Harbor Freight Tools USA Inc v. Champion Power Equipment Inc

1. Case Identification

• Case #: IPR2025-01463
• Patent #: 11,840,970
• Filed: September 19, 2025
• Petitioner(s): Harbor Freight Tools USA, Inc., Generac Power Systems, Inc., and MWE Investments, LLC
• Patent Owner(s): Champion Power Equipment, Inc.
• Challenged Claims: 1-52

2. Patent Overview

• Title: Dual Fuel Generator with Remote Regulator
• Brief Description: The ’970 patent relates to a dual fuel generator and fuel delivery system. The system uses an off-board fuel regulator assembly with primary and secondary pressure regulators to supply gaseous fuel (e.g., propane) from a pressurized source to the generator engine, which can also run on liquid fuel.

3. Grounds for Unpatentability

Ground 1: Obviousness over Chaudhari and Hallberg - Claims 1-5 and 34-37 are obvious over Chaudhari in view of Hallberg.

• Prior Art Relied Upon: Chaudhari (Indian Patent No. 207333) and Hallberg (Patent 4,492,207).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Chaudhari disclosed a dual-fuel generator system that meets most limitations of the independent claims, including an engine running on liquid (gasoline/kerosene) or gaseous (LPG) fuel and an off-board, two-stage regulator system for the gaseous fuel. However, Chaudhari used electronic solenoid valves for fuel selection. Hallberg disclosed a mechanical dual-fuel valve actuatable between two positions to select between gasoline and propane for an internal combustion engine.
  • Motivation to Combine: A POSITA would combine Hallberg’s mechanical fuel valve with Chaudhari’s generator to create a more robust and reliable system. Petitioner asserted that Chaudhari’s electronic selection system presented known points of failure (e.g., coil burnout, wiring issues), whereas a mechanical valve is less susceptible to vibrations and environmental conditions common to generator operation.
  • Expectation of Success: A POSITA would have a high expectation of success, as both systems perform the identical core function of selectively directing fuel from two sources to an engine. Mechanical fuel valves were well-known and widely used, making the integration straightforward.

Ground 2: Obviousness over DuroMax, Parlatore, and Elsdon - Claims 1-6, 8-14, 16-19, 34-38, 40-44, 47-48, and 50-52 are obvious over DuroMax in view of Parlatore and Elsdon.

• Prior Art Relied Upon: DuroMax (DuroMax XP4400EH Operator’s Manual), Parlatore (Application # 2011/0100335), and Elsdon (Patent 5,718,265).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner contended that DuroMax, a commercially available dual-fuel generator, disclosed the basic generator configuration. However, its regulator system was partially on-board. Parlatore taught a fully off-board, two-stage regulator system for use with any engine, including generators. The DuroMax generator had a simple gasoline fuel valve but lacked an integrated mechanism to prevent simultaneous connection of the LPG fuel source. Elsdon disclosed a "retrofit" fuel conduit coupler cap assembly that physically blocks and unblocks access to a fuel inlet.
  • Motivation to Combine: A POSITA would first combine the DuroMax generator with Parlatore's fully off-board regulator system to improve safety by locating high-pressure fuel lines and components away from the generator's heat and ignition sources. Subsequently, a POSITA would integrate Elsdon’s physical lockout cap with the DuroMax gasoline fuel valve. This would solve the known hazard of simultaneously running both fuels—a danger explicitly warned against in the DuroMax manual—by creating a single mechanical control that selects one fuel while physically blocking the other.
  • Expectation of Success: Success was expected because Parlatore's regulator system was disclosed for general use, and Elsdon's lockout cap was specifically described as a "retrofit" for existing equipment like generators. The combination involved applying known solutions to solve known problems.

Ground 3: Obviousness over Chaudhari, Hallberg, Jungmann, and Parlatore - Claims 8-11, 16-19, and 40-43 are obvious over Chaudhari in view of Hallberg, Jungmann, and Parlatore.

• Prior Art Relied Upon: Chaudhari (Indian Patent No. 207333), Hallberg (Patent 4,492,207), Jungmann (Application # 2014/0239645), and Parlatore (Application # 2011/0100335).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground builds upon the combination of Chaudhari and Hallberg from Ground 1. Petitioner argued that certain claims required additional features, such as mounting the regulators on the fuel tank. Parlatore disclosed mounting primary and secondary pressure regulators on a mounting device secured to the collar of an LPG tank. Jungmann taught mounting generator components within a protective housing.
  • Motivation to Combine: A POSITA would add Parlatore's tank-mounted regulator configuration to the Chaudhari/Hallberg system to reduce the risk of fire or explosion by ensuring high-pressure components are located far from the generator's ignition sources. This also simplifies the fuel system and protects the regulators from vibration. A POSITA would also add Jungmann's housing for protection, noise reduction, and portability.
  • Expectation of Success: Petitioner asserted success would be expected as mounting regulators on tanks and enclosing generators in housings were common, well-understood practices for improving the safety and durability of portable power equipment.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including grounds based on DuroMax in view of Parlatore and other references (Ground 6) and Chaudhari in view of Monros and Jungmann (Ground 7), which relied on similar component-swapping and design-improvement rationales.

4. Key Claim Construction Positions

• "fuel lockout apparatus": Petitioner argued this term, central to claims 3-6, 25-28, 35-38, and 50-52, is a means-plus-function term under 35 U.S.C. §112(f). Petitioner contended that "apparatus" is a generic, non-structural placeholder, and the claims fail to recite sufficient structure for performing the lockout function. The corresponding structure disclosed in the ’970 patent was identified as the specific flange mechanism (items 58 and 61) that physically blocks access to a fuel inlet.
• "prevent...coupling" and "permit...to couple": Petitioner argued these terms require physical blocking and unblocking of a connection, not merely preventing or permitting fluid flow through an already-connected line. This interpretation was based on the patent’s sole embodiment, where a flange physically obstructs the LPG hose from being attached, and was supported by the prosecution history of a related patent.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-52 of the ’970 patent as unpatentable.