Press Fitting Stop Ring Assembly for Secure Sleeve Clamping

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Solution Overview

Problem

Existing press fittings for pipe connections face challenges in producing a secure and impact-resistant connection between the press sleeve and stop ring, particularly during production and potential damage, and often require individual parts that can be reduced or avoided.

Innovation Solution

A press fitting design featuring a stop ring with a cylindrical inner contour having protruding and recessed areas that securely clamps onto the press sleeve, allowing for a stable connection even before assembly, and a press sleeve with a projection engaging a circumferential groove for direct attachment to the fitting body, reducing the risk of unintentional disconnection and enhancing stability against lateral impacts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional press fitting design is used with a press sleeve and stop ring, then the assembly can be produced, but the connection between press sleeve and stop ring is not secure and may loosen during production or before pressing

Engineering Contradiction:
Improveconnection stabilityVSAvoidassembly structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The inner contour of the stop ring is segmented into protruding first regions and recessed second regions. This segmentation creates multiple clamping points that engage with the press sleeve, distributing the clamping force and preventing loosening while maintaining a relatively simple overall structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The stop ring is designed to clamp the press sleeve in advance during assembly, before the actual pressing operation. The protruding regions engage with the press sleeve to create a secure connection that prevents unintentional disconnection and lateral impacts during production and storage.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the stop ring is designed to securely clamp the press sleeve, then connection stability improves, but manufacturing precision requirements increase

Engineering Contradiction:
Improveclamping connection securityVSAvoiddimensional tolerance
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The stop ring features localized protruding regions rather than a uniformly tight fit. This allows the clamping function to be concentrated at specific engagement points, providing secure connection while being more tolerant of variations in the overall dimensional tolerances of the press sleeve.

Inventive Principle:
Principle #3Local quality

3Strength

If the press sleeve is directly attached to the fitting body with a projection and groove, then stability against lateral impacts improves, but the device complexity increases

Engineering Contradiction:
Improveimpact resistanceVSAvoidstructural elements
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The connection between press sleeve and fitting body uses an asymmetric projection-groove mechanism. The projection on the press sleeve fits into a groove on the fitting body, creating a mechanically interlocked connection that resists lateral impacts while adding minimal structural complexity.

Inventive Principle:
Principle #4Asymmetry

4Reliability

If a secure clamping connection is implemented between stop ring and press sleeve, then the risk of parts coming loose decreases, but the manufacturing complexity increases

Engineering Contradiction:
Improveanti-loosening capabilityVSAvoidproduction simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The clamping connection is achieved through segmented protruding regions on the stop ring that engage with the press sleeve. This segmentation provides secure anti-loosening capability while using simple geometric features that are easy to manufacture with conventional processes.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4166835B1Assembly group for a press fitting for a pipe connection
Publication Date: 2025.01.15 UPONOR INNOVATION AB
  • EP4166835B1 patent drawingFigure 1
  • EP4166835B1 patent drawingFigure 2~4
  • EP4166835B1 patent drawingFigure 5~6

AI summary

The invention relates to a press fitting for a pipe connection. The press fitting (1) comprises a fitting body (2) for connecting the press fitting (1) to a pipe, a substantially cylindrical press sleeve (4) with a pressing area (11) fixed to the fitting body (2), and a stop ring (3) fixed to the press sleeve (4), which limits the pressing area (11) in an axial direction of the press sleeve (4). The stop ring (3) has a substantially cylindrical inner contour (14) with projecting first areas (15) and recessed second areas (16) relative to the first areas (15). The first areas (15) of the first stop ring (3) clamp around an outer contour of the press sleeve (4). The second areas (16) of the stop ring (3) are spaced apart from the outer contour of the press sleeve (4). The invention further relates to an assembly for such a press fitting.