Aircraft Light Drainage Valves Using Gravity and Flight Pressure

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Solution Overview

Problem

Existing exterior aircraft lights face issues with fluid accumulation, such as condensing water, which can deteriorate their operation, and existing solutions require mechanical pumping mechanisms or are not effectively passive.

Innovation Solution

An exterior aircraft light with a passive draining device featuring two drainage tubes, each with a gravity-actuated valve mechanism, that selectively opens or seals based on the light's orientation, utilizing pressure differences during flight to expel fluid without mechanical assistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a mechanical pumping mechanism is used to drain fluid, then fluid drainage effectiveness is improved, but device complexity and cost increase

Engineering Contradiction:
Improvefluid drainage effectivenessVSAvoidmechanical pumping mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The drainage tube system utilizes the aircraft's own flight-induced pressure differences to automatically drain fluid from the housing. The system requires no external power source or mechanical actuation, as the pressure gradient generated during normal aircraft operation suffices to drive fluid through the drainage tube and out through the discharge port.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces a mechanical pumping system with a passive pressure-driven flow system. Instead of using motors, pistons, or other mechanical pumps, the invention relies on fluid dynamics principles where pressure differences naturally drive fluid through the drainage pathway, eliminating complex mechanical components.

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

2Device complexity

If a passive draining device is used, then device complexity is reduced, but fluid drainage effectiveness may be insufficient

Engineering Contradiction:
Improvedraining deviceVSAvoidfluid drainage effectiveness
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The drainage tube serves multiple functions: it acts as both the fluid passage and the pressure-driven pump mechanism. The same structural element that provides the drainage pathway also utilizes the pressure differential to drive fluid flow, eliminating the need for separate pumping components and simplifying the overall system while maintaining effectiveness.

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

Solution Approach 2:

The invention employs hydraulic principles by utilizing pressure differences in the fluid system to drive flow. The pressure gradient, generated by aircraft flight conditions, acts as the driving force for fluid movement through the drainage tube, demonstrating a passive hydraulic system that is both simple and effective.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Ease of manufacture

If drainage tubes are oriented in fixed positions, then manufacturing is simplified, but adaptability to different aircraft orientations is reduced

Engineering Contradiction:
Improvedrainage tube orientationVSAvoidaircraft mounting orientation
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The drainage tube is positioned asymmetrically within the housing, specifically oriented toward a corner region. This asymmetric placement ensures that regardless of how the aircraft is oriented during flight, the drainage tube will always have a downward component relative to the fluid accumulation zone, enabling effective drainage in all mounting configurations.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The invention transitions from considering only vertical drainage orientation to utilizing three-dimensional spatial relationships. By positioning the drainage tube to extend toward a corner and utilizing pressure gradients in multiple directions, the system achieves adaptability to various aircraft orientations without requiring complex adjustable mechanisms.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 light's housing without mechanical pumping, ensuring reliable operation and reduced maintenance, while being cost-effective and easy to produce.

Implementation Method 1

each valve mechanism comprising a valve portion of the drainage tube and a sealing element arranged in the valve portion of the drainage tube, the sealing element being movable in the valve portion under the influence of gravity

Methodology Applied
Scientific EffectGravity: Gravitation

Implementation Method 2

utilizing pressure differences during flight to expel fluid without mechanical assistance

Methodology Applied
Scientific EffectPressure difference: Pressure Gradient

Data Source

PatentEP4477559B1Exterior aircraft light, aircraft comprising an exterior aircraft light and method of draining a fluid out of an exterior aircraft light
Publication Date: 2026.01.21 GOODRICH LIGHTING SYST GMBH
  • EP4477559B1 patent drawingFigure 1A
  • EP4477559B1 patent drawingFigure 1B
  • EP4477559B1 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). At least one of the light output generation unit (3) and the power supply electronics (10) is arranged within the interior space (9). The draining device (12) comprises a first drainage tube (14a) for receiving fluid (26), a second drainage tube (14b) for receiving fluid (26); and a fluid discharge port (19) for discharging fluid (26) out of the housing (8). Each of the first and second drainage tubes (14a, 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). Each valve mechanism (15a, 15b) comprises a valve portion (16a, 16b) and a sealing element (18a, 18b), arranged in the valve portion (16a, 16b) of the respective drainage tube (14a, 14b). The sealing element (18a, 18b) is movable within the valve portion (16a, 16b) under the influence of gravity. The valve portion (16a, 16b) and the sealing element (18a, 18b) are shaped and dimensioned such that the sealing element (18a, 18b), driven by gravity, opens the respective drainage tube (14a, 14b), when the respective drainage tube (14a, 14b) is oriented in a draining orientation; and seals the respective drainage tube (14a, 14b) in an air-tight manner, when the respective drainage tube (14a, 14b) is oriented in a sealing orientation.