Shape-Memory Locking Mechanism for Aircraft Oxygen Mask Release
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Solution Overview
Problem
Existing emergency oxygen devices for aircraft are limited by weight, occupied volume, and reliability, particularly in terms of energy consumption and stability during turbulence.
Innovation Solution
A locking device utilizing a shape-memory member with a first and second length, connected to an intermediate member, which reduces energy required for unlocking and is biased by elastic and magnetic components to optimize power consumption and stability, along with a shape-memory wire design that minimizes weight and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a shape-memory member is used to move the locking member from locked to unlocked position, then energy consumption is reduced, but the device complexity increases
Solution Approach 1:
An intermediate member is introduced as a mediator between the shape-memory member and the first locking member. The intermediate member translates the shape change of the shape-memory member into the unlocking motion of the locking member, enabling energy reduction while maintaining acceptable device complexity through functional decomposition
Solution Approach 2:
The patent replaces traditional mechanical actuation systems with a shape-memory member that uses thermal or chemical activation to produce mechanical motion. This substitution reduces the energy required for operation while the intermediate member manages the complexity of the actuation mechanism
2Reliability
If the first locking member is biased towards the release position independently of gravity, then reliability during turbulence is improved, but the device complexity increases
Solution Approach 1:
The locking member is designed with self-biasing characteristics that automatically maintain it in the release position without requiring external gravitational dependence or complex active control systems. This self-service mechanism ensures reliable operation during turbulence while avoiding additional complexity
Solution Approach 2:
The patent modifies the physical or material parameters of the locking member or its mounting to create an inherent bias towards the release position. This parameter change enables gravity-independent operation that improves reliability during turbulence without adding complex mechanical systems
3Force
If the shape-memory member has a shorter second length when activated, then the unlocking force is improved, but the occupied volume increases
Solution Approach 1:
The shape-memory member is configured to change its dimensions in a specific direction to generate unlocking force, while the intermediate member and support structure are designed to guide this dimensional change in a way that minimizes the overall volume occupied by the mechanism
Solution Approach 2:
The shape-memory member utilizes flexible, thin-walled construction that allows it to achieve the required force generation through dimensional change while occupying minimal volume. The flexible structure enables effective force transmission without requiring bulky components
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 solution reduces energy consumption, weight, and enhances reliability and stability, allowing for efficient operation in aircraft environments, including turbulence, while optimizing the force and space requirements of the locking mechanism.
Implementation Method 1
a shape-memory member having a first length when not activated and a second length when activated... the shape-memory member being connected to the intermediate member so as to move the intermediate member to the release position when the shape-memory member is activated
Implementation Method 2
the locking device preferably comprises an elastic arming member biasing the first locking member towards the unlocked position. The elastic member thus stores a portion of the energy required to move the first locking member from the locked position to the unlocked position
Implementation Method 3
the locking device preferably further comprises a permanent magnet magnetically biasing the first locking member towards the unlocked position
Data Source
AI summary
Locking device comprising:a support,a first locking member and a second locking member, the first locking member being mounted on the support and configured to move between a locked position and an unlocked position,an intermediate member movable between a retaining position and a release position, the intermediate member in the retaining position retaining the first locking member in the locked position, anda shape-memory member, the shape-memory member being connected to the intermediate member and configured to move the intermediate member to the release position when the shape-memory member is activated.