Aircraft Lavatory Ceiling Window Assemblies for Daylighting

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Solution Overview

Problem

Aircraft lavatories typically lack windows due to structural and privacy concerns, and existing solutions either compromise fuselage strength or passenger comfort with artificial lighting, while large windows increase weight and create uncomfortable glare and shadows.

Innovation Solution

The installation of two symmetrical window assemblies in the ceiling panel of the fuselage, flanked by frame members and stringers, which introduce daylight into the lavatory area without compromising structural integrity, using a small window pane and inner cover secured by a retainer, and are angled to minimize glare and shadows.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a large sized window is provided in the lavatory, then natural light is improved, but structural strength and passenger privacy deteriorate

Engineering Contradiction:
Improvenatural lightVSAvoidfuselage structure
Core Design Contradiction:
Illumination intensityVSStrength

Solution Approach 1:

The window assembly is divided into multiple components: a first window pane, a second window pane, and an inner cover, each serving specific functions. This segmentation allows the system to provide sufficient natural light while maintaining structural integrity and privacy through the coordinated arrangement of these smaller elements rather than a single large window

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The inner cover acts as an intermediary element between the window panes and the lavatory interior. It diffuses and redirects natural light into the lavatory space while obscuring the external view to preserve passenger privacy, thus mediating between the need for illumination and the need for privacy

Inventive Principle:
Principle #24Intermediary (Mediator)

2Illumination intensity

If a large sized window is provided in the lavatory, then natural light is improved, but aircraft weight increases

Engineering Contradiction:
Improvenatural lightVSAvoidaircraft weight
Core Design Contradiction:
Illumination intensityVSWeight of moving object

Solution Approach 1:

Instead of using a single large window pane that would be heavy, the invention segments the window into multiple smaller panes and an inner cover. This segmentation reduces the total weight of the window assembly while still providing adequate natural light illumination to the lavatory space

Inventive Principle:
Principle #1Segmentation

3Object-affected harmful factors

If artificial lighting is used in the lavatory, then privacy is maintained, but passenger comfort deteriorates due to cramped feeling

Engineering Contradiction:
ImproveprivacyVSAvoidpassenger comfort
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The invention merges the benefits of natural light (passenger comfort) with the benefits of privacy protection. By combining window panes for light entry with an inner cover for privacy, the system eliminates the need to choose between artificial lighting and natural light, providing both comfort and privacy simultaneously

Inventive Principle:
Principle #5Merging (Combining)

4Illumination intensity

If direct daylight is introduced through a large window, then natural light is improved, but passenger comfort deteriorates due to glare and deep shadows

Engineering Contradiction:
Improvenatural lightVSAvoidglare and shadows
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The inner cover serves as a light-diffusing intermediary that receives direct daylight from the window panes and redistributes it softly into the lavatory. This mediation eliminates harsh glare and deep shadows while maintaining adequate illumination, improving passenger comfort

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The inner cover changes the physical parameters of the light by diffusing and redirecting it at various angles. This transformation of light parameters converts direct, harsh daylight into soft, evenly distributed illumination that eliminates glare and shadows

Inventive Principle:
Principle #35Parameter changes

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

This design provides sufficient natural light to the lavatory, enhancing passenger comfort and privacy while maintaining the structural integrity of the aircraft, without increasing the weight significantly, and reduces the likelihood of glare and deep shadows.

Implementation Method 1

the inner cover introduces the daylight from the window pane into the interior area by reflection

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2996938B1Window of an aircraft
Publication Date: 2018.06.13 HONDA PATENTS & TECHNOLOGIES NORTH AMERICA LLC
  • EP2996938B1 patent drawingFigure 1
  • EP2996938B1 patent drawingFigure 2
  • EP2996938B1 patent drawingFigure 3~4

AI summary

An aircraft includes a fuselage including a plurality of frame members disposed at predetermined intervals in a longitudinal direction of the fuselage and a plurality of stringers extending substantially linearly in the longitudinal direction. The fuselage defines an aircraft interior. A compartment is located in the interior of the fuselage. The compartment defines an interior area. A first one window assembly is mounted to an upper portion of the fuselage for introducing daylight into the interior area. The first window assembly is flanked by adjacent frame members of the plurality of frame members and adjacent stringers of the plurality of stringers. The first window assembly includes a window pane, an inner cover and a retainer. The inner cover introduces daylight from the window pane into the interior area. The retainer secures the window pane and the inner cover to the fuselage.