Shape Memory Alloy Pin Release for Controlled Reusable Holding

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing pin release mechanisms are not suitable for repeated use, often release high forces leading to undesired movements, and are not cost-effective.

Innovation Solution

A pin holding and release apparatus using rod-shaped release elements made of shape memory alloy, arranged in parallel with a pin holding element and a force transfer element, which applies an elastic holding force. The release elements are deactivatable by heating beyond their transition temperature, allowing controlled release of the pin without high forces, and can be reused without mechanical resetting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a shape memory alloy actuator is used to release a bolt by breaking it, then the structure can be released, but the actuator must be mechanically reset and the bolt is destroyed, making it suitable for one-time use only

Engineering Contradiction:

Improvereusability of release mechanismVSAvoidcomplexity of resetting mechanism

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical resetting process with a thermal process. The shape memory alloy release elements are heated to undergo phase transformation and recover their original shape, automatically resetting without mechanical intervention. This substitution of thermal field for mechanical field enables repeated use of the same release elements.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes the phase transition properties of shape memory alloys. By heating the release elements above their transformation temperature, they transition from a deformed state to a recovered state, enabling automatic resetting. This phase transition mechanism allows the release elements to be reused multiple times without mechanical resetting.

Inventive Principle:

Principle #36Phase transitions

2Ease of operation

If a bolt is broken to release a structure, then the structure can be separated, but high elastic forces are set free at once causing undesired movements

Engineering Contradiction:

Improvecontrolled release of pinVSAvoidelastic forces during release

Core Design Contradiction:

Ease of operationVSForce

Solution Approach 1:

The patent divides the release function into multiple rod-shaped release elements arranged in parallel, each contributing to the total holding force. This segmentation allows the force to be distributed and released in a more controlled manner compared to a single bolt breaking event.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent changes the physical state of the shape memory alloy release elements by heating them above their transformation temperature. This parameter change (temperature) triggers the phase transformation that enables controlled shape recovery and force release, avoiding the sudden force release associated with bolt breaking.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If traditional release mechanisms are used, then the pin can be released, but the mechanisms are not cost-effective and require complex resetting procedures

Engineering Contradiction:

Improvecost-effectiveness of release apparatusVSAvoidcomplexity of resetting mechanism

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The shape memory alloy release elements automatically reset themselves through thermal activation without requiring external mechanical resetting operations. This self-service capability eliminates the need for complex resetting mechanisms and reduces operational complexity, improving cost-effectiveness.

Inventive Principle:

Principle #25Self-service

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

Enables controlled and repeatable pin release without high forces, maintaining a cost-effective construction, as the apparatus can be reused by simply reinserting the pin after cooling, eliminating the need for mechanical resetting.

Implementation Method 1

rod-shaped release elements made of a shape memory alloy, which are also supported at the base, wherein the holding element is deactivatable by heating up the release elements beyond a transition temperature of their shape memory alloy and by a resulting recovery of the release elements to a memory shape

Methodology Applied

Scientific EffectShape memory alloy effect: Shape Memory Alloy

Data Source

PatentUS11701716B2Apparatus for holding and releasing with rod-shaped release elements made of a shape memory alloy

Publication Date: 2023.07.18 DEUTSCHES ZENTRUM FÜR LUFT UND RAUMFAHRT E V

AI summary

An apparatus for holding and releasing a pin in a controlled manner comprises a base, a pin holding element supported at the base, a plurality of rod-shaped release elements made of a shape memory alloy and supported at the base, a holding force application device supported at the base for applying an elastic holding force, and a force transfer element. The force transfer element is subjected to the elastic holding force and, against the elastic holding force, supported at the base via a parallel arrangement of the pin holding element and the release elements. The release elements are arranged with radial play in blind holes in the base, which are arranged around the pin holding element. The pin holding element is deactivatable by heating up the release elements beyond a transition temperature of their shape memory alloy and by a resulting recovery of the release elements to straight memory shapes.