PTAB

IPR2017-02185

Caterpillar Inc v. Wirtgen America Inc

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Key Events
Petition

1. Case Identification

2. Patent Overview

  • Title: Road-Building Machine
  • Brief Description: The ’309 patent discloses a system for adjusting the height of a road-building machine to improve stability on uneven terrain. The system uses four double-acting, positively coupled hydraulic working cylinders—one for each wheel or caterpillar track—connected by coupling lines to enable coordinated height adjustments, such as moving diagonally opposing wheels in the same direction while adjacent wheels move in opposite directions.

3. Grounds for Unpatentability

Ground 1: Obviousness over Swisher and Neumeier - Claims 1-3, 5-10, 14-23, and 26-35 are obvious over Swisher in view of Neumeier.

  • Prior Art Relied Upon: Swisher (Patent 4,325,580) and Neumeier (German Patent Pub. No. DE1918393).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Swisher disclosed the foundational elements of a road-building machine, including a chassis and four individually height-adjustable leg assemblies using hydraulic actuators to maintain proper orientation. However, Swisher lacked the claimed "positively coupled" hydraulic system. Neumeier, which addresses stability for off-road vehicles, was alleged to supply this missing element by teaching a suspension system with four double-acting hydraulic cylinders connected by coupling lines to create a positive coupling. This system in Neumeier results in the same coordinated movement claimed in the ’309 patent, where diagonally opposing wheels move in the same direction.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Neumeier’s advanced suspension with Swisher’s road-building machine to solve the known problem of maintaining vehicle stability over uneven terrain. Petitioner asserted that improving the stability of a machine like Swisher's by incorporating a known, more effective suspension system like Neumeier's was a simple and predictable design choice to achieve a desired, well-documented benefit. The motivation was to improve stabilization, simplify the design, and potentially reduce cost.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because the combination involved applying a known hydraulic suspension solution (Neumeier) to a known type of heavy machinery (Swisher). Petitioner contended there were no technical hurdles to replacing Swisher's actuators with Neumeier's system, as the principles of hydraulic actuation in such vehicles were well-understood, and the outcome would be a predictable improvement in stability.

Ground 2: Obviousness over Swisher, Neumeier, and Frey - Claims 11-13, 24, and 36 are obvious over Swisher in view of Neumeier and Frey.

  • Prior Art Relied Upon: Swisher (Patent 4,325,580), Neumeier (German Patent Pub. No. DE1918393), and Frey (Application # 2002/0074758).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground builds upon the combination of Swisher and Neumeier to address claims requiring valve controls for individual wheel adjustment. While Swisher taught individual leg adjustment and Neumeier taught coupled adjustment, Frey was introduced to bridge the two functionalities. Petitioner argued Frey explicitly disclosed using decoupling valves within a positively coupled hydraulic circuit to allow for individual adjustment of a single cylinder. This teaching allegedly maps directly to the limitations in claims 11-13, which require a valve control designed to raise or lower an individual wheel or specific pairs of wheels.
    • Motivation to Combine: A POSITA, having created the base machine from Swisher and Neumeier, would be motivated to add Frey's decoupling valves to retain the useful ability to adjust individual leg assemblies for inspection, maintenance, or repair. Petitioner asserted that a POSITA would desire both the enhanced stability of Neumeier's coupled system during operation and the functionality of individual adjustment taught by Swisher and enabled by Frey's valves. Adding such valves was presented as a known method to add functionality to a hydraulic circuit.
    • Expectation of Success: Incorporating Frey’s well-known decoupling valve design into the hydraulic circuit taught by Neumeier was a straightforward engineering task. A POSITA would have expected the combination to predictably allow the system to operate in both a positively coupled mode for stability and a decoupled mode for individual wheel adjustment without technical difficulty.

4. Key Claim Construction Positions

  • Petitioner argued that the term "actuating member" in claim 1 should be construed to mean a "double-acting working cylinder." This construction was based on the patent's specification, which describes the actuating members as being designed as working cylinders and the working cylinders as being double-acting. This proposed construction aligns the claim language more directly with the disclosures of the prior art, particularly Neumeier.

5. Key Technical Contentions

  • Petitioner contended that the "four sided stability pattern" recited in several dependent claims was not a distinct, patentable feature but was an inherent property of any machine implementing Neumeier’s positively coupled hydraulic system. The argument was that the specific pivoting axes and diamond-shaped stability pattern would necessarily result from combining Swisher’s four-cornered machine with Neumeier’s hydraulic coupling design, without requiring any additional inventive step.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-3, 5-24, and 26-36 of the ’309 patent as unpatentable under 35 U.S.C. §103.