Passive Shaft Locking With Integrated Damper for Aircraft Pedals

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing aircraft control mechanisms, particularly pedal units, are complex, bulky, and consume excessive power due to active locking systems that require continuous power to maintain the locked state during autopilot mode.

Innovation Solution

A resistive and locking system (RLS) that integrates a damper mechanism and a passive locking mechanism within a single housing, where the locking mechanism engages with the damper mechanism to lock the shaft when power is off and unlocks when power is applied, reducing power consumption and size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an active locking mechanism is used to lock pedals during autopilot mode, then the locking reliability is improved, but the power consumption increases significantly

Engineering Contradiction:
Improvelocking reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent inverts the conventional locking approach by using a passive locking mechanism that automatically engages when power is off and disengages when power is applied. This reverses the traditional active locking logic, allowing the system to maintain reliability during autopilot mode without continuous power consumption, as the locking state is achieved through mechanical spring engagement rather than powered actuators

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

Solution Approach 2:

The passive locking mechanism utilizes the aircraft's electrical system state itself to control the locking function. When the aircraft is in autopilot mode (power off state for control surfaces), the spring mechanism automatically engages to lock the pedals. The system serves itself by using the absence of power as the triggering condition for locking, eliminating the need for separate sensors, controllers, or continuous power supply

Inventive Principle:
Principle #25Self-service

2Reliability

If traditional locking mechanisms are integrated into pedal units, then the locking function is achieved, but the device complexity and space occupation increase

Engineering Contradiction:
Improvelocking functionVSAvoidmechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the passive locking mechanism with the existing pedal unit structure, integrating the spring engagement system into the pedal assembly itself. This combination eliminates the need for separate locking components and reduces overall device complexity while maintaining the locking function within the autopilot control system

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent employs a simple spring-based passive locking mechanism that is mechanically robust and requires no complex electronics, control systems, or maintenance. The spring mechanism is a straightforward mechanical component that provides reliable locking through pure mechanical engagement, avoiding the complexity of electronic sensors, motors, or control algorithms

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 RLS achieves a compact design with reduced power consumption by utilizing a passive locking mechanism that engages mechanically when power is off, ensuring efficient operation and minimal space usage in the cockpit.

Implementation Method 1

a spring mechanism, configured to bias the friction plate towards the flying disk

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

a friction plate... configured to frictionally engage with the flying disk to lock the shaft

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

an electromagnetic actuator... configured to move the friction plate away from frictional engagement with the flying disk on application of power

Methodology Applied
Scientific EffectElectromagnetic: Electromagnet

Data Source

PatentEP4375185B1Control unit resistive and locking system
Publication Date: 2025.09.17 RATIER FIGEAC SAS
  • EP4375185B1 patent drawingFigure 1~2
  • EP4375185B1 patent drawingFigure 3~4
  • EP4375185B1 patent drawingFigure 5~6

AI summary

A resistive and locking system for locking rotation of a shaft, the system comprising: a housing (200) defining an axis AX therethrough, the housing (200) containing: a drive shaft (250) mounted in the housing and extending axially from a bottom end of the housing; a first stage comprising a resistive mechanism (210) provided in the housing around the drive shaft to resist rotation of the drive shaft relative to the housing; a second stage comprising a locking mechanism (230) arranged in the housing above the first stage, the locking mechanism biased axially to frictionally engage with and lock the first stage mechanism to prevent rotation of the drive shaft, the locking mechanism including a magnetic unlocking mechanism configured to remove the frictional engagement with the first stage on application of power to the locking mechanism.