PTAB

IPR2021-00136

Godbersen Smith Construction Co v. Guntert & Zimmerman Const Div Inc

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Slipform Paver with Swing Leg Position Sensing
  • Brief Description: The ’571 patent discloses a slipform paving machine for laying concrete. The purported invention involves a three-leg configuration (two forward, one aft), where each leg has a crawler track and sensors that measure the swing-leg’s movement to automate track positioning.

3. Grounds for Unpatentability

Ground 1: Claims 1-3, 5-7, and 14-15 are obvious over CIII in view of Rio.

  • Prior Art Relied Upon: CIII (Commander III New Generation Trimmer/Paver Operator/Service Manual) and Rio (Patent 7,523,995).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that CIII, a publicly distributed manual for a commercial slipform paver, discloses nearly all structural elements of the challenged claims. This includes a paving machine with a center module, forward and aft bolsters, and at least one pivoting swing leg with a jacking column and crawler track. However, CIII requires time-consuming manual adjustments to reposition the swing leg and crawler track. Petitioner asserted that Rio, which discloses a road-milling machine, teaches an automated system to address this exact problem. Rio discloses using a pivot sensor on the swing arm (leg) and a rotation sensor on the ground engaging unit (crawler track), which feed signals to a controller. The controller then uses actuators to automatically counter-rotate the track as the leg pivots, keeping it oriented in the desired direction.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine CIII and Rio because they are analogous art from the same field (road-construction machinery) and address the same problem of costly and inefficient manual repositioning of swing legs and crawler tracks. A POSITA would be motivated to integrate Rio’s automated sensor and control system into CIII’s paver to improve operational efficiency, reduce costs, and enhance safety by eliminating manual adjustments.
    • Expectation of Success: A POSITA would have a reasonable expectation of success, as the combination involves substituting known electronic control elements (from Rio) for manual ones (in CIII) using well-understood methods to achieve the predictable result of an automated swing-leg paver.

Ground 2: Claim 4 is obvious over CIII, Rio, and Widdrington.

  • Prior Art Relied Upon: CIII, Rio, and Widdrington (Patent 3,252,349).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground builds on the CIII-Rio combination and addresses the limitations of dependent claim 4, which recites a power drive comprising first and second diametrically opposed helical worm gear drives engaging a ring gear. Petitioner argued that the CIII-Rio combination teaches a rotary actuator for the crawler track. Widdrington was introduced because it explicitly discloses a compact, dual worm-gear drive mechanism matching the specific configuration claimed.
    • Motivation to Combine: A POSITA, seeking to implement the rotary actuator taught by Rio, would look to known gear drive designs like Widdrington. Widdrington’s dual-worm design offers advantages such as a more compact size, balanced torque, and reduced wear compared to a single, larger worm gear. These benefits would motivate a POSITA to use Widdrington’s design as the power drive in the CIII-Rio machine.

Ground 3: Claims 9-13 are obvious over CIII, Rio, and Smolders.

  • Prior Art Relied Upon: CIII, Rio, and Smolders (Patent 6,481,924).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground addresses claims requiring a second swing leg on the forward bolster. CIII discloses one forward swing leg and one forward telescoping leg. Petitioner argued that replacing CIII's telescoping leg with another swing leg would be an obvious modification. Smolders was introduced because it discloses a road-construction machine with two swing-leg assemblies coupled to the left and right ends of a forward bolster.
    • Motivation to Combine: A POSITA would be motivated to replace CIII's telescoping leg with a second swing leg, as taught by Smolders, to improve the paver’s overall maneuverability and steering flexibility. The use of multiple swing legs was a known method for increasing machine versatility. Applying Rio's automation technology to this second swing leg would be a logical extension of the logic from Ground 1.

Ground 4: Claim 8 is obvious over CIII, Rio, and Dahm.

  • Prior Art Relied Upon: CIII, Rio, and Dahm (Application # 2015/0354149).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground targets claim 8, which recites a "laterally telescoping leg" and a "linear position transducer" to monitor its position. Petitioner first contended that claim 8 is not entitled to the patent’s priority date. CIII discloses a telescoping leg, but it is controlled manually. Dahm was introduced because it discloses telescoping frame assemblies on a slipform paver that use linear actuators with integrated extension sensors (linear position transducers) to provide precise feedback to a controller.
    • Motivation to Combine: A POSITA would be motivated to modify the CIII-Rio paver’s existing telescoping leg with the sensor/actuator design from Dahm. This modification would provide precise, automated control over the leg's lateral position, allowing for greater stability and more accurate paving operations. It is an obvious improvement to add a known sensor (Dahm) to a known mechanical component (CIII's telescoping leg) to automate its function.

4. Key Claim Construction Positions

  • "mechanically coupled" (claims 1, 8, 11, 13): Petitioner argued this term should be construed to mean "directly or indirectly coupled." The petition asserted that the ’571 patent’s specification and figures show the claimed crawler tracks are only indirectly connected to the bolsters through intermediate components like jacking columns and swing legs. This construction is critical for mapping prior art where components are not directly attached.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that discretionary denial under Fintiv was not warranted. It contended that five of the six factors were neutral or weighed in favor of institution. Key arguments included that Petitioner intended to request a stay in the parallel district court case, which would conserve judicial resources. Further, the district court trial date was not certain due to potential COVID-19 delays, and the investment in the parallel proceeding was minimal at the time of filing. Petitioner also asserted that the prior art raised in the IPR had never been considered by the USPTO, and there was a strong public interest in reviewing and canceling claims of a potentially invalid patent.

6. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-15 of the ’571 patent as unpatentable.