PTAB

IPR2023-00273

ZF North America Inc v. SToneRidge Control Devices Inc

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1. Case Identification

2. Patent Overview

  • Title: Electro-Mechanical Actuator For An Electrically Actuated Parking Brake
  • Brief Description: The ’415 patent discloses an electromechanical actuator for a vehicle parking brake. The technology centers on using a motor and various gear train combinations (e.g., planetary gears, belt drives) to engage and release a brake caliper, with an emphasis on modular assembly using a sub-frame and the inclusion of isolators to dampen noise, vibration, and harshness (NVH).

3. Grounds for Unpatentability

Ground A: Claims 2, 6, and 9-13 are obvious over Poertzgen

  • Prior Art Relied Upon: Poertzgen (German Patent No. DE 19732168).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Poertzgen, a German patent for an electromechanical parking brake, discloses all elements of the challenged claims. Independent claim 2 recites an actuator with a drive gear and driven gear coupled by a drive belt, which in turn is coupled to a planetary gear set to drive a brake caliper. Petitioner asserted Poertzgen teaches a preferred two-stage reduction gear system that advantageously combines a belt gear stage with a planetary gear stage. Poertzgen’s motor and reduction gears form a subassembly that provides an output to engage and release a floating caliper disk brake, meeting the claim limitations.
    • Motivation to Combine (for §103 grounds): Not applicable as this ground relies on a single reference.
    • Expectation of Success (for §103 grounds): Not applicable.
    • Key Aspects: Petitioner argued that dependent claims 6 and 9-13 add only further well-known features also taught by Poertzgen, such as mounting the motor and gears on a sub-frame (subassembly 40) and enclosing them within a housing that separates the motor from the gears.

Ground B: Claims 3-5, 7-8, and 14-19 are obvious over Poertzgen in view of Boucheret

  • Prior Art Relied Upon: Poertzgen (German Patent No. DE 19732168) and Boucheret (Patent 6,098,948).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground builds on the Poertzgen reference by adding Boucheret to teach the claims requiring a component isolator for damping. Petitioner asserted Poertzgen provides the base actuator system, while Boucheret explicitly teaches using damping elements (isolators) when mounting motors within housings to reduce NVH in automotive applications. For example, claim 3 adds to the combination of claim 2 "a component isolator...coupled between said motor and a remainder of said" actuator. Petitioner argued this is taught by Boucheret's disclosure of placing damping members between a motor and its housing.
    • Motivation to Combine (for §103 grounds): A person of ordinary skill in the art (POSITA) would combine Boucheret’s teachings with Poertzgen’s actuator to achieve the predictable benefit of reducing NVH from the motor. Petitioner contended that both references relate to vehicle actuators, recognize the benefits of reducing NVH, and that using isolators was a well-known technique to improve such devices.
    • Expectation of Success (for §103 grounds): A POSITA would have a reasonable expectation of success in applying a known NVH-damping solution (Boucheret's isolator) to a standard actuator (Poertzgen's) to achieve the known result of reduced vibration and noise.

Ground H: Claims 20-25 are obvious over Weiler

  • Prior Art Relied Upon: Weiler (International Publication No. WO 00/61962).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground challenges method claims 20-25, which recite steps for assembling an actuator. Independent claim 20 recites mounting a motor and gear train to a sub-frame and coupling the sub-frame to an actuator housing to enclose the motor. Petitioner argued Weiler teaches these exact assembly steps, disclosing a modular design where a motor and planetary gears are mounted on a sub-frame (bearing plate 14). This subassembly is then placed into a housing-like recess in a brake caliper, with the sub-frame itself acting as a cover to enclose the motor within a motor isolation cavity.
    • Motivation to Combine (for §103 grounds): Not applicable as this ground relies on a single reference.
    • Expectation of Success (for §103 grounds): Not applicable.
    • Key Aspects: Petitioner asserted that dependent claims 21-25 add further conventional assembly steps also disclosed by Weiler's modular design, such as adding a second sub-frame (gear cover 54) to enclose the gears and providing motor isolation bushings (bearing bush 13) between the motor and housing.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including:

    • Claim 1 over Poertzgen and Schumann (Patent 6,179,097) to provide a worm gear.
    • Claims 6, 10-13 over Poertzgen and Drennen (Patent 6,390,247) to further support the sub-frame limitation.
    • Various claims over three-way combinations of Poertzgen, Boucheret, and either Drennen or Weiler to address limitations related to both sub-frames and isolators.
    • Claims 23-25 over Weiler and Boucheret to further support the use of isolation bushings for NVH reduction.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-25 of Patent 7,021,415 as unpatentable.