Compound Shim Tab Placement for Precise Gap Fitting

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Solution Overview

Problem

Traditional shimming and filling methods struggle to accurately fit gaps between complex structure components due to variations in exact geometries, leading to inefficiencies in stress reduction and force distribution in joints of structures like aircraft and automobiles.

Innovation Solution

A method and apparatus for forming a compound shim by identifying and applying multiple shim tabs with an end-effector, adjusting their placement and thickness based on surface characteristics of the components to be joined, allowing for customizable shimming sizes and shapes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If prebuilt shims and fillers are used to fill gaps between components, then joint stress reduction is improved, but manufacturing precision deteriorates due to difficulty in fitting exact component geometries

Engineering Contradiction:
Improvejoint stressVSAvoidgap fitting precision
Core Design Contradiction:
Stress or pressureVSManufacturing precision

Solution Approach 1:

The shim is divided into multiple shim tabs that can be individually applied to different locations on the component. Each shim tab can be independently positioned and sized to match the specific geometry of the gap, allowing precise adaptation while maintaining stress reduction benefits

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each shim tab is customized with specific dimensions, shapes, and thicknesses tailored to the local gap characteristics at its application location. This local customization ensures optimal fit precision for each specific gap while collectively providing comprehensive stress reduction across the entire joint area

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If multiple shim tabs are applied to form a compound shim, then adaptability to varying geometries is improved, but device complexity increases

Engineering Contradiction:
Improvegeometry adaptationVSAvoidshim application complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The shim tab system uses standardized tabs with consistent material properties and attachment methods that can be universally applied across different gap geometries. While each tab is customized in dimension, the fundamental application process and tab design remain consistent, reducing operational complexity despite geometric variability

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

Solution Approach 2:

The shim tabs are pre-configured with appropriate dimensions, shapes, and thicknesses before application. This preliminary customization allows the tabs to be ready-to-apply with minimal on-site adjustment, reducing the complexity of the application process while maintaining high adaptability to various geometries

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3354396B1Compound shimming
Publication Date: 2021.11.24 THE BOEING CO
  • EP3354396B1 patent drawingFigure 1
  • EP3354396B1 patent drawingFigure 2
  • EP3354396B1 patent drawingFigure 3A~3B

AI summary

Disclosed herein is a method. The method includes identifying a first location on a first part (110) to place a first shim tab (416) to form a first portion of a compound shim (100). The method also includes applying the first shim tab to the first location on the first part with an end-effector (204). The method also includes identifying a second location directly adjacent to the first location on the first part to place a second shim tab. The method also includes applying the second shim tab to the second location on the first part with the end-effector to form a second portion of the compound shim. The method also includes applying a third shim tab to the second shim tab at the second location to increase a thickness of the second portion of the compound shim.