Electric Tertiary Lock for Thrust Reverser Load Path Strength

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Solution Overview

Problem

Conventional tertiary lock systems for thrust reversers are heavy, complex, and challenging to integrate, with hydraulically actuated systems requiring extensive piping and hook-style systems providing a weaker load path.

Innovation Solution

A lightweight, compact, and robust tertiary lock system using a linear electric motor or solenoid to translate a lock member between locked and unlocked positions, preventing unwanted deployment of thrust reversers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hydraulically actuated lock systems are used, then the locking function is reliable, but the system becomes heavy and complex

Engineering Contradiction:
Improvelocking function reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the hydraulic actuation system with an electric motor-driven mechanism. The lock member is actuated by an electric motor that converts electrical energy to mechanical motion, eliminating the need for hydraulic fluid, pumps, valves, and associated piping. This substitution maintains the reliable locking function while dramatically reducing system complexity and weight.

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

2Reliability

If hydraulically actuated lock systems are used, then the locking function is reliable, but the system weight increases

Engineering Contradiction:
Improvelocking function reliabilityVSAvoidlock system weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The electric motor-driven lock mechanism replaces the heavy hydraulic system. Electric motors are significantly lighter than hydraulic systems of equivalent power output, as they eliminate the weight of hydraulic fluid, reservoirs, pumps, and control valves. This substitution maintains reliable actuation while reducing the lock system weight.

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

3Device complexity

If hook style locking members are used, then the locking mechanism is simple, but the load path strength is reduced

Engineering Contradiction:
Improvelocking mechanism simplicityVSAvoidload path strength
Core Design Contradiction:
Device complexityVSStrength

Solution Approach 1:

The locking system is segmented into distinct functional components: the lock member with its blocking surface, the electric motor actuator, and the mounting structure. This segmentation allows each component to be optimized for its specific function - the lock member provides a strong blocking surface that directly interrupts the movable component's path, creating a robust load path without the complexity of hook-style mechanisms.

Inventive Principle:
Principle #1Segmentation

4Weight of moving object

If electric motor actuation is used, then the system weight is reduced, but the integration complexity may increase

Engineering Contradiction:
Improvelock system weightVSAvoidintegration complexity
Core Design Contradiction:
Weight of moving objectVSDevice complexity

Solution Approach 1:

The electric motor is integrated directly into the lock member assembly, with the motor's output shaft directly coupled to the lock member. This merging of the actuator and locking mechanism into a single integrated unit simplifies installation and reduces the number of separate components that need to be assembled and connected, thereby reducing integration complexity despite the advanced actuation technology.

Inventive Principle:
Principle #5Merging (Combining)

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 system provides a reliable and efficient means to prevent thrust reverser deployment, offering a lightweight and robust solution compared to traditional hydraulically actuated or hook-style systems.

Implementation Method 1

a linear electric motor for translating the lock member between the locked position and the unlocked position

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

a solenoid for translating the lock member between the locked position and the unlocked position

Methodology Applied
Scientific EffectElectromagnetic attraction: Electromagnet

Data Source

PatentEP4253747B1Lock system for a thrust reverser
Publication Date: 2026.04.29 GOODRICH ACTUATION SYST
  • EP4253747B1 patent drawingFigure 1
  • EP4253747B1 patent drawingFigure 2A~2B
  • EP4253747B1 patent drawingFigure 3A~3B

AI summary

A lock system (120) for an aircraft thrust reverser includes a lock member (122) translatable between a locked position, in which the lock member is extended for preventing deployment of the thrust reverser by the lock member blocking the path of a movable component (110) of the thrust reverser, and an unlocked position, in which the lock member is retracted for permitting deployment of the thrust reverser by the lock member moving out of the path of the movable component. The lock system also includes a linear electric motor (134, 126) or a solenoid for translating the lock member between the locked position and the unlocked position.