Plug Contact Latching Mechanism for Reliable Mating Detection

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Solution Overview

Problem

In modern motor vehicles, plug contact sets face issues with half-mating connections due to mechanical loads, which are not visually recognizable and can only be detected by on-board diagnosis after electrical contact loss, leading to pseudo errors during assembly, causing delays and unnecessary reconnecting processes.

Innovation Solution

A plug contact set design featuring three latching points, where the third latching element ensures secure engagement of the plug connector with the contact strip, preventing detachment under mechanical loads and allowing for reliable detection of proper mating without pseudo errors, using latching elements on opposite side walls to minimize play and ensure complete contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a test contact with shorter length is used to detect proper mating, then detection capability is improved, but pseudo errors occur during assembly due to longitudinal play

Engineering Contradiction:
Improvedetection capabilityVSAvoidassembly accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The latching mechanism is divided into three independent latching points along the insertion direction. The first latching point engages locking elements at the beginning of mating, the second latching point engages at intermediate position, and the third latching point engages at the final position. This segmentation allows each latching point to perform its specific function without interfering with others, resolving the contradiction between detection capability and assembly accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first and second latching elements engage in preliminary latching points before the final mating position is reached. This preliminary action secures the connector at intermediate positions, preventing detachment due to longitudinal play before the test contact makes reliable electrical contact. The third latching element then provides final secure engagement, eliminating pseudo errors while maintaining detection capability.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If locking elements are used to prevent detachment under mechanical loads, then connection reliability is improved, but half-mating connections cannot be detected

Engineering Contradiction:
Improveconnection reliabilityVSAvoidhalf-mating detection
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

Different latching points are positioned at different locations along the connector assembly. The first latching point is positioned to engage early in the insertion process, the second latching point is positioned at an intermediate location, and the third latching point is positioned at the final mating position. This spatial distribution of latching points with different local qualities enables both secure connection and detection of proper mating status.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The test contact serves as an intermediary element that provides electrical contact only when all three latching points are properly engaged. The test contact's electrical continuity acts as a mediator that confirms both the mechanical latching status and the proper positioning of the connector, enabling detection of half-mating connections while maintaining connection reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If three latching points are implemented to ensure complete contact, then connection security is improved, but device complexity increases

Engineering Contradiction:
Improveconnection securityVSAvoidlatching mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The three latching points are merged into a single continuous latching mechanism that operates along the insertion direction. The first, second, and third latching elements work together as an integrated system, where each latching point contributes to the overall secure engagement. This merging approach provides enhanced connection security while avoiding the complexity of three completely separate latching mechanisms.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Instead of using a single complex latching mechanism that must detect and respond to multiple conditions, the invention inverts the approach by using three simple sequential latching points. Each latching point performs a single, straightforward function, and their combination provides the desired security without the complexity of a single sophisticated mechanism.

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentEP3446373B1Plug contact and method for testing latching mechanism of plug contact
Publication Date: 2021.09.29 ERNI PRODUCTION GMBH & CO KG
  • EP3446373B1 patent drawingFigure 1
  • EP3446373B1 patent drawingFigure 2
  • EP3446373B1 patent drawingFigure 3

AI summary

The invention relates to a plug contact set comprising a plug contact strip (10) having multiple first plug contacts (12, 14) arranged in a first housing (11), of which at least one is designed as a test contact (14) that is shorter than the other plug contacts (12), and comprising a plug connector (20) having multiple second plug contacts (22) arranged in a second housing (21), of which at least one is configured to be electrically contacted with the test contact (14), wherein the first housing (11) has at least one first engaging element (31) and the second housing (21) has at least one second engaging element (32), which are configured to engage with one another when the first plug contacts (12) are completely contacted with the second plug contacts (22), characterised in that the second housing (21) has a third engaging element (33) which can be engaged with the first engaging element (31), and which is arranged at a distance from the second engaging element (32) in the plugging direction (S) in such a way that, via an engaging of the third engaging element (33) with the first engaging element (31), a preferably play-free securing of the second housing part (21) to the first housing part (11) is achieved in the completely contacted state of the first and second plug contacts (12, 14; 22).