PTAB

IPR2017-01533

Westinghouse Air Brake Technologies Corporation v. Siemens Mobility, Inc.

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1. Case Identification

2. Patent Overview

  • Title: Train Safety System
  • Brief Description: The ’953 patent describes a train safety system that uses a controller and transceiver on the train. The system is designed to send an interrogation message to a wayside track circuit, receive a response indicating the condition of the track, and either permit the train to proceed or activate a warning device based on the response.

3. Grounds for Unpatentability

Ground 1: Claims 1-3, 8, 16, 20-22, and 27 are obvious over Birkin in view of Petit.

  • Prior Art Relied Upon: Birkin (Patent 4,932,614) and Petit (Patent 5,092,544).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Birkin taught a communication subsystem where a train interrogates an upcoming track circuit transponder and receives a response indicating a condition of the rail circuit (e.g., broken rail). However, Birkin was silent on what the train system does with this response. Petitioner contended that Petit supplied this missing element by teaching an onboard CPU that processes a response from a wayside device (a crossing) and, if an error is detected, activates the train's brakes or an alarm. Petit also taught including a device ID in messages to distinguish between different wayside devices.
    • Motivation to Combine: A person of ordinary skill in the art (POSA) would have been motivated to combine the references to solve known problems. Birkin proposed an interrogation/response system but failed to disclose how to use the response for safety enforcement or how to manage communications with multiple wayside devices. A POSA would look to analogous art like Petit, which explicitly taught using response messages to trigger alarms or brakes and using device IDs to ensure messages are sent to and received from the correct device, thereby improving the safety and functionality of Birkin’s system.
    • Expectation of Success: A POSA would have had a reasonable expectation of success in combining these systems because both relate to radio-based train control, use an interrogation/response protocol with wayside equipment, and address the same fundamental goal of ensuring safe train passage. Integrating Petit's onboard processing and safety logic into Birkin's track condition monitoring system was presented as a predictable and straightforward implementation.

Ground 2: Claims 1-3, 8, 16, 20-22, and 27 are obvious over Birkin in view of RSAC.

  • Prior Art Relied Upon: Birkin (Patent 4,932,614) and RSAC (a 1999 report from the Railroad Safety Advisory Committee on Positive Train Control systems).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground presented a similar argument to Ground 1, but used RSAC instead of Petit to supply the teachings missing from Birkin. Petitioner asserted that Birkin disclosed the basic concept of interrogating a track circuit for its condition. RSAC, a comprehensive survey of the state of the art in Positive Train Control (PTC) systems, was said to teach the solutions to Birkin's shortcomings. Specifically, RSAC described various PTC systems with onboard computers (OBCs) that automatically apply brakes or issue alerts in response to unsafe conditions reported from wayside devices and use unique identifiers for those devices.
    • Motivation to Combine: The motivation was framed as solving a known problem. A POSA implementing Birkin’s system would recognize the need for an automatic enforcement mechanism to address operator inattentiveness and a method to distinguish between devices. RSAC, representing the accumulated knowledge of the railroad industry, provided a known, obvious solution by detailing systems that performed these exact functions. Modifying Birkin with the widely-known safety features described in RSAC was argued to be a predictable step to create a commercially viable and safer PTC system.
    • Expectation of Success: Success was expected because the combination involved applying established, industry-standard safety principles (automatic braking, alerts), as documented in RSAC, to a specific monitoring technology (Birkin’s track circuit interrogation).

  • Additional Grounds: Petitioner asserted that claims 8-10 and 27-29 were obvious over Birkin, Petit, and Blesener (WO 02/091013) (Ground 3), and over Birkin, RSAC, and Blesener (Ground 4). In these grounds, Blesener was added to teach the use of an onboard database of device locations and a GPS positioning system to identify and trigger communication with upcoming track circuits. This combination allegedly rendered it obvious to replace the trackside beacons of Birkin/Petit with a more robust and less failure-prone onboard database system.

4. Key Claim Construction Positions

  • "indication as to a condition of a section of track": Petitioner argued that this term, central to the claims, must be construed as "data reflecting the state of a section of track." This construction was based on the patent's specification and prosecution history, where the applicant distinguished the invention from prior art that only detected train occupancy. Petitioner contended the term requires information about the physical integrity of the track itself (e.g., a broken rail), not simply whether another train is present. This construction was crucial for mapping the prior art, which taught monitoring for such physical conditions.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-3, 8-10, 16, 20-22, and 27-29 of the ’953 patent as unpatentable.