Induction-Melt Solder Release Mechanism for Ultralow-Shock Separation

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Solution Overview

Problem

Current Hold-down and Release Mechanisms (HRMs) in aerospace rely heavily on pyrotechnic systems, which pose hazards due to shock generation, are costly, and fail recurrently, while non-explosive alternatives like Shape Memory Alloys (SMAs) and fuse wire-based systems face limitations in tension, temperature, and reliability.

Innovation Solution

A non-explosive release system utilizing a segmented structural element with a solder joint that is electromagnetically heatable, employing a solder alloy with a predefined melting temperature, and a magnetic field to induce heating and separation, thus releasing the segments without shocks or debris.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pyrotechnic HRMs are used, then high reliability and strong holding capability are achieved, but severe shocks are generated that endanger delicate equipment

Engineering Contradiction:
ImproveHRM reliabilityVSAvoidshock generation
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the pyrotechnic (chemical) release mechanism with an electromagnetic system. A coil generates a magnetic field that induces eddy currents in a conductive disc, which melts a solder joint holding the disc in place. This electromagnetic-induction-based mechanism eliminates the explosive chemical reaction of pyrotechnics while maintaining reliable holding and release functionality.

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

Solution Approach 2:

The patent utilizes the phase transition of solder material from solid to liquid through electromagnetic induction heating. The solder joint connects the conductive disc to the housing, and when the coil is energized, the induced currents heat the solder to its melting point, causing it to transition from solid to liquid and release the disc. This controlled phase transition provides a reliable, non-explosive release mechanism.

Inventive Principle:
Principle #36Phase transitions

2Strength

If pyrotechnic HRMs are used, then high holding strength is achieved, but manipulation and storage become intrinsically hazardous

Engineering Contradiction:
Improveholding strengthVSAvoidmanipulation and storage safety
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent replaces the pyrotechnic (chemical) release mechanism with an electromagnetic system. A coil generates a magnetic field that induces eddy currents in a conductive disc, which melts a solder joint holding the disc in place. This electromagnetic-induction-based mechanism eliminates the explosive chemical reaction of pyrotechnics while maintaining reliable holding and release functionality.

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

3Object-affected harmful factors

If non-explosive alternatives like SMAs and fuse wire-based systems are used, then shock generation is reduced, but limitations in tension, temperature, and reliability occur

Engineering Contradiction:
Improveshock generationVSAvoidtension and temperature performance
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent employs a conductive disc with specific electrical and thermal properties, a solder joint with appropriate melting temperature, and an electromagnetic coil designed to generate sufficient induced currents. By carefully selecting and adjusting these parameters (electrical conductivity, thermal conductivity, melting point, coil turns, current amplitude), the system achieves reliable operation across required tension and temperature ranges without the limitations of SMAs or fuse wires.

Inventive Principle:
Principle #35Parameter changes

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 system achieves ultralow shock levels, meets demanding tension and temperature ranges, is cost-effective, and overcomes reliability and export control issues, providing a mechanically simple and debris-free solution for HRMs.

Implementation Method 1

a solder joint joining respective ends of the first and second segments, thus securely holding down the first and second structures with respect to one another; wherein said solder joint is electromagnetically heatable and includes a solder alloy (preferably an eutectic alloy) having a predefined melting temperature

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

magnetic field generating means configured to, upon reception of a release command, generate a time-varying magnetic field through the solder joint such that to cause heating thereof up to the predefined melting temperature of the solder alloy

Methodology Applied
Scientific EffectElectromagnetic heating: Electromagnetic Induction

Implementation Method 3

heating thereof up to the predefined melting temperature of the solder alloy, thereby causing melting of the solder alloy

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP3402624B1Non-explosive release mechanism based on electromagnetic induction melting
Publication Date: 2022.03.02 THALES ALENIA SPACE ITALIA SPA CON UNICO SOCIO
  • EP3402624B1 patent drawingFigure 1~2
  • EP3402624B1 patent drawingFigure 3~5
  • EP3402624B1 patent drawingFigure 6~8

AI summary

The present invention relates to a release system (1, 2, 3, 4, 5), that includes a segmented structural element (10) comprising : a first segment (10a) designed to be coupled to a first structure, a second segment (10b) designed to be coupled to a second structure, and a solder joint (11) joining respective ends of said first (10a) and second (10b) segments, thus holding down the first and second structures with respect to one another; wherein said solder joint (11) is electromagnetically heatable and includes a solder alloy having a predefined melting temperature. The release system (1, 2, 3, 4, 5) is characterized by further including magnetic field generating means (13, PW1, PW2, PW3, PW4, PW5) configured to, upon reception of a release command, generate a time-varying magnetic field through the solder joint (11) such that to cause heating thereof up to the predefined melting temperature of the solder alloy, thereby causing melting of said solder alloy; whereby separation of the first (10a) and second (10b) segments is caused, thus enabling release of the first and second structures from one another.