Threaded Locking Connector With Anti-Loosening Interference

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Solution Overview

Problem

Existing locking connectors fail to effectively prevent the loosening of the lock ring due to burrs or sink marks during the molding process. This leads to the loosening of the lock ring, which can cause unintentional disconnection of the connected tubes.

Innovation Solution

The locking connector includes a projecting portion on the male connector or lock ring and a slope portion on the other component, which interferes with the inclined surface during screwing to prevent loosening, ensuring a stable connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional locking connectors are used with simple thread portions, then the structure is simple and easy to manufacture, but the lock ring loosens due to burrs or sink marks from molding defects

Engineering Contradiction:
Improvelock ring stabilityVSAvoidconnector structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The connector is divided into distinct functional portions: a lock ring with a locking portion, a female connector with a slope portion, and a male connector. Each portion has specific features (projecting portions on the lock ring, corresponding recesses on the female connector) that work together to prevent loosening while maintaining manufacturing simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The slope portion is designed to engage with the locking portion before the final tightening is complete. This preliminary engagement creates a mechanical interlock that prevents the lock ring from loosening due to subsequent burr formation or sink marks during the molding process.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If molding is performed without anti-loosening features, then manufacturing is easier and faster, but burrs and sink marks cause the lock ring to loosen

Engineering Contradiction:
Improvemolding processVSAvoidcircumferential surface quality
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The anti-loosening structure with projecting portions and slope portions is designed to compensate for and cushion the adverse effects of molding defects such as burrs and sink marks. These features ensure that even if the circumferential surfaces have imperfections, the locking mechanism remains effective.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The design converts the potential harm of molding defects into a benefit by creating a mechanical interlock system where the projecting portions engage with corresponding features on the female connector. This engagement prevents loosening even when burrs or sink marks are present, effectively making the system tolerant to manufacturing imprecision.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If the lock ring is designed without anti-loosening structure, then the device is simpler, but unintentional disconnection occurs due to loosening

Engineering Contradiction:
Improveconnection stabilityVSAvoidthread portion structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The locking mechanism is segmented into a lock ring with projecting portions and a female connector with corresponding engagement features. This segmentation allows each component to perform its specific function while working together to prevent unintentional disconnection.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The slope portion and locking portion are designed to engage in a preliminary action during the tightening process, creating a mechanical interlock that secures the connection before the final tightening is complete. This preliminary engagement prevents loosening and unintentional disconnection.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4667041A1Locking connector
Publication Date: 2025.12.24 NIKKISO CO LTD
  • EP4667041A1 patent drawingFigure 1
  • EP4667041A1 patent drawingFigure 2
  • EP4667041A1 patent drawingFigure 3

AI summary

A locking connector 1 comprises: a female connector 2 having a male thread portion 23 on the outer circumferential surface thereof; a male connector 3; a lock ring 4 that has a ring shape for surrounding the male connector 3 and pushes the male connector 3 toward the female connector 2 to lock the male connector 3 in a connected state through a female thread portion 41 being screwed onto the male thread portion 23, the female thread portion 41 being provided on the inner circumferential surface of the lock ring 4; one or more projected portions 5 formed on one of the outer circumferential surface of the male connector 3 and the inner circumferential surface of the lock ring 4; and a slope portion 6 formed on the other of the outer circumferential surface of the male connector 3 and the inner circumferential surface of the lock ring 4, the slope portion 6 having one or more inclined surfaces 61 formed at an angle with respect to the circumferential direction so that the diameter of the slope portion 6 gradually increases along the rotation direction of the screwing. The locking connector 1 is configured to prevent the lock ring 4 from loosening through the projected portions 5 coming into interference with the inclined surfaces 61 as the female thread portion 41 is screwed onto the male thread portion 23.