Sealed Cable Bulkhead Insert with Harpoon Retention
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Solution Overview
Problem
Existing leaktight crossing devices for cable sheaths through motor vehicle bulkheads face issues with sealing and retention, particularly due to damage from front impacts and the need for easy after-sales replacement, which complicates the sealing process and can lead to deterioration of elastomer components.
Innovation Solution
A leaktight crossing device featuring a rigid elongated insert with a harpoon and snap-fastening teeth for axial retention, combined with frustoconical profiles and annular gadroons for secure sealing, and a gripping coil for tool-assisted removal, ensuring smooth insertion and retention without damaging the elastomer components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the COIC cable sheath is passed through the main elastomer body of the crossing piece, then the number of crossing parts is reduced, but the cable sheath cannot be easily replaced after-sales and may cause deterioration of the elastomer body
Solution Approach 1:
The crossing device is divided into two independent parts: the main elastomer body for sealing and the separate rigid insert for cable retention. This segmentation allows the cable sheath to be replaced by removing only the rigid insert without damaging the elastomer body, resolving the contradiction between reducing part count and enabling easy repair.
Solution Approach 2:
A rigid insert acts as an intermediary element between the COIC cable sheath and the elastomer body. This insert provides the retention function while being easily removable, allowing cable replacement without deteriorating the elastomer sealing component.
2Reliability
If retaining means with annular recess and rib are used to guarantee axial retention of the insert, then the insert is retained in the sealed mounted configuration, but the retaining means prove ineffective and can lead to degradation of the elastomer bushing part
Solution Approach 1:
The retention mechanism is changed from a passive rib-recess interface to an active harpoon engagement system. The harpoon features a hooked end that mechanically engages the rib, providing reliable axial retention through a different geometric parameter configuration that prevents elastomer degradation.
Solution Approach 2:
The harpoon is designed with a curved hooked end that engages the annular rib, using curved geometry to provide effective retention. This curved engagement distributes forces more favorably compared to the previous flat rib-recess interface, preventing elastomer degradation while maintaining retention reliability.
3Ease of operation
If force is applied during the introduction of the insert through the bore, then the insert is installed in the sealed mounted configuration, but excessive forcing can lead to deterioration of the elastomer body
Solution Approach 1:
The frustoconical shoulder on the insert is designed to engage the frustoconical countersink in the bulkhead before full insertion is completed. This preliminary engagement cushions the insertion process, distributing forces and preventing excessive forcing that could deteriorate the elastomer body while still enabling easy installation.
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 secure, leak-tight seal and easy after-sales replacement of the COIC cable sheath, preventing damage to the elastomer components and ensuring reliable anti-withdrawal retention while minimizing assembly effort and maintaining seal integrity.
Implementation Method 1
a harpoon arranged at the downstream end of said insert and comprising a head provided with a plurality of teeth capable of cooperating by snap-fastening, when said insert is introduced through said bore, with a annular rib projecting radially inside this bore
Implementation Method 2
said bore and the at least said interface portion of the insert have frustoconical profiles
Implementation Method 3
said main elastomer body comprises several annular flutes projecting radially inside said bore and capable of cooperating in leaktight manner, in said mounted configuration of the insert, with the external face of at least one interface portion of this insert
Data Source
Figure 1~2
Figure 3~4
AI summary
The invention relates to a device for the sealed leadthrough of a cable sheath through an opening of a motor vehicle bulkhead, comprising a leadthrough part (10) intended to be mounted in a sealed manner on said opening and comprising a main body (11) of elastomer material comprising a through-bore (18), and also a rigid elongate insert (30) overmoulded on said sheath (2) and configured to be able to be introduced with force through said bore (18) until a sealed mounted configuration has been achieved, said insert (30) additionally comprising a retaining harpoon (34) arranged at its downstream end and comprising a head provided with a plurality of teeth which, during the introduction of said insert (30) through said bore (18), are designed to engage by latching with an annular rib (21) projecting radially within this bore (18).