Fluid Line Coupling With Visual Locking State Indication

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Solution Overview

Problem

Existing fluid line couplings face challenges in securely locking the coupling socket into the coupling sleeve, particularly in automotive applications, where secure locking is difficult to automate and often requires increased assembly effort, and existing solutions with optical latching indicators can fail under axial loads or require manual rework.

Innovation Solution

A fluid line coupling design featuring a coupling sleeve with a stop collar, resilient locking arms, and a locking ring with actuation/signal surfaces that change visibility upon locking, allowing for automated optical control of the locking state, and additional features like inclined transitions and locking lugs to ensure proper alignment and secure engagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If a visual locking indicator is implemented using two interlocking locking elements, then the correct seating of the coupling socket becomes visible, but the elements may tilt under axial load during insertion, preventing proper locking

Engineering Contradiction:
Improvelocking state visibilityVSAvoidlocking reliability under axial load
Core Design Contradiction:
Loss of informationVSReliability

Solution Approach 1:

The patent introduces a separate indicator element that acts as an intermediary between the locking mechanism and the visual signal. This indicator is driven by the locking arms but is mechanically decoupled from the interlocking elements, preventing it from tilting under axial load while still providing visual feedback on the locking state

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The indicator element uses color changes to signal the locking state. The indicator has different colors for locked and unlocked states, providing clear visual information without requiring complex mechanical interlocking that could tilt under load

Inventive Principle:
Principle #32Color changes

2Reliability

If mechanical checking of secure locking is implemented, then assembly security is improved, but assembly effort increases and automation becomes difficult

Engineering Contradiction:
Improveassembly securityVSAvoidassembly effort
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces mechanical checking methods with an optical detection system. The visual indicator provides information about the locking state that can be detected by optical sensors, enabling automated inspection without requiring manual mechanical verification

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The indicator element provides immediate visual feedback on the locking state. This feedback mechanism allows operators or automated systems to quickly verify proper locking without complex mechanical checking procedures, reducing assembly effort while maintaining reliability

Inventive Principle:
Principle #23Feedback

3Loss of information

If existing visual indicators are used that only signal locking mechanism activation, then some visual information is provided, but manual rework is still required and the locking state cannot be reliably verified

Engineering Contradiction:
Improvelocking state signalVSAvoidmanual rework requirement
Core Design Contradiction:
Loss of informationVSEase of operation

Solution Approach 1:

The indicator element uses distinct colors to represent different locking states. When the locking arms are in the retracted position (unlocked), the indicator shows one color, and when the locking arms are extended (locked), the indicator shows a different color, providing unambiguous visual verification that eliminates the need for manual rework

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The indicator element automatically provides complete locking state verification without requiring manual intervention. The visual signal clearly indicates whether locking is proper, allowing the system to self-verify and eliminating the need for manual rework or additional checking steps

Inventive Principle:
Principle #25Self-service

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

Enables easy automated control of the locking state with visual indication, preventing misinterpretation of incorrect locking and ensuring secure engagement without manual rework, even under axial loads, through the use of differently colored actuation/signal surfaces and spring-loaded mechanisms.

Implementation Method 1

the base part and locking part are resiliently and variably spaced apart in the axial direction by means of the spring part, and the locking ring has an inner diameter that can be pushed over the outer circumference of the coupling sleeve with little play, wherein the play between the coupling sleeve and the locking part is dimensioned such that the locking part cannot be pushed over the actuating/signaling surfaces protruding from the openings of the coupling sleeve

Methodology Applied
Scientific EffectSpring force: Spring

Implementation Method 2

the locking element is arranged axially displaceably inside the coupling sleeve and has a number of resilient locking arms corresponding to the number of openings in the coupling sleeve, wherein the locking arms are distributed over the circumference of the locking element and extend in the axial direction and have actuating/signaling surfaces pointing radially outward at their axial ends

Methodology Applied
Scientific EffectResilient deformation: Elasticity

Data Source

PatentEP4121681B1Fluid line coupling
Publication Date: 2024.02.21 CONTITECH TECHNO CHEMIE GMBH
  • EP4121681B1 patent drawingFigure 1~2
  • EP4121681B1 patent drawingFigure 3~4
  • EP4121681B1 patent drawingFigure 5~6

AI summary

The invention relates to a reversibly detachable fluid line coupling (1), at least comprising a coupling sleeve (2), a locking element (3) and a coupling plug (4) with a locking collar (41). The invention was based on the problem of providing a fluid line coupling of the type depicted at the outset, the latching state of which can be automatically checked easily, wherein a visual check is preferred. Said problem is solved by virtue of the fact that the coupling comprises actuating/signal surfaces (312) which are visible only in the non-locked state of the coupling.