FryMaster LLC v. SherWood Sensing Solutions LLC

1. Case Identification

• Case #: IPR2020-00752
• Patent #: 10,285,539
• Filed: March 23, 2020
• Petitioner(s): Frymaster, L.L.C. and Henny Penny Corporation
• Patent Owner(s): Sherwood Sensing Solutions LLC
• Challenged Claims: 1-11

2. Patent Overview

• Title: Frying System and Method
• Brief Description: The ’539 patent discloses a frying system designed to mitigate cooking oil degradation caused by exposure to air. The system features a frying tank with an "interior chamber" that is closed during operation and a cooking oil delivery system that circulates oil between the frying tank and a separate vat.

3. Grounds for Unpatentability

Ground 1: Claims 1-11 are anticipated by Campbell under 35 U.S.C. §102.

• Prior Art Relied Upon: Campbell (Patent 5,404,796).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Campbell, which discloses an automated french fry vending machine, taught every limitation of the challenged claims. Independent claim 1 was allegedly met by Campbell’s disclosure of a "cooking chamber 150" that is enclosed during operation, satisfying the "frying tank having an interior chamber" limitation. Campbell’s "heating element 152" met the heater limitation. The system for pumping oil from a "reservoir 214" to the cooking chamber via "oil pump 236" constituted the claimed cooking oil delivery system, with the reservoir serving as the "vat." Petitioner asserted that Campbell’s use of thermocouples to monitor the oil level and activate the pump to replenish oil satisfied the limitation of maintaining a desired oil level. Petitioner further contended that Campbell disclosed the limitations of all dependent claims, including oil removal via absorption (inherent in frying) and the drainage and reintroduction of oil.

Ground 2: Claims 1-11 are anticipated by Van Den Berg under 35 U.S.C. §102.

• Prior Art Relied Upon: Van Den Berg (WO 93/04617).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Van Den Berg, which describes a "deep-frying device" with a continuous oil circulation system, anticipated all challenged claims. The "frying tank having an interior chamber" was allegedly disclosed as Van Den Berg’s "deep-frying vessel 2" fitted with a "cover 15," creating an enclosed space. The vessel was explicitly "provided with a heating element." The claimed delivery system was met by Van Den Berg’s disclosure of a system that continuously pumps oil from a "feedstock reservoir (3)" (the "vat") to the deep-frying vessel and back using a "pump 4’." Petitioner argued the limitation of maintaining a desired oil level was met by Van Den Berg’s "regulating system," which ensures a "continuous feed" to "keep the level in the deep-frying vessel constant" as oil is consumed during frying.

Ground 3: Claims 1-11 are anticipated by Sugimoto under 35 U.S.C. §102.

• Prior Art Relied Upon: Sugimoto (Japanese Application No. P2002-20924A).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground was presented as an alternative that anticipates the claims even under the Patent Owner's expected, broader claim construction where the "interior chamber" is not required to be enclosed during cooking. Petitioner argued Sugimoto’s open-top fryer met all claim limitations. The "frying tank" was Sugimoto’s "oil tank 6," and the "heater" was its "heat pipes 9c" penetrating the tank. The delivery system was described as Sugimoto’s "circulation path," which moves oil from a "storage tank 10" (the "vat") to the oil tank using a "pump 16" and includes a filter. The limitation of maintaining a desired oil level was allegedly met by Sugimoto’s control system, where a "float sensor 51" detects a low oil level and signals a "control unit 50" to increase the pump’s speed, thereby delivering more oil to raise the level to a "predetermined level."

4. Key Claim Construction Positions

• Petitioner dedicated significant argument to the construction of "a frying tank having an interior chamber."
  • Petitioner’s Proposed Construction: "a frying tank with an internal space that is enclosed during cooking."
  • Core Argument: Petitioner argued this construction is required by the specification, which consistently describes a closed or hermetically sealed system as the solution to the stated problem of oil oxidation from air exposure. Petitioner contended that the Patent Owner's expected broader construction, which would encompass open-top fryers, would improperly render the claim term "interior chamber" superfluous, as every frying tank has an interior space. The patent’s own distinction between the enclosed fryer of Figures 1-3 and the open deoiling system of Figure 4 (which is not described as having an "interior chamber") was cited as further support.

5. Arguments Regarding Discretionary Denial

• §325 Denial: Petitioner argued denial under 35 U.S.C. §325 would be improper because none of the asserted prior art references (Campbell, Van Den Berg, or Sugimoto) were considered during the original examination. The anticipation-based arguments in the petition were asserted to be entirely new.
• §314(a) Denial (Fintiv): Petitioner argued that discretionary denial under 35 U.S.C. §314(a) was unwarranted because the parallel district court litigations were in their infancy. At the time of filing, no trial dates had been set, and discovery had not commenced, making it likely that a Final Written Decision would issue well before any potential trial.

6. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1-11 of the ’539 patent as unpatentable.