Bayonet Fastener Assembly for Secure Reusable Locking
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Solution Overview
Problem
Existing bayonet fastener assemblies are not readily disassembled, prone to accidental rotation leading to unlocking, and have complex designs that increase manufacturing costs and susceptibility to corrosion, making them economically burdensome and not fully reusable.
Innovation Solution
A bayonet fastener assembly with a pin and expansion anchor design that includes a locking tab and expansion sleeve, allowing for intuitive assembly without special tools, using materials like polymeric materials to reduce corrosion and manufacturing complexity, and ensuring secure locking through snap-fit mechanisms and varying sleeve diameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metallic materials are used for bayonet fastener assemblies, then strength and durability are improved, but susceptibility to corrosion and manufacturing cost increase
Solution Approach 1:
The patent employs composite material construction where the fastener assembly integrates metallic components (pin, locking mechanism) with non-metallic components (expansion anchor, expansion sleeve). This hybrid approach leverages the strength of metals while using corrosion-resistant non-metallic materials for portions exposed to corrosive environments, thereby reducing overall corrosion susceptibility without sacrificing structural integrity
Solution Approach 2:
The expansion anchor and expansion sleeve are designed as consumable components that remain in the substrate after installation, while the metallic pin and locking mechanism can be removed and reused. This partial disposable approach reduces corrosion concerns for the permanent installed components while preserving reusability of the critical locking components
2Reliability
If complex design is used in bayonet fastener assemblies, then locking reliability is improved, but manufacturing cost and device complexity increase
Solution Approach 1:
The fastener assembly is divided into distinct functional segments: the pin with locking tab for engagement, the expansion anchor with slot for positioning, and the expansion sleeve with longitudinal portions for expansion. Each segment performs a specific function, simplifying the design of individual components while achieving reliable locking through their coordinated interaction
Solution Approach 2:
The expansion sleeve automatically expands when the pin is rotated, causing the longitudinal portions to press against the slot walls. This self-expanding mechanism eliminates the need for additional expansion tools or complex actuation systems, achieving reliable anchoring through the simple rotational motion of the pin
3Reliability
If bayonet fastener assemblies are designed for secure locking, then resistance to accidental unlocking is improved, but ease of disassembly deteriorates
Solution Approach 1:
The locking tab on the pin and the slot on the expansion anchor are designed with asymmetric geometries that permit rotation in only one direction. The tab can engage the slot during installation rotation, but the asymmetric shape prevents reverse rotation, providing resistance to accidental unlocking while maintaining controlled disassembly through deliberate rotational action
Solution Approach 2:
The fastener transitions between dynamic states: during installation, the pin rotates to expand the sleeve and engage the locking tab with the slot; during removal, deliberate rotation in the opposite direction disengages the tab from the slot and allows sleeve contraction. This dynamic state transition enables secure locking during use while permitting intentional disassembly
4Manufacturing precision
If special tools are used for assembly, then manufacturing precision is improved, but ease of manufacture and productivity deteriorate
Solution Approach 1:
The patent replaces complex mechanical assembly tools with a simplified system where the pin itself serves as the installation tool. The pin's geometry, including the locking tab and head, enables direct manual insertion and rotation to achieve precise engagement with the expansion anchor slot, eliminating the need for specialized assembly tools while maintaining assembly precision
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
Facilitates easy, cost-effective assembly and disassembly, reduces accidental unlocking, and provides a secure fit resistant to motion, while simplifying manufacturing and eliminating the need for corrosion-resistant coatings.
Implementation Method 1
the expansion sleeve includes first and second longitudinal portions that are spaced apart from each other... causes the expansion element to engage at least one of the first and second longitudinal portions to thereby outwardly expand the expansion sleeve
Data Source
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AI summary
The present disclosure provides a bayonet fastener assembly including a pin and an expansion anchor. The pin includes a head and a rod extending longitudinally therefrom. The rod includes a locking tab proximal the head. The expansion anchor includes a locking portion and an expansion sleeve extending longitudinally therefrom. The locking portion defines a slot for the locking tab and the expansion sleeve includes a first and a second longitudinal portion spaced apart from each other. Rotation of the pin within the expansion anchor causes the locking tab to engage the slot, thereby preventing retraction of the pin from the expansion anchor.