JTEKT CORPORATION v. GKN Automotive Ltd.

1. Case Identification

• Case #: IPR2016-00046
• Patent #: 8,215,440
• Filed: October 15, 2015
• Petitioner(s): JTEKT Corporation
• Patent Owner(s): GKN Automotive Ltd.
• Challenged Claims: 1-7

2. Patent Overview

• Title: Drive Train for a Vehicle
• Brief Description: The ’440 patent relates to manually connected four-wheel drive transmissions for vehicles. The core of the invention is a drive train configured so that a "shutdown section" of the secondary drive train can be decoupled from both the primary axle and the secondary drive wheels, allowing it to remain stationary when the vehicle operates in two-wheel drive mode. This configuration purports to reduce complexity, weight, and power loss compared to prior art systems.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 1, 4, and 5 under 35 U.S.C. §102(b) over Teraoka

• Prior Art Relied Upon: Teraoka (Japanese Application # 2002-370557).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Teraoka discloses all elements of independent claim 1 and dependent claims 4 and 5. The allegedly novel feature of the ’440 patent, a "shutdown section" that does not rotate in two-wheel drive mode, was asserted to be explicitly taught by Teraoka. Specifically, Teraoka's system uses a two-four switching mechanism (7) at the primary drive train and a clutch mechanism (71) at the secondary drive train. When these are disengaged for two-wheel drive operation, Teraoka states that rotation of the power transmission system—including the propeller shaft (21) connecting them—stops. Petitioner contended this directly corresponds to the claimed "shutdown section" being decoupled from both the primary axle and the secondary wheels. Furthermore, Teraoka's dog clutch (7) and angled gear set (9) were identified as meeting the "positively working power transmission gearing" of claim 4, and its placement on the primary axle met the limitations of claim 5.

Ground 2: Obviousness of Claims 2 and 3 under §103 over Teraoka in view of 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 asserted that claims 2 and 3 add the limitation of having a side shaft coupling for each side shaft of the secondary axle, which allows power distribution without a differential to provide compensation. While Teraoka teaches the core system, it was argued not to explicitly disclose this dual-coupling arrangement. Watanabe was cited to supply this teaching, as it discloses a rear differential (11) incorporating multiple plate clutches (89, 91) that function as side shaft couplings for each respective axle shaft. Watanabe explains these clutches can individually adjust the drive power to each wheel, thereby providing transverse compensation (claim 2) and enabling longitudinal compensation (claim 3) without conventional differential gearing.
  • Motivation to Combine: A person of ordinary skill in the art (POSITA) would have been motivated to replace Teraoka's differential with Watanabe's more advanced clutch-based system. This was presented as a simple substitution of known, interchangeable components to achieve the well-understood engineering goals of eliminating a heavy bevel gear differential, which in turn reduces overall vehicle weight and improves fuel economy.
  • Expectation of Success: The combination was argued to be predictable. Integrating Watanabe's dual-clutch differential into Teraoka's disconnectable drive train would predictably result in a lighter, more efficient system that retained the functional benefits of both references.

Ground 3: Obviousness of Claims 6 and 7 under §103 over Teraoka in view of Burrows

• Prior Art Relied Upon: Teraoka (Japanese Application # 2002-370557) and Burrows (Great Britain Application # 2407804).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that claim 6, which depends on anticipated claims, adds a requirement for "speed synchronization in the switch-on mechanism... supported by the at least one side shaft couplings." Teraoka discloses the necessary hardware—a claw clutch (7) for positive engagement and a wet multiple disc clutch (71) at the secondary axle—but does not explicitly state that clutch 71 is used to synchronize the engagement of clutch 7. Burrows was argued to teach this exact principle, disclosing a multi-plate wet clutch used to "spin-up" an auxiliary driveline to achieve speed synchronization before a dog clutch is engaged. A POSITA would see that Teraoka’s clutch 71 could similarly support the synchronization of its switch-on mechanism (clutch 7). Claim 7's detailed limitations for a multiple disc clutch were argued to be taught by a second embodiment within Teraoka itself.
  • Motivation to Combine: A POSITA would have been motivated to apply the known technique from Burrows to Teraoka's system to improve its function. It was well-known in the art that positively connected gearing (e.g., a dog clutch) requires speed synchronization of its input and output sides to prevent wear and ensure smooth, reliable engagement. Burrows provided an established method for achieving this.
  • Expectation of Success: Applying the known synchronization strategy from Burrows to the analogous components in Teraoka's drive train would have had a high expectation of success, predictably resulting in a more robust and smoothly operating four-wheel drive engagement without requiring substantial redesign or additional equipment.

4. Key Claim Construction Positions

• "shutdown section": Petitioner proposed this term be construed as any part of a secondary drive train that can be decoupled from both the primary axle and the wheels of the secondary axle. This construction was central to arguing that Teraoka's system, which stops its propeller shaft, met the claim limitation.
• "switch-on device" / "switch-on mechanism": Petitioner construed "device" as the overall structure for coupling/decoupling (e.g., Teraoka's transfer case 5) and "mechanism" as the specific component effecting the switch (e.g., Teraoka's dog clutch 7). These constructions were used to map the prior art components to the specific claim language.

5. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1-7 of the ’440 patent as unpatentable.