Spring-Loaded Sealing Element for Fluid-Tight Optical Instrument Housing
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Solution Overview
Problem
Existing optical instruments, such as endoscopes, face challenges in maintaining a reliable fluid-tight seal during autoclaving due to thermal stresses and material expansion coefficients, leading to potential leaks and the need for additional components and assembly steps.
Innovation Solution
The use of spring-loaded sealing elements, such as O-rings, combined with spring elements that provide a defined contact pressure on the end windows, ensures fluid-tightness by compensating for thermal stresses and maintaining constant contact pressure over the life of the sealing elements, with at least one sealing element arranged in front of and behind each end window.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If end windows are connected to the instrument housing by gluing, welding or soldering to ensure fluid-tight sealing, then sealing reliability is improved, but thermal stresses during autoclaving cause cracking and stress fractures leading to leaks
Solution Approach 1:
The sealing system is segmented into multiple independent sealing elements positioned at different locations (front and rear of each end window). This segmentation allows each sealing element to independently handle thermal expansion and stress, preventing the propagation of cracks that would occur in a rigid bonded connection during autoclaving.
Solution Approach 2:
The invention changes the mechanical parameters of the sealing system by introducing spring-loaded sealing elements with elastic properties. These elements can dynamically adjust their compression force to compensate for thermal expansion and contraction during autoclaving, maintaining sealing pressure without creating the rigid stress concentrations that lead to cracking in bonded connections.
2Ease of manufacture
If a flexible flange integral to the cover is used as a spring element, then assembly is simplified, but individual adjustment of spring force without modifying the cover design becomes impossible
Solution Approach 1:
The spring element is separated from the cover structure into an independent, replaceable component. This segmentation allows the spring force to be individually adjusted or replaced without modifying the cover design, while still maintaining simple assembly through standardized mounting interfaces.
Solution Approach 2:
The invention introduces dynamically adjustable spring elements that can be replaced with different spring constants to achieve desired sealing forces. This dynamic adaptability allows optimization of sealing performance for different operating conditions without requiring design changes to the cover structure.
3Device complexity
If sealing elements are indirectly spring-loaded, then the structure is simplified, but consistent contact pressure throughout service life cannot be maintained
Solution Approach 1:
The spring elements are pre-loaded during assembly to establish the optimal contact pressure on the sealing elements. This preliminary action ensures that the sealing elements maintain consistent contact pressure with the end windows throughout service life, compensating for any relaxation or deformation that may occur during autoclaving and use.
Solution Approach 2:
The spring-loaded system provides continuous feedback force to the sealing elements, automatically compensating for variations in sealing requirements. The elastic nature of the springs allows them to respond to changes in thermal expansion and material deformation, maintaining optimal sealing pressure without requiring complex control systems.
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
This solution effectively prevents leaks during autoclaving by maintaining a consistent sealing force and compensating for material changes, ensuring reliable fluid-tightness without the need for additional components or assembly steps.
Implementation Method 1
wherein the at least one spring-loaded sealing element is spring-loaded in the direction towards each of the end windows by means of at least one spring element
Implementation Method 2
To ensure that no moisture penetrates the instrument housing under high thermal stress
Data Source
Figure 1
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AI summary
The optical instrument comprises a hollow instrument housing (2) for receiving optical elements, where the distal side and proximal side are sealed fluid-tight by an end window (5). The end window is sealed fluid-tight by a spring-loaded sealing element (9) relative to the instrument housing. The sealing elements are spring-loaded by a spring element (11) in the direction towards the corresponding end window. The spring element is fit tightly direct to the assigned sealing element.