Push-to-Connect Conduit Fitting With Spring-Free Retention
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Solution Overview
Problem
Existing push-to-connect fitting assemblies face issues with spring overstressing and inconsistent compression due to fluid pressure, leading to potential permanent set and reduced service life, as well as difficulties in conduit installation and removal, especially with grooved conduits.
Innovation Solution
The design incorporates a retainer body with segmented colleting tabs and a floating gland to prevent fluid pressure-driven compression of the spring, along with a conduit releasing insert tool to facilitate easy installation and removal, and utilizes split ring gripping members for enhanced retention and colleting functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring is used to bias the retainer against the conduit in push-to-connect fittings, then the conduit can be securely retained, but the spring becomes overstressed and permanently deformed due to fluid pressure, reducing service life
Solution Approach 1:
The patent removes the spring component from the fitting assembly entirely. Instead of using a spring to provide biasing force against the conduit, the design employs a ratchet mechanism with asymmetric teeth that mechanically lock the retainer in position. This extraction of the spring eliminates the problem of spring overstressing while maintaining conduit retention capability through the ratchet's one-way locking action.
Solution Approach 2:
The patent replaces the elastic mechanical system (spring) with a rigid mechanical locking system (ratchet with asymmetric teeth). The ratchet mechanism uses geometric interlocking rather than elastic deformation to maintain force, substituting a permanent mechanical structure for a temporary elastic one, thereby eliminating spring fatigue and permanent set issues.
2Ease of operation
If traditional fitting assemblies are used, then conduit installation is straightforward, but removal is difficult and time-consuming
Solution Approach 1:
The patent introduces a dynamic ratchet mechanism that allows easy installation in one direction (conduit insertion pushes the retainer against the spring, causing asymmetric teeth to skip over each other) while preventing backward movement during operation. For removal, a release tool is inserted to compress the spring and disengage the ratchet, enabling quick conduit extraction. This dynamic design provides asymmetric ease of operation for installation versus removal.
Solution Approach 2:
The patent employs a release tool as an intermediary device for conduit removal. The tool is inserted into the fitting and engages with the ratchet mechanism, providing the necessary force to compress the spring and disengage the asymmetric teeth from the conduit groove. This intermediary tool simplifies the removal process compared to direct manual extraction, reducing time and effort required.
3Ease of operation
If a single action push-to-connect mechanism is used, then installation is simplified, but reliable sealing and retention under fluid pressure are difficult to achieve
Solution Approach 1:
The patent segments the retention and sealing functions into distinct components: the ratchet mechanism handles retention by mechanically locking the retainer position, while separate sealing elements (O-rings or gaskets) provide fluid-tight sealing. This segmentation allows the simple push-to-connect installation to reliably achieve both retention and sealing functions independently, with the ratchet preventing backward movement and seals preventing fluid leakage.
Solution Approach 2:
The patent employs a tapered or curved interface between the conduit end and the fitting interior. The conduit groove and retainer contact surfaces are designed with specific curvature profiles that enhance sealing effectiveness when the conduit is pushed into place. This geometric curvature ensures uniform contact pressure distribution, improving sealing reliability while maintaining the simplicity of the push-to-connect installation action.
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
This configuration ensures reliable and durable fluid-tight sealing, reduces spring overstressing, and simplifies conduit installation and removal, while maintaining robust retention and colleting capabilities.
Implementation Method 1
a spring member disposed between the retainer and the sealing arrangement to bias the retainer in an outboard direction toward a conduit gripping position
Implementation Method 2
a seal member that seals one of the first and second fitting components with an outer surface of a conduit end
Data Source
AI summary
A push to connect fitting includes first and second fitting components, a sealing arrangement, a gripping arrangement, and a colleting ring. The first fitting component has an outboard end that is adapted to receive a conduit end. The second fitting component is joined to the first fitting component to define an interior cavity. The sealing arrangement, disposed in the interior cavity, seals one of the first and second fitting components with an outer surface of a conduit end when the conduit end is inserted into the outboard end of the first fitting component. The gripping arrangement is disposed in the interior cavity, and the colleting ring is disposed in the interior cavity and has an inboard end surface engaging an outboard end surface of the gripping arrangement.