Expandable Nut Plate Structure for Rivetless Panel Attachment
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Solution Overview
Problem
Current nut plates require rivets, adhesives, and additional machining steps like reaming, counterboring, and countersinking, which complicate assembly and alignment, especially in non-perfectly aligned assemblies.
Innovation Solution
A rivetless nut plate design featuring a nut, washer, and cage that expands within a panel bore, allowing the nut to split into two sections for constrained motion, eliminating the need for rivets and associated machining steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If rivets and adhesives are used to attach the nut plate, then the attachment strength is improved, but the device complexity and manufacturing steps increase
Solution Approach 1:
The patent removes rivets and adhesives from the attachment system, extracting these separate fastening components entirely. The nut plate itself becomes the fastening element through its expandable cage structure that grips the panel bore directly, eliminating the need for additional fastening mechanisms.
Solution Approach 2:
The patent combines the attachment function and the nut plate function into a single integrated component. The expandable cage structure merges the fastening mechanism with the nut plate body, so that one component performs both attachment to the panel and provides the threaded interface for fasteners.
2Manufacturing precision
If reaming, counterboring, and countersinking steps are performed, then the manufacturing precision is improved, but the productivity decreases
Solution Approach 1:
The patent removes the need for reaming, counterboring, and countersinking operations by designing a cage structure that expands within the existing panel bore. This extracts these complex machining steps from the manufacturing process entirely.
Solution Approach 2:
The cage structure changes its dimensional parameters through expansion, transitioning from a compact transport state to an expanded grip state. This parameter change allows the same component to fit through a standard bore and then expand to create a secure fit without requiring precision machining of the panel.
3Strength
If the nut plate is rigidly fixed to the panel, then the strength is improved, but the adaptability decreases for imperfect alignments
Solution Approach 1:
The patent introduces dynamic capability to the nut plate through the expandable cage structure. The cage can expand radially to grip the panel bore, creating a mechanically interlocked connection that adapts to slight misalignments while maintaining strong attachment. The nut section also has constrained motion capability to accommodate alignment variations.
4Reliability
If additional rivet holes are created, then the attachment reliability is improved, but the loss of substance increases
Solution Approach 1:
The patent removes the need for additional rivet holes by using the existing panel bore for the expandable cage. The cage expands within this single bore to create attachment, eliminating the need for separate rivet holes that would require additional material removal.
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
Enables secure attachment without rivets or adhesives, facilitating easier assembly and alignment by allowing the nut plate to adjust to imperfect panel alignments while maintaining structural integrity.
Implementation Method 1
a cage that retains the nut and the washer. The nut plate has a nonactivated state and an activated state. In the activated state a portion of the cage is expanded to grip the panel bore
Data Source
AI summary
A rivetless nut plate for attachment to a panel via a panel bore, having a nut, a washer, and a cage that retains the nut and the washer. The nut plate has a nonactivated state and an activated state. In the activated state a portion of the cage is expanded to grip the panel bore, and the nut has split into two independent sections allowing one section to move throughout a constrained range of motion.