Self-Locking Clamping Nut Geometry for Secure Hose Connectors

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Solution Overview

Problem

Existing watering equipment hoses, particularly those made of materials like textile and PVC, face issues with inadequate connection and self-loosening due to lack of effective clamping mechanisms, leading to cumbersome applications and unsuitable fittings.

Innovation Solution

A hose connector with a clamping nut featuring a nut body with inner and outer threads, angular surfaces, and conical engagement portions that allow for self-locking without external force, ensuring secure attachment of hoses of varying diameters and materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a simple hose connector is used, then the device complexity is reduced, but the connection reliability deteriorates due to self-loosening

Engineering Contradiction:
Improveconnector structureVSAvoidconnection stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The clamping nut incorporates a self-locking mechanism with asymmetric thread geometry that automatically engages and locks the hose in place without requiring external fastening actions. The asymmetric threads create a mechanical interference fit that prevents loosening while maintaining simple installation

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The clamping nut features asymmetric thread profiles with different engagement angles on opposite sides. This asymmetry creates a self-locking effect where the threads naturally bind together under operational conditions, preventing the hose from loosening while keeping the overall structure simple

Inventive Principle:
Principle #4Asymmetry

2Reliability

If a clamping mechanism is added to prevent self-loosening, then the connection reliability improves, but the device complexity increases

Engineering Contradiction:
Improveconnection stabilityVSAvoidconnector structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The clamping function and connecting function are merged into a single integrated clamping nut component. The asymmetric threads perform both the fastening and self-locking functions simultaneously, eliminating the need for separate clamping mechanisms and reducing overall device complexity

Inventive Principle:
Principle #5Merging (Combining)

3Ease of operation

If a self-locking mechanism is implemented, then the ease of operation improves, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveinstallation convenienceVSAvoidthread geometry tolerance
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The asymmetric thread geometry uses specific angle parameters (different engagement angles on opposite sides) that optimize both the self-locking performance and manufacturing feasibility. By carefully selecting these angular parameters, the design achieves reliable self-locking while accommodating standard manufacturing tolerances

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3769001B1A hose connector with a clamping nut
Publication Date: 2023.10.25 HUSQVARNA AB
  • EP3769001B1 patent drawingFigure 1A~1B
  • EP3769001B1 patent drawingFigure 2A~2B
  • EP3769001B1 patent drawingFigure 3

AI summary

A clamping nut (100) for a hose connector (200) includes a first angular surface (302) and a second angular surface (304) defined on an inner surface (122) of a nut body (110) towards the first end (112) and the second end (114) of the nut body (110). The first angular surface (302) and the second angular surface (304) are provided at a first angle (α) and a second angle (β) with a central axis (A-A') of the nut body (110). A contact section (306) is defined on the inner surface (122) of the nut body (110) between the first angular surface (302) and the second angular surface (304). The contact section (306) is adapted to contact a hose (120) when the clamping nut (100) is threadedly coupled to the hose connector (200). Further, inner diameter (d) of the inner surface (122) of the clamping nut (100) across the contact section (306) is substantially identical to an outer diameter (D) of the hose (120), and the first angle (α) has a value in a range of about 90 to 120 degrees.