Deformable Sleeve Nut with Selective Strain Hardening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing blind fasteners face challenges in restricted access environments, where failure on the blind side can make it difficult and time-consuming to remove and replace failed fasteners, and the two-piece construction of nut and sleeve structures can lead to slippage and incomplete installations.
Innovation Solution
A deformable sleeve nut is manufactured by selectively strain hardening a single material blank to combine the functions of the nut and sleeve into a unitary structure, with a machined transition and separate material properties for the nut and sleeve portions, allowing for improved clamping and reduced failure modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a two-piece nut and sleeve structure is used in blind fasteners, then the fastener can be installed from one side, but slippage between components can occur leading to incomplete installations
Solution Approach 1:
The patent combines the nut and sleeve into a single integrated deformable sleeve nut component. The unitary structure eliminates the interface between separate nut and sleeve parts, preventing slippage while maintaining the ability to install from one side. The integrated design features a compressed portion that deforms under installation forces to create a non-rotating interface, ensuring reliable fastening without component separation.
2Ease of operation
If blind fasteners are used in restricted access environments, then installation is simplified, but removal and replacement of failed fasteners becomes difficult and time-consuming
Solution Approach 1:
The deformable sleeve nut incorporates a compressed portion that can dynamically change shape during installation and removal. The deformation characteristics allow the fastener to be inserted and locked in place from one side, while the same deformability enables tools to access and manipulate the fastener for removal even in restricted environments. The dynamic deformation property facilitates both installation simplicity and repair accessibility.
3Reliability
If a unitary deformable sleeve nut structure is used, then slippage is prevented, but manufacturing complexity increases due to selective strain hardening requirements
Solution Approach 1:
The deformable sleeve nut employs selective strain hardening where different regions of the single component have different material properties. The compressed portion is strain-hardened to provide high strength and resistance to slippage, while other portions remain more ductile to facilitate deformation during installation. This local differentiation of material properties within the unitary structure achieves reliable slippage prevention without requiring entirely different materials or complex assembly processes.
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 solution reduces the occurrence of failed installations and facilitates easier removal and replacement of fasteners by ensuring a secure, non-rotating interface and optimized material properties within a single, integrated component.
Implementation Method 1
selectively strain hardening a single material blank to combine the functions of the nut and sleeve into a unitary structure
Data Source
AI summary
Disclosed is a method of manufacturing a deformable sleeve nut that includes selectively strain hardening only a first portion of a material blank while not strain hardening a second portion of the material blank, then, after strain hardening the first portion of the material blank, internally threading the first portion of the material blank to define a nut portion and machining the second portion of the material blank to define a deformable sleeve portion that includes an end portion and a bulbing portion positioned between the end portion and the nut portion, where the bulbing portion is constructed to bulb outwardly and form a load bearing flange when the bulbing portion is compressed between the end portion and the nut portion. Also disclosed is a deformable sleeve nut made with this process.