Expandable Inner Sleeve Sealing for Main-Branch Pipe Transitions

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Solution Overview

Problem

Existing sealing devices for transitions between main and branch lines, particularly underground fluid lines, face issues with leaks due to soil displacement and imprecise fits, leading to material stress and increased leaks over time.

Innovation Solution

A sealing device with expandable inner sleeves made of elastomer, featuring collar-shaped sealing areas and a locking device with a pretensioning mechanism to ensure a secure fit without the need for hardening processes, allowing for adaptation to pipeline diameters and resistance to soil displacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If locking gears are used to prevent reduction in diameter of the inner sleeve, then the inner sleeve can be expanded, but play in the gearwheels causes the inner sleeve to snap back into a position with a slightly smaller diameter creating leaks

Engineering Contradiction:
Improvesealing reliabilityVSAvoidlocking device complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the complex locking gears entirely and replaces them with a simple elastomeric locking element that engages with the expandable inner sleeve through friction and elastic deformation, eliminating the play problem while maintaining the expansion function

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the material parameter of the locking element to elastomer, which provides both the necessary elasticity for engagement and the friction characteristics to prevent snapping back, resolving the reliability issue without complex mechanics

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the area around the inner sleeve is sprayed and cured to seal leaks, then sealing can be achieved, but the process becomes time-consuming and lengthy

Engineering Contradiction:
Improvesealing reliabilityVSAvoidinstallation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The elastomeric locking element automatically seals leaks through its own elastic deformation and friction-based engagement when the inner sleeve expands, eliminating the need for separate spraying and curing operations

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the chemical spraying and curing process with a mechanical elastomeric sealing mechanism that achieves sealing through physical expansion and friction, dramatically reducing installation time

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

3Ease of manufacture

If a rigid cap is used to seal the branch line, then the cap can be inserted and hardened, but imprecise fit causes leaks and soil displacement stresses damage the material leading to increased leaks

Engineering Contradiction:
Improveinstallation simplicityVSAvoidsealing durability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent uses an elastomeric locking element that acts as a flexible sealing component, allowing it to conform to slight displacements and maintain the seal without rigid stress concentrations

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The elastomeric material provides dynamic adaptability to soil displacement and line movement, maintaining sealing contact through elastic deformation rather than rigid resistance

Inventive Principle:
Principle #15Dynamics

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, long-term sealing mechanism that maintains a tight fit despite slight displacements, reducing the risk of leaks and material damage, while being easy to install and maintain.

Implementation Method 1

an inner sleeve which is designed to be braced against the branch line via the socket made of an elastomer

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a first expandable inner sleeve for bracing the main part in the main line and at least one second expandable inner sleeve which is provided for bracing the socket in the branch line

Methodology Applied
Scientific EffectRadial expansion:

Data Source

PatentEP3814665B1Sealing device and associated inner sleeve
Publication Date: 2023.03.29 WENK CHRISTOPH
  • EP3814665B1 patent drawingFigure 1
  • EP3814665B1 patent drawingFigure 2
  • EP3814665B1 patent drawingFigure 3

AI summary

The invention relates to a sealing device for sealing a transition between a main line (24) and a branch line (26), comprising an insert (1) having a main part (2) to be arranged in the main line (24) and having a connecting piece (3) to be arranged in the branch line (26), a first expandable inner sleeve (4) being provided for clamping the main part (2) in the main line (24) and at least one second expandable inner sleeve (5) being provided for clamping the connecting piece (3) in the branch line (26). The invention further relates to an inner sleeve having a locking device. The invention further relates to a method for sealing a transition between a main line (24) and a branch line (26).