PTAB

IPR2016-01049

Am General LLC v. Uusi LLC

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1. Case Identification

2. Patent Overview

  • Title: Glow Plug Controller
  • Brief Description: The ’666 patent is directed to a glow plug controller for diesel engines. The controller includes an analog temperature sensor, a microprocessor for analyzing operating parameters, and circuitry for controlling glow plugs during a "preglow" period before engine cranking and an "afterglow" period responsive to the cessation of a cranking signal.

3. Grounds for Unpatentability

Ground 1: Claims 10, 11, and 13 are obvious over Yasuhara.

  • Prior Art Relied Upon: Yasuhara (Patent 4,491,100).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Yasuhara, by itself, teaches every element of the challenged claims. Yasuhara discloses a complete glow plug control system featuring a user-actuated key switch for initiating a preglow period, circuitry for actuating a starter motor which produces a cranking signal, a temperature sensor, and a programmable controller (control unit 15). Petitioner argued Yasuhara’s controller calculates a preglow time based on engine temperature and is responsive to the cessation of the cranking signal (when the key switch is released from the "start" position) to apply power during an afterglow period. Specifically, Yasuhara’s controller keeps the glow plugs active for a period after the starter motor is deactivated.

Ground 2: Claims 10, 11, and 13 are obvious over Yasuhara in view of Masaka.

  • Prior Art Relied Upon: Yasuhara (Patent 4,491,100) and Masaka (Patent 4,939,347).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that to the extent Yasuhara is found insufficient to explicitly teach initiating an afterglow period in response to the cessation of a distinct cranking signal, Masaka supplies this teaching. Yasuhara provides the base system of a programmable glow plug controller. Masaka teaches an "ST position detector" that generates a discrete signal only when the starter is cranking. Petitioner contended this directly teaches the claimed limitation of circuitry responsive to the "cessation of said cranking signal" to initiate the afterglow period. This combination overcomes any potential ambiguity in Yasuhara, where cessation might be inferred from key position rather than a direct cranking signal.
    • Motivation to Combine: A POSITA would combine Masaka's advantageous and precise cranking signal detection with Yasuhara's established control system. Both references are in the same technical field and address the same problem of improving cold starts in diesel engines. Petitioner asserted the combination would predictably improve the efficiency and reliability of the afterglow initiation.
    • Expectation of Success: A POSITA would have a reasonable expectation of success, as integrating Masaka’s ST position detector signal as an input into Yasuhara’s microprocessor-based control unit was argued to be a straightforward modification of its control logic.
    • Key Aspects: Petitioner argued that during the original prosecution of the ’666 patent, the patentee mischaracterized Masaka as inferring cranking from a battery voltage drop, when in fact Masaka teaches an actively monitored, discrete cranking signal.

Ground 3: Claims 10, 11, and 13 are obvious over Demizu in view of Masaka.

  • Prior Art Relied Upon: Demizu (Patent 4,566,410) and Masaka (Patent 4,939,347).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner presented Demizu as an alternative primary reference to Yasuhara, arguing it teaches a similar computer-controlled glow plug system that is rendered obvious by the addition of Masaka’s afterglow control method. Demizu discloses a glow plug controller using a "one-chip computer" that receives inputs from a temperature sensor and a key switch (including an ST or "start" position) to control a preglow period. Masaka again provides the teaching of initiating an afterglow period in direct response to the cessation of a cranking signal from its "ST position detector."
    • Motivation to Combine: A POSITA would be motivated to combine the references for reasons similar to the Yasuhara/Masaka combination. Since Demizu’s controller already monitors an ST signal from the key switch, Petitioner argued it would be a simple and logical step to incorporate Masaka’s teaching of using the cessation of that same signal to trigger the afterglow timer for improved engine starting performance.
    • Expectation of Success: The combination was presented as predictable and logical. A POSITA would understand how to use the control system of Demizu to achieve the function disclosed in Masaka, as both operate on similar principles of monitoring key switch positions to control engine start sequences.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 10, 11, and 13 of Patent 5,570,666 as unpatentable under 35 U.S.C. § 103.