Pipe Segment Coupler With Expanding Claws for Fast Longitudinal Joining

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Solution Overview

Problem

Existing pipe rehabilitation methods face challenges in efficiently coupling segments in the longitudinal direction without using fixtures like bolts and nuts, leading to insufficient strength, complexity, and increased construction time.

Innovation Solution

A pipe rehabilitation method using elastically deformable claws in a coupler that protrude through segment insertion holes, expand in diameter to clamp side plates, and couple segments in the longitudinal direction, allowing for quick assembly by attaching the coupler and expansion pin before transport to the site.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If nuts are staggered for fixation in the circumferential direction with coupling bolts disposed in a zigzag manner, then segments can be joined with sufficient strength, but it requires expensive nuts that extend between the side plate and inner plate

Engineering Contradiction:
Improvejoining strength of segmentsVSAvoidcost of nuts
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The coupling system is segmented into multiple independent coupling points around the circumference, each with its own coupling bolt and nut. This allows the use of smaller, less expensive nuts at each location rather than requiring one large, expensive nut that spans the entire length between side plate and inner plate.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coupling arrangement transitions from a single longitudinal dimension to a two-dimensional circumferential distribution. Coupling bolts and nuts are arranged around the circumference rather than in a single line, allowing the use of smaller nuts at multiple locations instead of one large nut, thereby reducing cost while maintaining joining strength.

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

2Strength

If a long nut is used that extends between the side plate and inner plate, then segments can be coupled with sufficient strength, but it requires dedicated tools with torque control and increases replacement work time

Engineering Contradiction:
Improvecoupling strengthVSAvoidconstruction time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The coupling system is divided into multiple independent coupling points around the circumference. Each coupling point uses its own nut and coupling bolt that can be installed and tightened independently. This segmentation eliminates the need for long nuts that require dedicated torque control tools and reduces the time required for installation and replacement work.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple coupling points are prepared in advance around the circumference, allowing workers to install and tighten coupling bolts and nuts at different locations simultaneously or in sequence without waiting for one long nut to be fully installed and torqued. This preliminary arrangement of multiple coupling points significantly reduces construction time.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If ridges on the coupling pin are made low, then the coupling pin can be inserted, but both segments cannot be clamped with sufficient force

Engineering Contradiction:
Improveinsertability of coupling pinVSAvoidclamping force
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The coupling pin features localized ridges with increased height at specific circumferential positions where clamping force is needed. These locally enhanced ridges provide sufficient clamping force at critical points while maintaining the overall insertability of the coupling pin. The ridges are strategically positioned to maximize clamping effectiveness without requiring the entire pin to have uniformly high ridges that would prevent insertion.

Inventive Principle:
Principle #3Local quality

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 method enables secure and rapid coupling of pipe segments, reducing on-site construction time and eliminating the need for complex fixtures, while ensuring strong longitudinal connections.

Implementation Method 1

a coupler having a plurality of claws that are radially elastically deformable and long so as to protrude through the insertion holes of the side plates of the butted segments

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4269748B1Pipe regenerating method
Publication Date: 2025.10.29 SHONAN GOSEI JUSHI SEISAKUSHO KK
  • EP4269748B1 patent drawingFigure 1
  • EP4269748B1 patent drawingFigure 2
  • EP4269748B1 patent drawingFigure 3

AI summary

A coupler having elastically deformable claws 32, 33 is fixed to the side plate 103 of one segment 1a. The side plate 103 of the one segment 1a and the side plate 102 of the other segment 1b are butted against each other, and the claws of the coupler are passed through the side plate of the other segment to protrude into the segment. The claws of the coupler protruding into the other segment are elastically deformed by a diameter expansion pin 11 to expand the diameter of the claws 32 and 33. The claws of the coupler whose diameter has been expanded presses the side plate of the other segment against the side plate of the one segment to couple both the segments in the longitudinal direction.