On September 12, 2019, the United States Court of Appeals for the Federal Circuit (“Federal Circuit”) made a decision in Henny Penny Corporation v. Frymaster LLC. Frymaster LLC is the owner of U.S. Patent No. 8,497,691 (“the ‘691 patent”), titled “Oil Quality Sensor and Adapter for Deep Fryers.”

The ‘691 patent “relates to an oil quality sensor that is installed in a fryer for the purpose of indicating when the cooking oil should be changed for one or more fryer pots.” More specifically, the use of a total polar materials (“TPMs”) sensor in the fryer. “Henny Penny Corporation (“HPC”) appeals from the inter partes review decision of the United States Patent and Trademark Office Patent Trial and Appeal Board (the “Board”) holding claims 1-3, 5-12, 17-21, and 23 of [the ‘691 patent] not unpatentable as obvious.” HPC has further arguments on how the ‘691 patent should be unpatentable based on obviousness, which provides the grounds for their appeal.


Per the standard, “[they] review[ed] the Board’s legal determinations de novo… [they] review[ed] the Board’s factual findings underlying those determinations for substantial evidence.” HPC has two arguments in regard to their appeal of the original decision. HPC’s arguments are “(1) the Board procedurally erred by too narrowly construing the petition; and (2) that the Board erred in its conclusion of nonobviousness.”

First, “HPC argues that the Board erroneously interpreted the petition as limited to the physical substitution of Iwaguchi’s sensor for Kauffman’s,” which was related prior art to the ‘691 patent. It is known that “because of the expedited nature of [inter partes review] proceedings, ‘[i]t is of the utmost importance that petitioners in the [inter partes review] proceedings adhere to the requirement that the initial petition identify ‘with particularity’ the ‘evidence that the supports the grounds for the challenge to each claim.’” It has been determined that the Board did not abuse its discretion because they were not responsible to “‘an entirely new rationale’ for why a claim would be obvious,” which was what HPC had done.

Second, HPC argues that the Board made errors when reevaluating claim 1 as nonobvious. HPC further argues that the Board did not “combine Iwaguchi’s TPM sensor with Kauffman’s system,” which they claim is a mistake of the Board’s. HPC also argues that the Board did not find the proper evidence and “erred in finding Frymaster’s evidence of industry praise to be probative of nonobvious.” There was “substantial evidence [that] supports the Board’s finding of no motivation to combine” Iwaguchi’s TPM sensor with Kauffman’s system. Frymaster’s evidence of prior industry awards praising the product lead the Board to find that “this evidence weighed in favor of nonobviousness because claim 1 was commensurate in scope with Frymaster’s praised product.”

For the reasons above, the Federal Circuit affirms the Board’s judgement.


This decision determines that even though a device may be well known in the prior art, a novel combination of the well-known device with other components may be enough for ensuring a patent is nonobvious.

Full Henny Penny Corporation v. Frymaster LLC decision can be read here:

Disclaimer: The views and opinions expressed throughout this blog are the views and opinions of the individual author(s) and/or contributor(s) and do not necessarily reflect the views and opinions of our firm, CIONCA IP Law. P.C.


PATENT, Trademark and IP Law Blog

  • CIONCA IP10/7/2019 5:44:50 PM

    A Decision in Henny Penny Corporation v. Frymaster LLC

Marin Cionca | Founder of CIONCA IP

Marin Cionca, Esq.

Registered Patent Attorney

USPTO Reg. No. 63899

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