Elastomer Floating Nut Assembly for Low-Mass Misalignment Compensation

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Solution Overview

Problem

Existing floating nut systems require tedious installation processes and contribute significantly to assembly mass, especially in large-scale applications like aircraft ventral fairings, due to their metal construction and installation methods.

Innovation Solution

A low-mass floating nut system utilizing an elastomer cage device and nut device, which includes deformable rings and a washer, allows for easy alignment and secure fastening of parts with reduced material usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If traditional metal floating nuts are used, then assembly strength and reliability are ensured, but assembly mass increases significantly and installation becomes tedious

Engineering Contradiction:
Improveassembly massVSAvoidassembly reliability
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent changes the material parameter from metal to elastomer for the cage device, fundamentally altering the weight characteristic while maintaining functional performance. This material substitution reduces assembly mass significantly while the elastomer's inherent properties provide the necessary reliability for the floating nut function.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention employs composite construction by integrating the elastomer cage with a metal nut device, creating a hybrid structure that combines the weight advantages of elastomer with the strength advantages of metal, thereby resolving the contradiction between reduced mass and maintained reliability.

Inventive Principle:
Principle #40Composite materials

2Productivity

If traditional metal floating nuts are used, then secure fastening is achieved, but installation time increases due to tedious operations

Engineering Contradiction:
Improveassembly speedVSAvoidinstallation complexity
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The elastomer cage device is designed to be self-installing through its elastic properties. The cage can be compressed to pass through the opening and then automatically expands to its original shape, securing itself without requiring separate installation operations like cold expansion or riveting, thereby dramatically improving productivity and simplifying the installation process.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent introduces dynamic characteristics to the previously static metal cage by using elastomer material. The cage can dynamically change its shape during installation (compressing to pass through, then expanding to secure), making the installation process simpler and faster while maintaining secure fastening capability.

Inventive Principle:
Principle #15Dynamics

3Object-affected harmful factors

If metal cage is used for floating nut, then structural strength is sufficient, but galvanic corrosion risk increases

Engineering Contradiction:
Improvegalvanic corrosion resistanceVSAvoidcage structural strength
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent changes the material composition parameter from pure metal to elastomer composite, which fundamentally eliminates galvanic corrosion risk. The elastomer material is inherently resistant to galvanic corrosion, and the composite structure maintains sufficient structural strength for the application.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The elastomer cage acts as an intermediary between the metal nut and the surrounding structure, preventing direct contact between dissimilar metals and thereby eliminating galvanic corrosion pathways while still providing the necessary structural support and fastening function.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The system reduces assembly time, mass, and prevents misalignment while maintaining secure fastening, offering versatility in alignment tolerance and reducing galvanic corrosion risks.

Implementation Method 1

the first cylinder being configured to deform when the screw is tightened so that the first axis of revolution and the third axis of revolution are substantially coincident when a screw is tightened into the thread

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

the second ring being elastically deformable so that, on the one hand, it bends against the first cylinder to pass through the second opening when a user forces the passage of the cage device through the second opening

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 3

the washer being embedded in the first ring, the washer being intended to press the first ring against the second piece when the screw is tightened into the thread

Methodology Applied
Scientific EffectMechanical force: Mechanical Force

Data Source

PatentEP4600508B1Reduced mass floating nut system and method of assembling two parts using same
Publication Date: 2026.03.25 AIRBUS OPERATIONS (SAS)
  • EP4600508B1 patent drawingFigure 1~3
  • EP4600508B1 patent drawingFigure 4~6
  • EP4600508B1 patent drawingFigure 7~9

AI summary

- Floating nut system of reduced mass and method for assembling two parts using said system. - The floating nut system 1 being intended to assemble a part (2) and a part (3), the part (2) comprising an opening (4) having an axis of revolution (A1), the floating nut system (1) comprising at least one cage device (6) made of elastomer and a nut device (7), the cage device (6) comprising a cylinder (8) intended to be inserted into an opening (9) made in the part (3) and a crown (11) around the cylinder (8); the nut device (7) comprising a cylinder (13) having an axis of revolution (A3) and a washer (15) intended to press the crown (11) against the part (3) when the screw (5) is screwed into the cylinder (13); the cylinder (8) being configured to deform when screwing the screw (5) so that the axis of revolution (A1) and the axis of revolution (A3) are substantially the same.The elastomer cage device (6) makes it possible to reduce the mass of the floating nut system (1).