Elastomer Pipe Connection Insert for Leak-Tight Threaded Sealing

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Solution Overview

Problem

Existing connecting devices with elastomer inserts and connecting pieces often suffer from insufficient fluid tightness due to leaks between the external and internal threads, leading to undesirable fluid penetration or escape.

Innovation Solution

A connecting device design where the elastomer insert and connecting piece are configured such that the connecting piece is screwed in to displace the elastomer insert's end section, compressing it radially and pressing it against the central part and reveal surface, enhancing fluid tightness, and optionally featuring markings and sealing elements for improved sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the connecting piece is screwed into the elastomer insert using conventional methods, then the connection can be assembled, but fluid leaks occur between the external thread and internal thread

Engineering Contradiction:
Improvefluid tightnessVSAvoidfluid leakage
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The elastomer insert is pre-compressed axially before the threading operation begins. This preliminary compression ensures that the elastomer is already under radial tension, creating a seal between the threads before fluid pressure can exploit any gaps. The pre-compression is maintained throughout the screwing process to prevent leakage.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the stress state parameters of the elastomer insert by applying axial compression force during the threading operation. This parameter change transforms the elastomer from a relaxed state to a compressed state, generating radial tension that seals the thread interface and prevents fluid leakage.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the elastomer insert is compressed radially to improve sealing, then fluid tightness increases, but the end section may be displaced in the direction of the receiving section

Engineering Contradiction:
Improvefluid tightnessVSAvoidposition stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

A positioning element is provided that engages with the connecting piece at a predetermined position. This preliminary positioning action prevents the end section from being displaced axially during the compression and threading operations, maintaining positional stability while still allowing radial compression for sealing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The positioning element acts as a counteracting mechanism that balances the axial displacement force generated by radial compression. It provides a counter-force that prevents the end section from moving in the direction of the receiving section, thereby maintaining the elastomer insert's positional stability.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

3Stability of the object's composition

If a positioning element is added to prevent displacement, then position stability is maintained, but the device complexity increases

Engineering Contradiction:
Improveposition stabilityVSAvoidstructure complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The positioning element is designed to serve multiple functions: it positions the end section axially, prevents displacement during compression, and may also serve as a stop or reference feature for the threading operation. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 design significantly improves fluid tightness by generating radial tension in the elastomer insert, preventing fluid migration and ensuring a secure, leak-proof connection.

Implementation Method 1

the end section of the elastomer insert is compressed, so that a radial tension is generated, which presses the elastomer insert at least in sections, but in particular its end section, against the central part of the connecting piece and against the reveal surface

Methodology Applied
Scientific EffectRadial tension: Tension

Implementation Method 2

a relatively soft elastomer insert

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3489565B1Connection device
Publication Date: 2021.12.15 REHAU IND SE & CO KG
  • EP3489565B1 patent drawingFigure 1~2
  • EP3489565B1 patent drawingFigure 3a~3c
  • EP3489565B1 patent drawingFigure 4a~4c

AI summary

The present invention relates to a connection device (100) for a secondary pipeline in combination with a transverse opening in a main pipeline, in a shaft or in a wall, comprising a hollow plug-shaped, relatively soft elastomer insert (10), the outer surface (11) of which is adapted to the transverse opening, and the inner surface (12) of which has a screw area (13) into which a connection fitting (20) can be screwed, and a relatively harder connection fitting (20) comprising an engagement end (21), a central part (22) with external thread (23), a receiving section (24) and a drive end (25), characterized in that the inner surface (12) of the elastomer insert (10) and the outer surface (26) of the central part (22) of the connection fitting (20) are each designed as cylindrical shell surfaces, such that the connection fitting (20) can be screwed into the elastomer insert (10).wherein, with the connection device (100) mounted, the connection spigot (20) is first screwed into the elastomer insert (10) to a first screw-in position (31) without the end section (14) of the elastomer insert (10) being displaced towards the receiving section (24) of the connection spigot (20), and subsequently the connection spigot (20) is screwed into the elastomer insert (10) to a second screw-in position (32), whereby the end section (14) of the elastomer insert (10) is displaced towards the receiving section (24) of the connection spigot (20), so that the elastomer insert (10) is pressed at least partially against the central part (22) of the connection spigot (20) and against the reveal surface (40) of the transverse opening in the main pipeline, in the shaft or in the wall.