Blind Fastener Visual Verification of Correct Bulb Formation

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Solution Overview

Problem

Existing one-sided fasteners lack a practical means to verify correct installation, leading to potential limitations in shear and tensile load capabilities and requiring time-consuming manual inspections, especially in confined workspaces.

Innovation Solution

A fastener design incorporating a sleeve, pin, and visual indicator that deforms into a bulb upon installation, allowing for visual verification of correct formation without physical inspection, using reference marks and geometric changes to indicate proper installation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If manual inspection of the expansion member is performed to verify correct installation, then installation reliability is improved, but inspection time and productivity are significantly reduced

Engineering Contradiction:

Improveinstallation verification reliabilityVSAvoidinspection speed

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies color change principles through the visual indicator system. The indicator changes its visual state (from hidden to visible, or from one color to another) to indicate whether the expansion member has been correctly installed. This allows instant verification without manual measurement, resolving the contradiction between reliable verification and inspection speed.

Inventive Principle:

Principle #32Color changes

Solution Approach 2:

The patent replaces the mechanical inspection system (manual measurement and physical access to the expansion member) with a visual indication system. The visual indicator provides automatic feedback on installation correctness, eliminating the need for time-consuming manual inspection while maintaining verification reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If manual inspection methods are used to verify expansion member installation, then installation correctness can be confirmed, but the complexity and time required for inspection increase significantly

Engineering Contradiction:

Improveinstallation correctness verificationVSAvoidinspection time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The fastener system performs self-verification through the visual indicator. The indicator automatically indicates whether the expansion member is correctly installed without requiring external inspection tools or personnel. This self-service mechanism confirms installation correctness instantly, eliminating time loss associated with manual inspection.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The visual indicator provides immediate feedback on installation correctness. When the expansion member is properly installed, the indicator assumes a specific visual state that confirms correct installation. This real-time feedback mechanism eliminates the need for delayed manual inspection, reducing inspection time while maintaining verification reliability.

Inventive Principle:

Principle #23Feedback

3Measurement precision

If physical access to the expansion member is obtained for inspection, then detailed verification is possible, but the difficulty of accessing confined workspaces increases the complexity of the inspection process

Engineering Contradiction:

Improveexpansion member verification accuracyVSAvoidaccessibility to blind side

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The visual indicator serves as an intermediary that translates the installation state of the hidden expansion member into a visible signal on the accessible side. This intermediary allows verification of the expansion member's correctness without physical access to the confined blind side, maintaining measurement precision while improving ease of operation.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent moves the verification interface from the blind side (where the expansion member is located) to the accessible side through the visual indicator. This dimensional shift allows inspectors to verify installation correctness from the accessible side without needing to physically access the confined workspace where the expansion member is installed.

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

Facilitates quick and efficient visual confirmation of correct installation, reducing the need for manual inspections and ensuring proper load-bearing capabilities without accessing the blind side of the assembly.

Implementation Method 1

Application of a force to the pin deforms the expansion member radially outward and draws the expansion member into engagement with an inaccessible side of the blind-side workpiece

Methodology Applied

Scientific EffectDeformation: Deformation

Data Source

PatentUS12188508B2Fasteners with visual indication of correct installation and method for fastening

Publication Date: 2025.01.07 THE BOEING CO

AI summary

A fastener includes a sleeve, a pin, and a visual indicator. The sleeve includes a tubular body. The pin includes a shank. At least a portion of the shank of the pin is configured to extend through the tubular body of the sleeve and to facilitate deformation of a portion of the tubular body into a bulb in response to a force applied to the tubular body of the sleeve by the shank of the pin. The visual indicator is configured to provide a visual verification of correct formation of the bulb.