PTAB

IPR2015-00758

Ford Motor Co v. Paice LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Hybrid vehicles
  • Brief Description: The ’634 patent describes a control strategy for hybrid electric vehicles. The system operates an internal combustion engine and one or more electric motors in different modes based on the instantaneous torque required ("road load") relative to a predetermined torque "setpoint" to ensure the engine runs only under conditions of high efficiency.

3. Grounds for Unpatentability

Ground 1: Obviousness over Severinsky – Claims 161-166 and 215-220 are obvious over Severinsky in view of general knowledge of a POSA.

  • Prior Art Relied Upon: Severinsky (Patent 5,343,970) and general knowledge of a Person of Ordinary Skill in the Art (POSA).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Severinsky teaches all limitations of the challenged one-motor claims. Severinsky discloses a parallel hybrid system that determines the required propulsion torque and selects an operating mode to keep the engine in its most efficient range. Petitioner asserted that Severinsky’s threshold for engaging the engine—when the required torque is sufficient for efficient operation (e.g., 60-90% of maximum torque output (MTO))—is the claimed "setpoint (SP)." Below this threshold, Severinsky operates the electric motor alone (meeting limitations for RL < SP); between this threshold and MTO, it operates the engine (meeting limitations for RL between SP and MTO); and when torque demand exceeds MTO, it operates both. Petitioner also cited admissions in the ’634 patent stating its control strategy is the same as that shown in the Severinsky ’970 patent.
    • Motivation to Combine: A POSA would apply general knowledge of hybrid vehicle control principles to the Severinsky system to achieve the claimed method. The motivation was inherent in implementing Severinsky's disclosed torque-based control strategy.
    • Expectation of Success: A POSA would have a high expectation of success in implementing Severinsky's control logic, as it relied on well-understood principles of engine efficiency and torque management in hybrid vehicles.

Ground 2: Obviousness over Severinsky and Frank – Claims 80-85 and 114-119 are obvious over Severinsky in view of Frank and general knowledge of a POSA.

  • Prior Art Relied Upon: Severinsky (’970 patent) and Frank (Patent 5,842,534).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon the teachings of Severinsky for the base hybrid control system and introduced Frank to teach the specific hysteresis limitations required by claims 80 and 114. Frank discloses using hysteresis control—either a time-based delay after a threshold is crossed or the use of separate "on" and "off" thresholds—to prevent "undesirable or excessive cycling" of the engine when operating near a setpoint. Petitioner mapped Severinsky to the primary control limitations and argued that adding Frank’s hysteresis methods would render the remaining limitations obvious.
    • Motivation to Combine: A POSA would combine Frank’s teachings with Severinsky’s system to solve the well-known problem of engine cycling near a control threshold, which causes noise, emissions, and component wear. Both references disclose control strategies based on thresholds, making the combination a logical and predictable solution to a known issue.
    • Expectation of Success: Applying a standard control technique like hysteresis (from Frank) to a threshold-based system (like Severinsky) was a routine design choice for a POSA, who would have a clear expectation of successfully reducing engine cycling.

Ground 3: Obviousness over Severinsky, Frank, Field, and SAE 1996 – Claims 86-90, 120-124, 167-171, 221-225, and 294 are obvious over Severinsky & Frank in view of Field, SAE 1996, and general knowledge of a POSA.

  • Prior Art Relied Upon: Severinsky (’970 patent), Frank (’534 patent), Field (WO 93/23263), and SAE 1996 (SAE Special Publication SP-1156).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground addressed claims requiring a two-motor hybrid architecture. Petitioner asserted that Severinsky taught a one-motor "parallel" system that met most claim limitations related to the "second" motor's control logic. SAE 1996 and Field were introduced because they taught the design and well-known benefits of two-motor "series-parallel" architectures. The petition argued that it would have been an obvious modification for a POSA to add a "first" electric motor/generator to Severinsky's engine, thereby converting its one-motor parallel design into the claimed two-motor series-parallel architecture.
    • Motivation to Combine: A POSA would have been motivated to modify Severinsky’s one-motor design to gain the known advantages of a two-motor series-parallel system, which were widely understood and documented in references like SAE 1996 and Field. These advantages included the ability to simultaneously provide propulsion torque and charge the battery, as well as eliminating the need for a conventional starter and alternator.
    • Expectation of Success: The modification was presented as a predictable design choice, involving the combination of known hybrid architectures to achieve a well-understood blend of benefits. A POSA would have a high expectation of success in adapting Severinsky’s parallel system by adding a motor/generator as taught by Field and SAE 1996.

4. Key Claim Construction Positions

  • "setpoint (SP)": Petitioner proposed this term be construed as a "predetermined torque value." This construction was argued to be critical for mapping the prior art, particularly Severinsky's disclosure of using a specific percentage of the engine's maximum torque output (e.g., 60% MTO) as the threshold for engaging the engine. Petitioner contended this construction was consistent with the specification and prosecution history and was narrower than constructions proposed by the Patent Owner in related proceedings.
  • "road load (RL)": Petitioner proposed construing "road load" as "the amount of instantaneous torque required to propel the vehicle, be it positive or negative." This construction was asserted to be consistent with previous PTAB decisions involving the parties.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 80-90, 114-124, 161-171, 215-225, and 294 as unpatentable.