Electrical Connector Terminal Locking With Rigid and Flexible Nibs
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Solution Overview
Problem
Existing electrical connector assemblies for automotive wiring harnesses face issues with terminal lock nibs being sheared off in unreinforced thermoplastics and stiffness of flexible cantilever beams in glass fiber reinforced thermoplastics, which fail to meet retention and insertion force requirements.
Innovation Solution
The electrical connector assembly incorporates a fixed terminal lock nib and a moveable terminal lock nib within a flexible terminal lock arm, along with a compliant seal and a terminal retainer that blocks the opening to prevent removal, ensuring secure terminal retention and insertion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If unreinforced thermoplastics are used for connector bodies, then ease of manufacture is improved, but the lock nibs are sheared off by terminal forces
Solution Approach 1:
The connector body is manufactured from glass fiber reinforced thermoplastic material, combining the ease of thermoplastic manufacturing with the high shear strength of glass fiber reinforcement. This composite material resolves the contradiction by providing both manufacturability and structural integrity for the lock nibs.
2Strength
If glass fiber reinforced thermoplastics are used for connector bodies, then shear strength is improved, but the flexible cantilever beams become too stiff for acceptable insertion force
Solution Approach 1:
The connector body uses glass fiber reinforced thermoplastic only in specific high-stress areas (lock nibs and structural walls) while using unreinforced thermoplastic for the flexible cantilever beams. This localized material differentiation allows the reinforced sections to provide shear strength while the unreinforced sections maintain flexibility and low insertion force.
Solution Approach 2:
The connector body is divided into distinct functional zones with different material properties: reinforced zones for structural support and lock nibs, and unreinforced zones for flexible beams. This segmentation allows each zone to be optimized for its specific function without compromising the other.
3Device complexity
If a single fixed terminal lock nib is used, then device complexity is reduced, but terminal retention reliability is insufficient
Solution Approach 1:
The terminal retention system is segmented into multiple independent lock nibs (fixed and moveable) that engage with different features of the terminal. This segmentation provides redundant retention paths, increasing reliability while maintaining relatively simple overall device structure.
Solution Approach 2:
The terminal retainer incorporates a moveable terminal lock nib that can dynamically adjust during terminal insertion and retention. This dynamic element provides adaptive retention force and ensures reliable engagement even with manufacturing tolerances, enhancing reliability without significantly increasing complexity.
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 enhances the shear strength and insertion force, meeting automotive standards while preventing terminal removal and maintaining a secure connection.
Implementation Method 1
a flexible terminal lock arm having a moveable terminal lock nib that projects inwardly into the terminal cavity from the flexible terminal lock arm
Implementation Method 2
a flexible retaining arm... removably retained to the connector housing by a flexible retaining arm
Data Source
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AI summary
An electrical connector assembly (100, 200) includes an electrical terminal (102, 202) defining a pair of retaining ridges (114A, 114B, 214A, 214B), a connector housing (106, 206) having a terminal cavity (116, 216) extending therethrough from a first opening (118, 218) to a second opening (120, 220) and a fixed terminal lock nib (122, 222) that projects inwardly into the terminal cavity (116, 216) from a rigid first wall (124, 224) to engage a first ridge (114A, 214A) of the pair of retaining ridges (114A, 114B, 214A, 214B) of the electrical terminal (102, 202), and a terminal retainer (108, 208) inserted within the connector housing (106, 206) proximate the first opening (118, 218) and removably retained to the connector housing (106, 206) by a flexible retaining arm (126, 226). The terminal retainer (108, 208) further includes a flexible terminal lock arm (128, 228) having a moveable terminal lock nib (130, 230) that projects inwardly into the terminal cavity (116, 216) from the flexible terminal lock arm (128, 228) to engage a second ridge (114B, 214B) of the pair of retaining ridges (114A, 114B, 214A, 214B) of the electrical terminal (102, 202), thereby inhibiting removal of the electrical terminal (102, 202) from the terminal cavity (116, 216) through the second opening (120, 220).