Brake Lid Pyrotechnic Charge for Impact Velocity Reduction

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Solution Overview

Problem

Existing active bodies for deploying pyrotechnic effect charges face issues with reliable ignition and even combustion, often resulting in high impact velocities upon ejection, which can lead to premature conversion or extinguishment, and rely on error-prone delay elements that may not be REACh-compliant.

Innovation Solution

The active body features a combustible cover with ignition holes and a brake cover with a flexible brake loop to ensure even combustion and maintain internal pressure, eliminating the need for delay elements by using an ejection charge to ignite the effect charge and slow the submunition's descent through air resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If delay elements are used to ensure timed ignition of the effect charge, then the ignition timing is controlled, but the device complexity increases and reliability decreases due to error-prone delay elements and REACh compliance issues

Engineering Contradiction:
Improveignition reliabilityVSAvoiddelay element complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention removes delay elements entirely from the system. Instead of using complex delay mechanisms, the effect charge is ignited directly by the ejection charge through the combustible lid, simplifying the device structure while maintaining reliable timed ignition through the natural sequence of ejection followed by combustion.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The combustible lid serves dual functions: it contains the effect charge during ejection and then automatically ignites to burn the effect charge after the ejection charge fires. This self-service mechanism eliminates the need for separate delay elements, improving reliability while reducing complexity.

Inventive Principle:
Principle #25Self-service

2Duration of action of moving object

If the active body is ejected at high altitude, then the deployment height is increased, but the impact velocity on the ground increases causing premature decomposition or extinguishment of the effect charge

Engineering Contradiction:
Improveeffect charge deployment durationVSAvoidimpact velocity
Core Design Contradiction:
Duration of action of moving objectVSSpeed

Solution Approach 1:

The brake cover acts as an aerodynamic brake that creates air resistance opposing the downward motion of the active body. This counterforce reduces the impact velocity when the active body returns to ground level, preventing premature decomposition or extinguishment of the effect charge while allowing high-altitude deployment.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

3Ease of manufacture

If a combustible lid is used to ignite the effect charge, then the ignition is simplified, but the effect charge may be released towards the lid causing safety issues

Engineering Contradiction:
Improveignition system simplicityVSAvoideffect charge release direction
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The active body is divided into two detachable parts: the lid and the main body. The ejection charge is positioned to push the lid off the main body, ensuring that the effect charge is ejected away from the lid. This segmentation allows the lid to safely combust without risking effect charge release toward it, while maintaining simple ignition through the combustible lid design.

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

This design ensures reliable, homogeneous, and prolonged application of the effect charge without delay elements, reducing impact speed and maintaining REACh compliance, thereby ensuring effective and consistent deployment of pyrotechnic charges.

Implementation Method 1

brake cover with a flexible brake loop to ensure even combustion and maintain internal pressure, eliminating the need for delay elements by using an ejection charge to ignite the effect charge and slow the submunition's descent through air resistance

Methodology Applied
Scientific EffectAir resistance: Drag

Implementation Method 2

an ejection charge 7 is provided. When the ejection charge 7 is ignited by suitable means, a force acts on the active element 1 and also on the housing elements 6

Methodology Applied
Scientific EffectForce generation from ejection charge: Explosion

Implementation Method 3

The lid is designed to be flammable, so that the burning lid can also ignite the effect charge

Methodology Applied
Scientific EffectCombustion: Combustion

Data Source

PatentEP3457076B1Explosive body with brake lid
Publication Date: 2020.12.16 RHEINMETALL WAFFE MUNITION GMBH
  • EP3457076B1 patent drawingFigure 1~2
  • EP3457076B1 patent drawingFigure 3~4
  • EP3457076B1 patent drawingFigure 5

AI summary

The device (1) is designed to deliver at least one effect charge, and the projectile contains a corresponding effect charge. The effect charge is provided with a brake cover (4) which is designed to be movable along a brake loop (5). When the effect charge is delivered, the brake cover moves away from the effect charge along the brake loop, thus enabling the delivery of the effect charge. Furthermore, the brake cover acts against the direction of flight due to air friction, thereby slowing the effect charge according to the invention.