Elastomer Floating Nut Assembly for Misalignment and Mass Reduction
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Solution Overview
Problem
Existing floating nut systems, typically made of metal, require complex installation processes and result in significant mass when numerous nuts are used, leading to long assembly times and potential issues like galvanic corrosion.
Innovation Solution
A reduced-mass floating-nut system comprising an elastomer cage device and a nut device, where the cage device includes a deformable collar and a nut device with a washer, allowing for alignment and secure assembly of parts with reduced material usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional metal floating nuts are used to accommodate misalignment between parts, then assembly tolerance is handled effectively, but the mass increases significantly and installation becomes complex and time-consuming
Solution Approach 1:
The patent changes the material parameter from metal to elastomer for the cage device, fundamentally altering the density and mass characteristics while maintaining the floating nut functionality. This material parameter change enables the cage to deform elastically to accommodate misalignment between parts, replacing the traditional rigid metal construction with a flexible elastomeric structure that is significantly lighter yet equally effective at handling assembly tolerances
Solution Approach 2:
The patent employs composite construction by embedding a metal nut within an elastomer cage, creating a hybrid structure that combines the advantages of both materials. The elastomer provides flexibility, light weight, and deformation capability to accommodate misalignment, while the embedded metal nut provides the necessary threading and structural integrity. This composite approach resolves the contradiction by integrating multiple material properties into a single functional unit that achieves both low mass and effective misalignment accommodation
2Reliability
If traditional metal floating nuts are installed using cold expansion or riveting operations, then secure attachment is achieved, but the installation process becomes complex and time-consuming
Solution Approach 1:
The elastomer cage device is designed to be self-installing by simply pushing it into the counterbored hole, where it automatically secures itself through elastic deformation and friction fit. The cage's flexible nature allows it to compress during insertion and then expand to engage with the hole walls, creating a secure attachment without requiring external fastening operations. This self-service mechanism eliminates the need for complex cold expansion or riveting processes, dramatically simplifying installation while maintaining reliable attachment
Solution Approach 2:
The patent utilizes the flexible elastomer cage as a thin-walled structure that can deform elastically during installation and service. The flexible shell design allows the cage to be compressed radially during insertion into the counterbored hole, then spring back to engage with the hole walls through friction and elastic recovery. This flexible shell approach replaces rigid metal construction with a compliant structure that achieves secure attachment through deformation rather than mechanical fastening, thereby simplifying the installation process while ensuring reliable fixation
3Adaptability or versatility
If numerous floating nuts are installed in large assemblies such as aircraft ventral fairings, then assembly tolerance accommodation is achieved, but assembly time increases significantly
Solution Approach 1:
The patent changes the material parameter from metal to elastomer, which enables the cage to be installed in a single push operation rather than requiring multi-step fastening procedures. This parameter change transforms the installation from a complex mechanical fastening process to a simple elastic deformation and friction-fit operation, dramatically reducing the time required per floating nut installation across large assemblies with thousands of nuts
Solution Approach 2:
The self-installing elastomer cage eliminates the need for operators to perform repeated cold expansion or riveting operations on each floating nut. By designing the cage to automatically secure itself through elastic deformation upon insertion, the system converts a multi-step manual fastening process into a single push operation, thereby significantly improving productivity when installing large numbers of floating nuts in assemblies such as aircraft ventral fairings
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, minimizes mass, accommodates misalignment, and prevents galvanic corrosion, while maintaining secure assembly and vibration isolation.
Implementation Method 1
the first cylinder being configured to deform as the screw is screwed in so that the first axis of revolution and the third axis of revolution become substantially coincident
Implementation Method 2
the second collar being elastically deformable so that, on the one hand, it bends against the first cylinder in order to pass through the second opening
Implementation Method 3
the washer being embedded in the first collar, the washer being intended to press the first collar against the second part when the screw is screwed into the screw thread
Data Source
AI summary
A floating-nut system for assembling a part and a part, the part including an opening having an axis of revolution, the floating-nut system including at least one elastomer cage device and a nut device, the cage device including a cylinder to be introduced into an opening made in the part and a collar around the cylinder. The nut device includes a cylinder having an axis of revolution and a washer to press the collar against the part when the screw is screwed into the cylinder. The cylinder is deformable as the screw is screwed in so that the axis of revolution and the axis of revolution become substantially coincident. The elastomer cage device makes it possible to reduce the mass of the floating-nut system.