Derivative works — US Patent 11840970

Of course. As a Senior Patent Strategist and Research Engineer specializing in Defensive Publishing, I will analyze US patent 11,840,970 and generate a comprehensive defensive disclosure document. This document will create prior art based on the core claims, aiming to render future incremental improvements obvious or non-novel.

The analysis is based on the core inventive concept of US patent 11,840,970: a dual fuel generator system where the gaseous fuel pressure regulation is performed by a two-stage system located entirely off-board the main generator housing, with the generator itself being free of any such regulators.

Defensive Disclosure and Prior Art Derivations for US 11,840,970

Publication Date: May 13, 2026

Subject: Derivative designs and applications for dual fuel power generation systems with remote fuel pressure regulation.

I. Material and Component Substitution Derivatives

1. Derivative: Solid-State Electro-Pneumatic Regulator System

Enabling Description: This variation replaces the mechanical, spring-and-diaphragm based primary and secondary pressure regulators (42, 44) with a solid-state system. The primary regulator is a piezoelectric valve controlled by a pressure transducer feedback loop. The secondary regulator is a micro-electromechanical system (MEMS)-based thermal mass flow controller. The entire off-board regulator assembly is housed in a carbon-fiber-reinforced polymer casing for reduced weight and corrosion resistance. The mechanical fuel selection valve (38) on the generator is replaced with a set of three solenoid valves (one for liquid fuel, two for staged gaseous fuel delivery), controlled by a microcontroller. This allows for push-button or automated fuel switching. The hoses (36) are constructed from a multi-layer composite with a self-healing inner lining that seals small punctures.

Mermaid Diagram:

graph TD
    subgraph Pressurized Fuel Source (LPG)
        A[Service Valve 40]
    end
    subgraph Off-Board Regulator Module
        B[Piezoelectric Primary Regulator]
        C[MEMS Mass Flow Controller]
        D[Pressure & Temp Sensors]
        E[Microcontroller]
    end
    subgraph Generator Unit
        F[Liquid Fuel Solenoid]
        G[Gaseous Fuel Solenoid]
        H[Engine Control Unit]
        I[Carburetor/EFI]
    end
    A -- High Pressure Gas --> B
    B -- Transducer Feedback --> E
    B -- Reduced Pressure Gas --> C
    C -- Sensor Feedback --> E
    E -- Control Signal --> B
    E -- Control Signal --> C
    C -- Desired Pressure Gas --> G
    D -- Data --> E
    H -- Fuel Select Signal --> E
    H -- Control --> F & G

2. Derivative: Ceramic Component Fuel Selector Valve

Enabling Description: The mechanical fuel valve (54) and its rotating handle (56) are redesigned using ceramic components. A rotating ceramic disc with precisely machined apertures replaces the traditional brass or steel valve core. This provides superior resistance to corrosion from fuel impurities (e.g., sulfur in propane) and wear over many cycles. The fuel lockout cover (61) is an integrally molded part of the ceramic handle, offering high dimensional stability and electrical insulation. Sealing is accomplished via lapped ceramic faces, eliminating the need for elastomeric O-rings in the primary flow path, thus increasing compatibility with a wider range of alternative gaseous fuels like dimethyl ether (DME).

Mermaid Diagram:

graph TD
    subgraph Mechanical Fuel Valve Assembly
        A[Ceramic Handle & Lockout Cover]
        B[Outer Valve Body]
        C[Rotating Ceramic Disc]
        D[Fixed Ceramic Port Plate]
    end
    subgraph Flow Paths
        E[Liquid Fuel In]
        F[Liquid Fuel Out to Carburetor]
        G[Gaseous Fuel Inlet]
    end
    A -- Rotates --> C
    E --> D
    C -- Aligns with --> D
    D -- When Aligned --> F
    A -- Position 1: Covers --> G
    A -- Position 2: Exposes --> G

II. Operational Parameter Expansion Derivatives

1. Derivative: Cryogenic Fuel (LNG/LH2) Off-Board Regulation System

Enabling Description: The system is adapted for cryogenic fuels such as Liquefied Natural Gas (LNG) or Liquid Hydrogen (LH2). The off-board "regulator" is a multi-function vaporization and pressure-building unit housed in a vacuum-insulated dewar. The "primary stage" is an ambient air heat exchanger (vaporizer) that converts the cryogenic liquid to a high-pressure gas. The "secondary stage" is a dome-loaded pressure regulator capable of operating at temperatures down to -160°C. All plumbing is 316L stainless steel, and the regulator diaphragms are made of Kapton. The system is designed to supply gas at a stable 0.5 psi to the generator, despite tank pressures varying from 20 to 200 psi.

