Uplock Retention Detection Using a Single Sensor and Target

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Solution Overview

Problem

Existing latching mechanisms in aircraft components fail to reliably detect whether the olive is actually retained by the hook, despite the hook being in the engaged position, due to complex sensor arrangements or calibration issues with multiple targets.

Innovation Solution

A single proximity sensor system with an indicator lever and movable support, where the target position changes only if both the hook is in the holding position and the olive is present, implementing a mechanical AND function without logical processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a second proximity sensor is added to detect olive presence, then detection reliability is improved, but device complexity increases

Engineering Contradiction:
Improvedetection reliabilityVSAvoidsensor arrangement complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the detection of hook position and olive presence into a single proximity sensor system. The indicator lever integrates both functions: its position indicates olive presence while its interaction with the movable support indicates hook position, allowing one sensor to detect both conditions through the mechanical coupling of the lever system.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The indicator lever serves multiple functions simultaneously: it acts as an olive presence indicator, a hook position indicator through its interaction with the movable support, and a mechanical linkage that translates both conditions into a single detectable target position. This multi-functionality eliminates the need for separate sensors.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Device complexity

If a single proximity sensor detects multiple targets simultaneously, then device complexity is reduced, but measurement precision deteriorates due to calibration difficulties

Engineering Contradiction:
Improvesensor configuration simplicityVSAvoiddetection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system performs preliminary mechanical processing of the detection conditions through the indicator lever and movable support mechanism. The mechanical AND function is executed beforehand by the kinematic constraints, so the proximity sensor only needs to detect the final integrated position without needing to process multiple target signals or perform complex calibration.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The indicator lever and movable support act as mechanical intermediaries that translate the complex condition of hook engagement and olive presence into a simple binary target position. This mechanical mediation eliminates the need for the sensor to directly interpret multiple conditions, maintaining high detection accuracy with a single sensor.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If logical processing is used to combine sensor signals, then detection reliability is improved, but device complexity increases

Engineering Contradiction:
Improvedetection reliabilityVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the electronic logical processing system with a mechanical AND function implemented through the indicator lever and movable support. The mechanical constraints ensure that the target only reaches the sensor when both conditions are met, eliminating the need for electronic logic circuits or software processing while maintaining reliable detection.

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

Ensures safe and reliable detection of the hook's position and olive presence using a simplified sensor configuration, eliminating false readings and ensuring the moving element is securely retained.

Implementation Method 1

a single target positioned between a first position and a second position, a proximity sensor arranged to detect the position of the target

Methodology Applied
Scientific EffectProximity sensing:

Data Source

PatentEP4045401B1Uplock provided with retention detection means
Publication Date: 2025.12.03 SAFRAN LANDING SYSTEMS
  • EP4045401B1 patent drawingFigure 1~2
  • EP4045401B1 patent drawingFigure 3~4

AI summary

The invention concerns an uplock for the selective retention of an olive (200) of a moving element, the uplock comprising a hook (3) that can move between a release position and a retaining position of the olive of the moving element, and a locking member (10) that can move between a locking position, in which it immobilises the hook in the retaining position, and an unlocking position, in which the hook is free to move under the thrust of the olive of the moving element, the uplock being equipped with detection means which include a sensor (31) associated with a single target (32) that can move between two positions so that the sensor emits a signal which is modified when the target moves from one of the positions to the other, the target being in kinematic interaction with the hook and the olive so that the target is maintained in one of its positions and can only be brought into the other of its positions if the hook is in the retaining position and the olive is actually present in the hook.