The Software IP Report

Limits on Obviousness – Beyond the Claim Elements

Here is a lesson on obviousness. The Federal Circuit agreed with the Patent Trial and Appeal Board (PTAB) that claims for a system to measure degradation of cooking oils in a deep fryer were non-obvious under 35 U.S.C. §103. The PTAB had found that a skilled artisan would not have been motivated to combine the identified references, and that secondary evidence provided by the patentee supported non-obviousness. The court agreed in Henny Penny Corp. v. Frymaster LLC, No. 2018-1596 (Fed. Cir., September 12, 2109).

Henny Penny Corporation’s (HPC) appeal was from the PTAB’s Inter Partes Review final decision Henny Penny Corp. v. Frymaster L.L.C., No. IPR2016-01435, 2017 WL 6551237(P.T.A.B. Dec. 21, 2017) holding claims 1-3, 5-12, 17-21 and 23 of U.S. Patent 8,497,691 not unpatentable as obvious.


This case relates to measuring total polar materials (TPMs) that build up in aging cooking oil. High TPM levels in cooking oil indicate that the oil is degraded. Representative claim 1 of the ‘691 patent recites:

A system for measuring the state of degradation of cooking oils or fats in a deep fryer comprising:

at least one fryer pot;

a conduit fluidly connected to said at least one fryer pot for transporting cooking oil from said at least one fryer pot and returning the cooking oil back to said at least one fryer pot;

a means for re-circulating said cooking oil t o and from said fryer pot; and

a sensor external to said at lest one fryer pot and disposed in fluid communication with said conduit to measure an electrical property that is indicative of total polar materials of said cooking oil as the cooking oil flows past said sensor and is returned to said at least one fryer pot;

wherein said conduit comprises a drain pipe that transports oil from said at least one fryer pot and a return pipe that returns oil to said at least one fryer pot,

wherein said return pipe or said drain pipe comprises two portions and said sensor is disposed in an adapter installed between said two portions, and

wherein said adapter has two opposite ends wherein one of said two ends is connected to one of said two portions and the other of said two ends is connected to the other of said two portions.

In its IPR petition, HPC challenged claim 1 as obvious over U.S. Patent No. 5,071,527 (Kauffman) and Japanese Unexamined Patent Application Publication No. 2005-55198 (Iwaguchi).

Kauffman discloses an apparatus for monitoring oil quality in equipment such as deep fryers, engines and gear boxes including an electrode positioned between drain and return lines of a reservoir. The electrode measures conductivity and current to monitor undesirable properties of the oil. Kauffman does not disclose measuring TPM levels.

Iwaguchi discloses an apparatus for monitoring TPMs in cooking oil. The apparatus includes a heat dissipator through which the cooking oil is diverted to cool the oil prior to measurement with a TPM sensor.

HPC took the position that a skilled artisan would have been motivated to combine the sensor from Iwaguchi with the apparatus of Kauffman to measure TPMs in cooking oil. Frymaster countered that integrating the temperature sensitive sensor from Iwaguchi would not have yielded a predictable outcome of measuring oil quality.

The Board agreed with Frymaster. The operational temperature of a fryer is between 150-180°C. Iwaguchi taught cooling its TPM sensors to 40-80°C. Adding the heat dissipator from Iwaguchi to cool the oil prior to measurement would have introduced additional complexity to the apparatus of Kauffman. On balance, the Board found that the disadvantages outweighed the uncertain benefits of adding the TPM sensor from Iwaguchi to the apparatus of Kauffman.

Additionally, the Board found that evidence of secondary considerations supported nonobviousness. Frymaster submitted evidence that a product including its TPM sensor had won praise from two industry organizations and one customer. Each industry award specifically praised the TPM sensor. The product containing the TPM sensor was commensurate in scope with the claims, and therefore had the required nexus for secondary evidence. The Board found that the industry awards and praise from the customer weighed in favor of patentability.


In its appeal, HPC argues that the Board placed undue weight on the disadvantages of introducing Iwaguchi’s TPM sensor into Kauffman’s system. “The fact that the motivating benefit comes at the expense of another benefit . . . should not nullify its use as a basis to modify the disclosure.” Winner Int’l Royalty Corp. v. Wang, 202 F.3d 1340, 1349 n.8 (Fed. Cir. 2000). The Court, rebuts, however, that the very next sentence in Winner states “[T]he benefits, both lost and gained, should be weighed against one another.” (Id. at 1349 n.8.) Prior art must be considered for all its complexities. (See, e.g., Merck & Cie v. Gnosis S.p.A., 808 F.3d 829,834 (Fed. Cir. 2015).

The Court found the Board’s analysis to be consistent with these principles. The heat dissipator of Iwaguchi would introduce additional plumbing and complexity and lead to decreased efficiency. A person of ordinary skill would not have been motivated to integrate Iwaguchi’s TPM sensor into Kauffman’s system.

Regarding the secondary evidence, HPC argues that there was insufficient nexus between Frymaster’s product and the industry praise, because a deep fryer with an integrated TPM sensor was already taught by Iwaguchi. “[T]he objective indicia (of nonobviousness) must be directed to what was not known in the prior art.” Novartis AG v. Torrent Pharm. Ltd., 853 F.3d 1316, 1331 (Fed. Cir. 2017).

The Court disagreed, citing from the same case that “what was not known in the prior art . . . may well be the novel combination or arrangement of known individual elements.” (Id., at 1331.) Claim 1 is commensurate with the praised product. The praise was directed to the product as a whole including the claimed integrated TPM sensor. Iwaguchi did not teach this specific combination.

The Court affirmed the Board’s finding that claim 1 was nonobvious. Substantial evidence supported the Board’s finding of no motivation to combine, and Frymaster’s evidence of secondary considerations supports nonobviousness.

Lessons for Practice

Here, a straight forward obviousness argument was overcome based on lack of motivation to combine references and secondary evidence of commercial success. When defending a claim from against an obviousness argument, at least at the PTAB, it can be good to remember that “the benefits, (of combined references) both lost and gained, should be weighed against one another,” and that secondary considerations can matter.