Push-to-Connect Conduit Fitting With Fixed Gland Spring Protection

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Solution Overview

Problem

Existing push-to-connect fitting assemblies face issues with fluid pressure-driven spring compression, leading to potential overstressing and permanent set, and require complex gland designs to accommodate varying spring compression ranges, affecting service life and manufacturing tolerances.

Innovation Solution

The design incorporates a retainer body with a gland axially fixed to prevent fluid pressure-driven compression of the spring, using a retainer body with segmented colleting tabs and a floating gland to limit axial compression, and a separate colleting ring for enhanced gripping and colleting functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a floating gland design is used to accommodate spring compression, then the fitting can handle fluid pressure variations, but the gland design becomes complex and manufacturing tolerances are affected

Engineering Contradiction:
Improveability to handle fluid pressure variationsVSAvoidgland design complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The colleting arrangement is segmented into discrete colleting members that can move independently within the fitting body, allowing each member to respond to pressure changes without requiring a complex floating gland structure. This segmentation enables simplified gland design while maintaining adaptability to pressure variations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The gland structure is extracted from the floating configuration and replaced with fixed gland elements combined with mobile colleting members. This separation of functions simplifies the overall gland design while achieving the same pressure accommodation through the mobile colleting members.

Inventive Principle:
Principle #2Taking out (Extraction)

2Stress or pressure

If spring compression range is increased to accommodate fluid pressure, then the spring can handle higher pressures, but the spring becomes overstressed and experiences permanent set

Engineering Contradiction:
Improvefluid pressure handling capacityVSAvoidspring service life
Core Design Contradiction:
Stress or pressureVSReliability

Solution Approach 1:

The colleting members are designed to move dynamically within the fitting body in response to fluid pressure changes. This dynamic adjustment allows the system to handle varying pressures without requiring excessive spring compression, thereby preventing spring overstressing and permanent set while maintaining reliable operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters by allowing the colleting members to adjust their position and contact force based on fluid pressure. This parameter adjustment enables the spring to operate within its elastic limit across a range of pressures, preventing permanent deformation and extending service life.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If gripping and colleting functions are combined in one arrangement, then the device structure is simplified, but the gripping and colleting members cannot be independently loaded

Engineering Contradiction:
Improveretaining arrangement structureVSAvoidindependent loading capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The retaining arrangement is segmented into separate gripping members and colleting members that are positioned at different locations within the fitting. This segmentation enables independent loading of each function - gripping members handle axial insertion forces while colleting members handle radial retention forces - while the overall structure remains relatively simple.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The gripping and colleting functions are separated in different spatial dimensions within the fitting body. Gripping members are positioned to handle axial forces during insertion, while colleting members are positioned to handle radial forces for retention. This dimensional separation enables independent loading capability without significantly increasing structural complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 conduit retention, reduces spring stress, and maintains manufacturing tolerances, enhancing the service life and performance of push-to-connect fittings by preventing fluid pressure-driven spring compression and allowing independent loading of gripping and colleting members.

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

Methodology Applied
Scientific EffectSpring biasing force: Spring

Implementation Method 2

The gripping portion is received in the circumferential groove

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

a colleting portion engaging an interior tapered surface of the second fitting component at least when the conduit is subjected to one of a pulling force and a fluid pressure force

Methodology Applied
Scientific EffectMechanical force: Mechanical Force

Implementation Method 4

The sealing arrangement seals one of the first and second fitting components with an outer surface of a conduit end portion

Methodology Applied
Scientific EffectSealing contact: Friction

Data Source

PatentEP3948042B1Push to connect conduit fitting assemblies and arrangements
Publication Date: 2025.01.08 SWAGELOK CO
  • EP3948042B1 patent drawingFigure 1
  • EP3948042B1 patent drawingFigure 2
  • EP3948042B1 patent drawingFigure 2A~2B

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.