Derivative works

Defensive Technology Disclosure: Firearm Trigger Mechanism with Multi-Mode Reset

Publication Date: April 29, 2026

Abstract: This document discloses multiple variations, enhancements, and alternative applications of a firearm trigger mechanism that features a selectable mode of operation, including a standard semi-automatic mode and a forced-reset semi-automatic mode. The disclosed embodiments are intended to enter the public domain to act as prior art against future patent applications in this and adjacent fields. The core mechanism involves a cam system actuated by the firearm's bolt carrier, which, in a specific mode, physically resets the trigger, and a selector that can disable the disconnector function.

Claim 1/14/15/20: Firearm Trigger Mechanism with Selectable Reset and Disconnector Lockout

Derivative 1.1: Material and Component Substitution - Polymer-Ceramic Composite Fire Control Group

• Enabling Description: The hammer (36), trigger (38), disconnector (60), and cam (72) are manufactured from a high-pressure, injection-molded, carbon-fiber-reinforced ceramic-polymer composite. This material offers reduced weight, self-lubricating properties (by impregnating with PTFE), and significantly lower thermal expansion compared to steel, ensuring consistent trigger-pull weight under high-temperature firing schedules. The pivot pins (30, 32, 74) are replaced with case-hardened S7 tool steel for superior wear resistance at critical rotation points. The cam lobe (78) and hammer's sear catch (52) feature a vapor-deposited diamond-like carbon (DLC) coating to minimize friction and wear during the forced-reset cycle, improving reliability and component lifespan.
• Mermaid.js Diagram:

  graph TD;
      subgraph Firearm Receiver
          A[Bolt Carrier - Rearward Movement] --> B{Cam Actuation};
          B --> C{Cam Lobe Engages Trigger};
          C --> D[Trigger Reset];
          D --> E{Sear Re-engagement};
          E --> F[Hammer Cocked];
          A --> F;
      end
      subgraph Material Composition
          G[Hammer/Trigger/Disconnector/Cam] -- Injection Molded --> H(Carbon-Fiber/Ceramic-Polymer Composite);
          I[Sear/Cam Lobe Contact Surfaces] -- Vapor Deposition --> J(Diamond-Like Carbon Coating);
          K[Pivot Pins] -- Case Hardened --> L(S7 Tool Steel);
      end
      H --> G;
      J --> G;
      L -- Supports --> G;
  

Derivative 1.2: Material and Component Substitution - Magnetorheological Fluid Damper

• Enabling Description: The disconnector spring (67) is replaced with a miniature, sealed magnetorheological (MR) fluid damper. An electric coil, controlled by the safety selector (110), surrounds this damper. In standard semi-auto mode, no current is applied, and the damper provides standard spring-like resistance. In forced-reset mode, the selector sends a current through the coil, increasing the viscosity of the MR fluid to the point where it becomes semi-solid. This effectively locks the disconnector (60) in a downward position, preventing it from engaging the hammer hook (53). This provides a non-contact, wear-free method of disconnector deactivation.
• Mermaid.js Diagram:

  sequenceDiagram
      participant User
      participant SafetySelector as Selector
      participant MCU
      participant MR_Damper as Magnetorheological Damper
      participant Disconnector
  
      User->>+Selector: Set to "Forced Reset"
      Selector->>MCU: Send "Forced Reset" Signal
      MCU->>MR_Damper: Apply Current to Coil
      MR_Damper->>MR_Damper: Fluid Viscosity Increases (Semi-Solid)
      MR_Damper-->>Disconnector: Lock in Downward Position
      Disconnector-->>User: Disconnector Disabled
  

Derivative 2.1: Operational Parameter Expansion - High-Frequency/Low-Mass Application

• Enabling Description: The mechanism is scaled down for use in a high-speed, electrically-actuated, low-mass projectile launcher, such as a pneumatic or coilgun system. The "bolt carrier" is a lightweight, high-speed reciprocating shuttle. The hammer (36) is replaced by a miniaturized, high-speed solenoid-driven striker. The cam (72) and trigger member (38) are fabricated from titanium alloys (e.g., Ti-6Al-4V) to minimize inertia. The system is designed to operate at cyclic rates exceeding 3,000 rounds per minute. The forced-reset mechanism is critical at this speed, as human reflex is insufficient to reset the trigger between shots. The cam profile (78) is optimized with a logarithmic spiral to ensure a smooth, non-jerky reset force on the trigger member's cam follower (58) even at extreme speeds.
• Mermaid.js Diagram:

  graph TD
      subgraph High-Frequency Actuator
          A[Reciprocating Shuttle - Rearward Motion] --> B(Actuates Micro-Cam);
          B --> C(Resets Titanium Trigger);
          D[Solenoid Striker] --Reset by Shuttle--> E[Ready State];
          C --> F{Sear Re-engages Solenoid};
      end
      subgraph Control System
          G[Fire Control Unit] --Trigger Pull--> H{Release Striker Solenoid};
          H --> D;
          F --> G;
      end
  

