Fluke Corporation v. AMETEK DENMARK A/S

1. Case Identification

• Patent #: 8,342,742
• Filed: July 13, 2016
• Petitioner(s): Fluke Corporation
• Patent Owner(s): AMETEK DENMARK A/S
• Challenged Claims: 1-20

2. Patent Overview

• Title: Thermal Calibrating System
• Brief Description: The ’742 patent describes a technique for controlling heat transfer in a temperature calibrating system. The system uses a heat-transfer device, such as a thermosiphon or heat pipe, connected between a cooling unit and a calibration unit, with an "external chamber" used to control the thermal conductivity between them.

3. Grounds for Unpatentability

Ground 1: Claims 1-20 are anticipated or obvious over Marcarino, alone or in view of Kögler and Sone.

• Prior Art Relied Upon: Marcarino (a 2003 article on gas-controlled heat pipes), Kögler (UK Application GB 2 003 596 A), and Sone (Application # 2005/0109057).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted two main theories. First, claim 1 is anticipated under 35 U.S.C. §102 by the system in Figure 1 of Marcarino, which petitioner argued discloses all elements of the claim. Marcarino shows a gas-controlled heat pipe for temperature calibration, where a "Helium Pressure Line" functions as the claimed "external chamber" to control thermal conductivity by adjusting the pressure of a non-condensable gas. Second, Petitioner argued that the system in Figure 6 of Marcarino, which shows a heat pipe open to the atmosphere, renders the claims obvious. This system controls thermal conductivity by allowing the working fluid to boil off, thereby stopping heat transfer.
  • Motivation to Combine (for §103 grounds): Petitioner argued that if the ’742 patent is construed to require a "liquid-flow modulated" variable conductance heat pipe (VCHP) instead of the "gas-loaded" VCHP in Marcarino's Figure 1, a person of ordinary skill in the art (POSITA) would combine Marcarino with Kögler. Kögler teaches a liquid-flow modulated VCHP that uses an external chamber to collect condensed working fluid, advantageously eliminating the need for a separate non-condensable gas system. A POSITA would combine the teachings to simplify Marcarino's design. For the Figure 6 embodiment, a POSITA would add an external chamber (taught by Kögler or Marcarino Fig. 1) to the open end to prevent the loss of expensive working fluid and expand the system's operating temperature range. Sone was introduced to render claims 13-17 obvious, as it teaches using a Stirling cooler as the cooling unit, a well-known and portable alternative to the water cooler in Marcarino.
  • Expectation of Success: The combination involved substituting known types of VCHPs and cooling systems for their predictable functions. A POSITA would have expected success in simplifying Marcarino's system with Kögler's design or in making Marcarino's open system more efficient and robust by adding a collection chamber.

Ground 2: Claims 1-20 are obvious over Kögler in view of Bronlund and Sone.

• Prior Art Relied Upon: Kögler (UK Application GB 2 003 596 A), Bronlund (Patent 6,709,152), and Sone (Application # 2005/0109057).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Kögler discloses a liquid-flow modulated VCHP that meets every limitation of claim 1 except for a specific "temperature calibration unit." Kögler's device is a general-purpose controllable heat pipe. Bronlund, in turn, discloses an apparatus specifically for calibrating temperature sensors, including a calibration body with an "inner wall" that functions as the missing "temperature calibration unit."
  • Motivation to Combine: A POSITA would combine the references to provide a specific, useful application for Kögler's heat pipe and to simplify Bronlund's calibration apparatus. It was well-known to use the stable internal environment of a VCHP for temperature calibration. By incorporating Bronlund's "inner wall" into Kögler's heat pipe, a POSITA could create a more efficient and portable calibration system that eliminates the need for Bronlund's complex fluid circulation pumps and piping. As in Ground 1, Sone was combined to teach the use of a Stirling cooler for claims 13-17.
  • Expectation of Success: The combination was presented as a predictable integration of a known heat control system (Kögler) with a known functional component (Bronlund's calibration unit) to achieve a desired, improved system. Modifying a heat pipe's end cap to include a sensor or calibration well was a well-known technique.

4. Key Claim Construction Positions

• "connected between" (claim 1): Petitioner proposed this term means the heat transfer device is disposed so as to transfer heat from the calibration unit to the cooling unit. This construction supports mapping prior art where the components are thermally linked for heat transfer, even without direct physical connection.
• "external chamber for controlling the thermal conductivity..." (claim 1): Petitioner argued this phrase pertains to any container operatively associated with the heat transfer device to adjust heat transfer between the calibrator and the cooler. This broad construction allows Marcarino’s "Helium Pressure Line" and Kögler's condensate container to meet the claim limitation.

5. Key Technical Contentions (Beyond Claim Construction)

• A central technical contention was the distinction between two types of VCHPs. The petition distinguished "gas-loaded" VCHPs (like Marcarino), which control heat transfer by varying the pressure of a non-condensable gas, from "liquid-flow modulated" VCHPs (like Kögler and the ’742 patent's preferred embodiment), which control heat transfer by moving the working fluid into and out of an external chamber. This distinction was critical to Petitioner's alternative obviousness arguments and its refutation of the Patent Owner's arguments from a prior reexamination.

6. Arguments Regarding Discretionary Denial

• The petition was filed before a prior Supplemental Examination where the Patent Owner had submitted Kögler and Bronlund. Petitioner argued against discretionary denial under §325(d) by asserting that the art and arguments were not substantially the same. During the prior examination, the Patent Owner had proposed combining Kögler as a secondary reference with an incompatible primary reference (JP ’037) that taught against controlling thermal conductivity. Petitioner argued that its new grounds, which used Kögler as a primary reference and combined it with the compatible teachings of Bronlund, were far more material and had not been previously considered on their merits by the Office.

7. Relief Requested

• Petitioner requested institution of an IPR and cancellation of claims 1-20 of Patent 8,342,742 as unpatentable.