Pipe Coupling Dynamic Axial Restraint Rolling Grip
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Solution Overview
Problem
Existing pipe couplings with axial restraint systems, particularly those using gripping rings, face issues with degradation and loss of grip on plastic pipes under high axial loads and temperature variations, leading to reduced performance and potential deformation of the pipe.
Innovation Solution
A dynamic axial restraint system featuring a resilient gripping ring that rolls relative to the casing, increasing its gripping surface area under high axial loads, thereby reducing radial stress on the pipe and maintaining a strong axial grip without cutting into the pipe surface, using a design with annular projections and channels to adapt to increased loads and prevent pipe migration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a gripping ring with gripping teeth is used to restrain axial movement of pipes, then axial restraint is improved, but the pipe surface is cut into causing degradation
Solution Approach 1:
The gripping ring is designed to change its operational parameters dynamically. Under low axial loads, the gripping teeth engage the pipe surface to prevent rotation. Under high axial loads, the gripping ring rolls along the pipe surface, changing from a static gripping position to a dynamic rolling motion, which distributes the cutting action over a larger area and reduces degradation.
Solution Approach 2:
The gripping ring transitions from a static component to a dynamic one that can roll along the pipe surface. This rolling motion allows the gripping teeth to progressively engage different portions of the pipe surface, distributing the mechanical stress and reducing concentrated cutting damage while maintaining effective axial restraint.
2Reliability
If a gripping ring is clamped around the pipe to provide axial restraint, then grip on pipe surface is improved, but plastic pipe material migrates away from gripping teeth under high axial loads
Solution Approach 1:
The gripping ring is designed to dynamically adapt its position through rolling motion. When plastic pipe material begins to migrate away from the gripping teeth under high axial loads, the gripping ring rolls along the pipe surface to a new position where fresh pipe material is engaged, maintaining effective grip without causing concentrated degradation at a single location.
3Reliability
If gripping teeth are forced deeper into the pipe surface to improve grip under high axial loading, then axial restraint is improved, but radial stress on the pipe increases
Solution Approach 1:
Instead of forcing gripping teeth deeper into the pipe surface, the gripping ring is designed to roll along the pipe surface under high axial loads. This dynamic rolling motion maintains effective axial restraint by engaging different portions of the pipe surface, while avoiding the concentration of radial stress that would occur with deeper tooth penetration.
4Stress or pressure
If the gripping ring is allowed to rotate away from the pipe surface under high axial loading, then radial stress on the pipe is reduced, but the level of grip is reduced and the gripping ring may lose contact
Solution Approach 1:
The gripping ring is designed with controlled rotational freedom that allows it to roll along the pipe surface rather than rotate away from it. This controlled rolling motion maintains continuous contact with the pipe surface, preserving axial grip while limiting radial stress. The rolling action ensures the gripping teeth remain engaged with the pipe surface at all times, preventing loss of contact.
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 provides improved axial restraint and resistance to pipe movement, reducing degradation and maintaining grip over extended periods, even under high axial loads and temperature variations, with enhanced performance compared to traditional systems.
Implementation Method 1
the resilient gripping ring is able to adapt to a higher level of axial loading on the pipe by rolling relative to the casing such that a larger area of the inner gripping surface of the gripping ring is brought into engagement with the outer surface of the pipe
Implementation Method 2
a resilient gripping ring which is able to adapt to a higher level of axial loading on the pipe by rolling relative to the casing
Data Source
Figure 1
Figure 2~3
AI summary
A pipe coupling (10) for connecting together the ends of two pipes comprises: a tubular casing (12) for fitting around a pipe; tensioning means (26) for tightening the casing around the outer surface of the pipe; and a dynamic axial restraint system comprising at least one resilient gripping ring (16) mounted within the casing (12) for gripping the outer surface of the pipe. The gripping ring (16) comprises: an outer surface (42) engaging with an inner surface of the casing (12) and adapted to roll against the inner surface of the casing upon axial loading of the pipe; and an inner gripping surface (46) for engaging the outer surface of the pipe. The gripping surface (46) of the resilient gripping ring is adapted such that upon rolling of the outer surface (42) against the inner surface of the tubular casing (12), the area of the gripping surface (46) in contact with the pipe increases.