Rubber Protective Sleeve with Offset Plastic Locking Means
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Solution Overview
Problem
Existing protective sleeves with rubber sleeve bodies and hard-elastic plastic locking means face challenges in core removal, especially when the heads are inclined relative to the central portion, leading to difficulties in demolding and increased production costs.
Innovation Solution
A protective sleeve design with a rubber sleeve body and hard-elastic plastic locking means, where the locking means are configured with a larger opening cross-section than the sleeve body, allowing for easy core removal through a translational movement, and the use of a two-component injection molding method for integral formation, enabling elastic engagement hooks and a radially offset inner peripheral surface for improved retention and demolding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the locking means are formed first and then overmolded with rubber, then the retention and sealing are improved, but the core removal becomes difficult when heads are inclined
Solution Approach 1:
The invention divides the protective sleeve into two distinct material components: a rubber sleeve body and hard-elastic plastic locking means. This segmentation allows each component to be optimized independently - the rubber provides flexibility and sealing, while the hard-elastic plastic provides rigid retention features. The locking means are formed separately first, then overmolded with rubber, enabling the core to be removed through the locking means structure without compromising the sealed connection between components.
Solution Approach 2:
The locking means are formed in advance as separate components before the rubber overmolding process. This preliminary formation allows the core to be easily removed through the locking means structure during demolding. The pre-formed locking means with their rigid structure provide defined pathways for core extraction, solving the core removal difficulty that would otherwise exist with inclined heads in a monolithic rubber construction.
2Reliability
If the sleeve body is made of rubber with hard-elastic plastic locking means, then the compression set and tightness are improved, but the tooling cost and manufacturing complexity increase
Solution Approach 1:
The invention employs composite construction by combining rubber material for the sleeve body with hard-elastic plastic material for the locking means. The rubber provides high compression set resistance and tightness, particularly important for water tightness in vehicle applications. The hard-elastic plastic provides rigid structural support for the locking features. This composite approach, implemented through two-component injection molding, achieves superior performance while integrating both materials into a single molded part.
Solution Approach 2:
The invention merges two different material systems (rubber and hard-elastic plastic) into a single integrated protective sleeve component through overmolding technology. The locking means are formed first, then the rubber sleeve body is molded over them in a continuous process. This merging creates a unified part that combines the advantages of both materials - the elasticity and sealing of rubber with the rigidity and retention capability of hard-elastic plastic - while eliminating the need for separate assembly steps.
3Reliability
If the locking means have a smaller opening cross-section than the sleeve body, then the retention in assembly openings is improved, but the core removal becomes impossible
Solution Approach 1:
The invention resolves the dimensional conflict by using the longitudinal dimension of the protective sleeve to solve the cross-sectional constraint problem. The locking means are configured with a smaller opening cross-section than the maximum cross-section of the sleeve body, which provides excellent retention in assembly openings. However, the locking means extend along the longitudinal axis with sufficient length to accommodate core removal through their structure. This dimensional approach allows the core to be extracted through the locking means in the longitudinal direction despite the reduced cross-sectional opening.
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 allows for efficient demolding of the core and enhanced retention of the protective sleeve in assembly openings, reducing production costs and improving the ease of installation, particularly in inclined configurations, while maintaining high sealing integrity.
Implementation Method 1
the rubber may be expanded for demolding
Implementation Method 2
the engagement hook is configured so as to be elastic in a radial direction
Data Source
AI summary
Bush to be arranged between two fitting elements for passing through cables, lines or the like in protected fashion, comprising an elongate, hose-shaped bush body (10) with a substantially linearly running central section (11) and heads (12, 13) at the ends, wherein the heads (12, 13) form a first inner circumferential face (20) at their open ends and a latching device (14, 15) for knocking the bush into installation openings in the fitting elements (M) is formed on each of the heads (12, 13) and integrally therewith, which latching device has a circumferential web (16) with at least one latching hook (17), which is formed thereon and has at least one radially outer latching tab (18), wherein the web forms a second inner circumferential face (19) opposite the latching tab (18), characterized in that the bush body (11) is formed from rubber and the latching devices (14, 15); are formed from hard-elastic plastic, and in that at least one of the second inner circumferential faces (19) is configured in such a way that it runs radially out of alignment with the corresponding first inner circumferential face (20).