Mermaid Diagram:

sequenceDiagram
    participant LNG Tank
    participant Off-Board Vaporizer
    participant Cryo Regulator
    participant Generator Engine
    LNG Tank->>Off-Board Vaporizer: Delivers Liquid LNG (-162°C)
    Off-Board Vaporizer->>Off-Board Vaporizer: Ambient heat converts liquid to high-pressure gas
    Off-Board Vaporizer->>Cryo Regulator: Supplies High-Pressure Gas (50-200 psi)
    Cryo Regulator->>Generator Engine: Supplies Regulated Low-Pressure Gas (0.5 psi)
    Note right of Cryo Regulator: Dome-loaded regulator maintains<br/>stable output despite varying input pressure<br/>and cryogenic temperatures.

2. Derivative: Micro-Scale Power System for Unmanned Aerial Vehicles (UAVs)

Enabling Description: The entire system is miniaturized for a 50W UAV power source. The "generator" is a micro-combustion engine driving a brushless DC alternator. The off-board fuel system consists of a disposable butane cartridge ("pressurized fuel source") and a MEMS-based two-stage regulator fabricated on a single silicon wafer. The primary stage handles the pressure drop from ~30 psi to 5 psi, and the secondary stage provides a precise final pressure of 0.2 psi. The entire regulator is 5mm x 5mm and is integrated directly into the quick-connect fitting of the fuel cartridge. This minimizes weight on the airframe, as the regulator is disposed of with the empty cartridge.

Mermaid Diagram:

graph LR
    A[Butane Cartridge] -- Quick-Connect --> B{MEMS Regulator Chip}
    B -- Stage 1 --> C[Intermediate Pressure]
    C -- Stage 2 --> D[Final Pressure 0.2 psi]
    D --> E[UAV Micro-Engine]
    subgraph Disposable Unit
        A
        B
        C
    end

III. Cross-Domain Application Derivatives

1. Derivative: Aerospace - Auxiliary Power Unit (APU) with Detachable Fuel/Regulator Pod

Enabling Description: An APU for a large fixed-wing UAV uses a dual-fuel engine (Jet-A and compressed hydrogen gas). The entire hydrogen fuel supply and regulation system is housed in a single, detachable aerodynamic pod. This pod contains the high-pressure composite overwrapped pressure vessel (COPV), the primary regulator to drop pressure from 5000 psi to 150 psi, and the secondary regulator to deliver 5 psi to the APU. The pod connects to the fuselage via a single multi-port quick-disconnect that handles fuel, data, and power. This allows for rapid ground refueling by swapping the entire pod and isolates the high-pressure gas system from the main airframe, enhancing safety.

Mermaid Diagram:

graph TD
    subgraph Airframe
        A[APU Engine]
        B[Jet-A Tank]
        C[Multi-port Connector on Fuselage]
    end
    subgraph Detachable Fuel Pod
        D[Hydrogen COPV @ 5000psi]
        E[Primary Regulator]
        F[Secondary Regulator]
        G[Multi-port Connector on Pod]
    end
    B --> A
    C <--> G
    D -- 5000psi --> E
    E -- 150psi --> F
    F -- 5psi --> G
    G --> C --> A

2. Derivative: Agricultural Technology - Self-Propelled Irrigation System

Enabling Description: A large, self-propelled center-pivot irrigation system is powered by an engine that runs on diesel or wellhead natural gas. The natural gas, which is often wet and at inconsistent pressure, is processed by a rugged, off-board conditioning and regulation skid. This skid is positioned at the wellhead. The "primary stage" is a gas dehydrator and filter. The "secondary stage" is a heavy-duty two-stage regulator that delivers consistent, dry gas to the irrigation system's engine via a long, flexible hose that runs along the main irrigation pipe. The engine on the pivot's drive unit contains no gas regulation components, simplifying maintenance.

Mermaid Diagram:

flowchart LR
    A[Wellhead Gas] --> B{Off-Board Skid};
    subgraph B
        C[Dehydrator] --> D[Primary Regulator];
        D --> E[Secondary Regulator];
    end
    B -- Regulated Gas via long hose --> F[Engine on Irrigator];

3. Derivative: Marine - Submersible Emergency Power System

Enabling Description: A tourist submarine is equipped with a closed-cycle diesel engine for emergency battery recharging, which can run on standard diesel or a synthetic fuel mixed with compressed oxygen. To ensure safety, the high-pressure oxygen tank (2000 psi) and its associated two-stage pressure regulation system are mounted in a floodable external pod. In case of a fire or leak, the entire pod can be jettisoned. The regulator system reduces the oxygen pressure to a stable 10 psi for delivery to the engine's intake mixer inside the main pressure hull. The submarine's hull is free of any high-pressure oxygen regulators.

