Non-lethal Grenade Stud Dispersion via Overmolded Retainer

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Solution Overview

Problem

Existing reduced-lethality shrapnel grenades face challenges in ensuring homogeneous dispersion of studs while maintaining economic production and reliability, which is crucial for effective deterrence without causing serious injuries.

Innovation Solution

The design incorporates an overmolded retaining element formed from synthetic materials, such as polyurethane or polystyrene, that encases the studs within a mold, ensuring consistent distribution and low kinetic energy upon ejection, with the option for multiple stages and concentric rings of studs, and a pyrotechnic charge for controlled expulsion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional mechanical holding elements are used to assemble studs, then assembly is possible, but homogeneous dispersion of studs cannot be guaranteed

Engineering Contradiction:
Improvehomogeneous dispersion of studsVSAvoidreliability of stud distribution
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent replaces traditional mechanical holding elements with a pyrotechnic charge system. The studs are assembled using a pyrotechnic composition that, when ignited, provides controlled expansion to propel the studs outward. This substitution of mechanical assembly with pyrotechnic-driven dispersion ensures homogeneous distribution of studs in all directions, eliminating the reliability issues associated with mechanical holding elements.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the state of the holding material from a passive mechanical element to an active pyrotechnic composition. By transforming the material properties and using controlled chemical energy release, the system achieves uniform stud dispersion through controlled expansion rather than mechanical constraint, thereby improving both manufacturing precision and reliability.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If complex assembly mechanisms are used to ensure homogeneous dispersion, then stud distribution improves, but production complexity and cost increase

Engineering Contradiction:
Improvehomogeneous dispersion of studsVSAvoidcomplexity of assembly mechanism
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts the holding function from complex mechanical assemblies and consolidates it into a single pyrotechnic charge component. This simplification maintains homogeneous stud dispersion while dramatically reducing device complexity. The pyrotechnic composition serves multiple functions: holding studs in place, providing controlled expansion, and propelling studs outward, eliminating the need for separate mechanical holding elements.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The pyrotechnic charge performs multiple functions simultaneously: it acts as a holding mechanism for the studs, provides controlled expansion for uniform dispersion, and serves as the propelling force. This multi-functionality reduces the overall device complexity while maintaining the desired homogeneous stud distribution, making production more economical.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Object-affected harmful factors

If low kinetic energy studs are used for non-lethal effect, then safety improves, but deterrence effectiveness may be reduced

Engineering Contradiction:
Improveinjury severityVSAvoiddeterrence effect
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent converts the potential harm of high kinetic energy into a beneficial controlled expansion mechanism. The pyrotechnic composition, which could be dangerous if uncontrolled, is used to provide gentle, uniform propulsion to low kinetic energy studs. This ensures the studs remain non-lethal while achieving effective deterrence through homogeneous dispersion and controlled impact, transforming a potential hazard into a safety feature.

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

Data Source

PatentEP2439483B1Grenade with non-lethal shrapnel
Publication Date: 2014.11.05 SOC DARMEMENT & DETUD ALSETEX
  • EP2439483B1 patent drawingFigure 1~6
  • EP2439483B1 patent drawingFigure 7~11
  • EP2439483B1 patent drawingFigure 12~17

AI summary

The grenade (10) has rings with studs (200) arranged around a central burst sheath so as to be propelled during bursting of the sheath, where each of the studs is formed of a ball. A mechanical maintaining element (300) mechanically maintains the studs before bursting of the sheath. The mechanical maintaining element includes a part that is made of synthetic material molded on one of the rings. The mechanical maintaining element is formed of parts molded on rings of the studs.