Electric Claw Wagon Control for Clean Pulp Unit Lifting

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Solution Overview

Problem

Existing lifting devices for pulp units face challenges in releasing pulp units at the target load handling area due to space constraints, which can lead to safety risks for machinery and personnel, and existing technologies do not allow selective control of claw wagons for efficient handling.

Innovation Solution

A lifting device with claw wagons equipped with electric actuators and a controller unit connected to a crane's control bus, enabling selective control of claw wagons for gripping and releasing pulp units, reducing the need for a hydraulic system and minimizing the risk of contamination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a hydraulic system is used for gripping and releasing pulp units, then the gripping force and reliability are improved, but the risk of hydraulic oil spillage contaminating pulp units increases

Engineering Contradiction:
Improvegripping reliabilityVSAvoidhydraulic oil spillage contamination
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the hydraulic system with an electric actuator system. The electric actuators (motors) directly drive the gripping mechanism through gear mechanisms, eliminating hydraulic oil and the risk of contamination while maintaining reliable gripping through controlled mechanical force transmission.

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

2Ease of operation

If all claw wagons are controlled together for gripping and releasing, then the operational simplicity is improved, but the handling efficiency and adaptability to space constraints worsen

Engineering Contradiction:
Improvecontrol simplicityVSAvoidhandling efficiency
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

The patent divides the control system into independent segments, where each claw wagon can be controlled individually or in groups through the controller unit. This segmentation allows selective operation of specific claw wagons based on load requirements and target area space availability, improving handling efficiency while maintaining operational simplicity through centralized control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control system transitions from a static all-or-nothing approach to a dynamic selective control mechanism. The controller unit can adaptively determine which claw wagons to operate based on real-time conditions, enabling flexible and efficient handling operations that respond to varying space constraints and load configurations.

Inventive Principle:
Principle #15Dynamics

3Area of stationary object

If the target load handling area has limited space, then the space utilization is improved, but the ability to release all pulp units safely worsens

Engineering Contradiction:
Improvetarget area space utilizationVSAvoidsafe release capability
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent enables selective release of individual claw wagons or groups of claw wagons at the target area. When space is limited, the controller unit can determine which claw wagons to release and which to retain, allowing partial release that maintains safety while optimizing space utilization. This segmented approach prevents the need to release all units simultaneously, reducing safety risks in constrained spaces.

Inventive Principle:
Principle #1Segmentation

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 solution allows for safer and more efficient handling of pulp units by enabling selective control of claw wagons, improving space utilization, and reducing the risk of hydraulic oil spillage, thus enhancing safety and operational efficiency.

Implementation Method 1

claw wagons comprising gripping means operatively connected to electric actuators for gripping and releasing pulp units by the gripping means

Methodology Applied
Scientific EffectElectric actuator: Linear Motor

Data Source

PatentEP4110718B1Lifting device for pulp units
Publication Date: 2026.04.15 STEVENEL
  • EP4110718B1 patent drawingFigure 1a-1~1b-2
  • EP4110718B1 patent drawingFigure 2~3
  • EP4110718B1 patent drawingFigure 4~5

AI summary

A lifting device for pulp units with reduced risk of contaminating the pulp units and selective control of claw wagons (1103). The lifting device comprises one or more claw wagons, said claw wagons comprising gripping means operatively connected to electric actuators for gripping and releasing pulp units by the gripping means, a controller unit (1102) configured to connect to a control bus (1114) of a crane and said controller unit being connected to the electric actuators of the claw wagons, and the controller unit is arranged to, in response to receiving at least one control command from the control bus of the crane, to control at least one claw wagon for gripping or releasing pulp units by the gripping means of the at least one claw wagon.