Exterior Aircraft Light Dual-Tube Drainage for Passive Fluid Removal

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Solution Overview

Problem

Existing exterior aircraft lights face issues with fluid accumulation within their housings, which can deteriorate their operation, and existing draining solutions require mechanical pumping mechanisms or power sources.

Innovation Solution

A passive draining device with two drainage tubes, each equipped with a valve mechanism using materials with different water absorption and expansion characteristics, allows fluid to be drained via pressure differences during flight, eliminating the need for mechanical pumping or power sources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanical pumping mechanism or power source is used to drain fluid, then the draining effectiveness is improved, but the device complexity and power consumption increase

Engineering Contradiction:
Improvedraining effectivenessVSAvoidmechanical pumping mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The drainage tube system utilizes the aircraft's own flight operations (pressure differences during ascent and descent) to automatically drain fluid from the housing, eliminating the need for external power sources or mechanical pumping mechanisms. The system serves itself by harnessing environmental conditions already present during normal aircraft operation.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces mechanical pumping systems with a passive drainage mechanism that relies on pressure differentials created during aircraft flight. This substitution eliminates complex mechanical components while achieving the same fluid removal function through physical pressure gradients.

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

2Adaptability or versatility

If a single drainage tube is used, then the device complexity is reduced, but the adaptability to different mounting orientations is limited

Engineering Contradiction:
Improvemounting orientation adaptabilityVSAvoidnumber of drainage tubes
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The multiple drainage tubes are designed to serve different mounting orientations of the aircraft light. Each tube is positioned to effectively drain fluid when the light is mounted in a specific orientation, making the same housing adaptable to various installation positions without requiring orientation-specific components.

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

Solution Approach 2:

The drainage system is divided into multiple separate drainage tubes, each optimized for a specific mounting orientation. This segmentation allows the housing to be mounted in different positions while ensuring that at least one drainage tube will always be positioned to effectively drain fluid regardless of the aircraft's attitude or light orientation.

Inventive Principle:
Principle #1Segmentation

3Object-affected harmful factors

If the housing is sealed to prevent fluid entry, then the protection against fluid accumulation is improved, but the pressure equalization during flight is hindered

Engineering Contradiction:
Improvefluid accumulation protectionVSAvoidpressure equalization
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The drainage tube acts as an intermediary element that connects the sealed housing interior to the exterior environment. It allows pressure equalization during flight while preventing fluid from entering the housing during normal operation, serving as a controlled interface between the sealed interior and external conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The drainage tube system extracts the pressure equalization function from the sealed housing structure. By providing a dedicated pathway for pressure regulation separate from the main sealing system, the housing can maintain its sealed protective function while still allowing necessary pressure communication with the external environment during flight maneuvers.

Inventive Principle:
Principle #2Taking out (Extraction)

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

Effectively and reliably drains fluid from the exterior aircraft light housing without mechanical assistance, ensuring reliable operation and reduced maintenance, while being adaptable to different mounting orientations.

Implementation Method 1

The valve portions (16a, 16b) and the sealing elements (18a, 18b) are made of a first and second material, respectively, having different water absorption and expansion characteristics

Methodology Applied
Scientific EffectWater absorption: Absorption (physical)

Implementation Method 2

The valve portions (16a, 16b) and the sealing elements (18a, 18b) are made of a first and second material, respectively, having different water absorption and expansion characteristics

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 3

the pressure difference drives the fluid (26) into the lower drainage tube (14a, 14b) and via the fluid discharge port (19) out of the aircraft (100)

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP4461653B1Exterior aircraft light, aircraft comprising an exterior aircraft light and method of draining a fluid out of an exterior aircraft light
Publication Date: 2025.11.05 GOODRICH LIGHTING SYST GMBH
  • EP4461653B1 patent drawingFigure 1A
  • EP4461653B1 patent drawingFigure 1B
  • EP4461653B1 patent drawingFigure 2

AI summary

An exterior aircraft light (1) comprises a housing (8) defining an interior space (9); a light output generation unit (3) comprising at least one light source (2); power supply electronics (10), coupled to the light output generation unit (3) for driving a light output of the exterior aircraft light (1); and a draining device (12) for draining the interior space (9). The draining device (12) comprises a first drainage tube (14a) for receiving fluid (26), which is to be drained from the interior space (9); a second drainage tube (14b) for receiving fluid (26), which is to be drained from the interior space (9); and a fluid discharge port (19) for discharging fluid (26) out of the housing (8), wherein the fluid discharge port (19) is in fluid communication with the first drainage tube (14a) and with the second drainage tube (14b). Each of the first drainage tube (14a) and the second drainage tube (14b) comprises a valve mechanism (15a, 15b) for selectively sealing and opening the respective drainage tube (14a, 14b) with respect to the interior space (9). The valve mechanism (15a, 15b) comprises a valve portion (16a, 16b) of the respective drainage tube (14a, 14b) and a sealing element (18a, 18b), arranged in the valve portion (16a, 16b) of the respective drainage tube (14a, 14b). The valve portion (16a, 16b) of the respective drainage tube (14a, 14b) is made of a first material and the sealing element (18a, 18b) is made of a second material having different water absorption and expansion characteristics than the first material. The valve portion (16a, 16b) and the sealing element (18a, 18b) are sized to open the valve mechanism (15a, 15b), when immersed in fluid (26), and to seal the valve mechanism (15a, 15b) in an air-tight manner, when not immersed in fluid (26).