Push-Fit Tubular Fitting With Anti-Rotation Locking Ring

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Solution Overview

Problem

Existing fittings for pipe and hose connections are costly due to complex manufacturing processes, require soldering for attachment, and lack an anti-rotation device, especially in applications like heat exchangers.

Innovation Solution

A tubular fitting with a separately manufactured locking ring, featuring an annular projection as a cam, allows for easy attachment via soldering or press-fitting and incorporates an anti-rotation device, made from materials like hot-dip galvanized sheet steel or stainless steel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If turned and milled parts are used for fittings, then manufacturing precision and strength are improved, but material costs and weight increase significantly

Engineering Contradiction:
Improvefitting precisionVSAvoidmanufacturing complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent changes the manufacturing method from traditional turned and milled processes to deep-drawn forming processes. This parameter change in manufacturing technique allows achieving the required precision and strength while significantly reducing material costs and simplifying the manufacturing process. The deep-drawn fitting can be produced more efficiently with less material waste.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite construction by combining the deep-drawn metal fitting with a separately manufactured locking ring that can be made from different materials (such as plastic or different metal alloys). This allows optimization of each component for its specific function while reducing overall complexity and cost compared to monolithic turned and milled parts.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If fittings are molded directly onto the tube, then manufacturing complexity is reduced, but the ability to equip with anti-rotation device is lost

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidanti-rotation capability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent divides the fitting into separate components: the main tubular fitting body (molded or deep-drawn) and a separate locking ring assembly. This segmentation allows the fitting body to be manufactured simply while the separate locking ring can be equipped with anti-rotation devices (such as cams or protrusions) that engage with corresponding features on the tube or connector, thus providing both manufacturing simplicity and anti-rotation capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The locking ring acts as an intermediary component between the fitting body and the tube/connector. It provides the anti-rotation functionality through integrated cams or protrusions while allowing the main fitting body to remain simple and easy to manufacture. The locking ring mediates between the simple molded fitting and the requirement for anti-rotation protection.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If conventional components with integrated plastic elements are used, then functionality is improved, but soldering attachment is precluded

Engineering Contradiction:
Improvefunctional integrationVSAvoidsoldering compatibility
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent separates the metal fitting body (which can be soldered to the tube) from the locking ring assembly (which can contain plastic elements or other functional components). This segmentation allows the fitting body to maintain soldering compatibility while the separate locking ring can incorporate functional elements like plastic seals, cams, or locking mechanisms without interfering with the soldering process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the functional elements (such as locking mechanisms, seals, or anti-rotation devices) from the main fitting body and places them in a separate locking ring. This extraction allows the main fitting body to remain suitable for soldering attachment while the extracted functional elements provide the required versatility and functionality in the separate component.

Inventive Principle:
Principle #2Taking out (Extraction)

4Adaptability or versatility

If a separate locking ring is manufactured and connected to the fitting, then anti-rotation device integration is enabled, but device complexity increases

Engineering Contradiction:
Improveanti-rotation integrationVSAvoidassembly complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines the locking ring with the fitting body through firm connection (such as pressing, soldering, or threading) to create an integrated assembly. While the locking ring is a separate component, its integration with the fitting body creates a unified structure that provides anti-rotation functionality without requiring a completely separate assembly process. The merging of components reduces overall assembly complexity compared to using entirely separate parts.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4311969B1Plug-in connector for connecting conduits for liquid or gaseous media
Publication Date: 2026.04.15 HENN GMBH & CO KG
  • EP4311969B1 patent drawingFigure 1~2
  • EP4311969B1 patent drawingFigure 3~4
  • EP4311969B1 patent drawingFigure 5~6

AI summary

The invention relates to a tubular fitting (1) for a push-fit connection on pipes and hoses, for connection with a tubular plug (13, 18), wherein the fitting (1) can be connected to a pipe and/or a hose on one side and can be inserted and locked into the plug (13, 18) on the other, sealingly. For this purpose, the fitting (1) has at least one locking shoulder or locking edge (4) that is at least partially circumferential. The fitting (1), including the at least one locking shoulder or locking edge (4), is manufactured in one piece as a deep-drawn metal part. The invention further relates to a push-fit connection on pipes and hoses using a fitting (1) as described above.