Breathable Cable Bushing With Nested Diaphragm Valve
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Solution Overview
Problem
Cable bushings with membrane valves often require larger fastening holes due to air duct dimensions, disrupting the practical cable diameter to mounting hole relationship, which can complicate installation in existing housings.
Innovation Solution
A multi-piece breathable cable/hose bushing design featuring an upper, middle, and lower part, including a semi-permeable filter/diaphragm valve and adjustable ventilation duct, maintains the standard cable diameter to mounting hole ratio by optimizing the air duct guidance and using interchangeable semi-permeable filters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a membrane valve is integrated into the cable bushing, then moisture protection is improved, but the mounting hole size increases
Solution Approach 1:
The membrane valve is nested within the cable bushing structure itself, with the membrane (21) integrated into the middle part (2) of the bushing. The air duct (24, 25) is guided through the bushing components, allowing the moisture protection function to be embedded within the existing bushing geometry without requiring a separate mounting hole for the valve.
Solution Approach 2:
The air duct is oriented longitudinally through the bushing structure rather than requiring a transverse mounting hole. The duct runs from the front side through the middle part to the rear side, utilizing the longitudinal dimension of the bushing to accommodate the ventilation path without increasing the radial mounting hole diameter.
2Reliability
If the air duct dimensions are increased for better ventilation, then moisture protection is improved, but the mounting hole size increases
Solution Approach 1:
The membrane valve provides localized moisture protection at the critical sealing point where the cable enters the housing, rather than requiring large-scale ventilation openings. The membrane's microporous structure allows vapor transmission while blocking liquid water, providing effective moisture protection with minimal impact on mounting hole dimensions.
3Adaptability or versatility
If a multi-piece design is used with integrated membrane valve, then adaptability to existing installations is improved, but device complexity increases
Solution Approach 1:
The cable bushing is divided into three separate parts: front part (1), middle part (2) containing the membrane valve, and rear part (3). This segmentation allows each component to be manufactured independently and assembled in sequence, facilitating adaptation to existing installations while maintaining a relatively simple overall structure.
Solution Approach 2:
The middle part (2) of the bushing serves multiple functions: it houses the membrane valve (21) for moisture protection, contains the air duct (24, 25) for ventilation, and provides structural connection between the front and rear parts. This multi-functionality reduces the need for additional separate components, offsetting the complexity introduced by the multi-piece design.
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 design prevents moisture condensation and allows for seamless integration with existing installations, ensuring minimal spatial and weight requirements without additional precautions, while maintaining effective sealing and strain relief.
Implementation Method 1
a semi-permeable filter/diaphragm valve 21
Implementation Method 2
The filter/diaphragm valve 21 is a so-called breathable membrane
Data Source
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AI summary
The invention proposes a breathable cable/hose bushing for the mechanically and, on one side, hydroscopically tight bushing of a shielded or unshielded electrical cable with or without strain relief, with or without anti-kink means for this cable in accordance with the main patent 'Cable bushing with diaphragm valve', patent application No. DE 10 2005 035 210 C2 from 28 July 2005. Cable/hose bushings in closed housings, with and without strain relief, which are even protected from water and explosion and with or without electromagnetic shielding, with or without anti-kink means and classified in accordance with the type of protection are known from the prior art. Such cable/hose bushings are required for a very wide variety of applications and correspondingly have a variety of designs. They are produced from plastic and/or metal depending on the intended use, contain additional discs and/or seals/sealing rings/bushes and different strain relief means depending on requirements, such as pinching or clamping. Cable bushings and/or their individual parts are subject to standard. Cable bushings of the old type with the designation armoured conduit thread (Pg) screw connection with a nonmetric screw thread, Pg7 … Pg48, corresponding to the new type with a metric screw thread M12 … M63, are dealt with in installation engineering. An advantage over the cable bushing in the main patent is that with the proposed breathable cable/hose bushing of the new type, the cross-sectional area of the air channel is taken into consideration in so far as, for a given cable diameter and therefore for a specific dimension of the fixing bore of the cable bushing, a relatively large connecting piece dimension, which is dependent on the required volume/dimension of the ventilation channel, cannot be used.