Firearm Safety Device with Rotary Selector and Intermediary Stop

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Solution Overview

Problem

Machine guns with open breech architecture face safety risks due to the lack of semi-automatic firing capability, unreliable safety mechanisms, and excessive wear on trigger components, particularly in adverse conditions, leading to potential accidental firings and reduced operational flexibility.

Innovation Solution

A safety device with a rotary fire selector that integrates a rocker and disconnector mechanism, allowing semi-automatic firing while maintaining trigger function, enabling safety engagement regardless of weapon condition and rearming, and limiting wear on stopper components, using a combination of elastic return elements and longitudinal offsets to control the safety element's movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If machine guns use open breech architecture with automatic fire only, then the risk of cook-off is eliminated, but semi-automatic firing capability is lost and operational flexibility is reduced

Engineering Contradiction:
Improvecook-off riskVSAvoidfiring mode flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent implements a dynamic fire selector mechanism that can switch between automatic and semi-automatic firing modes. The selector is movable between positions, allowing the weapon system to adapt its firing behavior dynamically based on operational requirements, thus providing versatility while maintaining the open breech safety advantage

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The machine gun is designed to perform multiple functions through a single system: it can operate in both automatic fire mode (for suppressive fire) and semi-automatic fire mode (for precision shooting). This multi-functionality is achieved through the fire selector mechanism that controls the engagement of the stop, allowing the same weapon to serve different tactical purposes

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

2Ease of operation

If traditional safety mechanisms are used in open breech machine guns, then safety engagement is simple, but the mechanisms are unreliable in adverse conditions and may fail to prevent accidental firings

Engineering Contradiction:
Improvesafety engagement simplicityVSAvoidsafety mechanism reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent introduces an intermediary stop component that acts as a mediator between the fire selector and the trigger mechanism. This stop prevents direct engagement between the trigger and firing components when in safe position, providing an additional layer of safety that is more reliable than traditional direct-blocking mechanisms while remaining simple to operate

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The safety mechanism is designed to prevent accidental firings before they can occur by having the stop pre-positioned to block the trigger path when safety is engaged. The mechanism anticipates potential accidental discharges and prevents them through the predetermined positioning of the stop, which must be deliberately moved by the fire selector to enable firing

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Device complexity

If the trigger directly controls the catch in open breech firearms, then the mechanism is simple, but excessive wear on trigger components occurs and safety is compromised

Engineering Contradiction:
Improvetrigger mechanism simplicityVSAvoidtrigger component durability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The stop serves as an intermediary component between the trigger and the catch mechanism. When the stop is in the blocking position, it prevents the trigger from directly engaging the catch, thereby reducing wear on trigger components. The stop absorbs the mechanical stress and wear that would otherwise be transferred directly to the trigger and catch

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The firing control mechanism is segmented into distinct functional components: the trigger, the stop, and the catch. This segmentation allows each component to perform its specific function with reduced stress. The stop can be independently positioned to control whether the trigger is allowed to engage the catch, distributing mechanical loads more evenly across the system

Inventive Principle:
Principle #1Segmentation

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

The solution provides a safer and more reliable semi-automatic firing mode, ensures safety engagement regardless of weapon state, and reduces wear on trigger components, enhancing ergonomic control and operational flexibility comparable to rifles while maintaining support capabilities.

Implementation Method 1

pushed into the trajectory of the stop by an elastic return element

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3749912B1Safety device for a firearm
Publication Date: 2024.01.24 FN HERSTAL SA
  • EP3749912B1 patent drawingFigure 1
  • EP3749912B1 patent drawingFigure 2a~2b
  • EP3749912B1 patent drawingFigure 2c~2d

AI summary

The present invention relates to a safety device for a firearm that makes it possible to prevent a shot from being fired, without blocking the rearming function, the said safety device comprising a retainer (5) that can be moved between a stopping position that blocks the moving parts (2) of the weapon in a rear position, and a released position that allows the said moving parts (2) to move in both directions, the said safety device comprising a safety element (1) that can move between a position that blocks the retainer (5) in the stopping position and a position that releases the retainer (5), the said safety element (1) bearing against an immobile part of the safety device and the said safety element (1) being able to be moved towards the position that releases the retainer (5) through a rearward movement of the moving parts (2).