Clevis System for Vertical Stabilizer Attachment

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The attachment of a vertical stabilizer to an aircraft fuselage is complex and difficult due to the need for multiple fasteners and pieces, making installation and inspection challenging, especially in confined spaces, and current joint systems require shimming, increasing production time and making rework costly and difficult.

Innovation Solution

A method using a clevis system with a composite skin and frame members, where clevises are inserted through apertures in the composite skin and secured to frame members, allowing the vertical stabilizer's base rib assembly with lugs to be attached, enabling installation and inspection from outside the aircraft.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If multiple fittings and fasteners are used to attach the vertical stabilizer to the fuselage, then the connection strength is improved, but the device complexity and difficulty of installation increase

Engineering Contradiction:

Improveconnection strengthVSAvoidjoint system complexity

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent combines multiple fittings and fasteners into a single integrated clevis system. The clevis assembly integrates the function of multiple separate fittings into one unified component that attaches the vertical stabilizer to the fuselage, reducing the total number of parts while maintaining structural strength.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The clevis system serves multiple functions simultaneously: it provides structural attachment, alignment reference, and inspection access. The design allows the same component to fulfill several roles in the attachment process, reducing the need for additional specialized parts.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If multiple fittings and fasteners are positioned between the vertical stabilizer and fuselage, then the connection reliability is improved, but the ease of operation deteriorates due to confined spaces

Engineering Contradiction:

Improveconnection reliabilityVSAvoidinstallation ease

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent inverts the traditional approach by positioning the clevis system externally on the fuselage rather than internally. This allows installation and inspection operations to be performed from the outside of the aircraft, eliminating the need for workers to access confined internal spaces while maintaining secure attachment.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The clevis system acts as an intermediary component that bridges the vertical stabilizer and fuselage in a location that is externally accessible. This mediator component allows fastening operations to be performed from outside the aircraft, improving ease of operation while ensuring reliable connection.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Stability of the object's composition

If lugs and standard dual wall clevises are oriented in longitudinal and lateral directions, then the structural stability is improved, but the ease of manufacture deteriorates due to required attachment between mid-spars

Engineering Contradiction:

Improvejoint stabilityVSAvoidassembly ease

Core Design Contradiction:

Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent segments the attachment system into modular components (clevises, lugs, retaining members) that can be independently manufactured and then assembled. This segmentation allows each component to be produced separately using standard processes, improving ease of manufacture while maintaining the multi-directional stability provided by the combined assembly.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11655019B2Method and system for coupling a vertical stabilizer to an aircraft fuselage

Publication Date: 2023.05.23 THE BOEING CO

AI summary

A method and system for attaching a vertical stabilizer to an aircraft fuselage using a clevis system is disclosed. A composite skin is installed over the aircraft fuselage. The composite skin has apertures for receiving a plurality of clevises in a clevis system. The plurality of clevises is inserted through the apertures in the composite skin. Each of the plurality of clevises is secured to a frame member in the aircraft fuselage. The vertical stabilizer has a multi-spar box connected with a base rib assembly having a plurality of lugs. The base rib assembly of the vertical stabilizer is engaged with the clevis system. The plurality of lugs in the base rib assembly is secured to the plurality of clevises in the clevis system. Attachment of the vertical stabilizer to the aircraft fuselage, as well as subsequent inspection, may be performed from outside the aircraft.