PTAB

IPR2025-01384

MWE Investments, LLC v. Champion Power Equipment, Inc.

Key Events

Petition

petition

Case #: IPR2025-01384
Patent #: 11,905,895
Filed: August 20, 2025
Petitioner(s): MWE Investments, LLC, Harbor Freight Tools USA, Inc., and Generac Power Systems, Inc.
Patent Owner(s): Champion Power Equipment, Inc.
Challenged Claims: 1-21

Title: Dual Fuel Lockout Switch for Generator Engine
Brief Description: The ’895 patent discloses a mechanical fuel lockout switch for a dual-fuel engine, such as one operating on gasoline and LPG. The system features a mechanical fuel valve that is actuated between two positions to select a fuel source. A "fuel lockout apparatus" is coupled to the valve and configured to physically block the inlet of the non-selected fuel source, preventing the simultaneous delivery of both fuels to the engine.

Prior Art Relied Upon: DuroMax (DuroMax XP4400EH Operator’s Manual) and Elsdon (Patent 5,718,265).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that DuroMax discloses a dual-fuel (gasoline/LPG) generator with a mechanical fuel valve to switch between fuels. However, DuroMax lacks a physical lockout mechanism and instead relies on a user warning to prevent the known problem of simultaneous fuel operation. Elsdon was argued to teach a safety cap assembly for a fluid conduit coupler, where the cap rotates to physically cover and block access to the coupler interface.
- Motivation to Combine: A POSITA would combine Elsdon's physical blocking cap with the mechanical fuel valve of DuroMax to solve the known safety and performance issues associated with simultaneous fuel delivery. By linking the cap to the valve handle, a POSITA could create an automatic and reliable mechanical lockout that physically prevents the connection of the LPG hose when the generator is set to run on gasoline.
- Expectation of Success: Petitioner asserted a high expectation of success, as Elsdon's cap is a simple mechanical component designed to be retrofitted onto existing equipment like generators. Integrating this simple rotating cap with DuroMax's simple rotating valve handle was presented as a straightforward mechanical task for a POSITA.

Prior Art Relied Upon: DuroMax, Elsdon, Parlatore (Application # 2011/0100335), and LP-Gas Handbook (2008 edition).
Core Argument for this Ground:
- Prior Art Mapping: This ground built upon the DuroMax/Elsdon combination to address claims requiring an off-board fuel regulator system and quick-disconnect couplings. Petitioner contended that Parlatore teaches an off-board, two-stage pressure regulator system for supplying propane to various engines, including generators. The LP-Gas Handbook was cited to establish that quick-connectors were a standard and well-understood solution for creating releasable connections in propane fuel systems.
- Motivation to Combine: A POSITA would combine Parlatore’s off-board regulator with the DuroMax/Elsdon generator for enhanced safety (by locating the high-pressure components away from the engine) and improved serviceability. The LP-Gas Handbook and Parlatore's teaching of a "releasable" connection provided the motivation to use a standard quick-connect coupling for user convenience and safety.
- Expectation of Success: Success was expected because Parlatore explicitly suggests its system for use with generators, and both multi-stage regulators and quick-connect couplings were commonplace technologies in LPG fuel systems at the time.

Prior Art Relied Upon: Hallberg (Patent 4,492,207).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Hallberg discloses a complete dual-fuel system with a single control actuating a fluid dual valve that inherently performs the claimed lockout function. When the control is set to "gasoline," Hallberg's valve spool rotates to open the gasoline fuel line while simultaneously blocking the propane fuel line. Conversely, when set to "propane," the spool blocks the gasoline line and actuates the propane supply. Petitioner contended this single, integrated mechanism meets all the limitations of the claimed mechanical valve and coupled lockout apparatus. The obviousness argument for dependent claims was based on the inherent interconnectedness of Hallberg's valve preventing actuation to the gasoline position while the propane system is active.
Additional Grounds: Petitioner asserted an additional obviousness challenge (Ground 4) for claims 14, 15, and 17-21 based on the combination of Hallberg and Parlatore in view of LP-Gas Handbook, relying on similar motivations to add an off-board regulator system to Hallberg's dual-fuel engine.

"fuel lockout apparatus": Petitioner argued this term is a means-plus-function limitation under 35 U.S.C. §112(f) because it fails to recite sufficient structure for performing its function. The corresponding structure in the ’895 patent specification was identified as a flange (items 58, 61) rigidly coupled to the valve handle, which rotates to physically cover and block access to the inlet for the unused fuel source.
"prevent...coupling" / "permit...to couple": Petitioner contended that these terms require the physical blocking or unblocking of a connection port to prevent or permit the physical attachment of a fuel hose. This construction, based on the patent specification and prosecution history, is narrower than simply preventing or permitting fluid flow.

Petitioner requested institution of an inter partes review and cancellation of claims 1-21 of the ’895 patent as unpatentable.