Aircraft Door Locking Cone Mechanism for Self-Centering Under Load

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Gate locking systems for aircraft doors face challenges in centering the gate during closure and dissipating large tensile forces into the frame structure, particularly in aerospace and automobile applications, where high load differences and manufacturing tolerances can lead to misalignment and deformation.

Innovation Solution

A gate locking device featuring an eccentric bushing with a press cone sleeve and clamping cone sleeve, actuated by linear actuators, which allows for the transmission of forces and moments, enabling self-centering of the gate and effective force dissipation into the frame structure, utilizing hydraulic actuators and Teflon coatings for reduced friction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional locking mechanisms are used, then the door can be locked, but the gate cannot self-center during closure and manufacturing tolerances cause misalignment

Engineering Contradiction:
Improvealignment precisionVSAvoidlocking mechanism complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent employs conical surfaces (press cone and clamping cone) instead of cylindrical surfaces to enable self-centering. The conical geometry allows the locking bolt to automatically align itself during the locking process, compensating for manufacturing tolerances and ensuring precise engagement without requiring additional alignment mechanisms.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The locking mechanism is designed to self-center automatically during closure. The interaction between the conical press surface and clamping cone surface generates self-aligning forces that guide the locking bolt into correct position, eliminating the need for external alignment devices or complex adjustment mechanisms.

Inventive Principle:
Principle #25Self-service

2Force

If standard locking devices are used, then the door can be secured, but large tensile forces cannot be effectively dissipated into the frame structure

Engineering Contradiction:
Improvetensile force dissipationVSAvoidinstallation space
Core Design Contradiction:
ForceVSArea of stationary object

Solution Approach 1:

The conical geometry of the press and clamping surfaces converts axial locking forces into radial clamping forces and tangential friction forces. This geometric transformation enables the locking mechanism to effectively dissipate large tensile loads into the frame structure through multiple force vectors, maximizing force transmission in a compact design.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The locking force is distributed through multiple contact surfaces (press cone surface, clamping cone surface, and friction interfaces) rather than concentrated at a single point. This segmentation of force transmission paths allows effective dissipation of large tensile forces across the frame structure while maintaining a compact installation footprint.

Inventive Principle:
Principle #1Segmentation

3Strength

If the locking mechanism is made robust to handle high loads, then force transmission improves, but the device size and complexity increase

Engineering Contradiction:
Improveload bearing capacityVSAvoidmechanism complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The conical surfaces provide inherent mechanical advantage and force multiplication. The geometry naturally distributes and amplifies forces through the locking sequence, enabling a compact mechanism to handle high loads that would otherwise require much larger, more complex structural components.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent replaces complex multi-component locking mechanisms with a streamlined conical press-and-clamp system. The geometric design inherently provides the necessary strength and force transmission capabilities that would traditionally require additional brackets, bolts, and structural reinforcements, thereby simplifying the overall mechanism while maintaining robust load-bearing capacity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 ensures reliable locking and unlocking, compensates for manufacturing tolerances, and effectively transfers high tensile loads into the aircraft frame, maintaining alignment and sealing integrity under varying loads.

Implementation Method 1

an inner cone surface of the press cone sleeve (7) which is in displaceable engagement with an outer cone surface of the clamping cone sleeve (8)

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

utilizing hydraulic actuators and Teflon coatings for reduced friction

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP4098554B1Door locking device and aircraft with door locking device
Publication Date: 2023.10.25 AIRBUS OPERATIONS GMBH
  • EP4098554B1 patent drawingFigure 1~2

AI summary

A door locking device for an aircraft door comprises an eccentric bushing which can be connected to a door frame of the aircraft door leaf, an inner lining inserted in the eccentric bushing which has a bolt receptacle aligned centrally along a bolt receptacle axis for receiving a locking bolt, a press cone sleeve arranged in the inner lining, a clamping cone sleeve whose outer conical surface is in slidable engagement with an inner conical surface of the press cone sleeve, and whose inner cylindrical surface is aligned with the outer wall of the bolt receptacle, and linear actuators mounted on two opposite sides of the press cone sleeve in the inner lining which are designed to displace the press cone sleeve along the bolt receptacle axis relative to the clamping cone sleeve.