Electromagnetic Trigger Mechanism for Adjustable Pull Force

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Traditional firearm triggers require complex mechanical adjustments to alter the trigger pull force and displacement profile, which can lead to wear and failure, and lack the ability to dynamically change the force-displacement characteristics without physical component modifications.

Innovation Solution

An electromagnetically variable trigger mechanism that uses a programmable microcontroller and electromagnetic actuator to adjust the trigger pull force and displacement profile electronically, incorporating magnetorheological fluids or magnetic fields to dynamically change the resistance, allowing for customizable and adjustable trigger characteristics without mechanical component changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If mechanical linkages and springs are used to adjust trigger pull force, then the trigger force-displacement profile can be customized, but the device complexity increases and mechanical wear occurs

Engineering Contradiction:
Improvetrigger force-displacement profile customizationVSAvoidmechanical linkage complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces the traditional mechanical linkage and spring system with an electromagnetic actuator system. The electromagnetic actuator uses magnetic fields to control the trigger pull force, eliminating the need for complex mechanical adjusters, multiple springs, and linkages. This substitution reduces mechanical wear while maintaining the ability to customize the trigger force-displacement profile through electronic control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical state or parameters of the electromagnetic actuator to adjust trigger characteristics. By varying electrical parameters (voltage, current, pulse duration) supplied to the electromagnetic actuator, the system dynamically adjusts the magnetic field strength, thereby changing the trigger pull force and displacement profile without any mechanical component changes.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If mechanical components are adjusted to change trigger characteristics, then the force-displacement profile can be modified, but the adjustment process becomes time-consuming and requires physical component changes

Engineering Contradiction:
Improvetrigger characteristic adjustmentVSAvoidadjustment time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent replaces time-consuming mechanical adjustment procedures with instantaneous electronic control. The electromagnetic actuator responds immediately to electrical signals, allowing the trigger force-displacement profile to be changed in real-time without disassembling or physically adjusting mechanical components. This eliminates the time loss associated with mechanical reconfiguration.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent makes the trigger system dynamically adjustable through electronic control rather than static mechanical settings. The electromagnetic actuator can change its characteristics on-the-fly based on electrical input, enabling dynamic reconfiguration of trigger properties during operation without requiring physical component changes or time-consuming adjustments.

Inventive Principle:
Principle #15Dynamics

3Productivity

If electromagnetic actuators are used to adjust trigger force, then the adjustment speed increases, but the device requires additional electronic components and power sources

Engineering Contradiction:
Improveadjustment speedVSAvoidelectronic control system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent integrates the electromagnetic actuator into the existing firearm structure, allowing it to perform multiple functions: providing the primary trigger pull force, enabling dynamic adjustment of trigger characteristics, and potentially serving as part of the firing mechanism. This multi-functionality reduces the need for separate dedicated components, thereby managing overall device complexity while maintaining high adjustment speed.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables quick and easy adjustment of trigger pull force and displacement profile, reducing mechanical complexity and wear, while providing customizable resistance settings that can be programmed for various shooting applications and preferences.

Implementation Method 1

a permanent magnet generating a static magnetic field in the stationary yoke and rotating member, the static magnetic field creating a primary resistance force opposing movement of the trigger when pulled by the user

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

the electromagnet coil when energized generating a user-adjustable secondary magnetic field interacting with the static magnetic field, the secondary magnetic field operating to change the primary resistance force dynamically during a trigger pull event initiated by the user

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

An electromagnetic actuator trigger mechanism for use in a firearm... incorporating magnetorheological fluids or magnetic fields to dynamically change the resistance

Methodology Applied
Scientific EffectMagnetorheological effect: Magnetorheological Fluid

Data Source

PatentEP3874221B1Single loop user-adjustable electromagnetic trigger mechanism for firearms
Publication Date: 2024.07.24 STURM RUGER & CO INC
  • EP3874221B1 patent drawingFigure 1
  • EP3874221B1 patent drawingFigure 2A
  • EP3874221B1 patent drawingFigure 2B~2D

AI summary

A hybrid magnetically variable firing system for a firearm includes a trigger mechanism configured to allow a user to selectively adjust the trigger pull force- displacement profile. In a closed magnetic flux loop configuration, the trigger mechanism includes a selectively energizable electromagnetic and mechanical biasing member providing a static holding torque which creates resistance opposing movement of the trigger. Energizing the electromagnetic at a user- preselected point during the trigger pull event creates a magnetic force opposing the static holding torque, which dynamically changes the trigger pull force required to discharge the firearm. The electromagnetic assists the user in completing the trigger pull thereby creating an adjustable lighter trigger pull. In one embodiment, the electromagnet is energized when the actual trigger pull force applied or trigger displacement reaches a corresponding trigger setpoint preprogrammed into a control circuit. A microcontroller may control operation of the trigger mechanism.