Aircraft Door Emergency Opener With Tubular Spring Retention

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Solution Overview

Problem

Existing aircraft door emergency opening devices are bulky, require frequent maintenance, and involve complex mechanical parts that increase weight and size, while pneumatic and pyrotechnic solutions pose safety and logistical challenges.

Innovation Solution

A compact, mechanically designed emergency opening device with a tubular actuating member, elastic compression means, and a retaining member that uses a tubular spring and triggering means to facilitate effortless activation, eliminating the need for external power sources and reducing maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If pneumatic actuators with additional reserve of working fluid are used, then emergency opening function is achieved, but weight and size increase significantly

Engineering Contradiction:
Improveemergency opening functionVSAvoidweight of actuating means
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent extracts and eliminates the additional reserve of working fluid from the system. The actuating means are redesigned to function without requiring stored pneumatic pressure, removing the heavy reservoir and associated monitoring/maintenance systems while maintaining the emergency opening capability through alternative mechanical means.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the pneumatic system with a mechanically-driven system. Instead of using compressed gas stored in a reservoir, the emergency opening function is achieved through mechanical actuation mechanisms that do not require working fluid reserves, thereby eliminating the weight and volume associated with pneumatic storage systems.

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

2Weight of moving object

If pyrotechnic cylinders are used, then weight and size are reduced, but periodic inspection and replacement of explosive elements is required

Engineering Contradiction:
Improveweight of actuating meansVSAvoidmaintenance requirements
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The patent avoids using disposable pyrotechnic elements with limited shelf lives. Instead, it employs durable mechanical components that can be inspected and maintained over extended periods, eliminating the need for periodic replacement of explosive elements while keeping the system lightweight.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The mechanical actuating system is designed to be inherently reliable without requiring active monitoring or periodic intervention. The system uses passive mechanical retention and release mechanisms that do not degrade over time like explosive elements, reducing maintenance complexity while maintaining low weight.

Inventive Principle:
Principle #25Self-service

3Reliability

If complex mechanical actuation means are used, then reliability is increased, but device size and weight increase

Engineering Contradiction:
Improveoperational reliabilityVSAvoidsize of emergency opening device
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent employs a nested arrangement where the retaining member is positioned within or around the tubular actuating member, and components are arranged concentrically or in compact configurations. This nesting reduces the overall volume of the device while maintaining the necessary mechanical complexity for reliable operation.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The actuating system is divided into distinct functional segments: the tubular actuating member, the retaining member with peripheral attachment, and the elastic compression means. This segmentation allows each component to be optimized independently for compactness while maintaining overall system reliability through modular design.

Inventive Principle:
Principle #1Segmentation

4Adaptability or versatility

If control means are added to control door movement, then door movement control is achieved, but overall device size increases

Engineering Contradiction:
Improvedoor movement controlVSAvoidoverall device size
Core Design Contradiction:
Adaptability or versatilityVSVolume of moving object

Solution Approach 1:

The tubular actuating member serves multiple functions: it acts as the structural component, the actuator that generates opening force, and the guide for controlled door movement. The retaining member simultaneously provides retention and serves as a mounting structure. This multi-functionality eliminates the need for separate control mechanisms, maintaining compact size while achieving door movement control.

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

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, lightweight, and compact solution that ensures rapid door opening with minimal effort, while simplifying maintenance and eliminating the need for complex mechanical parts, thus enhancing safety and reducing costs.

Implementation Method 1

elastic compression means adapted to bias the tubular actuating member from its retracted position to its deployed position; the elastic compression means comprise a tubular spring compressed between the first end plate and the second end plate

Methodology Applied
Scientific EffectElastic compression: Elasticity

Data Source

PatentEP4188795B1Device for emergency opening of an aircraft door with peripheral retaining member
Publication Date: 2025.09.10 LATECOERE
  • EP4188795B1 patent drawingFigure 1
  • EP4188795B1 patent drawingFigure 2
  • EP4188795B1 patent drawingFigure 3

AI summary

A device for emergency opening of an aircraft door, comprising: - a tubular actuating member (7) which comprises a first end plate (8) and a second end plate (9); - elastic compression means which comprise 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 comprises at least one peripheral attachment connecting the first end plate (8) to the second end plate (9), this peripheral attachment being radially outside the tubular spring (10).