Magnet Device with Dislodging Member for Rebar Extraction

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Solution Overview

Problem

Existing magnet devices struggle to efficiently pull out rebars from compacted rubble due to concrete fragments acting as anchors, making it difficult to dislodge and remove rebars, especially when the rubble layer is densely compacted during demolition.

Innovation Solution

A magnet device equipped with a dislodging member that can be extended beyond the magnet to dislodge rubble, allowing the magnet to attract and pull out rebars while maintaining relative orientation with the dislodging member, which can be selectively moved between operative and inoperative modes to handle different debris types, and featuring an actuator for vibration to ease force requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a magnet device is brought close to the surface of compacted rubble to attract rebars, then the magnet can engage the portion of rebar lying on the surface, but it becomes difficult to pull the rebar extending into the rubble from the compacted rubble due to concrete fragments acting as anchors

Engineering Contradiction:
Improveease of rebar extractionVSAvoidforce required to pull rebar
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The dislodging member performs preliminary action by breaking the compacted rubble and freeing the rebar from concrete anchors before the magnet attempts to extract it. This preliminary loosening action reduces the force needed for subsequent rebar extraction by eliminating the anchoring effect of compacted concrete fragments.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The dislodging member acts as an intermediary tool between the magnet and the rebar. Instead of the magnet directly pulling the rebar from compacted rubble (which requires excessive force), the dislodging member first prepares the rebar by breaking surrounding concrete, making the extraction process feasible with normal magnetic force.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the dislodging member extends beyond the magnet to dislodge rubble, then space is created for easier rebar extraction, but the device complexity increases due to additional components and mounting mechanisms

Engineering Contradiction:
Improveefficiency of rebar removalVSAvoidcomplexity of magnet device structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The magnet and dislodging member are merged into a single integrated device with a common frame and mounting mechanism. This combination allows both functions (magnetic attraction and mechanical dislodging) to be performed simultaneously or sequentially by one device, improving productivity without requiring separate equipment.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The magnet device is designed with multi-functionality, combining the rebar-attracting magnet with the rubble-dislodging member in one universal tool. This allows the device to handle both the loosening of compacted rubble and the extraction of rebars, making it suitable for various debris types and conditions.

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

3Adaptability or versatility

If the dislodging member is mounted on the magnet or frame, then the magnet and dislodging member are displaceable as a unit by the operating arm, but the magnet cannot be brought close to the rubble surface without the dislodging member potentially contacting the surface first

Engineering Contradiction:
Improveadaptability to different rubble orientationsVSAvoidease of magnet positioning
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The device employs dynamic positioning where the dislodging member can be selectively extended or retracted relative to the magnet. This dynamic adjustment allows the operator to position only the necessary component (dislodging member or magnet) close to the rubble surface depending on the specific task, making the device adaptable to different rubble orientations while maintaining ease of operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The device is segmented into functionally independent but mechanically connected components (magnet and dislodging member) that can move or adjust independently. This segmentation allows the magnet to be positioned separately from the dislodging member, enabling the magnet to approach the rubble surface without the dislodging member necessarily contacting it first.

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

Enables easier extraction of rebars from compacted rubble by creating space for dislodging and allowing the magnet to attract and pull out rebars effectively, with the ability to handle various debris types and reduce force requirements through vibration, enhancing operational efficiency.

Implementation Method 1

the magnet can attract rebars present in the rubble

Methodology Applied
Scientific EffectMagnetic attraction: Magnetism

Implementation Method 2

featuring an actuator for vibration to ease force requirements

Methodology Applied
Scientific EffectVibration: Vibration

Data Source

PatentEP2918732B1Magnet device and method
Publication Date: 2021.01.13 K W SUPPLY BEHEER
  • EP2918732B1 patent drawingFigure 1
  • EP2918732B1 patent drawingFigure 2
  • EP2918732B1 patent drawingFigure 3

AI summary

The present invention relates to a magnet device (1) for clearing rubble (35) containing rebars (37). Demolition of concrete structures results in a quantity of rubble which contains not only broken concrete but also rebars which have served as reinforcement in the concrete structure and have pieces of broken concrete thereon. A magnet device (1) according to the invention comprises a magnet (3) and at least one dislodging member (5, 7, 9, 11) positioned at the magnet (3).