claims can evince an inventor's intent that the preamble limit the scope of the claim.” Id.
Nonetheless, the court determined that, even with the preamble limitation, substantial evidence supported the PTAB’s finding of obviousness. Id. at 1373.
Practitioners should keep in mind the consequences of this seemingly minor difference in claim language when drafting claims. If the applicant wishes the claim to encompass the limitation in the preamble, the body of the claim should independently recite that limitation, or reintroduce the limitation in the body of the claim using the preamble terms as the antecedent basis. If the applicant does not want the preamble to be limiting, the body of the claim should not use the preamble as antecedent basis.
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