Segmented Pipe Coupler With Backlocking Fingers for Airtight Joints

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Solution Overview

Problem

Existing pipe joining methods, particularly for thermoplastics like polyethylene and polypropylene, face challenges in achieving reliable and air-tight connections using solvent welding, and thermal welding methods like electrofusion may not provide sufficient sealing and mechanical engagement.

Innovation Solution

A unitary single-piece plastic pipe coupler with surface enhancements such as circumferential ridges and inward radial projections, combined with a band clamp and annular gasket, ensures secure engagement and sealing between pipes and fittings through axial compression and backlocked finger projections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrofusion heating elements are embedded in fittings to heat and weld pipes, then thermal welding capability is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvewelding capabilityVSAvoidfitting structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The heating element is extracted from the fitting body and placed in a separate collar that receives the pipe end. This separates the welding function from the fitting structure, simplifying the fitting while maintaining welding capability through the collar assembly.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The coupling system is divided into distinct functional components: the fitting body, the electrofusion collar with heating element, the clamp for compression, and the gasket for sealing. Each component performs a specific function, improving manufacturability and reliability.

Inventive Principle:
Principle #1Segmentation

2Reliability

If clamps are used to compress fittings and collars to prevent air entry, then sealing capability is improved, but ease of operation deteriorates due to additional tightening steps

Engineering Contradiction:
Improvesealing capabilityVSAvoidassembly process
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The collar is pre-comformed with a non-circular cross-section that matches the fitting socket geometry. This preliminary shaping allows the collar to be compression-molded directly into the fitting, creating a mechanical interlock that maintains sealing without requiring post-installation adjustment or complex tightening procedures.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If pipe ends are inserted into fittings without additional sealing mechanisms, then device complexity is reduced, but air-tight sealing capability deteriorates

Engineering Contradiction:
Improvecoupling structureVSAvoidair-tight sealing
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

A gasket is introduced as an intermediary sealing element between the pipe end and the fitting. The gasket is compressed by the collar and clamp to create an air-tight seal, while the collar's non-circular cross-section provides mechanical engagement that maintains this sealing under operational conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

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, air-tight, and mechanically secure pipe joint with enhanced sealing capabilities, resisting axial extraction and maintaining compression of the gasket for effective operational sealing.

Implementation Method 1

resistive heating elements are at least partially embedded in fittings. A pipe may be inserted into the fitting so as to be encircled by the heating element.

Methodology Applied
Scientific EffectResistive heating: Joule Heating

Implementation Method 2

The clamp is tightened around the fitting (or collar outer wall) to radially compress the fitting and collar to the pipe to insure no air enters the welding zone.

Methodology Applied
Scientific EffectRadial compression: Compression

Implementation Method 3

The heating element may be energized by an electric power source to heat the fitting and the pipe sufficiently to weld the two together.

Methodology Applied
Scientific EffectThermal energy transfer: Conduction (thermal)

Data Source

PatentEP3354955B1Pipe coupler and coupling method
Publication Date: 2023.03.22 FISCHER GEORG HARVEL LLC
  • EP3354955B1 patent drawingFigure 1
  • EP3354955B1 patent drawingFigure 2
  • EP3354955B1 patent drawingFigure 3

AI summary

A pipe coupler (30) comprises: an axis (500); a body portion (70) surrounding the axis; a circumferentially segmented collar (72) extending from a first axial end of the body portion and having an inner diameter surface (80) and an outer diameter surface (82); and a plurality of fingers (90) projecting from a second axial end of the body portion, axially opposite the first end and having inward radial projections (96).