Crane Derrick Ballast Synchronization via Force Feedback

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Solution Overview

Problem

The integration of heavy-duty transport devices as ballast carts in cranes poses safety risks due to the lack of synchronized movement and the inability to handle large forces, which can lead to damage and instability during crane operations.

Innovation Solution

A crane system that integrates a heavy-duty transport device with a mechanical connection and a control system to detect and manage forces resulting from non-synchronous movements, allowing for synchronized operation and minimizing the risk of damage by controlling the transport device through the crane's control system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If heavy-duty transport devices are used as ballast carts, then mobility and cost-effectiveness are improved, but safety and stability deteriorate due to lack of synchronized movement and inability to handle large forces

Engineering Contradiction:
Improveuse of heavy-duty transport devicesVSAvoidsafety during crane operation
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements a control system that continuously monitors the position and movement of the heavy-duty transport device and provides feedback to synchronize its movement with the crane. The control system detects deviations from the desired trajectory and adjusts the transport device's position accordingly, ensuring safe and stable operation throughout the crane's working range.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces a guide structure that acts as an intermediary between the crane and the heavy-duty transport device. The guide provides a defined movement path and mechanical guidance, ensuring that the transport device follows the correct trajectory while allowing for controlled movement. This intermediary structure enables the use of standard transport devices while maintaining crane safety requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the ballast cart is allowed to move independently with its own drive control, then ease of operation is improved, but safety and force control deteriorate due to non-synchronous movement

Engineering Contradiction:
Improveindependent control of transport deviceVSAvoidsynchronized movement
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent merges the control systems of the crane and the heavy-duty transport device into a unified control architecture. The transport device's drive control is integrated with the crane's control system, allowing centralized control while maintaining the transport device's mobility capabilities. This integration ensures synchronized movement while preserving operational flexibility.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements a dynamic control system that adapts the transport device's movement characteristics based on the crane's operational state. The system continuously adjusts the transport device's speed, position, and acceleration to match the crane's movements, enabling safe operation throughout the entire working range while maintaining ease of operation.

Inventive Principle:
Principle #15Dynamics

3Strength

If the structural connection between crane and transport device is made stronger to handle large forces, then strength is improved, but device complexity and cost increase

Engineering Contradiction:
Improveforce transmission capabilityVSAvoidconnection structure
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent uses a guide structure as an intermediary that provides mechanical guidance and force distribution. The guide structure distributes the forces between the crane and the transport device along a defined path, reducing peak forces on individual connection points. This approach provides adequate strength while avoiding the need for overly complex and expensive direct structural connections.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements a dynamic connection system that adapts its force transmission characteristics based on the operational conditions. The connection structure between the crane and transport device can flexibly accommodate force variations through controlled movement along the guide, providing sufficient strength handling capability without requiring a permanently rigid and complex structural connection.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4461693B1Crane with a derrick ballast
Publication Date: 2025.08.13 LIEBHERR WERK EHINGEN
  • EP4461693B1 patent drawingFigure 1
  • EP4461693B1 patent drawingFigure 2~3
  • EP4461693B1 patent drawingFigure 4a

AI summary

The invention relates to a crane comprising a movable undercarriage, a superstructure rotatably mounted on the undercarriage, a luffing jib connected to the superstructure, a derrick jib articulated to the superstructure and braced over it, a crane control system, a guide connected to the superstructure, and a derrick ballast. The derrick ballast comprises a ballast plate for stacking ballast elements, which is connected to the derrick jib via ballast bracing and to the superstructure via the guide, as well as a ballast carriage. The ballast carriage includes a standard heavy-duty transport device with its own drive and drive control. According to the invention, the guide is connected to the ballast plate or the ballast carriage via a connecting device, which includes a measuring device and is configured to detect a force that opposes a relative movement between the ballast carriage and the guide.According to the invention, the crane control is furthermore connected to the drive control of the heavy-load transport device via a control connection and is configured to control and/or regulate the heavy-load transport device depending on the force detected by the measuring device.