U-Shaped Pipe Clamp Axial Sealing for Combustion Air Pipes

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Solution Overview

Problem

Existing pipe clamps for combustion air pipes in heating exhaust gas systems fail to ensure optimal tightness, especially when pipes with different diameters and non-parallel end faces are connected, due to lack of effective sealing mechanisms.

Innovation Solution

A U-shaped pipe clamp with an overlapping section that extends radially inward, featuring oblique contact surfaces and a wedge-like design, creates a labyrinth seal by supporting the tongue on both axial sides, compensating for diameter differences and ensuring secure sealing without additional elastomer seals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a simple pipe clamp design is used, then the device complexity is reduced, but the sealing tightness of the combustion air pipe connection deteriorates

Engineering Contradiction:
Improvepipe clamp structureVSAvoidconnection tightness
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The overlapping section extends in the axial direction beyond the tongue, creating a multi-dimensional sealing structure. This axial extension allows the seal to engage with both pipes at different positions, transforming a simple radial clamp into a three-dimensional sealing system that accommodates pipe misalignment while maintaining connection tightness.

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

Solution Approach 2:

The U-shaped overlapping section with oblique contact surfaces creates an asymmetric geometry that specifically addresses the problem of non-parallel pipe ends. The oblique surfaces are designed to match the typical angular misalignment between connected pipes, providing effective sealing for asymmetric conditions without requiring complex adjustable mechanisms.

Inventive Principle:
Principle #4Asymmetry

2Manufacturing precision

If pipe clamps are designed for perfect parallel pipes, then the manufacturing precision is simplified, but the adaptability to diameter variations and non-parallel connections deteriorates

Engineering Contradiction:
Improvepipe alignment toleranceVSAvoidaccommodation of diameter differences
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The oblique contact surfaces are designed with specific angles that allow the sealing geometry to adapt to varying pipe parameters. By changing the angular parameter of the contact surfaces rather than requiring precise linear alignment, the design accommodates diameter variations and non-parallel connections while maintaining manufacturing feasibility.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The sealing function is segmented into multiple contact points: the tongue provides central alignment, while the overlapping section with its two legs provides distributed contact along the pipe surfaces. This segmentation allows each element to handle specific aspects of misalignment, collectively accommodating diameter variations without requiring the entire structure to be precisely manufactured.

Inventive Principle:
Principle #1Segmentation

3Reliability

If additional elastomer seals are added, then the sealing efficacy is improved, but the device complexity and cost increase

Engineering Contradiction:
Improvesealing efficacyVSAvoidnumber of sealing components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pipe clamp structure itself provides the sealing function through its geometric design. The overlapping section and oblique contact surfaces create a self-sealing mechanism where the mechanical compression of the plastic material against the pipe surfaces generates the necessary sealing force, eliminating the need for separate elastomer seal components.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The entire pipe clamp is made of the same plastic material, creating a homogeneous sealing structure. This uniform material composition allows the clamp body itself to deform and conform to the pipe surfaces, providing sealing through the homogeneous plastic material rather than requiring heterogeneous combinations of metal and elastomer components.

Inventive Principle:
Principle #33Homogeneity

Data Source

PatentEP2865944B1Pipe clamp for combustion air pipes and flue gas pipe system
Publication Date: 2018.03.07 BACHLE DIETER
  • EP2865944B1 patent drawingFigure 1
  • EP2865944B1 patent drawingFigure 2~7
  • EP2865944B1 patent drawingFigure 8~10

AI summary

The invention relates to a pipe clamp for gripping a circumferential joint between two axially adjacent combustion air pipes (20, 21) of an exhaust pipe system of a heating system, with a contact ring (2) for contact with the outer surfaces of both combustion air pipes, which can be clamped around the combustion air pipes with fixing means (15), wherein the contact ring (2) has a first and a second free end region (3, 4) for opening the contact ring (2) for assembly purposes, and wherein in the assembled state an end-side overlap section (5) of the first end region (3) radially overlaps an end-side tongue (6) of the second end region (4) in the circumferential direction.According to the invention, the overlapping section (5) in the assembled state overlaps the tongue (6) in both axial directions (7, 8) and has a contact surface (11, 12) on each of the axial sides of the tongue (6) in order to support itself axially next to the tongue (6) on both sides of the joint with a contact surface (11, 12) on the outer shell surfaces of the combustion air pipes (20, 21), that the overlapping section (5) is U-shaped in an axial section plane and has two legs (9, 10) axially spaced apart from each other over the tongue (6), having internally chamfered side surfaces, each leg forming one of the contact surfaces (11, 12) at its end, and that the tongue (6) in the assembled state of the pipe clamp is supported on the chamfered side surfaces with inclined counter surfaces that are congruent with the side surfaces.