Composite Tube Assembly Locking Mechanism for Reusable End Fittings
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Solution Overview
Problem
Conventional composite tube assemblies with metallic end fittings hinder the reuse of these fittings when replacing composite tubes, due to bonding issues.
Innovation Solution
A composite tube assembly design featuring a locking collar nut, locking key, and jam nut configuration that secures the end fitting without bonding, allowing for easier disassembly and reuse, utilizing lightweight polymer-matrix composite materials and metallic inserts for enhanced strength and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metallic end fittings are bonded to composite tubes, then structural strength is improved, but reusability of end fittings deteriorates
Solution Approach 1:
The end fitting is divided into two separate components: a reusable metallic body and a non-reusable composite tube interface. The metallic body can be detached and reused, while only the composite tube portion is replaced, resolving the contradiction between maintaining structural strength and enabling reusability.
Solution Approach 2:
The composite tube interface is designed to be discarded with the composite tube, while the metallic end fitting body is recovered and reused. This selective discarding approach maintains structural integrity while enabling component reuse and reducing waste.
2Strength
If metallic end fittings are bonded to composite tubes, then structural integrity is improved, but manufacturing complexity increases
Solution Approach 1:
The assembly is segmented into modular components (metallic body, composite tube interface, locking mechanism) that can be manufactured separately and assembled through simple mechanical operations, reducing manufacturing complexity while maintaining structural integrity.
Solution Approach 2:
The bonding process is replaced with a mechanical locking system comprising a locking collar, locking key, and jam nut. This mechanical substitution eliminates complex bonding processes while achieving equivalent or superior structural integrity with simpler manufacturing.
3Ease of operation
If locking collar nut and locking key mechanism are added, then ease of disassembly is improved, but device complexity increases
Solution Approach 1:
The locking mechanism components are nested within each other: the locking key is received by the locking collar nut, which in turn engages with the metallic body. This nested arrangement provides easy disassembly through a compact, integrated mechanism that does not significantly increase overall device complexity.
Solution Approach 2:
The locking and unlocking mechanisms are designed to be self-contained and self-explanatory, requiring minimal external tools or complex procedures. The jam nut provides additional self-locking capability, enabling easy operation while maintaining a relatively simple device structure.
Data Source
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AI summary
Composite tube assemblies (100) comprising a composite tube (130) comprising a variable diameter portion comprising a first frustoconical portion (165) and a second frustoconical portion (160), wherein a diameter of the composite tube (130) at an interface between the first frustoconical portion (165) and the second frustoconical portion (160) is a maximum diameter value (16) with respect to the first frustoconical portion (165) and is a maximum diameter value (16) with respect to the second frustoconical portion (160), a locking wedge (120) disposed at least partially around a circumference of the first frustoconical portion (165), a locking collar nut (150) disposed at least partially around a circumference of the locking wedge (120); and an end fitting (110) disposed at least partially around a circumference of the second frustoconical portion (160), wherein the end fitting (110) is coupled to the locking collar nut (150) are disclosed. Methods of manufacture are also disclosed.