Automated Cable Tensioning for Crane Distributor Carriage

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Solution Overview

Problem

Manual tensioning of distribution cables in cranes is hazardous, costly, and requires frequent maintenance, affecting safety and productivity due to the need for manual effort at height and frequent re-tensioning.

Innovation Solution

An automated tensioning device for distribution cables, featuring a motor, differential drum mechanism, and an automated control system with a stop, elastic return member, and proximity sensor, allowing for autonomous tension adjustment and zeroing of the distributor carriage's reference position, eliminating the need for manual intervention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If manual tensioning of distribution cable is performed by operator on jib, then cable tension can be adjusted, but safety risk increases and operational cost increases

Engineering Contradiction:
Improvecable tension maintenanceVSAvoidsafety risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system performs automatic self-tensioning of the distribution cable through the control unit receiving signals from the distributor carriage position sensor and activating the winch motor to wind the cable onto the drum when slack is detected, eliminating the need for manual intervention and thereby removing the safety risks associated with operators working at height on the jib

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the manual mechanical tensioning operation with an automated electromechanical system comprising a control unit, sensor for detecting carriage position, and winch motor that automatically winds the cable onto the drum to maintain proper tension, substituting human physical effort with automated mechanical and electrical components

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

2Reliability

If manual tensioning operation is performed, then cable tension is adjusted, but maintenance downtime increases and productivity decreases

Engineering Contradiction:
Improvecable tension maintenanceVSAvoidcrane operation continuity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The automatic tensioning system operates continuously in the background, monitoring distributor carriage position and actively winding cable onto the drum when slack is detected, ensuring uninterrupted maintenance-free operation and eliminating periodic shutdowns for manual re-tensioning, thereby maintaining continuous crane productivity

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The control unit receives continuous feedback signals from the position sensor monitoring the distributor carriage location, and based on this feedback automatically activates the winch motor to wind the cable when the carriage reaches predetermined positions indicating cable slack, creating a closed-loop automatic control system that maintains tension without intervention

Inventive Principle:
Principle #23Feedback

3Reliability

If frequent re-tensioning is performed manually, then cable tension is maintained, but operational cost increases

Engineering Contradiction:
Improvecable tension maintenanceVSAvoidmaintenance complexity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system automatically monitors and maintains cable tension through the control unit receiving position signals and activating the winch motor as needed, eliminating the need for manual maintenance operations and thereby reducing operational costs associated with worker deployment, equipment, and safety measures for manual tensioning

Inventive Principle:
Principle #25Self-service

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 automated system ensures safe, efficient, and precise tensioning of distribution cables, reducing maintenance costs and downtime, improving crane operation and productivity by allowing automated re-tensioning without manual effort, thus enhancing safety and reliability.

Implementation Method 1

a return member (8) of elastic nature inserted between said fixed structural element (22) and said stopper (7)

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3415458B1Device and method for automatic tensioning of a dispensing cable for a crane
Publication Date: 2020.03.11 MANITOWOC CRANE GROUP FRANCE
  • EP3415458B1 patent drawingFigure 1
  • EP3415458B1 patent drawingFigure 2~3
  • EP3415458B1 patent drawingFigure 4

AI summary

An automated tensioning device (1) for a distributor cable (4) ensuring the movement of a distributor trolley (3) along a crane boom, comprising a motor cooperating with the cable for the movement of the trolley, a tensioning mechanism for adjusting the cable tension, and an automated control system comprising: - a stop (7) movable between a rest position and several working positions in the presence of a pushing force exerted by the trolley; - a return member (8) urging said stop towards its rest position and offering a force resisting a push exerted by the trolley; and - a proximity sensor (9) detecting the stop in its rest position and its working positions; - a control unit connected to the motor and the sensor to control an adjustment of the cable tension according to a stroke of the stop between its rest position and its working positions.