Clip-Ring Pipe Fitting for Solvent-Free c-PVC Connections
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Solution Overview
Problem
Existing connection methods for c-PVC and PVC-U piping systems, such as compression fittings, do not provide reliable seals and are not suitable for solvent-free connections due to the brittle nature of c-PVC materials.
Innovation Solution
A mechanical fitting with a clip ring and nut mechanism that redistributes insertion and pull-out forces, utilizing a clip ring with a specific geometry and conical shape to facilitate insertion and secure the pipe, along with a groove on the pipe to compensate for ovalization, and a tool for on-site groove creation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If compression fittings are used to connect c-PVC pipes, then the connection method is simple and solvent-free, but the connection reliability is poor due to the brittle nature of c-PVC material
Solution Approach 1:
The connection system is divided into distinct functional components: a fitting body, a clip ring for mechanical engagement, and a groove in the pipe. This segmentation allows each component to perform its specific function optimally - the groove accommodates the clip ring without requiring deformation of the brittle c-PVC pipe material, while the clip ring provides secure mechanical engagement through its geometry designed to distribute forces.
2Adaptability or versatility
If deformation-based connection methods are used, then the connection can be achieved for ductile materials, but the method is unsuitable for brittle c-PVC materials
Solution Approach 1:
The clip ring acts as an intermediary element between the fitting body and the pipe. Instead of deforming the brittle c-PVC pipe directly, the clip ring engages with the groove in the pipe and is compressed by the fitting body, transferring the connection forces through the clip ring rather than through direct deformation of the pipe material. This mediator approach enables reliable connection of brittle materials.
3Strength
If a clip ring with specific geometry is used, then the insertion and pull-out forces are redistributed improving connection strength, but the device complexity increases
Solution Approach 1:
The clip ring features localized geometric variations - an insertion surface with a specific insertion angle and a pull-out surface with a different angle - that are optimized for their respective functions. The insertion surface geometry facilitates easy insertion by guiding the clip ring into the groove, while the pull-out surface geometry with a smaller angle provides mechanical advantage for resisting pull-out forces. This local optimization of geometry provides high connection strength without requiring overall system complexity.
Data Source
AI summary
The present invention proposes a mechanical fitting for connecting pipes or for attaching a pipe, a method of assembling such a fitting and a pipe, and a tool for the assembly of a fitting and a pipe. The mechanical fitting comprises a main body (10, 210) extending axially from an open end (11) and defining an insertion space for a pipe, a clip ring (30, 130, 230) designed to close over a pipe, and a nut (40, 240) movably mounted at least in part into the main body for tightening the clip ring. The clip ring (30; 130) is arranged inside the main body for being contactable by the nut (40; 240) and has an inner circumferential boss or protrusion (32; 132), to be clipped into a corresponding outer circumferential groove (4) of the pipe (2).