Exro Technologies Inc v. ePRopelLED Inc

1. Case Identification

• Case #: IPR2022-01154
• Patent #: 7,382,103
• Filed: June 15, 2022
• Petitioner(s): EXRO Technologies Inc.
• Patent Owner(s): ePROPELLED, INC.
• Challenged Claims: 1-17

2. Patent Overview

• Title: Magnetic Gearing of Permanent Magnet Brushless Motors
• Brief Description: The ’103 patent discloses a permanent magnet brushless motor with "magnetic gearing" capability. The invention uses a switch means to dynamically reconfigure a plurality of stator winding sections for a given phase into series, parallel, or combination circuits while the motor is operating, thereby altering its torque and speed characteristics. The asserted novelty is that all winding sections are utilized in every configuration, eliminating unused or "redundant" windings to minimize copper loss.

3. Grounds for Unpatentability

Ground 1: Claims 1-3, 5, 8, 9, and 13-17 are obvious over Pyntikov.

• Prior Art Relied Upon: Pyntikov (Patent 6,853,107).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Pyntikov teaches a multiphase permanent magnet (PM) motor with a control circuit that reconfigures stator windings into different configurations, including all-series, all-parallel, and series-parallel combinations, based on motor speed. Critically, Pyntikov's abstract stated that "all winding sections for a stator element are energized throughout the motor operating speed range." Petitioner contended this directly teaches the core concept of avoiding redundant windings, which was the primary basis for the allowance of the ’103 patent. Petitioner asserted that Pyntikov's switch arrangement and functionality are indistinguishable from those disclosed in the challenged patent.
  • Key Aspects: The argument emphasized Pyntikov's direct teaching against "redundant windings" and the visual similarity between the switching circuit diagrams in Pyntikov and the ’103 patent.

Ground 2: Claims 6 and 7 are obvious over Pyntikov, either alone or in combination with Rivera.

• Prior Art Relied Upon: Pyntikov (Patent 6,853,107), Rivera (Patent 5,912,522).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground addressed dependent claim 6, which adds pulse-width modulation (PWM) by selectively energizing the switch means. Petitioner contended that Pyntikov's disclosure of "electronically controlled pulsed energization" and "control of pulse width" inherently teaches this limitation. To the extent Pyntikov is found not to, Petitioner argued Rivera discloses a reconfigurable winding system for a PM motor that operates from a constant DC voltage source. Rivera identifies PWM as a technique used by external converters it seeks to replace, which implies that its internal switches can perform the same function. Claim 7, which recites repeatedly actuating switches for an intermediate motor characteristic, was argued to be another way of describing the effect of PWM.
  • Motivation to Combine: A POSITA would combine Rivera's internal PWM control concept with Pyntikov's motor design because both relate to controlling PM motors via winding reconfiguration. Rivera teaches that this approach eliminates the need for external power converters, a known design goal, providing a clear motivation for the combination.
  • Expectation of Success: Applying a well-known control strategy (PWM) to a known motor topology would have yielded the predictable result of modulated voltage and intermediate performance characteristics.

Ground 3: Claims 1-5 and 8-15 are obvious over Nipp.

• Prior Art Relied Upon: Nipp (Eckart Nipp, Permanent Magnet Motor Drives with Switched Stator Windings, Ph.D. Dissertation, 1999).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner asserted that Nipp, a Ph.D. dissertation, describes the same fundamental technology of using "switched stator windings" to increase the speed range of PM motors, an effect Nipp called an "electronic gearbox." Nipp explicitly disclosed dividing phase windings into parts and using switches to achieve all-series, all-parallel, and series-parallel combinations. Critically, Petitioner argued that in all of Nipp's disclosed configurations, all winding sections are always connected to the power source, thus teaching the non-redundant winding feature that was central to the patentability of the ’103 patent.
  • Key Aspects: This ground relied on a non-patent literature reference that allegedly describes the core inventive concept in detail, including similar diagrams and performance curves.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including that claims 10 and 12 are obvious over Pyntikov in view of Maslov (Patent 6,727,668) for specific control system features, and that claim 11 is obvious over Pyntikov in view of Masino (Patent 6,901,212) for using back-emf for sensorless control.

4. Key Claim Construction Positions

• Petitioner proposed constructions for means-plus-function limitations in claim 1 that it argued were critical to the invalidity analysis.
• "switch means...for simultaneously connecting all of the winding sections": Petitioner argued this term's function requires that all winding sections are connected in any given configuration, meaning no redundant or unused windings are possible. This construction was based on the specification and arguments made during prosecution to overcome prior art that left windings unused. The corresponding structure was identified as "relays or semiconductor devices."
• "wherein said switching devices...are arranged to connect each winding section in series and/or parallel...": Petitioner argued this clause requires the switch means to be capable of establishing configurations that are all-series, all-parallel, or combinations thereof, reinforcing that all winding sections remain in use across different operational modes.

5. Arguments Regarding Discretionary Denial

• Fintiv Factors (§314(a)): Petitioner argued against discretionary denial, stating that the co-pending district court litigation (ePropelled, Inc. v. Exro Technologies Inc., D. Mass.) was in its infancy, with no trial date or scheduling order set. Petitioner asserted that the merits of the petition are strong and an IPR would be a more efficient resolution of the invalidity issues.
• §325(d): Petitioner argued this section does not apply because the primary prior art references asserted in the petition (Pyntikov, Rivera, Nipp, Maslov, and Masino) were never considered by the examiner during the original prosecution of the ’103 patent.

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-17 of Patent 7,382,103 as unpatentable.