Frusto-conical Linking Device for Coaxial Hinges

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Solution Overview

Problem

Existing mechanical linking devices for parts with coaxial bores face challenges such as accessibility issues, size constraints, and sealing problems, particularly when one side is not accessible or when bores are not through bores, requiring complex machining and multiple parts for assembly.

Innovation Solution

A mechanically linking device featuring a cylindrical body with a frusto-conical bore and a complementary insert, allowing for adjustable clearance and deformation to fit different bore diameters and lengths without the need for tapping or specific machining, using a screw to lock the device in place and create a rotoide joint.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a tapped bore is provided to allow attachment of an axle when one side is not accessible or the bore is not a through bore, then the mechanical link can be established, but the manufacturing complexity and machining requirements increase

Engineering Contradiction:
ImproveAccessibility for assemblyVSAvoidMachining complexity
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The device employs a frusto-conical expandable element that changes its dimensional parameters (diameter) upon insertion and expansion. This allows the same basic structure to adapt to different bore diameters and lengths without requiring custom-tapped bores for each application, thereby reducing machining complexity while maintaining ease of assembly in restricted spaces

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The mechanically linking device is designed as a universal solution that can be installed in various bore configurations (through bores, blind bores, different diameters, different lengths) without requiring specialized variants. The expandable frusto-conical element provides this universality by adapting to the specific bore dimensions encountered, eliminating the need for complex pre-machining operations

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

2Manufacturing precision

If the mechanically linking device is adapted to exact dimensions of coaxial bores, then precise fitting is achieved, but the adaptability to different bore sizes is reduced

Engineering Contradiction:
ImproveFitting precisionVSAvoidAdaptability to different bore dimensions
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The frusto-conical element transitions from a compressed state (smaller diameter) during insertion to an expanded state (larger diameter) after installation. This dynamic behavior allows a single standardized component to achieve precise fitting in bores of varying dimensions, simultaneously maintaining both manufacturing precision and adaptability across different applications

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The device changes its critical dimensional parameter (diameter of the frusto-conical element) from a fixed value to a variable value that adapts to the bore size. This parameter change enables the same component to fit precisely in different bore dimensions without requiring custom manufacturing for each size

Inventive Principle:
Principle #35Parameter changes

3Reliability

If multiple parts (nuts, circlips, etc.) are used to maintain the junction axle, then the mechanical link is secure, but the device complexity increases

Engineering Contradiction:
ImproveConnection securityVSAvoidNumber of parts
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention merges multiple functions (expansion, locking, securing, and positioning) into a single integrated frusto-conical element. This element simultaneously provides the mechanical expansion force, creates the locking action against bore walls, and maintains the connection security that would otherwise require separate nuts and circlips, thereby reducing part count while maintaining reliability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The frusto-conical element is self-actuating through the insertion process itself. As the element is inserted into the bore, it automatically expands and locks into position without requiring additional fastening operations or separate securing components. The insertion action serves multiple purposes: positioning, expansion, and locking, eliminating the need for additional parts

Inventive Principle:
Principle #25Self-service

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

Enables flexible assembly of parts with coaxial bores of varying diameters and lengths, reducing manufacturing constraints and eliminating the need for complex machining or additional parts, while providing a robust and adjustable mechanical link suitable for hinges and rotoide joints.

Implementation Method 1

the slotted end portion is radially deformed by the cooperation of the insert of frusto-conical shape accommodated in the frusto-conical bore of substantially complementary shape

Methodology Applied
Scientific EffectMechanical expansion: Deformation

Data Source

PatentEP2452083B1Device for mechanically linking at least two parts having coaxial bores
Publication Date: 2019.09.04 AIRBUS OPERATIONS (SAS)
  • EP2452083B1 patent drawingFigure 1A~1C
  • EP2452083B1 patent drawingFigure 2A~2C
  • EP2452083B1 patent drawingFigure 3~4

AI summary

The present invention relates to a device for mechanically linking with rotating axis at least two parts (P1, P2), which is adapted to extend in a longitudinal direction (X) in coaxial bores (A1, A2) formed respectively in said at least two parts (P1, P2) hinged in relation to each other around the axis (X), wherein it comprises: - a cylindrical body (10) comprising at least one end portion (13) provided with at least one longitudinal slot (13a), said cylindrical body (10) comprising in said longitudinal direction (X) a cylindrical bore extended by a frusto-conical bore (12) extending in said at least one end portion (13) intended to be located in the bore (A2) of part (P2); - an insert (20) of frusto-conical shape substantially complementary to said frusto-conical bore (12), said insert (20) including a tapped aperture (21) extending in said longitudinal direction (X) when said insert (20) is accommodated in said frusto-conical bore (12), and - a screw (30) with a threaded end (31) adapted to cooperate by screwing with said tapped aperture (21) of said insert (20) allowing to lock the cylindrical body (10) in the bore (A2) and making a rotoide joint around axis (X).