PTAB

IPR2019-00662

Tetra Tech Canada Inc v. Georgetown Rail Equipment Co

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: System and Method for Inspecting Railroad Ties
  • Brief Description: The ’956 patent discloses a vehicle-mounted system for automatically inspecting railroad tracks. The system uses a laser to project a line of light across track components, a camera to capture 2D contour range images of the illuminated profile, and a processor to analyze these images to identify defects such as misaligned or sunken tie plates.

3. Grounds for Unpatentability

Ground 1: Obviousness over Davis, Kowalski, Bostrom, and Kanade - Claims 21-29 are obvious over Davis in combination with Kowalski, Bostrom, and Kanade.

  • Prior Art Relied Upon: Davis (a 1990 railroad research report), Kowalski (Patent 7,023,539), Bostrom (Patent 6,496,254), and Kanade (a 1987 machine vision publication).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Davis taught the importance and methodology of measuring "tie plate cut"—the depth a tie plate has worn into a wooden crosstie—as a key indicator of track health, using a semi-automated device. Kowalski taught a vehicle-mounted automated laser scanning system for detecting alignment defects in railroad components by comparing their height contours. The combination of Davis and Kowalski allegedly rendered obvious an automated, vehicle-mounted system for measuring tie plate cut. Bostrom supplied the well-known technical means for such a system, disclosing a sheet-of-light range imaging device that captures 2D profile images of an object for analysis by a processor. Finally, Kanade provided known image processing algorithms for analyzing 2D image contours to detect and extract defects, which a processor would use to determine if a tie plate was misaligned or sunken based on the captured contour data.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine these references to automate a known, important, but largely manual inspection task (Davis's tie plate cut measurement) using a known automated platform (Kowalski's vehicle-mounted system). The motivation was to achieve predictable benefits in inspection speed, accuracy, objectivity, and safety, which were known advantages of machine vision systems.
    • Expectation of Success: A POSITA would have a high expectation of success, as the combination involved applying established machine vision technologies (Bostrom, Kanade) to automate a well-defined measurement problem (Davis) in a known environment (Kowalski).

Ground 2: Obviousness over Holmes, Bostrom, Davis, and Kanade - Claims 21-29 are obvious over Holmes in combination with Bostrom, Davis, and Kanade.

  • Prior Art Relied Upon: Holmes (Patent 6,647,891), Bostrom (Patent 6,496,254), Davis (a 1990 railroad research report), and Kanade (a 1987 machine vision publication).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Holmes disclosed a vehicle-mounted, range-finding based railway inspection system that uses a laser and sensor to generate a "range-based virtual surface" (image) and a processor to identify features like ties and tie plates. Petitioner argued that the Examiner allowed the ’956 patent claims over Holmes for lacking a processor that determines if a tie plate is misaligned or sunken. The proposed combination remedies this by incorporating the specific method from Davis for measuring tie plate cut depth to assess crosstie health. A POSITA would implement Davis's algorithm in Holmes's system, using the processor to analyze the captured image data. As in Ground 1, Bostrom and Kanade provided the known technical means for capturing 2D contour images and analyzing them for defects.
    • Motivation to Combine: A POSITA would be motivated to enhance Holmes's general-purpose inspection system by incorporating the specific, industry-recognized tie-failure metric from Davis. This would improve the system's defect-detection capabilities and provide a more reliable measure of crosstie health, thereby increasing railroad safety. The references all target the common field of surface inspection.
    • Expectation of Success: The integration was characterized as a straightforward application of a known measurement algorithm (Davis) to an existing automated inspection platform (Holmes), using conventional machine vision techniques (Bostrom, Kanade), leading to predictable improvements.

4. Key Claim Construction Positions

  • "image": Petitioner argued this term, central to claims 21, 26-27, and 29, should be construed as "a collection or data structure of pixels forming a two-dimensional representation." This construction was asserted to be critical, as the challenged claims require analysis of "an image" (singular). Petitioner contended that both the patent's specification and relevant machine vision literature consistently use "image" or "frame" to refer to a single 2D cross-sectional profile, not a compiled 3D representation formed from multiple images.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that the grounds presented in the petition are not cumulative of art or arguments previously considered by the USPTO during prosecution of the ’956 patent. Specifically, the Examiner never considered Davis, Kowalski, or Bostrom, nor the combination of Holmes with Bostrom and Davis. Further, Petitioner noted that while a concurrent IPR petition was filed (IPR2019-00620), the grounds asserted here were distinct and substantially different, warranting institution.

6. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 21-29 of the ’956 patent as unpatentable under 35 U.S.C. §103.