PTAB

IPR2013-00268

MotivePower Inc v. Cutsforth Inc

Log In
Key Events
Petition
petition Intelligence

1. Case Identification

2. Patent Overview

  • Title: Brush Holder Apparatus, Brush Assembly, and Method
  • Brief Description: The ’906 patent relates to brush holder assemblies for electrical devices, such as motors and generators, used to pass electrical current between a stationary contact and a moving surface. The technology purports to provide a modular assembly that maintains good electrical contact as the brush wears down and enables quick, safe replacement of worn brushes.

3. Grounds for Unpatentability

Ground 1: Anticipation by Ohmstedt - Claims 1-2, 4-5, 10-14, 16-19, and 21-22 are unpatentable under 35 U.S.C. §102 over Ohmstedt.

  • Prior Art Relied Upon: Ohmstedt (Patent 3,864,803).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Ohmstedt, which was not considered during prosecution, discloses every element of the challenged claims. Independent claim 1 requires a two-part assembly where a mountable first portion includes a stationary brush release and a separable second portion includes a brush catch. Petitioner contended that Ohmstedt’s first portion (13), mountable to a base, includes a stationary brush release in the form of tabs or ramps (59). This release contacts the brush catch (inwardly extending teeth 23, 25) on the separable second portion (11) when the two portions are engaged, causing the catch to disengage from the brush (27). This structure and function, Petitioner asserted, directly map to the limitations of claims 1 and 14.

Ground 2: Anticipation by Krulls '155 - Claims 1-2, 4-5, 10-11, 14, 16-19, and 21-22 are unpatentable under §102 over Krulls ’155.

  • Prior Art Relied Upon: Krulls ’155 (Patent 3,387,155).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Krulls ’155, also not cited during prosecution, anticipates the claims. It allegedly discloses a first portion (cross-bus bar 30) mountable to a base (14) that includes a stationary brush release (portion 78). The separable second portion (brush magazine 12) includes a brush catch (tab 72) that retains a brush (76). Petitioner argued that when the magazine (12) is inserted into its operating position, the release (78) engages and deflects resilient legs (66, 68) of the magazine, which causes the catch (72) to retract and release the brush to contact a collector ring, thus teaching all limitations of the independent claims.

Ground 3: Obviousness over Ohmstedt and Kartman - Claims 1-2, 4-5, 10-14, 16-19, and 21-22 are obvious over Ohmstedt in view of Kartman.

  • Prior Art Relied Upon: Ohmstedt (Patent 3,864,803) and Kartman (Patent 5,043,619).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground was presented as an alternative in case the Patent Owner successfully argued for a narrower construction of "mounting block" than what Ohmstedt discloses. Petitioner argued that Kartman teaches a mounting block (46) that serves the same purpose as Ohmstedt’s mounting block (13). A person of ordinary skill in the art (POSITA) would have recognized Kartman's mounting block as a simple design alternative to Ohmstedt's.
    • Motivation to Combine: A POSITA would combine these references because both teach removable brush holders for the same application (dynamoelectric machines) and address the common goal of quick, efficient, and safe mounting of brushes. The references disclose functionally equivalent components, making the substitution of Kartman’s mounting block design into the Ohmstedt system a predictable and logical modification.
    • Expectation of Success: Petitioner contended that substituting the shape of the mounting block taught in Kartman for the one in Ohmstedt would be a simple modification that would not alter the fundamental function of the brush release mechanism, leading to a high expectation of success.
  • Additional Grounds: Petitioner asserted additional obviousness challenges based on combinations including Krulls ’155 with Kartman or Bissett; Blank alone (as anticipation) and in combination with Ohmstedt; and Krulls ’478 in view of Krulls ’155.

4. Key Claim Construction Positions

  • Petitioner argued that disputed claim terms should be given their broadest reasonable interpretation consistent with their plain and ordinary meaning.
  • "mounting block": The central construction dispute concerned this term. Petitioner proposed the plain meaning: "a structure for mounting." This broad construction was contrasted with the Patent Owner’s narrower construction from a related district court case. Petitioner's broader interpretation was critical to its argument that references like Ohmstedt directly anticipated the claims without needing modification.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-2, 4-5, 10-14, 16-19, and 21-22 of the ’906 patent as unpatentable.