Aircraft Window Frame Offset Seams for Uniform Resin Distribution

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Solution Overview

Problem

The existing manufacturing methods for aircraft window frames result in non-homogeneous resin distribution due to localized resin accumulation at seams and junction areas, leading to visual inconsistencies in the paintwork.

Innovation Solution

The method involves creating offset seams perpendicular to the visible surface and using a barrier layer to prevent resin migration, ensuring a homogeneous resin distribution and avoiding visible seams.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If seams are positioned at the visible surface to connect fiber layers and reinforcement, then the manufacturing process is simplified, but resin accumulation occurs at the seams causing non-homogeneous resin distribution and visual inconsistencies in paintwork

Engineering Contradiction:
Improveseam positioningVSAvoidresin distribution uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The harmful effect of resin accumulation at visible seams is eliminated by extracting the seam location from the visible surface and relocating it to an offset position. The seam is moved perpendicular to the visible surface into the composite structure, removing the source of visual defects while preserving the structural function of the seam.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The seam is repositioned from a two-dimensional surface location to a three-dimensional offset position within the composite structure. By moving the seam perpendicular to the visible surface, the solution transitions the problem from surface-level to volumetric space, eliminating visual defects while maintaining structural integrity.

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

2Manufacturing precision

If offset seams are created perpendicular to the visible surface, then resin distribution becomes homogeneous and visual consistency is improved, but the manufacturing process becomes more complex

Engineering Contradiction:
Improveresin distribution uniformityVSAvoidseam positioning complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The seam is pre-positioned at an offset location perpendicular to the visible surface before the composite manufacturing process begins. By establishing the correct seam position in advance, the solution prevents resin accumulation issues from occurring, eliminating the need for post-manufacturing corrections or additional processing steps.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If a barrier layer is added to prevent resin migration, then resin distribution uniformity is improved, but the device complexity and manufacturing steps increase

Engineering Contradiction:
Improveresin distribution uniformityVSAvoidlayer structure
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

Instead of adding a barrier layer to prevent resin migration, the solution extracts the seam from the visible surface where it causes harmful resin accumulation. By removing the source of the problem rather than adding a preventive layer, the solution achieves homogeneous resin distribution without increasing structural complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4385882B1Method for manufacturing an aircraft window frame comprising seams offset from a visible surface, window frame obtained from said method and aircraft comprising at least one such window frame
Publication Date: 2026.02.18 AIRBUS OPERATIONS (SAS)
  • EP4385882B1 patent drawingFigure 1~3
  • EP4385882B1 patent drawingFigure 4~5
  • EP4385882B1 patent drawingFigure 6~7

AI summary

The invention relates to a method for manufacturing an aircraft window frame (118.1), said frame comprising a first surface (S1) having a curved junction zone (133) extending around the entire perimeter of the frame (118.1), the latter being made of composite material and comprising a stack of fiber layers (132, 134, 134') as well as at least one reinforcement (136) located at the junction zone (133). The manufacturing method includes an assembly step of the different fiber layers (132, 134, 134') and the reinforcement (136) during which at least one first seam (140) is made to join at least the reinforcement (136) and certain layers (134', 138), the first seam (140) comprising stitches offset from the first surface (S1). The invention also relates to a porthole frame obtained from this process and to an aircraft comprising said frame.