Plug-Type Coupling Pre-Assembly Locking for Leak-Resistant Sealing

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Solution Overview

Problem

Existing connector designs face limitations in sealing large diameters, experiencing leaks at high pressures and temperatures due to improper use or external influences, and have issues with accidental loosening and assembly effort, especially with mating connectors over 14 mm in diameter.

Innovation Solution

The connector features a form-fitting element that is elastically expandable to secure the adapter sleeve in the receiving channel, with a locking element that prevents axial movement and ensures proper insertion depth, using a three-part seal with O-rings and a spacer ring for enhanced sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If locking tabs are dimensioned large to hold adapter sleeve securely, then reliability of connection is improved, but only circumferential seal can be arranged leading to limited applicability for larger plug diameters

Engineering Contradiction:
Improveconnection securityVSAvoidapplicability for different plug diameters
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The sealing function is segmented from the locking function. The locking tabs are dedicated to mechanical retention while a separate circumferential seal (O-ring) handles sealing. This allows independent optimization of each function and enables application to larger diameters without compromising either locking reliability or sealing capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solution transitions from relying solely on radial dimension (locking tab size) to utilizing axial dimension by introducing a circumferential seal that seals the gap between plug shaft and receiving channel. This dimensional shift enables secure connection and sealing for larger diameters.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If locking element is designed to prevent accidental release, then reliability is improved, but locking element may move into locked position without mating connector preventing insertion

Engineering Contradiction:
Improveprevention of accidental releaseVSAvoidinsertion ease
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The locking element is pre-positioned in a locked state during assembly, but the design ensures it cannot engage the locking groove until the mating connector is properly inserted. The locking groove position relative to the adapter sleeve ensures that without proper insertion, the locking element remains in a position that prevents engagement, thus preventing accidental locking while maintaining ease of insertion.

Inventive Principle:
Principle #10Preliminary action

3Stability of the object's composition

If locking arms cover plug shaft over certain axial length to maintain radial elastic properties, then connection stability is improved, but small surface area of overlap leads to failure under vibration and pressure

Engineering Contradiction:
Improveradial elastic propertiesVSAvoidresistance to vibration and pressure
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The locking arms are merged with the adapter sleeve structure, forming an integrated retaining means that combines radial elastic retention with axial positioning. This integration creates a more robust connection that resists vibration and pressure by distributing forces across the combined structure rather than relying solely on the locking arms' surface area.

Inventive Principle:
Principle #5Merging (Combining)

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 improves the safety and reliability of the plug connection by preventing accidental loosening and leaks, ensuring secure engagement and sealing even at high pressures and temperatures, and facilitating easier assembly by controlling insertion depth.

Implementation Method 1

The holding means (20) projects into the through-opening (14) in a rest state and is designed to be elastically expandable into a tension state radially with respect to the mounting axis (X)

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the plug shaft to exert a radially outward-acting force on the holding means when inserted into the through-opening, and as a result, the respective element is transferred into a tension state

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP4127543B1Plug-type coupling with pre-assembly locking
Publication Date: 2024.05.01 VOSS AUTOMOTIVE GMBH
  • EP4127543B1 patent drawingFigure 1
  • EP4127543B1 patent drawingFigure 2~3
  • EP4127543B1 patent drawingFigure 4~6

AI summary

The present invention relates to a plug-type coupling (1) for connecting at least a first fluid line to a second fluid line formed with a mating coupling (18) or for attaching a unit formed with a mating coupling (18), comprising a housing (2). One end of the housing (2) is formed as a socket portion (6) having a receiving channel (8) for receiving an adapter sleeve (10), wherein the adapter sleeve (10) can be inserted into the receiving channel (8) of the socket portion (6) in an assembly direction (M) and is held releasably in the receiving channel (8) in an axial direction in an interlocking manner. The adapter sleeve (10) has a passage opening (14) for a shaft (16) of the mating coupling (18) and a holding means (20) for releasably fixing the mating coupling (18). When the plug-type coupling (1) is in an assembly position, the holding means (20) can block the mating coupling (18) axially to the assembly axis (X). A locking element (22) moveable axially to the assembly axis (X) is arranged on an outer circumference (24) of the socket portion (6) so as to be movable from a release position, in which the holding means (20) are released, into a locking position in which the holding means (20) are locked. When the locking element (22) is in its release position and the plug-type coupling (1) is in a pre-assembly position, the locking element is fixed at least axially against movement into the locking position.