Pyrotechnic Casing with Flame-Propagating Gap for Reliable Ignition

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Solution Overview

Problem

Existing pyrotechnic devices for generating smoke or decoy targets face challenges in achieving reliable and rapid ignition, often requiring complex and expensive production processes, and may use sensitive quick-burning ignition charges that are hazardous to handle.

Innovation Solution

An active body design featuring a casing with a significant gap between the active mass and the casing, allowing a flame to propagate through at least 75% of the surface, which breaks open under pressure from the ignition charge or active mass, ensuring reliable and rapid ignition, and using materials like nitrocellulose or heat-resistant plastics to manage pressure and heat resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a hermetically sealed container is used to protect the active mass, then protection against environmental influences is improved, but reliable and rapid ignition of the active mass deteriorates

Engineering Contradiction:
Improveprotection against environmental influencesVSAvoidreliable and rapid ignition
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The hermetically sealed container is segmented by introducing gaps or openings that allow flame propagation while maintaining overall sealing. The container wall is divided into sealed portions and flame-permeable portions, enabling both protection and ignition reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

An intermediary structure (gap or opening) is introduced between the active mass and the container wall. This intermediary allows flame to propagate from the ignition charge to the active mass while the rest of the container remains hermetically sealed for environmental protection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If complex production processes are used to achieve reliable ignition, then ignition reliability is improved, but manufacturing complexity and cost deteriorate

Engineering Contradiction:
Improveignition reliabilityVSAvoidproduction process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The ignition charge is merged with the container structure by placing it in direct communication with the active mass through the gap or opening. This eliminates the need for separate ignition mechanisms and complex assembly procedures.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The gap or opening is pre-formed in the container structure during manufacturing, allowing flame propagation to occur automatically when the ignition charge is activated. This preliminary structural preparation ensures reliable ignition without requiring complex operational procedures.

Inventive Principle:
Principle #10Preliminary action

3Speed

If quick-burning ignition charges are used to achieve rapid ignition, then ignition speed is improved, but safety and ease of handling deteriorate

Engineering Contradiction:
Improveignition speedVSAvoidsafety and ease of handling
Core Design Contradiction:
SpeedVSEase of operation

Solution Approach 1:

The harmful sensitivity of quick-burning ignition charges is extracted by using a gap or opening in the container wall to transmit flame from a safer ignition source to the active mass. This separates the ignition initiation (safe) from the ignition propagation (rapid).

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The container wall with its gap or opening serves as an intermediary that transmits the ignition effect from a safe ignition charge to the active mass. This intermediary structure enables rapid ignition of the active mass while allowing the use of safer, less sensitive ignition charges.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 enables reliable and quick ignition of the active mass over a large area, reduces the sensitivity of ignition charges, and simplifies production by using less expensive and safer materials, while maintaining protection against environmental influences.

Implementation Method 1

an ignition charge for igniting the active mass, wherein either at least one gap exists between the active mass and the casing or the casing is designed in such a way that after ignition of the active mass and/or the ignition charge, if one is present, at least one gap forms between the active mass and the casing

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

an active mass for the pyrotechnic generation of a smoke or for providing a pyrotechnic decoy

Methodology Applied
Scientific EffectPyrotechnic reaction: Combustion

Data Source

PatentEP2988090B1Explosive body with material and a casing
Publication Date: 2018.03.07 DIEHL DEFENCE GMBH & CO KG
  • EP2988090B1 patent drawingFigure 1
  • EP2988090B1 patent drawingFigure 2

AI summary

The invention relates to an active element comprising an active mass (1) for the pyrotechnic generation of a fog or for providing a pyrotechnic decoy target and a casing (2) for enclosing the active mass (1) and optionally an ignition element, wherein at least one gap (3) is provided between the active mass (1) and the casing (2), wherein the gap (3) is designed such that it extends over at least 75% of the total surface area of ​​the active mass (1) and a flame can propagate through the entire gap (3) between the active mass (1) and the casing (2), wherein the casing (2) is designed such that it only ruptures after the flame has propagated through the entire gap (3) under pressure that builds up in the casing (2) through a reaction of the active mass (1) and - if present - the ignition element.