Rotatable Inner Strain Relief for Kevlar Fiber Cables
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Solution Overview
Problem
Existing strain relief solutions for glass fiber cables with Kevlar fibers lack effective mechanical fastening methods, leading to instability and potential slippage of the cables.
Innovation Solution
A strain relief design comprising an outer and inner part, where the inner part is rotatable relative to the outer part, with a receptacle for Kevlar fibers and a winding area, featuring a slot that transitions into a cylindrical bore for secure holding, and additional latching and hold-down mechanisms to apply tension and prevent slippage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cable ties or separate clamping of Kevlar fibers are used for mechanical fastening, then the cable can be secured, but the fastening is mechanically unstable and prone to slippage
Solution Approach 1:
The strain relief device is divided into two functional segments: an outer part with a slot for cable insertion and an inner part with a cylindrical bore for Kevlar fiber winding. This segmentation allows each part to perform its specific function optimally while working together to achieve secure mechanical fastening without slippage.
Solution Approach 2:
The inner part is designed to be rotatable relative to the outer part, enabling dynamic winding of Kevlar fibers around the cylindrical bore. This rotational mechanism transforms linear fiber tension into a secure wrapped configuration, creating reliable mechanical fastening that prevents cable slippage while maintaining operational flexibility.
2Reliability
If Kevlar fibers are simply inserted without winding mechanism, then the device structure is simple, but the fibers cannot be properly tensioned and strain relief is ineffective
Solution Approach 1:
The rotatable inner part creates a dynamic winding mechanism that allows Kevlar fibers to be wrapped around the cylindrical bore. This rotation enables proper fiber tensioning and creates friction-based mechanical interlocking, ensuring effective strain relief while keeping the winding mechanism simple and integrated into the device structure.
Solution Approach 2:
The inner part with the cylindrical bore is nested within the outer part, creating a compact integrated structure. The Kevlar fibers are inserted through the outer part's slot and wound around the inner part's bore, with both parts working together in a nested configuration to achieve reliable strain relief without requiring separate complex winding mechanisms.
3Manufacturing precision
If the slot and bore are designed without hold-down devices, then the device is simpler to manufacture, but the Kevlar fibers can move on protruding parts and fail to achieve proper tensioning
Solution Approach 1:
Hold-down devices are strategically positioned at specific locations within the slot and bore areas where fiber movement would occur. These localized features provide precise fiber positioning and prevent slippage on protruding parts, ensuring proper tensioning without requiring complex manufacturing processes throughout the entire device structure.
Data Source
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AI summary
The invention relates to a strain relief device (50) for cables, in particular for fibre-optic cables with Kevlar fibres, wherein the strain relief device (50) is embodied in at least two parts and has an outer part (30) and an inner part (10), wherein the inner part (10) has a receptacle for inserting at least one part of the cable, in particular the Kevlar fibres, and a winding region (10), wherein the inner part (10) is embodied such that it is rotatable with respect to the outer part (30), wherein the strain relief device (50) has a stop (43, 44; 45, 46) for the cable.