Female Quick Coupling Stem Locking via Radial Half Bushes

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Solution Overview

Problem

Existing quick coupling fittings for pipes face issues with the central stem loosening under hydraulic pressure and elastic forces, leading to potential leakage and instability in fluid transmission systems.

Innovation Solution

The female quick coupling element employs half bushes radially and axially locked in corresponding seats to securely fasten the central stem to the base, eliminating the need for a threaded fastening and lock nut, thereby preventing slacking or loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If threaded fastening with lock nut is used to secure the central stem to the base, then assembly is simplified, but the stem may slacken and the lock nut may slip off under hydraulic pressure and elastic forces

Engineering Contradiction:
Improveassembly simplicityVSAvoidstem positioning stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The fastening system is segmented into multiple functional elements: the base with threaded hole, the central stem with external thread, and the lock nut. This segmentation allows each component to perform its specific function - the base provides mounting, the stem provides adjustability, and the lock nut provides secure fastening - while working together to resolve the contradiction between ease of assembly and reliability under pressure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The lock nut is pre-threaded onto the central stem during assembly before the fitting is put into service. This preliminary action ensures that the stem is securely fastened to the base before hydraulic pressure and elastic forces are applied, preventing slacking and maintaining stable positioning throughout operation

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If the lock nut is used to secure the stem, then the stem can be adjusted and secured, but the lock nut may enter circulation in the hydraulic system

Engineering Contradiction:
Improvestem adjustabilityVSAvoidlock nut loss and circulation
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The lock nut is nested within the fitting structure, specifically positioned to be retained by the base or housing features. This nesting approach allows the lock nut to remain accessible for adjustment while preventing it from detaching and entering the hydraulic system, thus maintaining both adjustability and preventing harmful circulation

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The base acts as an intermediary element between the central stem and the external environment. The base provides a threaded hole that receives and secures the lock nut, creating an intermediate retention point that prevents the lock nut from entering circulation while still allowing the stem to be adjusted and secured

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If threaded fastening is used to secure the stem, then the stem can be firmly attached, but assembly and disassembly becomes more complex

Engineering Contradiction:
Improvestem attachment firmnessVSAvoidfastening mechanism complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The threaded fastening system serves multiple functions: it provides firm attachment of the stem to the base, allows for adjustable positioning, and enables easy assembly and disassembly. By designing the base with an integrated threaded hole and the stem with a matching external thread, the system achieves universal applicability that simplifies the overall fastening mechanism while maintaining strength

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 solution ensures a stable and secure positioning of the central stem, preventing leakage and ensuring easy assembly and disassembly while maintaining the structural integrity under hydraulic pressure.

Implementation Method 1

an axially sliding sealing bush coaxially arranged about said stem and elastically stressed to engage with said widened end of the stem to prevent the passage of fluid within the female quick coupling element

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a cleaning bush coaxially arranged about the sealing bush and axially stressed in position so as to prevent the entrance of dirt about the sealing bush

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP1913300B1Female quick coupling fitting element for pipes.
Publication Date: 2010.09.15 STUCCHI SPA
  • EP1913300B1 patent drawingFigure 1~2

AI summary

A female element (1) is described comprising a hollow internal body (2) having an end (3) provided with fastening means (5) to one of the pipes to be joined, a hollow external body (7) coaxial with said internal body (2) and having an end (8) which axially protrudes with respect to another end (4) of the internal body (2) opposite to that provided with fastening means (5), one rigid central stem (9) coaxially supported by said internal body (2) by means of a transversal perforated base (18) and having a widened end (10) near said protruding end (8) of the external body (7), an axially sliding sealing bush (12) coaxially arranged about said stem (9) and elastically stressed to be engaged with said widened end (10) of the stem (9) to prevent the passage of fluid within the female element (1), a cleaning bush (14) coaxially arranged about the sealing bush (12) and axially stressed in position so as to prevent the entrance of dirt about the sealing bush (12) and a lock sleeve (16) arranged about the protruding end (8) of the external body (7) and engageable with a complementary end of a male element to ensure the stable union of the two male and female elements of the fitting. The stem (9) is fixed to said base (18) by means of at least one half bush (25) radially fitted and axially locked in corresponding seats (26, 27) of said stem (9) and said base (18)