Expandable Pipe Liner With Segmented Locking Band

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Solution Overview

Problem

Existing inner sealing sleeves for pipes are complex and costly to manufacture, with suboptimal locking behavior and sealing security, particularly in rehabilitation of dilapidated pipelines where leaks need to be sealed without excavation.

Innovation Solution

A simple and cost-effective inner sealing sleeve design featuring a bent band with varying bending radii, an expandable structure, and a locking device that prevents contraction, ensuring improved sealing and mechanical stability through elastic deformation and a locking mechanism that maintains the expanded state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional inner sealing sleeves are used, then sealing function is achieved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvesealing securityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The band is segmented into an inner band part and an outer band part that overlap, with the locking device separating the engagement portion (on inner band) from the locked portion (on outer band). This segmentation allows independent optimization of each part's function while simplifying overall manufacturing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of having the locking device complexly engage with the band structure, the invention inverts the approach by creating a simple engagement portion on the inner band that locks onto a corresponding locked portion on the outer band. The locking mechanism works by preventing relative movement between these two simplified portions rather than using complex interlocking structures.

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

2Ease of operation

If traditional locking devices are used, then locking function is achieved, but locking behavior and sealing security are suboptimal

Engineering Contradiction:
Improvelocking behaviorVSAvoidsealing security
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The band's own elastic properties are utilized to create the locking mechanism. When the band is expanded, the inner band part's engagement portion automatically engages with the outer band part's locked portion, creating a self-locking effect that maintains sealing pressure without additional active components.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention changes the geometric parameters of the band, specifically creating different bending radii (R1 for outer band, R2 for inner band) to generate elastic forces that drive the locking mechanism. This parameter change transforms the band from a passive sealing element to an active locking system.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If the band is made expandable, then sealing adaptability improves, but structural complexity increases

Engineering Contradiction:
Improvesealing adaptabilityVSAvoidstructural complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The band is constructed as a flexible thin-walled structure that can be expanded radially to adapt to different pipe diameters and conditions. This flexible shell approach allows the sealing sleeve to be inserted in a compact state and then expanded in-place to achieve the required sealing dimensions.

Inventive Principle:
Principle #30Flexible shells and thin films

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 enhanced sealing security, reduced manufacturing complexity and costs, and improved mechanical stability for pipe rehabilitation, allowing for effective sealing of leaks without excavation.

Implementation Method 1

The band is expandable so that the inner band part relative to the outer band part along an expanding direction W is displaceable

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

at least one locking device which prevents the inner band part from being displaceable relative to the outer band part counter to the widening direction W

Methodology Applied
Scientific EffectMechanical constraint: Mechanical Force

Data Source

PatentEP2483586B8Liner and use
Publication Date: 2014.06.25 GRAF PATENTVERW

AI summary

The invention relates to a liner (1) for insertion into pipes, comprising: - a strip (3) which is bent about a bending axis (Z) along a circumference having a bending radius (Rb) in such a way that an inner strip part (7) and an outer strip part (9) overlap each other, wherein the strip (3) can be expanded, so that the inner strip part (7) can be displaced relative to the outer strip part (9) along an expansion direction (W), - at least one locking device (5), which stops the inner strip part (7) being displaced relative to the outer strip part (9) counter to the expansion direction (W), wherein a buckling region (15) is formed in the strip (3), parallel to the bending axis (Z), between the inner strip part (7) and the outer strip part (9), and wherein the strip (3) along the circumference in the outer strip part (9) has a maximum bending radius (R1) which is smaller than the maximum bending radius (R2) along the circumference in the inner strip part (7). The invention also relates to the use of a liner (1) according to the invention for sealing pipes.