Scrivet Coupling Assembly With Compliant Flange Retention
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Solution Overview
Problem
Conventional scrivet fasteners fail to provide effective retention of a cover panel to a production floor panel, leading to unintentional separation and potential debris formation, which causes damage and increased costs due to the limited surface area contact and deformation of conical features.
Innovation Solution
A scrivet fastener design featuring a compliant retention flange that secures to a deformable material of the panel and a shaft that friction-fits into the mating structure, providing enhanced retention and preventing separation, with a method for temporary coupling and easy removal without damaging the fastener or objects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional scrivet fastener with fluted shaft is used, then the fastener can be inserted through the cover panel and floor panel, but the retention force is insufficient causing the fastener to separate unintentionally
Solution Approach 1:
The shaft is divided into multiple conical features (first conical feature, second conical feature, third conical feature) along its length. Each conical feature engages with the deformable material at different positions, creating multiple retention points that collectively provide superior retention force compared to a single fluted design.
Solution Approach 2:
Different sections of the shaft have different geometric properties - the first conical feature has a greater included angle than the second and third conical features. This local variation in geometry allows each section to optimize its engagement with the deformable material, with broader engagement at the top and progressively tighter engagement deeper in the hole.
2Reliability
If the conical features are designed to engage the insert, then the fastener can be secured to the floor panel, but the conical features collapse upon entering the narrow hole reducing retention
Solution Approach 1:
The conical features are designed to be deformable during insertion, allowing them to compress elastically as they enter the narrow hole. After insertion, these features spring back to their original shape, creating strong radial engagement forces with the insert walls. This dynamic deformation and recovery mechanism enables the features to navigate tight spaces while maintaining retention capability.
3Ease of operation
If the fastener separates from the floor panel, then the cover panel can be removed, but the fastener falls out becoming debris causing damage and increased costs
Solution Approach 1:
The shaft is inserted through the cover panel and into the floor panel insert, with the conical features nesting within the insert cavity. This nested configuration ensures that when the fastener separates from the floor panel during cover removal, the shaft remains captured by the deformable material in the cover panel, preventing the fastener from falling out and becoming debris.
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 scrivet fastener effectively secures the panel to the mating structure with increased retention, preventing unintentional separation and reducing the risk of becoming foreign object debris, while allowing for easy removal and reuse.
Implementation Method 1
a distal section of the shaft friction-fit couples to the mating structure within the hole
Implementation Method 2
weight on the cover panel 108 applied by people walking on the cover panel 108 and/or equipment may cause the cover panel 108 to compress and then decompress when the weight is removed
Data Source
AI summary
A scrivet fastener for coupling a panel to a mating structure includes a head, a shaft extending from the head to a distal end of the shaft, and a compliant retention flange. The compliant retention flange extends radially outward from the shaft and is axially spaced apart from the head. The scrivet fastener is configured to at least temporarily couple the panel to the mating structure, such that the distal end of the shaft is secured to a hole of the mating structure and the compliant retention flange is secured to a deformable material of the panel.