PTAB

IPR2018-01636

T Max Hangzhou Technology Co Ltd v. Lund Motion Products Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Retractable Vehicle Step
  • Brief Description: The ’751 patent discloses a retractable vehicle step assembly that uses a four-bar linkage mechanism. The assembly comprises a stepping platform connected to a vehicle via pivotable support arms, allowing the step to move between a retracted (stowed) position and an extended (deployed) position.

3. Grounds for Unpatentability

Ground 1: Obviousness over Matthews and Dean - Claims 1-13 are obvious over Matthews in view of Dean.

  • Prior Art Relied Upon: Matthews (United Kingdom Patent No. GB936,846) and Dean (Patent 6,375,207).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Matthews, a 1960s reference not before the Examiner, taught the core mechanical design of the ’751 patent, including a retractable vehicle step with a four-bar linkage. Matthews disclosed a manually operated step using tension springs that, Petitioner contended, provides the “self-energizing” feature recited in claim 1. Dean taught a similar retractable step but added a motor for actuation, a feature recited in dependent claims 5, 6, and 12. Petitioner asserted that Matthews disclosed key features that the patent owner had argued were missing from Dean during prosecution, including non-parallel support linkages (claim 13), a linkage extending above the stepping platform (claim 7), and the self-energizing function.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Matthews and Dean because both address the same problem of providing a retractable step for high-clearance vehicles using a similar four-bar linkage design. Petitioner argued it would have been a predictable and obvious design choice to automate the well-established manual linkage of Matthews by incorporating the motor taught by Dean, especially once miniaturized motor technology became widely available.
    • Expectation of Success: A POSITA would have a high expectation of success in motorizing the Matthews linkage using Dean’s teachings. The addition of a motor to a known mechanical system was a routine and well-understood engineering task, presenting no technical hurdles or unpredictable results.

Ground 2: Obviousness over Matthews, Dean, and Norton - Claims 1-6 and 10-11 are obvious over Matthews and Dean in view of Norton.

  • Prior Art Relied Upon: Matthews (United Kingdom Patent No. GB936,846), Dean (Patent 6,375,207), and Norton (Design of Machinery, 2d Ed., 1999).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon the combination of Matthews and Dean, adding Norton as a reference providing fundamental background knowledge on linkage design. Petitioner introduced Norton, a mechanical engineering textbook, specifically to address the “self-energizing” limitation in claims 1, 4, 6, 10, and 11. Norton explicitly described the concept of “toggle positions” in four-bar linkages, which create a “self-locking” feature when the linkage is moved slightly beyond a point of collinearity against a fixed stop. Petitioner contended this well-known toggle principle is synonymous with the claimed “self-energizing” feature.
    • Motivation to Combine: The motivation to combine Matthews and Dean remained the same as in Ground 1. A POSITA designing the vehicle step would be motivated to consult a foundational text like Norton to understand and apply fundamental linkage principles. Norton’s discussion of self-locking toggle features in analogous applications, such as “pickup truck or station wagon tailgate linkages,” would have directly prompted a POSITA to apply this principle to the Matthews/Dean design to ensure the step remains stable in its extended and retracted positions.
    • Expectation of Success: Applying the well-documented and fundamental “toggle” principle from Norton to the four-bar linkage of Matthews/Dean would be a straightforward application of known engineering principles with a high expectation of success.

4. Key Claim Construction Positions

Petitioner proposed constructions for several key terms that were central to its invalidity arguments and were added or relied upon to overcome rejections during prosecution.

  • "self-energizing" (claims 1, 4, 10, 11): Petitioner proposed the construction “continuing its downward rotational movement somewhat when a load is placed on the step, so that the load is not carried by any motor driving the step,” based on language in the patent’s specification. This construction was critical because Petitioner argued that the spring-based system of Matthews and the toggle-locking principle described in Norton both met this definition, directly contradicting the patent owner’s arguments during prosecution that this feature was novel over the prior art of record.
  • "flange" (claims 1, 7, 13): Proposed as “a rib or rim for attachment to another object.” This term was not defined in the specification, and Petitioner’s construction aimed to show that the “cranked members” in Matthews satisfied this limitation.
  • "retain and straddle" (claims 1, 3, 7, 9, 13): Proposed as “connect on both sides to.” This construction was used to argue that the linkages in the prior art, which connect to the outer faces of the support arms, met the claim language.

5. Key Technical Contentions (Beyond Claim Construction)

  • Petitioner’s central technical contention was that the allegedly novel “self-energizing” feature was, in fact, a direct application of a long-established mechanical engineering principle known as a “toggle” or “over-center” mechanism. The petition argued that using springs (as in Matthews) or specific linkage geometry (as described in Norton) to create stable endpoints for a mechanism was a fundamental design technique well known to any POSITA. This contention aimed to re-characterize the patent’s main point of novelty as a routine and obvious design choice.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-13 of Patent 9,561,751 as unpatentable under 35 U.S.C. §103.