Derivative 3.1: Cross-Domain Application - Haptic Feedback System

• Enabling Description: The core mechanical principle is adapted for a haptic feedback device, such as a force-feedback joystick or surgical robot controller. The "bolt carrier" is a linear actuator, and the "hammer" is a weighted element that strikes an internal surface to create a sharp haptic impulse. The "trigger" is a user-operated button or joystick axis. In "standard" mode, the user must fully release the button to re-engage the haptic mechanism. In "forced-reset" mode, the linear actuator's return stroke engages the cam, which physically pushes the user's finger and the button back to the ready position, providing a tangible "kick" and enabling rapid, successive haptic events. This can be used to simulate recoil, impacts, or tool-surface interactions in a virtual environment.
• Mermaid.js Diagram:

  graph TD
      subgraph Haptic Controller
          A(User Pushes Button) --> B{Electrical Signal Sent};
          B --> C[Microcontroller];
          C --> D[Actuator Fired];
          D --Moves forward--> E(Weighted Hammer Strikes Surface);
          E --Generates--> F(Haptic Impulse);
          D --Begins Return Stroke--> G(Cam Engages Button Lever);
          G --> H(Button/Finger Physically Pushed Back to Reset);
          H --> A;
      end
  

Derivative 3.2: Cross-Domain Application - High-Speed Industrial Stapler/Nailer

• Enabling Description: In a pneumatic or electric industrial fastening tool (e.g., a framing nailer or assembly line stapler), the "bolt carrier" is the piston/driver blade assembly. The "hammer" is the firing valve release mechanism. The cam (72) is linked to the piston's return stroke. In "standard" single-shot mode, the operator must release and re-press the trigger for each nail. In "forced-reset" or "bump-fire" mode, the selector (110) disables the disconnector. With the trigger held down, each time the piston returns after driving a nail, the cam forces the trigger mechanism to reset instantly. The tool will then fire again as soon as the safety tip is re-compressed against the work surface, allowing for extremely rapid fastening.
• Mermaid.js Diagram:

  graph TD
      A[Press Tool to Workpiece] --> B{Depress Safety Tip};
      B --> C[Pull Trigger];
      C --> D{Actuate Firing Valve};
      D --> E[Drive Piston/Nail];
      E --> F[Piston Reciprocates];
      F --Engages--> G(Cam);
      G --Resets--> C;
      C --If Held & Safety Depressed--> D;
  

Derivative 3.3: Cross-Domain Application - Automated Textile Weaving/Tufting Machine

• Enabling Description: In a high-speed textile machine, a series of needles ("hammers") must be actuated to punch yarn through a backing material. The reciprocating motion of the needle bar assembly ("bolt carrier") can be harnessed. The cam mechanism (72) is adapted to reset a clutch or latching system ("trigger member" 58) for each needle. By engaging the "forced reset" mode, the needle bar's return stroke immediately re-engages the drive clutch for that needle, enabling continuous, high-speed tufting or weaving without a separate reset signal. This eliminates the need for complex electronic timing for the reset, simplifying the design and increasing the operational speed of the loom or tufting gun.

• Mermaid.js Diagram:

  graph TD
      A[Needle Bar Down-Stroke] --> B(Yarn Injected);
      B --> C[Needle Bar Up-Stroke];
      C --Engages--> D(Reset Cam);
      D --Resets--> E(Drive Clutch);
      E --Re-engages--> A;
  

Derivative 4.1: Integration with Emerging Tech - AI-Tuned Recoil Management

• Enabling Description: The firearm is equipped with an accelerometer and a small onboard microprocessor running a trained AI model. The cam (72) is not fixed but is mounted on a piezoelectric actuator. In "forced-reset" mode, the AI model analyzes recoil data from the accelerometer in real-time. It then precisely adjusts the position and angle of the cam via the piezoelectric actuator during the bolt carrier's cycle. This modulation of the cam's engagement with the trigger member (38) changes the timing and force of the trigger's reset. The AI can be trained to either (1) maximize the rate of fire by resetting the trigger at the exact peak of the recoil impulse, or (2) smooth out the "feel" of the reset to minimize sight picture disruption for the specific user. A companion smartphone app allows the user to select different recoil management profiles.
• Mermaid.js Diagram:

  sequenceDiagram
      participant User
      participant Trigger
      participant Bolt_Carrier
      participant Accelerometer
      participant AI_Processor
      participant Piezo_Cam
  
      User->>Trigger: Pull
      Trigger->>Bolt_Carrier: Fire and Cycle
      Bolt_Carrier->>Accelerometer: Generate Recoil Data
      Accelerometer->>AI_Processor: Send Data
      AI_Processor->>AI_Processor: Analyze Recoil Profile
      AI_Processor->>Piezo_Cam: Adjust Cam Position/Angle
      Bolt_Carrier->>Piezo_Cam: Actuate Adjusted Cam
      Piezo_Cam->>Trigger: Execute Optimized Reset
  

