PTAB

IPR2016-00046

JTekT Corp v. GKN Automotive Ltd

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Drive Train for a Vehicle
  • Brief Description: The ’440 patent describes a selectable four-wheel drive train for a vehicle featuring a "shutdown section." This design allows a majority of the secondary drive train to be decoupled from both the primary axle and the secondary drive wheels, enabling it to remain stationary when the vehicle operates in two-wheel drive mode to reduce power loss and improve fuel efficiency.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1, 4, and 5 by Teraoka

  • Prior Art Relied Upon: Teraoka (Japanese Application # 2002-370557).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Teraoka discloses every element of independent claim 1 and dependent claims 4 and 5. Teraoka describes a four-wheel drive system with a primary front drive train and a secondary rear drive train. The system includes a transfer case (the claimed "switch-on device") with a switching mechanism (7) and a rear clutch mechanism (71) that functions as a side shaft coupling. Critically, Petitioner asserted that Teraoka explicitly teaches that when the system is in two-wheel drive mode, the switching mechanism is uncoupled, causing the rotation of the propeller shaft and associated components—the claimed "shutdown section"—to stop. This directly meets the central limitation of the ’440 patent. Furthermore, Teraoka’s switch-on device includes a positively working dog clutch and an angled gear set, anticipating claim 4, and is arranged on the primary axle to engage the secondary drive train, anticipating claim 5.

Ground 2: Obviousness of Claims 2 and 3 over Teraoka and Watanabe

  • Prior Art Relied Upon: Teraoka (Japanese Application # 2002-370557) and Watanabe (Japanese Application # H02-57725).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that claims 2 and 3 are obvious over the combination of Teraoka and Watanabe. Claim 2 requires a "side shaft coupling for each side shaft of the secondary axle" that allows power distribution "without a differential gearing." While Teraoka’s base system includes a single clutch mechanism and a conventional differential, Watanabe teaches a rear differential assembly that incorporates multiple plate clutches (89 and 91) as side shaft couplings for each respective rear axle. Petitioner argued these clutches in Watanabe allow for power distribution to each wheel without traditional differential gearing.
    • Motivation to Combine: A POSITA would combine these references to achieve the well-known goal of reducing vehicle weight and fuel consumption. It would have been a matter of simple substitution to replace Teraoka's heavier, conventional bevel gear differential with the lighter, more efficient dual side-shaft coupling design taught by Watanabe.
    • Expectation of Success: The combination involved substituting known components in a predictable manner. A POSITA would have had a high expectation of success in integrating Watanabe's dual-clutch system into Teraoka's drive train to achieve the predictable result of reduced mass and rotational losses.

Ground 3: Obviousness of Claims 6 and 7 over Teraoka and Burrows

  • Prior Art Relied Upon: Teraoka (Japanese Application # 2002-370557) and Burrows (Great Britain Patent # 2407804).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that claims 6 and 7 are obvious over the combination of Teraoka and Burrows. Claim 6 adds the limitation of "a speed synchronization in the switch-on mechanism... for the establishment of a positive lock." Teraoka discloses the necessary hardware: a positively engaging dog clutch (7) connected via a propeller shaft to a remote multi-plate wet clutch (71). However, Teraoka does not explicitly state that the remote clutch provides speed synchronization for the dog clutch. Burrows was cited to supply this missing teaching, as it explicitly discloses using a remote multi-plate wet clutch connected via a drive shaft to "spin-up the auxiliary driveline" for speed synchronization before engaging a dog clutch. Claim 7, which details the structure of a multiple disc clutch, was argued to be disclosed in Teraoka’s embodiments.
    • Motivation to Combine: A POSITA would combine these teachings because it was a well-known engineering principle that positively locking gears, such as Teraoka's dog clutch, require speed synchronization to prevent component wear and failure. Burrows provides an express teaching of a known technique to solve this known problem using a system analogous to Teraoka's.
    • Expectation of Success: Applying the known synchronization strategy from Burrows to the structurally similar system in Teraoka would have been a straightforward application of a known technique to improve a known device, leading to a high expectation of success.

4. Key Claim Construction Positions

  • "shutdown section": Proposed as any portion of a secondary drive train that can be decoupled from both the primary axle and the wheels of the secondary axle.
  • "switch-on device": Proposed as a structure designed to couple or decouple the shutdown section.
  • "switch-on mechanism": Proposed as a point within the switch-on device, such as a clutch, that performs the coupling or decoupling function between the primary and secondary drive trains.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-7 of Patent 8,215,440 as unpatentable.