Memory-Polymer Clamping Ring for Room-Temperature Pipe Sealing

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Solution Overview

Problem

Existing clamping ring technologies for plastic pipes with memory properties lack efficient mechanical expansion and shrinkage mechanisms at room temperature, and do not effectively ensure correct positioning and sealing without heating, leading to potential leakage and handling difficulties.

Innovation Solution

A clamping ring made of polyolefins with memory properties, featuring a mechanically expandable and shrinkable design, including a stop edge and irregular outer surface for improved grip and strength, which can be injection molded to enhance the pressing force and sealing efficiency, and marked for easy identification of expansion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If a clamping ring is made from extruded pipe by cutting and bending, then the clamping ring can be formed with a stop edge, but the handling and grip of the clamping ring becomes difficult

Engineering Contradiction:
Improveclamping ring shape with stop edgeVSAvoidhandling and grip
Core Design Contradiction:
ShapeVSEase of operation

Solution Approach 1:

The outer surface of the clamping ring is provided with irregularities (ridges and grooves) at specific locations to improve grip and handling, while maintaining the overall cylindrical shape and stop edge structure. This local modification allows assemblers to easily grip the ring without compromising its sealing function.

Inventive Principle:
Principle #3Local quality

2Strength

If the clamping ring is made by injection molding, then the strength and pressing force are improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveclamping ring strength and pressing forceVSAvoidmanufacturing process
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The clamping ring is made from polyolefin material with specific memory properties that enable mechanical expansion and automatic shrinkage at room temperature. The injection molding process parameters are optimized to create the desired wall thickness distribution and structural features, achieving high strength and pressing force while maintaining manufacturability.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the clamping ring is expanded mechanically without heating, then the sealing efficiency is improved, but the positioning accuracy and leakage prevention become problematic

Engineering Contradiction:
Improvesealing efficiencyVSAvoidpositioning accuracy
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The clamping ring utilizes its own memory properties to automatically return to its original shape and size after mechanical expansion, enabling self-positioning and self-sealing. The ring expands during installation and then automatically shrinks to secure the connection, ensuring both sealing efficiency and positioning accuracy without external heating or complex control systems.

Inventive Principle:
Principle #25Self-service

4Ease of manufacture

If the wall thickness is uniform throughout the clamping ring, then the manufacturing is simplified, but the pressing force distribution becomes inefficient

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidpressing force distribution
Core Design Contradiction:
Ease of manufactureVSForce

Solution Approach 1:

The clamping ring features variable wall thickness with different sections having different thicknesses optimized for specific functions. The thicker sections provide structural strength and pressing force where needed, while thinner sections reduce material usage and facilitate expansion. This non-uniform wall thickness distribution optimizes the pressing force applied to the pipe end.

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 clamping ring provides secure, efficient sealing and handling by automatically expanding and shrinking at room temperature, ensuring correct positioning and preventing re-use, thus enhancing the quality and reliability of pipe connections.

Implementation Method 1

The body comprises a plastic material, which is polyolefins, having memory properties. The clamping ring is mechanically expandable and automatically shrinkable without heating or warming.

Methodology Applied
Scientific EffectMemory properties: Shape Memory Polymer

Implementation Method 2

The irregularities on the outer surface of the clamping ring improve the handling of the clamping ring because it is easy to grip and handle the clamping ring.

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2671011B1Clamping ring
Publication Date: 2022.04.20 UPONOR INNOVATION AB
  • EP2671011B1 patent drawingFigure 1~2
  • EP2671011B1 patent drawingFigure 3~5
  • EP2671011B1 patent drawingFigure 6~8

AI summary

The invention relates to a clamping ring (6) that presses an end of a pipe (1) against a connecting piece (2) by back shrinkage. The clamping ring (6) comprises a body (7) comprising a plastic material having memory properties. The body (7) has a first end (8) to be positioned at a distance from the end of the pipe (1) and a second end (9) to be positioned close to the end of the pipe (1). The body (7) of the clamping ring (6) has a first position at the first end (8) or at the distance from the first end (8) having a first radial wall thickness (A). The body (7) of the clamping ring (6) has at least one second position between the first position and the second end (9) such that the body (7) of the clamping ring (6) has a second radial wall thickness (B) at the second position. The second radial wall thickness (B) is smaller than the first radial wall thickness (A).