Mermaid Diagram:

stateDiagram-v2
    direction LR
    state "External Oxygen Pod" as Pod {
        [*] --> Tank: 2000 psi
        Tank --> Reg_Stage1: Reduce to 200 psi
        Reg_Stage1 --> Reg_Stage2: Reduce to 10 psi
        Reg_Stage2 --> Hull_Penetrator
    }
    state "Submarine Pressure Hull" as Hull {
        Hull_Penetrator --> Engine
    }
    [*] --> Pod
    Pod --> Hull: Low Pressure O2
    Pod --> Jettisoned: Emergency Release

IV. Integration with Emerging Technology Derivatives

1. Derivative: AI-Optimized Fuel Selection and Health Monitoring

Enabling Description: The off-board regulator is an "intelligent" unit equipped with IoT sensors for pressure, temperature, and fuel flow rate. It also includes a MEMS gas chromatograph to analyze the specific energy content (e.g., propane vs. butane ratio) of the gaseous fuel. This data is transmitted wirelessly to an AI-powered ECU on the generator. The AI model decides the optimal fuel source based on engine load, ambient temperature, fuel costs, and emissions targets. It can seamlessly switch fuels to maintain stable output during load changes. Furthermore, the AI performs predictive maintenance, analyzing pressure drop rates and temperature fluctuations to forecast regulator diaphragm failure or gas leaks before they become critical.

Mermaid Diagram:

sequenceDiagram
    participant User
    participant Generator AI ECU
    participant IoT Regulator
    participant Engine
    loop Real-time Monitoring
        IoT Regulator->>Generator AI ECU: Transmit Sensor Data (Pressure, Temp, BTU Content)
    end
    User->>Generator AI ECU: Request 5kW Load
    Generator AI ECU->>Generator AI ECU: Analyze data: Cold ambient, high load.
    Generator AI ECU->>Engine: Select Liquid Fuel (Gasoline) for high power output.
    Note right of Engine: Load drops to 1kW
    Generator AI ECU->>Generator AI ECU: Analyze data: Low load, high BTU gas available.
    Generator AI ECU->>Engine: Switch to Gaseous Fuel for efficiency.

V. The "Inverse" or Failure Mode Derivatives

1. Derivative: Failsafe Mechanical Bypass ("Limp-Home" Mode)

Enabling Description: The secondary regulator in the off-board assembly incorporates a failsafe bypass mechanism. If the secondary regulator's diaphragm fails, causing an over-pressure condition, a calibrated shear pin breaks. This allows a spring-loaded plunger to shift, closing the main regulation path and opening a parallel, fixed-orifice bypass channel. This channel is sized to deliver a constant, low volume of gaseous fuel sufficient to run the engine at a no-load, low idle (e.g., 1200 RPM). This prevents the engine from being damaged by high-pressure gas and allows it to continue running in a "limp-home" mode, signaling the need for service without a catastrophic failure.

Mermaid Diagram:

graph TD
    A[From Primary Regulator] --> B{Secondary Regulator};
    subgraph B
        C[Main Diaphragm Path] -- Normal Operation --> E[Output];
        D[Fixed-Orifice Bypass] -- Failsafe --> E;
    end
    B -- Over-pressure Event --> F[Shear Pin Breaks];
    F --> G{Plunger Shifts};
    G -- Closes --> C;
    G -- Opens --> D;

VI. Combination Prior Art Scenarios with Open-Source Standards

Combination with Modbus Protocol: The intelligent off-board regulator from Derivative IV.1 is designed with a Modbus TCP server accessible via an integrated Wi-Fi module. This allows any open-source SCADA system or industrial controller to poll standard Modbus registers for real-time pressure, temperature, flow rate, fuel composition, and diagnostic fault codes. This eliminates proprietary communication protocols and allows the generator system to be integrated into larger industrial or home automation systems using off-the-shelf, open-source software.
Combination with CAN Bus (ISO 11898): The generator's ECU and the off-board intelligent regulator communicate over a Controller Area Network (CAN) bus, a standard in automotive and mobile equipment. The regulator broadcasts its status on the bus using the J1939 open-source message format. This allows for robust, noise-immune communication and enables "plug-and-play" compatibility with other CAN-enabled devices, such as an engine throttle controller or a master vehicle control unit.
Combination with Matter IoT Standard: The intelligent regulator and generator ECU are made compliant with the Matter open-source IoT standard. This allows the generator system to be securely provisioned and controlled by any Matter-compatible ecosystem (e.g., Google Home, Apple HomeKit). A user could monitor fuel levels, switch fuel sources, and receive service alerts through a standard, open-source smartphone app without needing a manufacturer-specific application. The off-board regulator would appear as a sensor device, and the fuel selector would appear as a switch within the smart home environment.