Cable Fouling Detection Using Electrical Contact Sensor

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Solution Overview

Problem

Cable mis-wraps and fouling during winding and unwinding operations in cable hoist systems, such as rescue hoists, lead to equipment damage and operational delays due to misalignment, binding, and electrical conductivity issues, which existing technologies fail to address effectively.

Innovation Solution

A motor-driven hoist system with electrically-conductive cables and sensors that detect fouling by generating an alarm signal and adjusting motor control to prevent further winding or unwinding, utilizing an electrically-grounded sheave with a grounding brush and sensitivity adjusters to realign the cable and prevent damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cable winding operations are performed without contact detection, then the system structure remains simple, but cable mis-wraps and fouling cause equipment damage and operational delays

Engineering Contradiction:
Improvecable winding reliabilityVSAvoiddetection system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex optical or proximity sensors with a simple electrical contact sensor that detects cable fouling through direct physical contact. This mechanical/electrical substitution achieves reliable detection while maintaining system simplicity, resolving the contradiction between reliability improvement and complexity increase.

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

Solution Approach 2:

The cable itself serves as the detection trigger by making electrical contact with the sensor when fouling occurs. The system uses the cable's own position and contact properties to generate the detection signal, eliminating the need for complex external sensing mechanisms and achieving reliable detection with minimal added complexity.

Inventive Principle:
Principle #25Self-service

2Object-affected harmful factors

If real-time cable fouling detection is implemented, then equipment damage is prevented, but system complexity and cost increase

Engineering Contradiction:
Improveequipment damage from cable foulingVSAvoidsensor and control system complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent uses a simple electrical contact sensor instead of complex optical or capacitive sensors to detect cable fouling. This mechanical contact approach provides reliable real-time detection that prevents equipment damage while keeping the sensor and control system complexity minimal.

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

Solution Approach 2:

The contact sensor is a simple, low-cost component that can be easily replaced if needed. This approach allows for robust real-time protection against equipment damage using an inexpensive sensing element that does not require complex electronics or expensive materials.

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

3Speed

If contact sensors are used for cable fouling detection, then real-time response is achieved, but the cable may bind or flip on the sensor

Engineering Contradiction:
Improvedetection response speedVSAvoidcable smooth operation
Core Design Contradiction:
SpeedVSEase of operation

Solution Approach 1:

The patent introduces a cable guide positioned between the cable and the contact sensor. This intermediary component ensures the cable passes smoothly past the sensor without binding or flipping, while still allowing the sensor to detect cable fouling through electrical contact. The guide resolves the contradiction by mediating the interaction between the cable and sensor.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Device complexity

If cable mis-alignment is allowed to occur, then the system operates without alignment mechanisms, but the cable becomes fouled and strained

Engineering Contradiction:
Improvealignment mechanism complexityVSAvoidcable operation reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements a feedback system where the contact sensor detects cable fouling and mis-alignment, and the controller responds by adjusting the cable reel or alerting the operator. This feedback loop maintains cable operation reliability without requiring complex mechanical alignment mechanisms, as the system actively monitors and corrects alignment issues through electrical detection and control.

Inventive Principle:
Principle #23Feedback

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 real-time response to cable fouling, preventing equipment damage and operational delays by adjusting motor control and ensuring proper alignment of the cable, thus enhancing the reliability and safety of cable-reeling operations in hoist systems.

Implementation Method 1

the cable comprises helically wound, intertwined strands, in which the strands physically contact other strands along the cable. Where the cable is made of metal, it is electrically conductive.

Methodology Applied
Scientific EffectElectrical conductivity: Conduction (electrical)

Implementation Method 2

the electrically-grounded sheave includes a grounding brush

Methodology Applied
Scientific EffectElectrical grounding: Conduction (electrical)

Data Source

PatentEP3636581B1Cable offset detection with contact
Publication Date: 2023.03.15 GOODRICH CORP
  • EP3636581B1 patent drawingFigure 1~2
  • EP3636581B1 patent drawingFigure 3
  • EP3636581B1 patent drawingFigure 4~5

AI summary

A hoist system for cable-reeling operations includes a housing (28); a drum (22) disposed within the housing and configured to spin about an axis; a motor (20) configured to spin the drum about the axis; an electrically-conductive cable (14) configured to be wound and unwound from the drum as the motor spins the drum about the axis; an electrically-grounded sheave (38) configured to guide the electrically-conductive cable through the housing; and an electrical contact sensor (30) configured to detect contact with the electrically-conductive cable.