Derivative 4.2: Integration with Emerging Tech - IoT-Enabled Round Counting and Maintenance Alerts

• Enabling Description: The cam pin (74) is replaced with a smart pin containing a piezoelectric sensor and a low-power IoT communication module (e.g., LoRaWAN or NB-IoT). Each time the cam (72) is actuated by the bolt carrier, it exerts force on the pin, generating a detectable electrical pulse. This pulse is registered as a single firing cycle. The IoT module maintains a secure, blockchain-verified round count for the firearm. It transmits this data periodically to a cloud-based maintenance log. When the round count approaches a predetermined service interval (e.g., for barrel replacement, spring changes), the system automatically sends an alert to the user's mobile device or a designated armorer. The blockchain ledger ensures the firing history is tamper-proof, which is valuable for law enforcement or military inventory management.
• Mermaid.js Diagram:

  graph TD
      A[Bolt Carrier Cycles] --> B(Actuates Cam 72);
      B --Pivots on--> C[Smart Pin 74];
      C --Generates Piezo Pulse--> D{IoT Module};
      D --Increments Counter--> E(On-board Flash Memory);
      D --Transmits Data--> F((Cloud Server));
      F --Logs Data--> G[Blockchain Ledger];
      G --Check Condition--> H{Round_Count > Threshold?};
      H --Yes--> I[Send Maintenance Alert];
      H --No--> J[Continue Monitoring];
  

Derivative 5.1: The "Inverse" or Failure Mode - Failsafe Disconnector Engagement

• Enabling Description: The mechanism is designed with a "fail-safe" or "dead-man's switch" feature. The disconnector (60) is held out of engagement in the forced-reset mode by a small, spring-loaded plunger or an electromagnet integrated into the safety selector (110). If the firearm is dropped or experiences a significant shock, a simple inertia-based switch or accelerometer de-energizes the electromagnet (or releases the plunger). This immediately allows the disconnector spring (67) to force the disconnector (60) back into its active position. The result is that any shock or failure automatically reverts the trigger to the standard, safer semi-automatic mode, where the hammer will be caught by the disconnector after a single shot, preventing an unintended discharge during the subsequent forced-reset cycle.
• Mermaid.js Diagram:

  stateDiagram-v2
      [*] --> Standard_Semi
      Standard_Semi --> Forced_Reset: Selector Moved
      Forced_Reset --> Standard_Semi: Selector Moved
  
      state "Forced Reset (Disconnector Disabled)" as Forced_Reset {
          state "System Normal" as Normal
          state "Shock/Impact Detected" as Shock
          Normal --> Shock: Inertial Switch/Accelerometer Trigger
          Shock --> Revert: Deactivate Electromagnet
      }
      Revert --> Standard_Semi: Disconnector Re-Engages
  

Combination with Open-Source Standards

1. Combination with RISC-V Microcontroller Core: The trigger mechanism is integrated with an open-source RISC-V-based microcontroller unit (MCU). The safety selector (110) becomes a multi-position electronic switch. The MCU reads the selector's position and directly controls micro-actuators (solenoids or servos) that engage or disengage the disconnector and can even adjust the trigger pull weight by varying spring tension via a worm gear. This allows for a programmable trigger where "standard," "forced--reset," and potentially other modes (e.g., binary, burst) could be selected or even programmed by the user via a Bluetooth-connected app. All firmware for the RISC-V MCU is released under an open-source license like GPLv3.

2. Combination with Arduino-Compatible Sensor Shield: A custom "Fire Control Shield" is designed to mount onto a standard Arduino or similar open-source microcontroller board. This shield contains the complete trigger module (10) as described in the patent. The a cam (72) and hammer (36) positions are monitored by Hall effect sensors. The safety selector is a digital input. This allows hobbyists, researchers, and engineers to use an open-source hardware and software platform to analyze firearm performance, measure split times, and develop custom fire control logic for non-lethal training systems (e.g., laser-based simulators) or robotics applications, leveraging the mechanical principles of the forced-reset trigger.

3. Combination with open-source CAD/3D Printing Formats (STEP/3MF): The housing (12) and non-critical internal components like the trigger blade (54) are redesigned as a set of open-source 3D models released in STEP and 3MF formats. These models are specifically designed to be printed on widely available Fused Deposition Modeling (FDM) or Selective Laser Sintering (SLS) 3D printers using high-strength polymers like carbon-fiber-infused nylon. This allows for rapid prototyping of custom ergonomics, aesthetics, and integration with other accessories, while the core high-stress components (hammer, sear, cam) remain machined from metal. This separates the non-patentable housing from the patented mechanism, placing the housing's geometry and its interface with the receiver into the public domain.