PTAB

IPR2016-01435

Henny Penny Corp v. FryMaster LLC

Key Events

Petition

petition

Title: System for Measuring Cooking Oil Degradation
Brief Description: The ’691 patent discloses a deep fryer system that determines the degradation state of cooking oil by recirculating the oil through an external conduit loop. An in-line sensor, housed within a special "adapter" in the conduit, measures an electrical property of the oil as it flows past to assess its quality.

Prior Art Relied Upon: Iwaguchi (Japanese Patent Application Publication No. 2005-055198A).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Iwaguchi, which was not considered during prosecution, discloses every element of the challenged claims. Iwaguchi describes a fryer system with an oil vessel (fryer pot), a filter, a pump, and a recirculation conduit for monitoring oil degradation. Critically, Petitioner asserted Iwaguchi’s “detection vessel 200,” which houses sensor probes 111-115 external to the main oil vessel, is the same as the claimed “adapter” installed between two portions of a pipe. This adapter limitation was added during prosecution to secure allowance of the ’691 patent. Iwaguchi’s probes measure electrical characteristics to determine the amount of polar compounds in the oil, directly corresponding to the claimed sensor function.

Prior Art Relied Upon: Kauffman (Patent 5,071,527) and Iwaguchi.
Core Argument for this Ground:
- Prior Art Mapping: Petitioner contended that Kauffman teaches a general on-line system for evaluating oils, including in deep fryers, that contains all the structural elements of the claims. Kauffman discloses a reservoir, a recirculation line, a pump, and an in-line analyzer/sensor (16) housed in a chamber (17). Petitioner mapped Kauffman’s chamber 17 to the claimed "adapter" and its analyzer to the "sensor." While Kauffman teaches monitoring general oil properties, it does not explicitly disclose measuring properties "indicative of total polar materials," as taught by Iwaguchi.
- Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine Kauffman’s general fluid analysis framework with Iwaguchi’s specific teachings on cooking oil degradation. Iwaguchi’s focus on detecting polar compounds provides a specific, well-understood metric for oil quality, which would have been a desirable and logical feature to implement in Kauffman’s system to create a complete and effective deep fryer monitor.
- Expectation of Success: Both references operate in the analogous art of in-line fluid analysis using external sensors, making their combination straightforward and predictable.

Prior Art Relied Upon: Iwaguchi and Grob (Patent 4,974,501).
Core Argument for this Ground:
- Prior Art Mapping: The primary distinction in independent claim 22 is the requirement for a "plurality of fryer pots" and associated drain pipes. Petitioner argued that while Iwaguchi discloses a single-pot system, Grob explicitly teaches a fryer with a "side-by-side pair of...frypots," each with its own drain conduit.
- Motivation to Combine: A POSITA seeking to improve the efficiency and capacity of the Iwaguchi oil monitoring system would have been motivated to incorporate Grob’s well-known multi-pot configuration. Petitioner asserted this modification amounts to a simple duplication of parts to achieve a predictable increase in capacity, a common design choice in the art.
- Expectation of Success: Combining a known multi-pot fryer design with a known oil monitoring system was presented as a predictable design choice with a high expectation of success.
Additional Grounds: Petitioner asserted numerous additional obviousness challenges, primarily swapping Kauffman for Iwaguchi as the base reference or combining them with other art. These included combinations with Edwards (Patent 5,787,372) for a single-pipe drain/return conduit, Howard (Patent 4,148,729) for specific adapter shapes, and Discenzo (Application # 2005/0066711) for teaching the use of dielectric sensors.

"Adapter": Petitioner argued this term, which was added to the claims during prosecution to overcome prior art, should be construed as "a structure located outside of a fryer pot and any filtration unit and configured to house a sensor in fluid communication with the fryer pot and/or filtration unit." This construction was central to Petitioner's arguments that the "detection vessel" of Iwaguchi and the "chamber" of Kauffman met this key claim limitation.

Petitioner requests institution of an inter partes review (IPR) and cancellation of claims 1-23 of Patent 8,497,691 as unpatentable.