Volkswagen Group Of America Inc v. Michigan Motor Technologies LLC

1. Case Identification

• Case #: IPR2019-01274
• Patent #: 6,988,031
• Filed: July 2, 2019
• Petitioner(s): Volkswagen Group of America, Inc.
• Patent Owner(s): Michigan Motor Technologies LLC
• Challenged Claims: 1-17

2. Patent Overview

• Title: System for Determining Engine Stop Position
• Brief Description: The ’031 patent describes a system for internal combustion engines designed to prevent unintentional reverse rotation of the crankshaft ("swing back") during shutdown. The system uses an air flow control device, such as a throttle, to lower the air pressure in the intake manifold upon receiving a shutdown signal, thereby minimizing forces that could cause the crankshaft to move after stopping.

3. Grounds for Unpatentability

Ground 1: Obviousness over Miyamoto and Suda - Claims 1, 4-6, 13, 15, and 16 are obvious over Miyamoto in view of Suda.

• Prior Art Relied Upon: Miyamoto (Japanese Application # JP2000-257458) and Suda (Japanese Application # JP11-82076).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Miyamoto taught the core novelty of the ’031 patent: a system that lowers intake air pressure during engine shutdown to prevent unwanted crankshaft rotation and improve subsequent startup. Miyamoto disclosed a controller that, upon detecting a stopping condition, operates a throttle valve in a closure direction to reduce intake pressure and suppress rotational fluctuation. Suda was argued to supply the remaining limitation of independent claim 1: determining the precise angular stop position of the crankshaft using a sensor and storing it to improve restart performance. Dependent claims were allegedly met as Miyamoto taught increasing manifold pressure after stopping (claim 13) and specific fuel injection timing (claims 15-16), while Suda taught using an intake valve (claim 4) and ensuring reversal torque is less than friction torque to prevent swing-back (claim 6). Miyamoto also disclosed a throttle flow bypass valve (claim 5).
  • Motivation to Combine: A POSITA would combine Miyamoto and Suda because both references were in the field of engine control, addressed the problem of controlling the crankshaft during shutdown, and shared the goal of improving restart performance. Suda’s explicit teaching of determining the precise stop position was presented as an advantageous and predictable improvement to Miyamoto’s system for controlling crankshaft fluctuation, yielding better control and faster, more efficient restarts.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success, as combining Suda's known sensor technique with Miyamoto's engine control system involved applying a known technique to a known device to achieve predictable results.

Ground 2: Obviousness over Miyamoto, Suda, and Garrard - Claims 2, 3, and 14 are obvious over Miyamoto and Suda in view of Garrard.

• Prior Art Relied Upon: Miyamoto, Suda, and Garrard (Patent 6,253,145).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon the Miyamoto and Suda combination by adding Garrard to address specific dependent claims. Garrard was cited as teaching the use of specific, well-known sensor types for detecting crankshaft position, including a variable reluctance sensor (claim 2) and a Hall Effect sensor (claim 3). Garrard also explicitly taught storing the determined angular engine stop position in a memory (e.g., an EEPROM) for use during a subsequent engine startup (claim 14).
  • Motivation to Combine: A POSITA would have been motivated to incorporate Garrard’s teachings to improve the Miyamoto/Suda system. Garrard explained the benefits of using these specific sensor types for cost-effectiveness and accuracy, particularly in measuring crankshaft position as speed nears zero. Storing this data in memory, as taught by Garrard, was a known method for achieving faster, more synchronized fuel and spark delivery on restart. These were presented as obvious implementation choices from a POSITA's "toolbox" to enhance performance.

Ground 3: Obviousness over Miyamoto, Suda, and Yamada - Claims 7-12 are obvious over Miyamoto and Suda in view of Yamada.

• Prior Art Relied Upon: Miyamoto, Suda, and Yamada (Patent 5,975,051).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground added Yamada to the base combination to teach the limitations of claims 7-12. Yamada disclosed using a motorized throttle as the air flow control device (claim 7). It further taught fully closing the throttle based on a shutdown signal (claim 8) and keeping it closed until the engine has stopped (claim 9). Yamada also disclosed opening the throttle once the engine stop is determined (claim 10) and having a default open throttle position (claim 11), specifically one between 4° and 13°, which inherently includes the claimed 3° to 8° range (claim 12).
  • Motivation to Combine: A POSITA would have been motivated to use Yamada’s motorized throttle in the Miyamoto/Suda system to achieve more precise air pressure control and prevent the throttle from sticking, thereby improving restart capability. Yamada explicitly taught these benefits. The specific control logic (closing, opening, and default positions) was argued to be a straightforward implementation detail for optimizing engine shutdown and restart.

• Additional Grounds: Petitioner asserted an additional obviousness challenge against claim 17 based on the combination of Miyamoto, Suda, and Walker (Patent 3,251,352), which taught an ignition system configured to stop spark ignition only after the engine has fully stopped to improve restart and reduce emissions.

4. Key Claim Construction Positions

• Petitioner argued that two terms should be construed under 35 U.S.C. § 112(6) as means-plus-function terms due to the use of generic, functional language without corresponding structure in the claims.
• "air flow control device" (claim 1): Petitioner proposed the function is "to control air intake in order to lower air pressure in the engine based on an engine shutdown signal." The corresponding structure disclosed in the ’031 patent was identified as a throttle, throttle bypass valve, intake valve, exhaust valve, or equivalents thereof.
• "engine tracking system" (claim 10): Petitioner proposed the function is "to determine the engine is stopped." The corresponding structure disclosed in the ’031 patent was identified as a controller and sensor, or equivalents thereof.

5. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1-17 of the ’031 patent as unpatentable under 35 U.S.C. §103.