Aircraft Nacelle Hook Latch With Ergonomic Handle Access

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Solution Overview

Problem

Existing aircraft nacelle cowling locks are difficult to access and lack ergonomic design, making them cumbersome and potentially risky for operators.

Innovation Solution

A lock system with ergonomic handles forming a continuous surface in closed configurations, featuring a sliding body and connecting rods for easy operation, integrated with a telescopic device for enhanced accessibility and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the lock is positioned under the gondola to secure the hoods, then the locking function is achieved, but the accessibility and ergonomics for operators deteriorate

Engineering Contradiction:
Improvelocking functionVSAvoidaccessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The lock system transitions from a purely under-gondola position to a multi-dimensional configuration where the console can be oriented at different angles and positions. The telescopic device extends the lock mechanism outward, allowing operators to access handles from multiple directions while maintaining the secure under-gondola mounting position for the main locking function.

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

2Ease of operation

If the lock mechanism is simplified for easier operation, then ergonomics improve, but the security and reliability of the locking system may deteriorate

Engineering Contradiction:
ImproveergonomicsVSAvoidsecurity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The locking system is divided into two independent but interconnected lock mechanisms (first and second handles), each capable of securing the hoods independently. This segmentation allows each handle to be operated separately with improved ergonomics while maintaining overall security through the combined locking action of both handles on the hooking arm.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The console is pre-configured with the hooking arm and hooking bar in a fixed geometric relationship, so that when the handles are operated, the locking action occurs automatically through the pre-established mechanical linkage. This preliminary arrangement ensures secure locking without requiring complex manual manipulation during operation.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If a single handle is used for the lock, then the device complexity is reduced, but the ability to ensure proper closure sequences deteriorates

Engineering Contradiction:
Improvenumber of handlesVSAvoidclosure sequence control
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The two-handle system provides tactile and positional feedback to operators about the closure sequence. The first handle must be closed and secured before the second handle can be fully engaged, creating a natural feedback loop that guides operators through the proper sequence. This mechanical feedback ensures reliable closure without requiring complex electronic controls or increased device complexity.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4474286B1Hook latch for aircraft nacelle covers
Publication Date: 2025.11.05 LISI AEROSPACE
  • EP4474286B1 patent drawingFigure 1
  • EP4474286B1 patent drawingFigure 2
  • EP4474286B1 patent drawingFigure 3

AI summary

The present invention relates to a lock (22) comprising: a bracket (54) adapted to be fixed to a first cover; a latching arm (58) comprising a hook (94) adapted to cooperate with a latching bar (36) fixed to a second cover; a first handle (60) and a second handle (64) rotatable relative to the bracket, the first and second handles being configured such that the second handle (64) in a closed configuration locks the first handle (60) in a closed configuration. In the closed configuration of the second handle (64), a form of the second handle is fitted into a counter-form (106) of the first handle (60) so as to lock the first handle (60) in the closed configuration.