Grip Ring Fitting Geometry for Lower Nut Load and Better Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mechanical fittings are prone to nut failure due to high forces and are susceptible to leaks, requiring multiple components for gripping and sealing functions.
Innovation Solution
A fitting design with a grip ring that integrates inner teeth for gripping and a rubber joint for sealing, featuring a unique geometry that distributes force to reduce axial loads on the nut, using deflection zones and angled surfaces to absorb and redirect forces, thereby reducing the need for separate elements and minimizing material usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional mechanical fitting uses a nut to tighten the grip ring against the pipe, then the gripping function is achieved, but the nut is prone to failure due to high forces
Solution Approach 1:
The patent introduces curved surfaces (concave deflection surface and convex transition surface) in the force transmission path between the grip ring and the nut. These curved surfaces redirect the force vectors, transforming purely axial loads into a combination of radial and axial components, thereby reducing the peak axial force on the nut while maintaining effective gripping.
Solution Approach 2:
The patent modifies the geometric parameters of the grip ring, specifically introducing deflection zones with specific curvature radii and angles. These parameter changes allow the grip ring to deform elastically during tightening, distributing the load more evenly and reducing stress concentration on the nut.
2Strength
If the grip ring is tightened strongly to ensure gripping, then the mechanical strength is improved, but leakages become more prone
Solution Approach 1:
The patent makes the grip ring a dynamic component that can deform elastically during the tightening process. The deflection zones allow the ring to adapt its shape, enabling progressive engagement of the teeth with the pipe while controlling the compression of the sealing element to prevent leakage.
Solution Approach 2:
The curved deflection surfaces guide the force transmission in a controlled manner, ensuring that the sealing element is compressed uniformly and progressively. This prevents sudden or excessive compression that could cause leakage while still achieving adequate mechanical strength.
3Adaptability or versatility
If multiple separate elements are used for gripping and sealing functions, then the functionality is comprehensive, but the device complexity increases
Solution Approach 1:
The patent combines the gripping ring and the sealing element into a single integrated component. The grip ring incorporates both the teeth for gripping the pipe and the sealing surface for contacting the sealing element, eliminating the need for separate gripping and sealing components while maintaining both functions.
Solution Approach 2:
The grip ring is designed as a multi-functional element that simultaneously provides gripping through its teeth, force transmission through its body, and sealing through its contact surface. This universal component performs multiple functions that would traditionally require separate parts, reducing overall device complexity.
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 reduces nut failure by distributing forces more evenly, minimizing material requirements, and enhances sealing performance by reducing axial loads, thus improving the mechanical integrity and leak resistance of the fitting.
Implementation Method 1
The first deflection zone has an outer concave deflection surface... The second deflection zone has an inner concave deflection surface... force transmission part is connected to the nut contact part by a first deflection zone and is connected to the joint contact part by a second deflection zone
Implementation Method 2
The nut contact part has a radial outer sliding surface for receiving the nut, the radial outer sliding surface having a nut sliding surface in contact with the nut... A transition surface is provided between the nut sliding surface and the nut stop surface, the transition surface being curved in a concave manner
Data Source
Figure 1~3
Figure 4~6
Figure 7~9
AI summary
The present invention proposes a fitting 1 for the fixation of a pipe 3 inserted therein, comprising a fitting body 10, a grip ring 20 with inner teeth designed to penetrate into the pipe during tightening of the grip ring for gripping the pipe, a nut 15 for tightening the grip ring against the pipe, and a joint 17 for sealing between the fitting body and the pipe. The grip ring extends between a first ring end 23 and second ring end 26. The grip ring 20 is designed to allow a radial movement of the nut contact part towards the pipe and an axial movement of the grip ring for contacting the joint.