General Electric Company v. UNITED TECHNOLOGIES CORORATION

1. Case Identification

• Patent #: 8,365,513
• Filed: January 29, 2016
• Petitioner(s): General Electric Company
• Patent Owner(s): United Technologies Corporation
• Challenged Claims: 1-8

2. Patent Overview

• Title: Turbofan Engine with Variable Area Bypass Nozzle
• Brief Description: The ’513 patent discloses a turbofan engine featuring a variable area bypass nozzle. The invention centers on a controller programmed to command a "flow control device" (the nozzle) to adjust its exit area, thereby achieving a "target operability line" for the fan to optimize performance and stability across different flight conditions.

3. Grounds for Unpatentability

Ground 1: Anticipation over Willis - Claims 1, 2, and 4-8 are anticipated by Willis under 35 U.S.C. §102(b).

• Prior Art Relied Upon: Willis (William S. Willis, Quiet Clean Short-Haul Experimental Engine (QCSEE) Final Report, 1979).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Willis, a NASA report detailing the QCSEE engine program, discloses every element of the challenged claims. The QCSEE engine is a turbofan engine with a spool, turbine, and fan housed within core and fan nacelles, forming a bypass flow path. Willis describes a digital controller that commands a variable fan nozzle (the claimed "flow control device") based on power lever position (the "throttle position") to modulate the nozzle exit area between open and closed conditions. This modulation achieves different fan operating lines, including a higher line for cruise and a lower line for takeoff, which corresponds to the claimed "target operability line." Willis also explicitly teaches that the nozzle is in an "effectively open condition" at low-power ground idle and an "effectively closed condition" at cruise, anticipating the key limitations added during prosecution to secure the patent.
  • Key Aspects: Petitioner contended that Willis also anticipates the dependent claims by disclosing that the higher operating line at cruise is closer to the stall boundary (Claim 2), using a throttle position sensor (Claim 4), having physically open/closed nozzle areas (Claim 5), using actuators to move nozzle flaps (Claim 6), throttling flow in the closed condition (Claim 7), and corresponding the closed condition to cruise (Claim 8).

Ground 2: Obviousness over Willis in view of Gisslen - Claim 6 is obvious over Willis in view of Gisslen.

• Prior Art Relied Upon: Willis (1979 Report) and Gisslen (Patent 3,892,358).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued as an alternative that if the Board finds Willis does not explicitly disclose an "actuator adapted to move a flap" as required by claim 6, the limitation is rendered obvious by Gisslen. Gisslen teaches a variable area nozzle for a turbofan engine that uses an "annular array of flaps" moved by an "actuator means" to change the nozzle's cross-sectional area.
  • Motivation to Combine: A POSITA would combine these references because they both describe the same type of engine technology. Gisslen's actuator-driven flap system was a well-known and standard method for implementing the variable nozzle concept taught in Willis. Furthermore, both references originate from General Electric in a similar time frame (1975 and 1979), suggesting to a POSITA that their teachings were compatible and could be combined to achieve a predictable result.
  • Expectation of Success: A POSITA would have had a high expectation of success in using Gisslen's standard actuator mechanism to control the nozzle flaps of the Willis engine, as it was a known solution for a known component.

Ground 3: Obviousness over Willis in view of Harner - Claim 3 is obvious over Willis in view of Harner.

• Prior Art Relied Upon: Willis (1979 Report) and Harner (Patent 3,932,058).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner asserted that if Willis is found not to disclose the "airspeed sensor" required by dependent claim 3, the deficiency is supplied by Harner. Harner describes a control system for a gas turbine engine that uses flight Mach number (a direct measure of aircraft airspeed) as an input, along with throttle position, to determine the optimal fan nozzle area.
  • Motivation to Combine: A POSITA would combine Harner's control logic with the Willis engine to improve fan stability, a known issue for the low pressure-ratio fans used in Willis. Harner explicitly teaches using airspeed input to prevent fan surge. Petitioner also argued that Willis only omitted an airspeed sensor because it described an engine in a static test cell (where airspeed is zero); a POSITA would have naturally included such a common sensor for an engine installed on an aircraft for use in flight.
  • Expectation of Success: Incorporating an airspeed sensor as taught by Harner into the control system of the Willis engine was a straightforward modification that would have predictably improved fan stability during flight operations.

• Additional Grounds: Petitioner asserted an alternative obviousness challenge for claims 2 and 7 over Willis in view of the general knowledge of a POSITA, arguing that even if not explicitly disclosed, moving the operating line nearer the stall boundary (Claim 2) and throttling flow (Claim 7) are the obvious and inherent results of closing the nozzle at cruise as taught by Willis.

4. Key Claim Construction Positions

• "target operability line" (Claims 1, 2): Petitioner argued this term should be construed as "the series of points within a fan map at which the fan section is designed to operate (i.e., an operating line)." This construction was supported by the patent's specification and the patent owner's own statements during prosecution, anchoring the term to a well-understood concept in the art and linking it directly to the fan performance maps shown in the prior art.
• "flow control device" (Claims 1, 6): Petitioner proposed this term means "any structure or device that effectively changes the nozzle exit area of the bypass flow path." Petitioner argued that while the patent describes an example with hinged flaps, the term itself is broad and should encompass the "variable area composite fan nozzle" disclosed in the Willis reference, which serves the exact same function.
• "effectively open and closed conditions" (Claims 1, 5): Petitioner argued these are relative terms, where "open" means a larger effective nozzle exit area and "closed" means a smaller effective nozzle exit area, not necessarily a completely sealed nozzle. This construction was crucial for mapping the prior art, which showed a nozzle being modulated between larger and smaller areas (e.g., 2900 in² and 2500 in²) rather than being fully closed.

5. Relief Requested

• Petitioner requested the institution of an inter partes review and cancellation of claims 1-8 of Patent 8,365,513 as unpatentable under 35 U.S.C. §102 and §103.