Slotted Cutting Ring Pipe Union Assembly Force Reduction

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Solution Overview

Problem

Existing pipe connection arrangements require a large amount of force to assemble due to numerous small elements moving relative to each other, leading to user effort and potential reliability issues.

Innovation Solution

A connection arrangement featuring a slotted cutting ring with a cone angle of approximately 30°, allowing for easier radial deformation and precise radial cutting, along with a separate intermediate ring for sealing and preventing overassembly, reduces the force required for assembly and enhances connection security.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional cutting ring with multiple small movable elements is used, then the connection arrangement provides reliable form-fitting cutting, but a relatively large amount of force is required for assembly

Engineering Contradiction:
Improveconnection reliabilityVSAvoidassembly force
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The cutting ring is divided into two functionally independent parts: a slotted cutting ring that performs the cutting function, and a separate intermediate ring that provides sealing and structural support. This segmentation allows the cutting ring to be optimized for cutting performance with reduced assembly force, while the intermediate ring handles sealing requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cone angle of the cutting ring is changed from the conventional 12° to approximately 30°. This parameter change increases the radial cutting component for the same axial travel distance, improving cutting efficiency and reducing the total assembly force required while maintaining reliable connection.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the cone angle of the cutting ring is increased to approximately 30°, then radial cutting precision and depth are significantly improved, but the geometry becomes more complex

Engineering Contradiction:
Improveradial cutting precisionVSAvoidcutting ring geometry
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The cutting ring is segmented with a slit that divides it into two halves. This segmentation simplifies the manufacturing of the steep 30° cone angle geometry while maintaining precise radial cutting performance. The slit also allows the cutting ring to be deformed more easily during assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cone angle parameter is optimized to approximately 30°, which provides an optimal balance between radial cutting depth and geometric manufacturability. This parameter change ensures precise radial cutting while keeping the overall structure manageable through the segmented design.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If the cutting ring is slotted to reduce assembly force, then ease of assembly is improved, but the structural integrity may be compromised

Engineering Contradiction:
Improveease of assemblyVSAvoidcutting ring structural integrity
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The cutting ring is divided by a slit into two segments that can move relative to each other. This segmentation enables the cutting ring to deform radially with minimal resistance during assembly, significantly reducing the force required while the cutting edges remain intact and functional.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A separate intermediate ring is introduced as a mediator that provides structural support and sealing functionality. This allows the slotted cutting ring to be optimized for ease of assembly without compromising overall structural integrity, as the intermediate ring compensates for the reduced stiffness of the slotted design.

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 significantly reduces the assembly force needed while providing a more secure and reliable connection, with improved radial cutting precision and tolerance compensation, and a safer cutting edge rounding.

Implementation Method 1

By arranging various conical bores and counterparts sitting in them, the axial movement is transferred to a cutting ring with a cutting edge in such a way that when the union nut is tightened, there is a radial inward deformation in some areas.

Methodology Applied
Scientific EffectMechanical force transmission through conical geometry: Wedge

Data Source

PatentEP2158425B1Connecting arrangement for a pipe union
Publication Date: 2011.01.05 WEIDMANN
  • EP2158425B1 patent drawingFigure 1~2
  • EP2158425B1 patent drawingFigure 3~4

AI summary

A connecting arrangement connects a cylindrical pipe (10) or a pipe section to a connecting body (20). Said connecting body (20) has a first conical bore (23), extending away from a face (24), a first cylindrical bore (21) for receiving the pipe (10), which bore is contiguous to the conical bore (23), and a second cylindrical bore (22) that is contiguous to the first cylindrical bore (21) and the diameter of which is reduced. A union nut (30) has a bore (31) for the pipe (10) or the pipe section. Said union bore has a threaded section (38) by means of which the union nut (30) can be screwed onto a mating threaded section (28) of the connecting body (20), and a conical bore (33) that tapers in a direction opposite to that of the conical bore (23) of the connecting body (20). A cutting ring (40) has a first tapered section (42). Said tapered section (42) sits in the conical bore (33) of the union nut (30). The cutting ring (40) has a bore (46) for passing the pipe (10) or the pipe section through and at least one radial peripheral blade (41, 42) that faces the pipe (10) or the pipe section. An intermediate ring has a bore (51) for the pipe (10) or the pipe section. The intermediate ring (50) is interposed between the cutting ring (40) and the connecting body (20). The intermediate ring (50) has a conical bore (43) against which a second tapered section (44) of the cutting ring (40) presses. The cutting ring (40) is slotted parallel to the axis of the pipe (10) (slotted section 47).