Weapon Bolt Recoil Decoupling for Lower-Force Extraction

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Solution Overview

Problem

Existing externally powered weapon systems face challenges with large forces acting on the bolt drive during the unlocking and extraction of the cartridge case, necessitating significant energy expenditure.

Innovation Solution

The bolt and weapon barrel take over the unlocking and extraction of the cartridge case using the recoil energy of the weapon, mechanically separating and reconnecting the bolt drive during the recoil process, thereby reducing the forces required from the external drive.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the bolt is unlocked and the empty cartridge case is extracted using an external drive (e.g., chain), then the bolt can be moved to the rear position, but large forces act on the chain and significant energy is required for extraction

Engineering Contradiction:
Improvebolt unlocking and extractionVSAvoidenergy required for extraction
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The bolt carrier group utilizes the recoil energy of the weapon to automatically unlock the bolt and extract the cartridge case without requiring additional energy input from the external drive. The system serves itself by converting the recoil motion into the necessary unlocking and extraction actions.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The recoil energy, which would otherwise be wasted or require dissipation, is converted into a beneficial force that performs the unlocking and extraction functions. The harmful effect of recoil is transformed into a useful mechanism for bolt manipulation.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If the bolt is locked to the weapon barrel using a chamber sleeve connected to the weapon barrel, then the locking is achieved, but the bolt cannot be freely moved during recoil without affecting weapon functionality

Engineering Contradiction:
Improvelocking reliabilityVSAvoidbolt movement freedom
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The bolt assembly is divided into separable components (bolt head, bolt carrier, chamber sleeve) that can independently move relative to each other during recoil. This segmentation allows the bolt head to remain locked to the barrel while the bolt carrier group moves freely with the recoil motion.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The connection between the bolt components is made dynamic rather than rigid, allowing relative movement during recoil. The chamber sleeve can move independently from the bolt head, enabling the bolt to transition between locked and unlocked states based on the operational phase.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If the bolt carrier group is freely movable relative to the bolt head during recoil, then the unlocking is achieved, but the bolt drive must be mechanically separated and reconnected

Engineering Contradiction:
Improveunlocking easeVSAvoidmechanical separation and reconnection mechanism
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The mechanical separation and reconnection mechanisms are designed to automatically engage and disengage at predetermined positions during the recoil and return motions. The system prepares in advance for these transitions, requiring no active control or complex intervention.

Inventive Principle:
Principle #10Preliminary action

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 approach reduces the forces needed for bolt unlocking and extraction, allowing for a smaller drive mechanism and preventing unintentional firing during transport, while maintaining weapon functionality.

Implementation Method 1

the bolt and weapon barrel take over the unlocking and extraction of the cartridge case using the recoil energy of the weapon

Methodology Applied
Scientific EffectRecoil energy: Conservation of Momentum

Data Source

PatentEP4004477B1Weapon system
Publication Date: 2025.09.03 RHEINMETALL WAFFE MUNITION GMBH
  • EP4004477B1 patent drawingFigure 1~3
  • EP4004477B1 patent drawingFigure 4~6
  • EP4004477B1 patent drawingFigure 5

AI summary

The invention relates to a weapon system comprising a breechblock, formed at least by a breechblock carrier (5) and a breechblock head (3), wherein the breechblock carrier (5) is designed to support the breechblock head (3). In order to achieve a reduction or even an elimination of the forces acting on the breechblock drive during the unlocking of the breechblock and the removal of a cartridge casing, the breechblock head (4) is freely moveably relative to the breechblock carrier (3). In order to separate the breechblock and a breechblock drive of the weapon system during the recoil of the recoiling masses of the weapon system, a device (20) is designed in such a way that a mechanical separation can be produced between the breechblock and the breechblock drive with the recoil of the recoiling masses of the weapon system. With the forward motion of the recoiling masses, the mechanical connection between the breechblock drive and the breechblock is re-formed using the device (20). For the separating or connecting of the breechblock from/to a breechblock slider (6), which functionally cooperates with the breechblock carrier (5), the device (20) has at least one connection rod (23). The connection rod (23) is securely attached to the breechblock slider (6) by a rear end when viewed in the direction of fire. The front end can be connected to the breechblock carrier (5) and separated from same.