PTAB

IPR2018-01091

Caterpillar Inc v. Wirtgen America Inc

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Petition

1. Case Identification

2. Patent Overview

  • Title: Road Construction Machine, Leveling Device, as Well as Method for Controlling the Milling Depth or Milling Slope in a Road Construction Machine
  • Brief Description: The ’395 patent discloses a leveling system and method for controlling the milling depth and slope of a road construction machine's milling drum. The invention purports to solve a problem in the prior art by allowing an operator to switch the sensors used for control during a milling operation without halting the machine or causing erratic adjustments.

3. Grounds for Unpatentability

Ground 1: Obviousness over Davis in view of Brabec - Claims 1, 3, 5-8, 10, 11, 13, 15-17, 19, 20, 22, 24, 26, and 27 are obvious over Davis in view of Brabec.

  • Prior Art Relied Upon: Davis (Application # 2002/0047301) and Brabec (Application # 2002/0154948).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Davis discloses a road scarifier (a type of road construction machine) with nearly all the elements of the challenged claims, including a position-adjustable milling drum, a PLC-based leveling system, and a plurality of selectable sensors (two depth, one inclination) for controlling depth and slope. Davis’s system uses a subset of two of its three sensors for control at any given time, leaving one sensor redundant. However, Petitioner contended Davis lacks the claimed feature of switching between sensor subsets without interrupting the milling operation. Brabec allegedly supplies this missing element by teaching a machine control system that automatically switches to an alternate sensor when a primary sensor becomes unavailable, explicitly doing so to continue machine operations without interruption or erratic implement movement.
    • Motivation to Combine: A POSITA would combine Davis and Brabec to solve the known problem of machine downtime resulting from sensor failure, which was a recognized issue in the art. Brabec provides a known, desirable solution (seamless sensor backup) to a problem inherent in sensor-based control systems like that of Davis. The motivation would be to improve the reliability and productivity of the Davis system by incorporating Brabec's method for continuing operations in the face of sensor signal loss, thereby reducing costs.
    • Expectation of Success: A POSITA would have a high expectation of success in this combination. Davis already provides a controller capable of using different sensor combinations and includes a redundant sensor. Implementing Brabec’s established sensor-swapping logic into the Davis PLC controller was presented as a straightforward modification with no technical hurdles, leading to the predictable result of uninterrupted operation during a sensor switch.

Ground 2: Obviousness over Davis in view of Krieg - Claims 1, 6, 8, 10, 11, 16, 17, 19, 20, 24, 26, and 27 are obvious over Davis in view of Krieg.

  • Prior Art Relied Upon: Davis (Application # 2002/0047301) and Krieg (Patent 6,286,606).
  • Core Argument for this Ground:
    • Prior Art Mapping: As in Ground 1, Davis was asserted to teach the foundational road milling machine with a multi-sensor control system. Krieg was argued to teach an automatic "swap" of sensor assignments in a motor grader's control system. Specifically, Krieg discloses automatically reversing the 'grade sensor' and 'slope sensor' assignments between the left and right sides of the machine when it reverses direction for a second grading pass. Petitioner argued this automated sensor swapping for continuous operation is analogous to the functionality claimed in the ’395 patent. The combination of Davis's machine with Krieg's sensor-swapping functionality would allegedly render the claims obvious.
    • Motivation to Combine: A POSITA would be motivated to incorporate Krieg's sensor swap functionality into the Davis system to increase operational flexibility and efficiency. For example, a milling machine may need to switch its grade reference from the left side of a road to the right side when milling different segments. Krieg teaches a way to switch controlling sensors from one side to the other without stopping the machine, a clear benefit a POSITA would seek to apply to the Davis machine to avoid downtime and reduce operator error from manual reconfiguration.
    • Expectation of Success: Petitioner contended a POSITA would have a reasonable expectation of success because the combination involves applying a known technique (Krieg's sensor swap) to a similar system (Davis's machine) to achieve a predictable improvement (continuous operation while switching sensor references). Since the Davis PLC controller already processes multiple sensor inputs, modifying it to switch between them based on Krieg's teachings would be well within the skill of a POSITA.

4. Arguments Regarding Discretionary Denial

  • Petitioner argued that the grounds asserted in the IPR petition are new and differ significantly from those considered by the PTO during the original prosecution of the ’395 patent. The petition noted that while the European counterpart to Davis was applied as an anticipatory reference during prosecution, neither Brabec nor Krieg were cited or applied. Petitioner contended that Brabec and Krieg teach the specific features—switching sensors without stopping operations—that the Patent Owner previously argued were missing from the prior art of record. This argument was intended to weigh against a discretionary denial under §325(d).

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1, 3, 5-8, 10, 11, 13, 15-17, 19, 20, 22, 24, 26, and 27 of the ’395 patent as unpatentable under 35 U.S.C. §103.