Hairpin-Locked Pipe Coupling for Leak-Proof Assembly

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Solution Overview

Problem

Existing pipe connection methods in flow systems, such as threaded fittings, face issues with leakage, insulation problems, and inconsistent rotation, requiring manual sealing and leading to difficulties in quick and stable assembly, especially during maintenance.

Innovation Solution

A coupling system featuring a connecting insert with a locking groove and a locking member that extends through openings in the pipes to secure the insert's position, utilizing a tapered receptacle portion and sealing grooves with O-ring elements for a tight and leak-proof connection, allowing for independent orientation and increased rigidity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If threaded fittings are used for pipe connection, then the connection can be assembled, but manual sealing is required which increases the risk of leakage

Engineering Contradiction:
Improveleakage preventionVSAvoidmanual sealing requirement
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The connection insert includes integrated sealing elements (O-rings or elastomeric seals) that automatically seal the connection when the insert is positioned in the receptacle portion, eliminating the need for manual sealing operations by workers

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

A connection insert acts as an intermediary component between two pipes, providing integrated sealing elements that mediate the sealing function, thereby preventing leakage without requiring manual intervention

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If threaded fittings are used for pipe connection, then the connection can be made, but the distance between connections increases which causes insulation problems

Engineering Contradiction:
Improveconnection stabilityVSAvoiddistance between connections
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The connection system is segmented into a receptacle portion in one pipe and a connection insert in another pipe, allowing the pipes to be connected with minimal distance between connection points, thereby maintaining insulation integrity

Inventive Principle:
Principle #1Segmentation

3Ease of operation

If threaded fittings are used for pipe connection, then the connection can be assembled, but the rotation position varies which causes leakage risks when adjusting

Engineering Contradiction:
Improveassembly flexibilityVSAvoidrotation consistency
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The connection insert and receptacle portion feature asymmetric tapered surfaces that guide the pipes into a unique, consistent rotational position during assembly, eliminating rotation variability and associated leakage risks

Inventive Principle:
Principle #4Asymmetry

4Reliability

If a locking mechanism is added to secure pipe connection, then the connection stability improves, but the device complexity increases

Engineering Contradiction:
Improveconnection stabilityVSAvoidlocking mechanism structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking function is merged with the connection insert by incorporating locking grooves and protrusions directly into the insert structure, providing stable locking without requiring separate locking components or complex mechanisms

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

The solution provides a reliable, leak-proof, and easily assembled pipe connection that maintains insulation integrity and prevents rotation, ensuring stability and ease of maintenance by using a locking mechanism that secures the pipes together effectively.

Implementation Method 1

The receptacle portion has a tapered shape, and the end of the connecting insert accordingly has a sloping end section with a decreasing diameter from an midpart towards its end

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

The connecting insert comprises grooves circumventing the outer circumferential surface and positioned at an outer end of the connecting insert relative to a neighbouring locking groove and being adapted for a sealing element

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3736480B1Coupling assembled with hairpins
Publication Date: 2022.11.09 DANFOSS AS
  • EP3736480B1 patent drawingFigure 1~2
  • EP3736480B1 patent drawingFigure 3
  • EP3736480B1 patent drawingFigure 4

AI summary

The present invention relates to a coupling system of two pipes (100), such as metal pipes in heating and/or cooling system or manifold, the coupling comprising: a connecting insert (200) configured to couple to a receptacle portion (300) of one of the pipes and having a locking groove (210) formed in the outer circumferential surface, a locking member (400) comprising an extension (402), said extension adapted to extend through one or more openings (110) in said pipes to engage with the locking groove to secure the positioning of the connecting insert in the receptacle portion.