Cooking oil sensor on deep fryer patent upheld. HENNY PENNY v. FRYMASTER

Cooking oil sensor on deep fryer patent upheld. HENNY PENNY v. FRYMASTER

The owner of a patent is granted the exclusive right to make, use, sell and import the invention claimed in the patent.  In the United States patents are granted by the United States Patent and Trademark Office.  To be granted a patent, an inventor must file a patent application.  The patent application will be reviewed by an examining attorney at the USPTO and if all the statutory requirements are met, the application will be granted.  One of the primary requirements that must be met is that the invention is not obvious.  If the invention is obvious to experts or the general public, then the patent application cannot be granted.

Whether an invention is obvious is an objective test based on the prior art and a person having ordinary skill in that art.  Prior art is the sum of all knowledge in a given field of technology.  Research papers, granted patents, patent applications, and other forms of printed publications are all examples of prior art.  The person of ordinary skill in the art is a hypothetical person who is presumed to have known the relevant art at the time of the invention.  During the prosecution of a patent application, the examining attorney will perform a search of the prior art and determine whether the invention would have been obvious at the time of the invention.

After the grant of a patent, the patent is still open to attack on the grounds that the invention was obvious.  Obviousness can be raised as a defense in a patent infringement trial or it can be raised in an Inter Partes Review to get the patent invalidated.  Inter partes review is a trial proceeding conducted at the Patent Trial and Appeal Board (PTAB) of the USPTO to review the patentability of one or more claims in a patent only on a ground that could be raised under §§ 102 or 103, and only on the basis of prior art consisting of patents or printed publications.

HENNY PENNY CORPORATION v. FRYMASTER LLC, 2018-1596 (C.A.F.C. 2019) is an examples of an Inter Partes review which failed to invalidate a patent.  The case revolves around a patent on a sensor used to measure the quality of the cooking oil in a food fryer.  During frying, cooking oil gradually degrades and loses its cooking capacity, generating impurities called total polar materials (“TPMs”). Patent 8,497,691, owned by defendant, describes a system for measuring the state of cooking oil degradation with a TPM sensor. When the sensor detects that TPM levels are too high, the system instructs the fryer operator to change the oil. The purpose of the TPM sensor is to ensure that oil is neither “wasted by being prematurely changed” nor “overused thereby tainting food and harming consumers.”

The plaintiff, a competitor of the defendant, petitioned for inter partes review (“IPR”) of the ’691 patent. In its petition the plaintiff asserted that two pieces of prior art, when combined, rendered the patent obvious.  At the PTAB proceeding, the plaintiff changed their argument to, measuring TPMs could be achieved using  one piece of prior art and the other piece of prior art taught the idea of measuring TPMs. The PTAB held that the claims are not unpatentable as obvious because there was no motivation to combine the two pieces of prior art and that evidence of secondary considerations supported nonobviousness.

The plaintiff appealed this finding to the Court of Appeals for the Federal Circuit.  The claimed TPM sensor is central to the two issues on appeal, which are: (1) whether the Board abused its discretion in disregarding certain of HPC’s post-institution arguments about how to incorporate a TPM sensor into a deep fryer;  and (2) whether the Board erred in concluding that the deep fryer system claimed in the ’691 patent would not have been obvious.

The Federal Circuit found that the PTAB’s decision was supported by substantial evidence and affirmed.  The court held that the PTAB did not by holding the plaintiff to the original theory presented in the petition and rejecting the new theory presented at the proceeding.  The court also held that substantial evidence supported the PTAB decision of nonobviousness based on a lack of motivation to combine and secondary considerations.

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