Nested Spring Magazine for High Capacity Feeding

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Solution Overview

Problem

Conventional box magazines have limited capacity and reliability issues when increased, leading to frequent changes and potential jamming due to higher spring forces required for larger capacities, which can interfere with firearm operation.

Innovation Solution

A high capacity box magazine design utilizing nested followers and springs that reduce the required length and force needed to advance cartridges, maintaining reliability by using a four-column configuration that transitions into two columns, with a dividing wall and telescoping springs to synchronize cartridge movement and reduce stripping force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the capacity of a box magazine is increased to accommodate more cartridges, then the magazine capacity is improved, but the magazine length and spring force increase proportionally, causing reliability issues and potential jamming

Engineering Contradiction:
Improvemagazine capacityVSAvoidfeeding reliability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent employs nested followers where an inner follower is positioned within an outer follower, and nested springs where an inner spring is positioned within an outer spring. This nesting arrangement allows multiple followers and springs to occupy the same longitudinal space, enabling high capacity (100+ cartridges) without proportionally increasing magazine length. The nested configuration maintains compact dimensions while providing sufficient spring force distribution to advance cartridges reliably without excessive force that would cause jamming.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent divides the magazine into multiple columns (typically four columns) and uses multiple separate followers (outer follower and inner follower) to manage different sections of cartridges. This segmentation allows the spring force to be distributed across multiple columns rather than requiring a single high-force spring, improving reliability by reducing the risk of feed problems associated with excessive concentrated force while maintaining high capacity.

Inventive Principle:
Principle #1Segmentation

2Quantity of substance

If the spring force is increased to advance more cartridges, then the capacity is improved, but the stripping force becomes too high for the firearm to operate reliably

Engineering Contradiction:
Improvemagazine capacityVSAvoidstripping force
Core Design Contradiction:
Quantity of substanceVSForce

Solution Approach 1:

The patent segments the spring force application by using multiple springs (nested outer spring and inner spring) that independently advance different columns of cartridges. This distributes the total force requirement across multiple lower-force springs rather than requiring one high-force spring, keeping the stripping force within operational limits for the firearm while maintaining high capacity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The nested spring configuration allows the inner spring to operate within the space of the outer spring, enabling two or more springs to work in parallel within a compact volume. This nested arrangement provides sufficient cumulative force to advance cartridges in a high-capacity magazine without any single spring exceeding the stripping force threshold that would cause firearm malfunction.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Quantity of substance

If the magazine length is increased to accommodate more cartridges, then the capacity is improved, but the magazine becomes bulkier and less portable

Engineering Contradiction:
Improvemagazine capacityVSAvoidmagazine length
Core Design Contradiction:
Quantity of substanceVSLength of moving object

Solution Approach 1:

The patent uses nested followers and nested springs arranged in a compact configuration that allows multiple components to occupy overlapping spatial volumes. This nesting enables the magazine to accommodate 100 or more cartridges in a length comparable to conventional 30-cartridge magazines, avoiding the bulk and weight penalties of drum magazines while achieving high capacity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent transitions from a conventional single-column or double-column vertical arrangement to a multi-column configuration with nested followers operating in parallel. This dimensional reorganization allows cartridges to be stacked in four columns with nested followers managing each column, effectively utilizing horizontal space to increase capacity without proportionally increasing longitudinal length.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

4Quantity of substance

If multiple separate followers are used to advance cartridges in a high capacity magazine, then the capacity is improved, but the followers may move independently causing jamming

Engineering Contradiction:
Improvemagazine capacityVSAvoidsynchronization reliability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent uses nested followers where the inner follower is positioned within the outer follower, creating a hierarchical relationship that naturally synchronizes their movement. The nested configuration ensures that both followers move together as a coordinated unit, preventing independent motion that would cause cartridge misalignment or jamming, while still allowing each follower to manage its respective column of cartridges in a high-capacity multi-column arrangement.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 design allows for increased capacity without lengthening the magazine, maintaining reliability and reducing the stripping force required, thus minimizing jamming and ensuring consistent firearm operation.

Implementation Method 1

a first spring disposed substantially between the spring cup and the outer follower, a second spring disposed substantially between the outer follower and the inner follower, and a third spring disposed substantially between the inner follower and the top end of the housing

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2550500B1High capacity magazine with multiple springs
Publication Date: 2018.05.30 ARMWEST
  • EP2550500B1 patent drawingFigure 1
  • EP2550500B1 patent drawingFigure 2
  • EP2550500B1 patent drawingFigure 3

AI summary

A high capacity box magazine is provided. A plurality of nested followers may be adapted to nest one within another and a plurality of springs may be configured to nest one within another to facilitate the advancement of cartridges within the box magazine to a firearm. A spring cup or cups may be used to nest additional springs that work in series and are nested within each other to further reduce the required height of the springs. The reliability of a conventional lower capacity box magazine may be maintained or exceeded without requiring significantly greater length in order to accommodate the increased capacity. The high capacity box magazine typically requires less frequent magazine changes than conventional lower capacity box magazines.