Light Guide Assembly Offset Structure for Thermal Stress Relief
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Solution Overview
Problem
Existing assembly methods for light guides with fused fiber bundles and glass tubes are prone to stress-induced cracks due to thermal changes, particularly in medical applications, and existing cushioning methods fail to ensure a compact body, leading to germ contamination risks.
Innovation Solution
The assembly device features an offset between the common end face of the fiber bundle and glass tube relative to the adhesive, creating a spaced-apart arrangement to minimize mechanical stress and incorporate a groove for germ reduction, using a highly crosslinking adhesive and optional potting compound for stability and protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the fiber bundle with glass tube is fixed in the sleeve using adhesive, then the light guide is securely assembled, but thermal stress during sterilization causes cracks in the fused fiber-optic end
Solution Approach 1:
A cushioning layer made of PTFE tape or thread sealing tape is wrapped around the fused fiber-optic end before assembly. This cushioning layer compensates for thermal expansion and contraction differences between the glass tube and metal sleeve during sterilization cycles, preventing stress-induced cracks while maintaining secure assembly through the adhesive in the sleeve
2Strength
If a cushioning layer is added to protect the fused fiber-optic end, then thermal stress resistance is improved, but the compact body is compromised and germ contamination risk increases
Solution Approach 1:
The cushioning layer is applied locally only to the fused fiber-optic end region where thermal stress concentration occurs, rather than throughout the entire assembly. This localized application provides stress compensation exactly where needed while minimizing the creation of gaps and crevices that could harbor germs, thus reducing contamination risk compared to more extensive cushioning approaches
3Stability of the object's composition
If permanently elastic adhesives are used to avoid cracks during temperature changes, then flexibility is improved, but long-term stability deteriorates due to adhesive decomposition
Solution Approach 1:
The PTFE cushioning layer acts as an intermediary element between the fused fiber-optic end and the metal sleeve, absorbing thermal expansion differences mechanically rather than relying on the adhesive to provide flexibility. This allows the use of stable, non-elastic adhesives that maintain long-term chemical stability and structural integrity through multiple sterilization cycles without decomposition
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
The solution provides a robust, long-term stable light guide resistant to thermal stress and germ contamination, enabling multiple sterilization cycles without damage, suitable for medical and industrial applications.
Implementation Method 1
The at least one fiber bundle with the glass tube is cohesively fixed or fixable in the region of the taper at least in part or in sections in or on the sleeve in or on the fixing section of the sleeve by an adhesive
Implementation Method 2
the fiber bundle is circumferentially fused at least in part or in sections at its circumferential surface with a glass tube
Data Source
AI summary
An assembly device includes a sleeve having an end face and a fiber bundle circumferentially fused at its circumferential surface with a glass tube. The fiber bundle with the glass tube having a common end face. The fiber bundle with the glass tube forming a tapered region towards the common end face. The common end face has a fused, rigid section. The common end face is designed or designable as a ground and/or polished surface. The fiber bundle is cohesively fixed or fixable in the tapered region in or on a fixing section of the sleeve by an adhesive. The common end face has an offset relative to the fixing section such that the common end face is arranged or arrangeable to be spaced apart with an offset from the fixing section with the adhesive. The fixing section and the common end face are separated or separable from each other.