Aircraft Panel Hinge Pin With Bayonet Locking Against Vibration

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Solution Overview

Problem

Existing aircraft propulsion system hinges are difficult to assemble due to limited accessibility, and previous designs suffer from unreliable locking mechanisms that can unlock during vibrations.

Innovation Solution

A hinge design featuring a pin that can be inserted from one side of the yoke, secured by bayonet mounting means with lugs, a locking mechanism, and a handle for easy manipulation, ensuring reliable locking and unlocking without tools.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional screw and nut locking mechanism is used, then reliable locking is achieved, but assembly requires tools and is difficult due to limited accessibility

Engineering Contradiction:
ImproveAssembly easeVSAvoidLocking mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The locking mechanism is segmented into distinct functional elements: the axis with lateral protrusions, the yoke with corresponding receptacles, and the spring-based retention system. This segmentation allows each component to perform its specific function independently while enabling tool-free assembly through sequential engagement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The hinge assembly is designed to be self-servicing through the spring-loaded retention system that automatically secures the axis in the yoke once inserted. The spring mechanism provides automatic locking without requiring external tools or additional fastening operations, allowing maintenance personnel to assemble or disassemble the hinge simply by inserting or extracting the axis.

Inventive Principle:
Principle #25Self-service

2Ease of operation

If small-diameter expandable ball device is used, then tool-free assembly is achieved, but vibration resistance is insufficient causing axis to unlock

Engineering Contradiction:
ImproveAssembly easeVSAvoidLocking reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The invention uses spherical balls embedded in the lateral protrusions of the axis that engage with corresponding recesses in the yoke ears. The spherical geometry allows for smooth insertion and automatic centering during assembly, while the spring-loaded retention system ensures positive locking that resists vibrational forces during operation.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The spring-loaded retention system provides beforehand cushioning by pre-loading the spherical balls into the recesses with sufficient force to prevent accidental disengagement during vibration. The spring mechanism is designed to maintain constant contact pressure on the balls, ensuring reliable locking under dynamic loading conditions while still allowing easy insertion during assembly.

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

3Reliability

If expandable device is used, then axis immobilization is achieved, but assembly complexity increases

Engineering Contradiction:
ImproveAxis immobilizationVSAvoidAssembly mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention extracts the complex expandable mechanism from the assembly process by using a simple spring-loaded retention system instead. The axis can be freely inserted and extracted without requiring activation of complex mechanisms, while the spring balls provide reliable immobilization during operation. This separation of assembly simplicity from operational reliability resolves the contradiction.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using an expandable device that requires activation to lock the axis, the invention inverts the approach by using a spring-loaded system that maintains constant retention pressure on the spherical balls. The axis is immobilized by default through the spring force, and disassembly simply requires overcoming this spring force to extract the axis, eliminating the need for complex expansion mechanisms.

Inventive Principle:
Principle #13The other way round (Inversion)

Data Source

PatentEP4133191B1Pivoting hinge between two panels of an aircraft propulsion system
Publication Date: 2025.08.20 SAFRAN NACELLES
  • EP4133191B1 patent drawingFigure 1
  • EP4133191B1 patent drawingFigure 2
  • EP4133191B1 patent drawingFigure 3~5

AI summary

The invention relates to an aircraft propulsion assembly (10) comprising a hinge (20) for articulating a first and a second of its panels, the hinge (20) comprising a yoke (22) rigidly connected to the first panel (16) and a counter-yoke (24) rigidly connected to the second panel (18), which is received between two lugs (28) of the yoke (22), the yoke (22) and the counter-yoke (24) being passed through by a hinge pin (26), movable between an extended position between the lugs (28) of the yoke (26) and a retracted position outside the yoke (26), characterised in that the hinge comprises bayonet mounting means (30) interposed between the pin (26) and the yoke (22).