Captured Nut Strip Assembly for Anti-Rotation Fastening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fastening technologies using nut plates struggle with securing components together, particularly in situations where nuts cannot be readily held by a technician during mating with bolts, necessitating room for improvement.
Innovation Solution
A nut strip assembly featuring a monolithic carrier with first and second tabs that clamp nuts between segments and panels, utilizing an arcuate arrangement and fasteners to secure components, such as gas turbine engine cases, through a base with slots and a rail.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional nut plates are used to secure components, then the nuts can be held during mating with bolts, but the device complexity increases and manufacturing precision deteriorates
Solution Approach 1:
The fastening device is segmented into a base with multiple slots and a rail with multiple attachments, where each attachment independently secures a nut. This segmentation allows the device to handle multiple nuts simultaneously without increasing overall complexity, as each segment operates independently.
Solution Approach 2:
The rail acts as an intermediary component that connects multiple attachments to the base, providing a standardized interface that simplifies the overall structure. The attachments clamp nuts between themselves and the base, creating a reliable connection without requiring complex integration.
2Ease of operation
If multiple nuts are secured using traditional methods, then each nut can be held individually, but the loss of time increases due to repetitive manual handling
Solution Approach 1:
The attachments are pre-configured on the rail in positions that correspond to the nut locations on the component. This preliminary arrangement allows nuts to be secured in sequence without requiring the technician to reposition or reconfigure the fastening device between each nut, significantly reducing the time required to secure multiple nuts.
Solution Approach 2:
The attachments are designed to automatically clamp and hold nuts as they are placed in the slots, without requiring additional manual manipulation or adjustment. The spring-loaded or friction-based clamping mechanism provides self-retention, allowing the technician to simply place each nut and move to the next position.
3Reliability
If a monolithic carrier with tabs is used to clamp nuts, then nut rotation is prevented and alignment is ensured, but the manufacturing precision requirements increase
Solution Approach 1:
The tabs are designed with localized contact surfaces that engage specific features on the nuts, such as flat surfaces or notches. This localized engagement provides reliable anti-rotation capability without requiring high precision across the entire tab-nut interface, as only specific contact points need to be accurately positioned.
Solution Approach 2:
The tabs are configured with asymmetric geometries that match the asymmetric features on the nuts, such as flat sides or keyways. This asymmetric design provides inherent anti-rotation functionality, as the tab can only engage the nut in one specific orientation, eliminating the need for high-precision alignment in multiple directions.
4Manufacturing precision
If arcuate arrangement of nuts is implemented, then proper alignment with component flanges is achieved, but the device complexity increases
Solution Approach 1:
The rail and attachments are configured in an arcuate shape that matches the curvature of the component flanges. This curved geometry allows the attachments to align naturally with the arcuate pattern of holes in the flanges, achieving proper alignment without requiring complex adjustment mechanisms or non-standard component interfaces.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A nut strip assembly is provided that includes a carrier and a plurality of nuts. The carrier includes a base, a plurality of first tabs and a plurality of second tabs. The base is configured with a plurality of apertures. Each of the first tabs is connected to and project out from a first side of the base. Each of the second tabs is connected to and projects out from a second side of the base. The nuts are secured to the carrier. Each of the nuts are aligned with a respective one of the apertures. Each of the nuts is captured between the base and a respective one of the first tabs. Each of the nuts captured between the base and a respective one of the second tabs.