Tube Coupling Cap with Tapered Cam Collet for Secure Locking

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Solution Overview

Problem

Existing tube coupling technologies face challenges in securely locking tubes in place while allowing for easy insertion and visual inspection, and in preventing accidental disengagement and fluid leakage.

Innovation Solution

A tube coupling cartridge with a cap and collet design featuring a tapered cam surface, resilient fingers, and locking elements with angled teeth that engage with an annular recess to securely hold the tube, combined with windows for visual confirmation of proper engagement and a cover for added robustness and protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a tube locking device is used to securely hold the tube in the coupling body, then the tube locking reliability is improved, but the device complexity increases

Engineering Contradiction:
Improvetube locking reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The coupling device is divided into distinct functional components: a coupling body with throughways, separate tube locking devices for each throughway, and sealing elements. This segmentation allows each component to be optimized independently while maintaining overall system reliability without excessive complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The tube locking device is designed to be inserted into and nested within the coupling body, with the locking device fitting inside the enlarged diameter portion of the throughway. This nesting approach consolidates multiple functions into a compact integrated structure, improving reliability while controlling complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of operation

If windows are added to the cap for visual inspection of tube engagement, then the ease of operation is improved, but the device complexity increases

Engineering Contradiction:
Improveease of operationVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The cap incorporates transparent or translucent windows that allow visual inspection of tube engagement without requiring additional active components. This passive optical solution improves ease of operation while adding minimal structural complexity to the cap design.

Inventive Principle:
Principle #32Color changes

3Reliability

If locking elements with angled teeth are used to prevent accidental disengagement, then the reliability is improved, but the ease of manufacture decreases

Engineering Contradiction:
ImprovereliabilityVSAvoidease of manufacture
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The locking elements with angled teeth are pre-formed as integral features of the cap during the molding or forming process, rather than being added as separate components. This preliminary action approach ensures reliable locking while maintaining ease of manufacture through integrated production.

Inventive Principle:
Principle #10Preliminary action

4Reliability

If a collet with resilient fingers is used to grip the tube, then the tube locking reliability is improved, but the device complexity increases

Engineering Contradiction:
Improvetube locking reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The collet incorporates resilient fingers that can dynamically adjust their grip force on the tube based on insertion forces and operational loads. This dynamic response improves locking reliability while the simple spring-like structure of the resilient fingers adds minimal complexity compared to rigid locking mechanisms.

Inventive Principle:
Principle #15Dynamics

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 ensures secure tube locking, easy assembly, and visual verification of tube engagement, while preventing accidental release and fluid ingress, with a simple and cost-effective design suitable for various tube connections.

Implementation Method 1

A tube coupling cartridge with a cap and collet design featuring a tapered cam surface, resilient fingers, and locking elements

Methodology Applied
Scientific EffectTapered cam surface mechanism: Cam

Implementation Method 2

a collet comprising an annular member located in the open end of the cap having a plurality of resilient fingers extending into the cap which engage the tapered surface to be pressed radially inwardly thereby with an axially outward movement of the collet from the cap to engage and grip the outer surface of a tube inserted into the cap to lock the tube in the cap

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

the cap having locking elements for engaging in an annular recess encircling the head of the coupling body to lock the cap axially on the coupling body

Methodology Applied
Scientific EffectMechanical interlocking: Mechanical Fastener

Data Source

PatentEP1933074B1Improvements in or relating to tube couplings
Publication Date: 2013.09.18 JOHN GUEST INT LTD
  • EP1933074B1 patent drawingFigure 1
  • EP1933074B1 patent drawingFigure 2~3
  • EP1933074B1 patent drawingFigure 4

AI summary

The disclosure relates to a tube coupling for receiving and holding an end of a tube comprising, a coupling body (10) including a stem (12) having an end to engage in a tube and an encircling head (11) spaced from said end. A cap (23) is mounted on the head having an open end (29) encircling the stem to receive a tube inserted into the cap over the stem, the cap having an internal tapered cam surface (27) reducing towards the open end of the cap. A tube locking collet (35) is located in the open end of the cap comprising an annular member (37) having a plurality of resilient fingers (38) extending into the cap which engage the tapered cam surface in the cap to be pressed inwardly thereby with an outward movement of the collet from the cap to engage and grip the outer surface of the tube inserted into the cap over the stem to lock the tube in the cap. The cap (23) has locking elements (30) which engage the head (11) of the coupling body to hold the cap against axial movement on the head.