Adjustable Shoulder Brace Locking Mechanism for Handheld Firearms

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Solution Overview

Problem

Existing handheld firearms with adjustable shoulder braces face issues due to high stress from recoil, requiring metallic materials for the locking mechanism, which limits flexibility and increases weight, making them less competitive.

Innovation Solution

A shoulder brace structure with a transversal locking element attached to a carrier that swings about an axis in the firearm chassis, distributing recoil to two nodes, allowing for a plastic chassis and improved adjustability using a control button.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional locking mechanism with a transversal locking pin is used to secure the shoulder brace, then the locking reliability is improved, but the device weight increases and manufacturing complexity increases due to the need for metallic materials

Engineering Contradiction:
Improvelocking reliabilityVSAvoiddevice weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The invention changes the material parameter from metal to plastic for the locking mechanism components. The locking pin is made of plastic material with integrated ribs that engage with recesses in the shoulder brace rods, maintaining locking reliability while significantly reducing weight and manufacturing complexity compared to traditional metallic locking mechanisms

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses composite construction where the locking mechanism integrates plastic components (locking pin, carrier) with metallic elements (springs, control button) only where necessary for functional requirements. This allows achieving reliable locking with reduced overall weight by minimizing metallic material usage to essential components only

Inventive Principle:
Principle #40Composite materials

2Strength

If a metallic locking mechanism is used to withstand high recoil stresses, then the strength is improved, but the ease of manufacture deteriorates and cost increases

Engineering Contradiction:
Improverecoil resistanceVSAvoidmanufacturing ease
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The invention changes the material parameter from metal to plastic for the locking pin and carrier, enabling easier manufacturing through injection molding processes. The plastic locking pin with integrated ribs and the carrier with swinging motion can be manufactured as single-piece components, significantly simplifying production compared to traditional metallic mechanisms requiring multiple parts and assembly steps

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention merges multiple functions into the plastic locking pin and carrier components. The locking pin simultaneously provides locking engagement, recoil force distribution, and positioning functions. The carrier integrates the swinging motion mechanism and control button actuation, reducing the total number of parts and simplifying manufacturing

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If the shoulder brace is made adjustable with multiple positions, then the adaptability is improved, but the device complexity increases due to the locking mechanism requirements

Engineering Contradiction:
ImproveadjustabilityVSAvoidmechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention changes the complexity parameter by using a simplified plastic locking mechanism with a single locking pin that can engage multiple recesses positioned at different locations on the shoulder brace rods. This allows multiple adjustable positions (at least two spaced apart pairs of corresponding recesses) to be achieved with a simple, low-complexity locking system rather than complex multi-component mechanisms

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention implements self-service through the spring-loaded locking pin that automatically engages with the recesses when the shoulder brace is positioned. The control button on the carrier provides automatic actuation, allowing the locking mechanism to self-regulate and maintain positions without requiring complex external control systems

Inventive Principle:
Principle #25Self-service

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

This design effectively distributes recoil, enabling the use of a plastic firearm chassis and enhancing adjustability without the need for metallic materials, thus improving the shoulder brace's functionality and reducing weight.

Implementation Method 1

The locking element is biased by a spring towards the rods

Methodology Applied
Scientific EffectSpring: Spring

Data Source

PatentEP4008988B1Handheld firearm with an adjustable shoulder brace
Publication Date: 2023.07.19 TSESKA ZBROEVKA AS
  • EP4008988B1 patent drawingFigure 1
  • EP4008988B1 patent drawingFigure 2
  • EP4008988B1 patent drawingFigure 3

AI summary

A handheld firearm with an adjustable shoulder brace (7) that is seated in a firearm chassis (10) using a pair of rods (5), slidingly mounted in a guide (17). The current position of the shoulder brace (7) is lockable by a locking mechanism that comprises a transversal locking element (1), seated vertically adjustably under the pair of arms (5). Both the opposite ends of the locking element (1) are guided in opposite corresponding vertical grooves (9) formed in the firearm chassis (10). The locking element (1) is biased by a spring (4) towards the rods (5) where at the bottom side of each of the rods (5), at least two spaced apart pairs of corresponding recesses (2) are produced for snapping of the locking element (1). The locking element (1) can be manually pushed out of the recesses (2) by means of a control button (12). The locking element (1) is attached to a carrier (3) wherein the carrier (3) is seated in the firearm chassis (10) in a swinging way about an axis (6) that is arranged in a hole (8) in the firearm chassis (10) between the rods (5).