US 11143120

Here is a concise summary of US patent 11143120:

US Patent: 11143120

• Title: Fuel system for a multi-fuel internal combustion engine
• Assignee: Champion Power Equipment Inc
• Inventors: Kendall J. Collie, Mark J. Sarder, Aleko D. Sotiriades, James J. Dehn, Leigh A. Jenison
• Filing Date: June 22, 2020
• Issue Date: October 12, 2021
• Abstract: A multi-fuel engine includes an engine operable on a liquid fuel and first and second gaseous fuels. The multi-fuel engine also includes a liquid cutoff solenoid selectively operable between open and closed positions to allow and inhibit a flow of the liquid fuel to the engine and at least one gaseous cutoff valve selectively operable between open and closed positions to allow and inhibit a flow of the first and second gaseous fuels to the engine. A jet block couples the first gaseous fuel source and the second gaseous fuel source to a carburetor connected to an intake of the engine, with the jet block being located downstream from the at least one gaseous cutoff valve. The jet block includes a first gaseous fuel jet to meter the first gaseous fuel to the carburetor and a second gaseous fuel jet to meter the second gaseous fuel to the carburetor.

Plain-Language Overview of Independent Claims:

• Claim 1: This claim describes a multi-fuel engine capable of running on both liquid and gaseous fuels. It includes a carburetor with a float bowl. The system has two cutoff solenoids: one for the liquid fuel path and one for the gaseous fuel path. A switch allows a user to select and control which fuel path is open or closed. A key feature is the inclusion of one or more timing circuits that precisely manage when these solenoids activate, allowing for controlled fuel switching.
• Claim 12: This claim covers a multi-fuel generator and its fuel delivery system. The system uses an internal combustion engine that can run on liquid fuel and gaseous fuel from a pressurized source, with the engine driving an alternator. It specifically details a remote (off-board) fuel regulator system. This system consists of a primary pressure regulator that reduces the high pressure from the fuel source and a secondary pressure regulator that further lowers the fuel pressure to the exact level needed for the engine to operate.
• Claim 18: This claim describes a carburetor specifically designed for a multi-fuel internal combustion engine. It features a main passage (throat) for mixing air and fuel, a valve for choke and throttle control, and a float bowl for holding liquid fuel. The carburetor has a main fuel circuit for general operation and an idle fuel circuit for when the engine is idling. A unique component is a carburetor cutoff solenoid that is designed to control the flow of liquid fuel through both the main and idle fuel circuits.

CAFC 2026 Dockets:
As of April 26, 2026, a direct search of CAFC 2026 dockets for patent number 11143120 does not yield results specifically within the CAFC 2026 docket listings. However, the provided patent document indicates active litigation involving this patent family, including several US District Court cases filed in 2023 and 2024 (e.g., Wisconsin Eastern, California Central, Arizona, Nevada) and a PTAB case (IPR2025-01121) filed in 2025. It is possible that these cases are ongoing in their respective venues and have not yet reached the Court of Appeals for the Federal Circuit (CAFC) in 2026, or if they have, they are not immediately apparent through the search.