Gatekeeper Systems Inc v. Dane Technologies Inc

1. Case Identification

• Case #: IPR2013-00338
• Patent #: Patent 7,493,979
• Filed: June 7, 2013
• Petitioner(s): Gatekeeper Systems, Inc.
• Patent Owner(s): Dane Technologies, Inc.
• Challenged Claims: 1-21

2. Patent Overview

• Title: Power-Assisted Cart Retriever with Attenuated Power Output
• Brief Description: The ’979 patent discloses a motorized shopping cart retriever with an electronic controller that manages power to the drive system. The controller uses multiple power limits: a first, self-limiting "internal limit" based on a sensing feature (e.g., temperature), a second, selectable "selected limit" to act as a governor, and a "burst mode" to temporarily exceed the selected limit for a power boost.

3. Grounds for Unpatentability

Ground 1: Obviousness over Schugt and Curtis 1297 Manual - Claims 1-5, 7-8, and 14-21 are obvious over Schugt in view of the Curtis 1297 Manual.

• Prior Art Relied Upon: Schugt (Patent 6,220,379) and the Curtis 1297 Manual (a 2001 motor controller manual).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued Schugt disclosed the foundational motorized shopping cart retriever, including an electric motor, drive system, and controller. The Curtis 1297 Manual, a controller for small industrial vehicles, taught the allegedly novel power-limiting features. Specifically, it disclosed a first power limit (an "overtemperature" feature that self-limits current), a selectable second power limit (a programmable "drive current limit"), and a "burst mode" (a "boost enable" feature providing a "burst of extra torque").
  • Motivation to Combine: A POSITA would combine the known controller features from the Curtis 1297 Manual with the cart retriever of Schugt to achieve predictable improvements. This combination would address known needs for overload protection and provide a temporary power boost to overcome obstacles (e.g., "getting the vehicle out of a pothole"), a common challenge for such vehicles.
  • Expectation of Success: The integration of a commercially available motor controller's features into a standard electric vehicle was a straightforward design choice with a high expectation of success, as it involved combining known components to perform their expected functions.

Ground 2: Obviousness over Schugt, Curtis 1237 Manual, and Allen-Bradley Manual - Claims 1-5, 7-8, and 14-21 are obvious over Schugt in view of the Curtis 1237 Manual and the Allen-Bradley Manual.

• Prior Art Relied Upon: Schugt (Patent 6,220,379), the Curtis 1237 Manual (a 2000 motor controller manual), and the Allen-Bradley Manual (a 2002 motor controller manual).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted Schugt again provided the base cart retriever. In this combination, the Curtis 1237 Manual disclosed a first power limit (a "thermal protection" feature) and a selectable second power limit (an adjustable "main current limit"). The Allen-Bradley Manual was cited for its "selectable kickstart" feature, which provided the claimed "burst mode" by delivering a "boost at startup to break away loads." The power profile of the Allen-Bradley "kickstart" feature was argued to be strikingly similar to that shown in the ’979 patent.
  • Motivation to Combine: A POSITA seeking to improve cart retriever performance would look to various off-the-shelf motor controllers. The Curtis 1237 Manual provided well-known temperature and overload protection, while the Allen-Bradley Manual's "kickstart" feature directly addressed the known problem of initiating movement of a heavy, static load of carts, making it an advantageous feature to incorporate.
  • Expectation of Success: The combination involved selecting and implementing well-documented features from established commercial controllers into a known vehicle type, which would predictably result in a retriever with improved startup torque and safety limits.

Ground 3: Obviousness over Schugt, Curtis 1297 Manual, and Dykstra - Claims 14-17 are obvious over Schugt in view of the Curtis 1297 Manual and Dykstra.

• Prior Art Relied Upon: Schugt (Patent 6,220,379), the Curtis 1297 Manual, and Dykstra (Patent 5,388,176).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground focused on method claims. Petitioner argued Schugt taught the basic method of operating a cart retriever, and the Curtis 1297 Manual taught setting power limits and activating a boost mode. Dykstra was introduced to further teach a motor controller that provides an "extra power increase upon engine starting or whenever a heavier load is temporarily encountered." Dykstra explicitly described increasing current for a short period to overcome initial inertia without causing component overheating.
  • Motivation to Combine: Dykstra provided a clear technical rationale for the very functionality claimed, reinforcing the motivation to apply a "burst" feature like that in the Curtis 1297 Manual to the Schugt retriever. Dykstra explained the benefits of a temporary power increase for starting and maneuvering heavy loads, directly aligning with the purpose of a cart retriever.
  • Expectation of Success: The principles of motor control taught by Dykstra were directly applicable to the electric vehicle field, and a POSITA would expect the described power boost to function predictably in the context of Schugt's retriever.

• Additional Grounds: Petitioner asserted additional obviousness challenges over combinations of Schugt with the Curtis 1288 Manual, the Electric Motors Handbook, and applicant-admitted prior art, relying on similar theories of combining known motor controller features for predictable results.

4. Key Claim Construction Positions

• Means-Plus-Function Terms: Petitioner argued that claims 18-21 invoked 35 U.S.C. §112, Sixth Paragraph, because they used "means for" language without reciting sufficient structure. Petitioner identified the corresponding structure for terms like "first power-limiting means," "second power-limiting means," and "burst means" as the disclosed "controller 12" and its associated functionalities (e.g., "internal limit 20," "selected limit 24," and "burst mode"). This construction was critical to mapping the prior art controller manuals, which disclosed these specific structural features, onto the claims.

5. Key Technical Contentions (Beyond Claim Construction)

• Disputed Priority Date: A central contention was that the ’979 patent was not entitled to the priority date of its provisional application (the ’546 provisional). Petitioner argued the provisional application, which was nearly identical to the Schugt patent, failed to disclose the claimed "burst mode" functionality. Because the entire basis for the "burst mode" was added in the later non-provisional application, Petitioner asserted the earliest possible priority date was September 23, 2004, which rendered several key prior art references, including the Curtis and Allen-Bradley manuals, available under §102(b).

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-21 of the ’979 patent as unpatentable.