Female Coupling Element With Frustoconical Locking Member

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Solution Overview

Problem

Existing fluid coupling connections, particularly in motor vehicle hydraulic braking systems, face issues with radial compactness and surface matting due to point contact between locking members and surfaces, leading to weak locking and potential jamming or breakage under high operating pressures.

Innovation Solution

A female coupling element with a locking member capable of combined pivoting and translation movement, featuring a surface of revolution contact area and elastic return mechanism, along with lateral guidance and tapered surfaces to distribute forces and prevent surface caulking, ensuring secure locking and compact design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If balls are used as locking members in point contact with the male element, then radial compactness is achieved, but surface matting occurs and locking firmness deteriorates

Engineering Contradiction:
Improveradial compactnessVSAvoidlocking firmness
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The locking member transitions from point contact (0D) to linear segment contact (1D) to surface contact (2D). The locking part features a frustoconical surface that contacts the male element over an extended area, distributing forces and preventing surface matting while maintaining radial compactness through the compact overall geometry of the locking member.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The contact geometry is changed from spherical (balls) to frustoconical surfaces. This parameter change in contact area and distribution transforms the stress concentration into distributed stress, eliminating surface matting while preserving the compact radial dimension through optimized surface geometry.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If clearance is provided between the locking part and housing to allow movement, then locking member mobility is enabled, but misalignment and jamming risk increase

Engineering Contradiction:
Improvelocking member mobilityVSAvoidalignment stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The connection part acts as an intermediary element between the locking part and control part. It provides lateral guidance through grooves in the housing, constraining the locking member's movement path while allowing the necessary pivoting and translation for locking/unlocking operations, thus preventing misalignment and jamming.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The locking member is designed to perform a combined movement of pivoting and translation along the coupling axis. This dynamic motion path, guided by the connection part and housing grooves, enables smooth transitions between locked and unlocked positions while maintaining proper alignment throughout the movement sequence.

Inventive Principle:
Principle #15Dynamics

3Volume of moving object

If a small contact surface is used between male element and locking part, then radial compactness is maintained, but surface matting occurs and locking strength is limited

Engineering Contradiction:
Improveradial sizeVSAvoidlocking strength
Core Design Contradiction:
Volume of moving objectVSStrength

Solution Approach 1:

The contact interface is expanded from a small area to a frustoconical surface extending over a sector angle of at least 30 degrees. This dimensional expansion in the angular direction increases the effective contact area and locking strength while the compact radial profile is maintained through the conical geometry that tapers toward the axis.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 enhances the locking firmness and longevity of the connection while maintaining radial compactness, reducing surface caulking and preventing jamming or breakage, thereby improving the reliability and service life of the coupling.

Implementation Method 1

at least one elastic member for returning the locking member to the locked position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2048425B1Female connection element and connection including such a female element
Publication Date: 2012.04.11 STAUBLI FAVERGES SA
  • EP2048425B1 patent drawingFigure 1
  • EP2048425B1 patent drawingFigure 2~6
  • EP2048425B1 patent drawingFigure 3~5

AI summary

The element (2) has a body (30) with a duct to receive a male element (3) along a coupling axis (X-X'). Three locking units are movable between locking and unlocking positions. An annular control ring (37) drives the locking units from the locking position to the unlocking position. Side guiding units guide a connecting part (331) and/or a controlling part (332) during movement of the locking units. A surface of a locking part (330) is in contact with the element (3). A width, along the orthoradial direction, of the part (331) and/or the part (332) is lower than the width of the locking part.