Aircraft Door Opening Mechanism Using Tubular Spring Actuation

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Solution Overview

Problem

Existing emergency opening devices for aircraft doors are bulky, require significant maintenance, and often rely on pneumatic or pyrotechnic elements that need periodic inspection and replacement.

Innovation Solution

A compact, mechanical emergency opening device featuring a tubular actuating member with elastic compression means, a retaining member, and triggering means that allow for rapid deployment without external energy sources or complex maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pneumatic actuators with secondary reserve of engine fluid are used, then the emergency opening device can be activated, but the weight and spatial requirements increase significantly

Engineering Contradiction:

Improveemergency opening capabilityVSAvoidweight of actuating means

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent extracts and eliminates the secondary reserve of engine fluid from the actuating system. The mechanical actuator is designed to function independently without requiring pneumatic fluid storage, thereby removing the weight and volume associated with fluid reservoirs while maintaining emergency opening capability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the pneumatic actuation system with a purely mechanical actuator. This substitution eliminates the need for pneumatic components, fluid pressure systems, and associated control mechanisms, significantly reducing weight and spatial requirements while providing reliable emergency opening function.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If pneumatic actuators with secondary reserve of engine fluid are used, then the emergency opening device can be activated, but the device requires periodic maintenance and overhaul

Engineering Contradiction:

Improveemergency opening capabilityVSAvoidmaintenance requirement

Core Design Contradiction:

ReliabilityVSEase of repair

Solution Approach 1:

The mechanical actuator is designed to be self-contained and self-sufficient, requiring no external fluid supply systems or periodic maintenance of pneumatic components. The system serves itself by using stored mechanical energy in the form of compressed spring, eliminating the need for fluid pressure monitoring, reservoir refilling, or pneumatic system maintenance.

Inventive Principle:

Principle #25Self-service

3Weight of moving object

If pyrotechnic jacks are used, then the spatial requirement and weight are reduced, but explosive elements must be transported and stored

Engineering Contradiction:

Improveweight of actuating meansVSAvoidexplosive elements storage

Core Design Contradiction:

Weight of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent converts the harmful aspect of requiring explosive storage by replacing pyrotechnic initiation with a mechanical triggering system. The compressed spring stores energy benignly without explosive risk, and the mechanical trigger releases this energy safely through purely mechanical means, eliminating the need to transport and store hazardous explosive materials.

Inventive Principle:

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

4Weight of moving object

If complex mechanical emergency opening devices are used, then weight and spatial requirements are reduced, but the device becomes bulky and requires additional control means

Engineering Contradiction:

Improveweight of actuating meansVSAvoidstructural complexity

Core Design Contradiction:

Weight of moving objectVSDevice complexity

Solution Approach 1:

The patent merges the actuating function and control function into a single integrated mechanical actuator. The trigger mechanism is incorporated directly into the actuator structure, eliminating the need for separate control systems. This integration reduces overall device complexity while maintaining the weight and space advantages of mechanical actuation.

Inventive Principle:

Principle #5Merging (Combining)

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 device provides a reliable, low-maintenance solution with reduced weight and spatial requirements, capable of delivering a significant opening force for rapid door opening while minimizing the effort needed to trigger it.

Implementation Method 1

elastic compression means able to attract the tubular actuating member from its retracted position to its deployed position

Methodology Applied

Scientific EffectElastic compression: Elasticity

Implementation Method 2

the elastic compression means comprise a tubular spring compressed between the first end plate and the second end plate

Methodology Applied

Scientific EffectSpring expansion: Spring

Data Source

PatentUS12209447B2Device for emergency opening of an aircraft door with peripheral retaining member

Publication Date: 2025.01.28 LATECOERE

AI summary

A device for emergency opening of an aircraft door having: a tubular actuating member (7) which includes a first end plate (8) and a second end plate (9); an elastic compression device having a tubular spring (10) compressed between the first end plate (8) and the second end plate (9); an expansion regulator (17, 18) arranged inside the tubular spring (10); a retaining member which includes at least one peripheral attachment connecting the first end plate (8) to the second end plate (9), the peripheral attachment being radially outside the tubular spring (10).