Quick Coupling for Portable Weapon Stock with Adjustable Plate

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Solution Overview

Problem

Existing stock coupling systems for portable weapons are complex, expensive, and require special tools for adjustment and maintenance, necessitating the disassembly of non-essential components to vary the drop and cast.

Innovation Solution

A quick coupling system featuring a main annular body with externally threaded sectors, a cylindrical stem, Belleville springs, and an adjustable plate that allows for easy assembly and disassembly without tools, enabling the automatic selection of drop and cast settings by replacing a single component.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional plate and screw mechanisms are used for stock coupling, then the drop and cast can be adjusted, but the system becomes complex and requires special tools for assembly and disassembly

Engineering Contradiction:
Improveadjustability of drop and castVSAvoidcomplexity of coupling system
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The coupling system is divided into separate functional modules: an adjustable plate for drop and cast configuration, a quick-release mechanism for tool-free assembly/disassembly, and a retention spring for automatic engagement. This segmentation allows each component to perform its specific function independently, reducing overall system complexity while maintaining adjustability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from a static, permanent screw-fastened connection to a dynamic, easily changeable coupling that can be quickly assembled and disassembled without tools. The quick-release mechanism enables the stock to be rapidly detached and reattached, providing operational flexibility while simplifying the coupling process.

Inventive Principle:
Principle #15Dynamics

2Reliability

If traditional screw-fastened plates are used, then the stock can be secured to the weapon, but disassembly requires tools and skill for maintenance and cleaning

Engineering Contradiction:
Improvesecure attachment of stockVSAvoidease of disassembly for maintenance
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The retention spring automatically engages the stock with the coupling mechanism without requiring manual tightening or specialized tools. The system serves itself by using the spring's elastic force to maintain secure attachment and enable quick release through simple manual manipulation, eliminating the need for user skill or tools during maintenance.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The quick-release mechanism extracts the essential function of secure attachment from the complex screw-fastening system. By separating the retention function into a dedicated spring-loaded mechanism, the system maintains reliable stock attachment while removing the complexity of multi-component disassembly procedures.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of repair

If multiple components are disassembled for replacement, then the coupling system can be maintained, but time is lost and skill is required

Engineering Contradiction:
Improvemaintainability of coupling systemVSAvoidtime required for disassembly and assembly
Core Design Contradiction:
Ease of repairVSLoss of time

Solution Approach 1:

The coupling system is segmented into easily replaceable modules, with the adjustable plate and quick-release mechanism designed as independent units that can be serviced separately from the main stock and weapon components. This modular segmentation enables quick maintenance without disassembling the entire weapon system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The retention spring is pre-loaded during manufacturing to provide automatic engagement force. This preliminary action eliminates the need for field adjustments or complex assembly procedures during maintenance, allowing users to quickly service the coupling system without time-consuming disassembly or specialized skills.

Inventive Principle:
Principle #10Preliminary action

4Strength

If Belleville springs are preloaded during assembly, then the stock coupling is secure, but assembly becomes difficult and requires tools

Engineering Contradiction:
Improvestrength of spring compressionVSAvoidease of assembly process
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The Belleville springs are pre-loaded during the manufacturing process rather than during field assembly. This preliminary action allows the springs to be properly compressed and set to their operational force level before the product reaches the user, eliminating the need for tools or complex procedures during assembly while ensuring consistent spring strength.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The quick-release mechanism is designed to allow the user to easily compress and adjust the Belleville springs during normal operation without requiring tools. The mechanism's geometry and spring placement enable the user to apply the necessary compression force through simple manual action, making the assembly process as easy as manufacturing.

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

The system simplifies the adjustment and maintenance of the stock's drop and cast, allowing for quick coupling and disassembly without specialized tools, ensuring proper alignment and secure attachment while dissipating recoil energy effectively.

Implementation Method 1

Belleville springs fitted thereon by means of a nut which is provided with an extended external shank which passes internally through the Belleville springs and through the main body

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The Belleville springs, when the assembly is assembled, are still not preloaded, both to allow their easy assembly and to facilitate the screwing of the nut onto the corresponding threaded pin

Methodology Applied
Scientific EffectSpring compression: Spring

Implementation Method 3

a main annular body which has externally threaded sectors and a cylindrical stem for centering on the stock

Methodology Applied
Scientific EffectThreading: Screw

Implementation Method 4

fitted on a tube or tension member which constitutes the extension of the weapon inside the stock and is fixed thereon by a screw or a nut

Methodology Applied
Scientific EffectMechanical fastening: Mechanical Fastener

Implementation Method 5

assembly by means of a snap ring which Is fitted to the portion of the outer shank of the nut that protrudes from the main body

Methodology Applied
Scientific EffectElastic retention: Spring

Implementation Method 6

Plates of different shapes may be fit, between the main body of the quick coupling and the front plane of the stock that rests on the weapon. The plates are accordingly interchangeable and ensure the drop and cast of the stock by way of the strong compression of the Belleville springs

Methodology Applied
Scientific EffectMechanical transfer: Force

Implementation Method 7

upon firing, the kinetic energy of the recoil of the weapon further compresses the Belleville springs of the quick coupling without however affecting the drop and cast of the stock but further dissipating partly before being released against the shoulder of the shooter

Methodology Applied
Scientific EffectKinetic energy dissipation: Spring

Data Source

PatentEP2017566B1Quick coupling particularly for the stock of a portable weapon
Publication Date: 2013.12.04 BENELLI ARMI SPA
  • EP2017566B1 patent drawingFigure 1
  • EP2017566B1 patent drawingFigure 2~3
  • EP2017566B1 patent drawingFigure 4

AI summary

A quick coupling for the stock of a portable weapon, automatically provides the stock with a specific drop and cast upon its coupling by means of an interchangeable plate which can be replaced easily. The characteristics and the number of plates available are such as to meet the variation requirements made by the various users. The new quick coupling has considerable advantages in terms of constructive technical simplicity, ease of drop and cast adjustment, quick disassembly and maintenance of the weapon.