PTAB

IPR2019-00213

General Electric Co v. United Technologies Corp

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Geared Turbofan Engine with Specific Engine Unit Thrust Parameter (EUTP)
  • Brief Description: The ’827 patent discloses a geared turbofan engine architecture comprising a gas generator, a power turbine, and a speed reduction device (gearbox). The novelty asserted resides in the engine achieving a specific mathematical value for an "Engine Unit Thrust Parameter" (EUTP), which is a formula combining net engine thrust, bypass mass flow rate, fan tip diameter, and power turbine speed.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1-18 and 20-24 under §102 over Wendus

  • Prior Art Relied Upon: Wendus (Bruce E. Wendus et al., Follow-On Technology Requirement Study for Advanced Subsonic Transport, August 2003).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Wendus, which describes an Advanced Ducted Propulsor (ADP) engine, discloses every limitation of the challenged claims. Wendus expressly teaches a geared turbofan architecture with all the required structural components: a gas generator section, a power turbine (a six-stage low-pressure turbine), a speed reduction device (a 4.2:1 gearbox), and a propulsor section. For the crucial EUTP limitation, Petitioner calculated the EUTP for the Wendus engine based on disclosed performance parameters. Wendus explicitly provides values for a "maximum climb" condition that result in a calculated EUTP of approximately 0.078, which anticipates claims requiring an EUTP less than 0.10 or 0.08 (e.g., claims 9, 10, 18). For claims requiring an EUTP less than 0.15 at a "take-off condition" (e.g., claims 1, 11, 17), Petitioner contended that a person of ordinary skill in the art (POSITA) would understand from Wendus's disclosures that the bypass mass flow rate at takeoff would be significantly higher than at climb, resulting in a calculated EUTP well below the 0.15 threshold. All other claimed parameter ranges, such as fan diameter, thrust, and pressure ratios, were also alleged to be expressly disclosed or inherently present in the Wendus engine design.

Ground 2: Obviousness of Claims 1-24 under §103 over Wendus in view of POSITA Knowledge

  • Prior Art Relied Upon: Wendus and the general knowledge of a POSITA.
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that to the extent any limitation is not explicitly disclosed by Wendus, it would have been obvious to a POSITA. This ground particularly addressed the EUTP limitations as being obvious "result-effective variables." Petitioner asserted that EUTP is a formula composed of four parameters (net thrust, fan diameter, bypass mass flow, turbine speed) that were individually and collectively known to affect engine efficiency. The prior art, including Wendus, taught that using a geared architecture allows designers to optimize these parameters (e.g., increase fan diameter and bypass ratio) to improve fuel efficiency and reduce weight for a given thrust requirement. This optimization process inherently leads to a lower EUTP value.
    • Motivation to Combine (for §103 grounds): A POSITA would be motivated to modify the Wendus engine design by applying well-known aerodynamic principles to meet specific performance goals, such as takeoff thrust. This routine design optimization to improve efficiency and performance would have naturally led to an engine with an EUTP value within the claimed ranges. The motivation was not to achieve a specific EUTP, but to improve overall engine performance, with the claimed EUTP ranges being an obvious result of that effort.
    • Expectation of Success (for §103 grounds): A POSITA would have had a high expectation of success because the relationships between the individual components of the EUTP formula and overall engine performance were well-understood and predictable.
    • Key Aspects: This ground asserted that claiming a specific range for a known result-effective variable, derived from optimizing known components of a known engine architecture, does not confer patentability without evidence of unexpected results, which Petitioner argued the ’827 patent lacks.

4. Key Claim Construction Positions

  • "mass flow generated by the propulsor section is between about 625 lbm/hour and about 80,000 lbm/hour" (Claims 5, 13, 22): Petitioner argued this phrase should be construed to mean lbm/second instead of lbm/hour. This construction was based on the specification's consistent use of lbm/second for mass flow rates and an amendment submitted by the Patent Owner during prosecution (though not incorporated into the final patent) to correct this apparent typographical error. This construction is critical, as the prior art values for mass flow are in lbm/second.
  • "gas generator defines an overall pressure ratio" (Claims 8, 16): Petitioner contended that, based on the specification, this term refers to the pressure at the gas generator exit (after a turbine) divided by the pressure at the inlet (before a compressor or fan). However, anticipating that the Patent Owner might propose alternative constructions (e.g., pressure ratio across only the compressors), Petitioner analyzed the prior art under multiple interpretations and argued that Wendus discloses a ratio between 40 and 80 under each plausible construction.

7. Relief Requested

  • Petitioner requests institution of an IPR for claims 1-24 and cancellation of those claims as unpatentable under 35 U.S.C. §§ 102 and 103.