Anchor Plate Load Indicator Using Dome Washers and Color Deformation

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Solution Overview

Problem

Existing roof bolting systems in underground mines lack an efficient and immediate method to assess when the bolting load threshold is exceeded, especially under dynamic loads, without requiring additional measuring devices.

Innovation Solution

A lining system with dome-shaped bolting washers and a thin-walled, toroidally shaped container filled with a liquid colouring agent is placed between the washers, converting load-induced stresses into visual deformations, allowing for quick estimation of stress levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional bolting systems are used without indicators, then the structure is simple, but the ability to assess load threshold is lost

Engineering Contradiction:
Improveload threshold assessmentVSAvoidbolting system structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the bolting system with a load indicator by integrating a thin-walled container filled with liquid coloring agent between the dome-shaped washers. The container is structurally merged with the bolting components, allowing load assessment without adding separate measuring devices. The indicator becomes an inherent part of the bolting assembly.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses a thin-walled container filled with liquid coloring agent that changes color or becomes visible when deformed under load. The container is designed to deform at specific load thresholds, making the color change visible through the dome-shaped washers or through dedicated observation windows, providing immediate visual feedback on bolting load status.

Inventive Principle:
Principle #32Color changes

2Measurement precision

If additional measuring devices are added to assess bolting load, then measurement capability is improved, but device complexity and cost increase

Engineering Contradiction:
Improvebolting load measurementVSAvoidnumber of components
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The bolting system performs its own load assessment function through the integrated thin-walled container indicator. The container automatically deforms and changes color based on the applied load, eliminating the need for external sensors, gauges, or measurement devices. The system serves itself by using its structural components to provide measurement information.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent extracts the measurement function from separate measuring devices and embeds it directly into the bolting system's structural components. The thin-walled container serves dual purposes: maintaining washer spacing and providing load indication through its deformation and color change, thereby removing the need for additional dedicated measuring equipment.

Inventive Principle:
Principle #2Taking out (Extraction)

3Loss of time

If immediate load assessment is required, then response time is improved, but the system requires complex sensing and signaling mechanisms

Engineering Contradiction:
Improveload assessment timeVSAvoidsensing and signaling system
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The patent employs a thin-walled container filled with liquid coloring agent that provides immediate visual indication of load threshold exceedance through color change or visibility changes. When the bolting load deforms the container, the color change is instantly observable, eliminating the need for electronic sensors, signal processing, or complex indication systems while providing immediate assessment.

Inventive Principle:
Principle #32Color changes

Solution Approach 2:

The patent replaces complex electronic sensing and signaling mechanisms with a simple mechanical-deformation-based visual indicator. The thin-walled container's physical deformation under load directly translates to visible color change or positional change, substituting sophisticated electronic systems with a straightforward mechanical-optical indication method that provides immediate feedback.

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

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 immediate macroscopic evaluation of stress levels, identifying compromised stability sections and necessitating protective measures, without the need for additional devices, by utilizing the deformation of the washers and container to indicate when loads reach the yield strength of the bolting material.

Implementation Method 1

a thin-walled container of known compressive strength filled with liquid colouring agent is located between the bolting washers

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 2

filled with liquid colouring agent - enabling immediate macroscopic evaluation of stress levels

Methodology Applied
Scientific EffectColor indication:

Data Source

PatentEP4123119A1Anchor plate system with a bolt load indicator
Publication Date: 2023.01.25 ACAD GORNICZO HUTNICZA IM STANISLAWA STASZICA
  • EP4123119A1 patent drawingFigure 1
  • EP4123119A1 patent drawingFigure 2
  • EP4123119A1 patent drawing

AI summary

The invention relates to an anchor plate system for a rock bolt with a load indicator, containing two bolting washers, at least one lining element and a load indicator element located between the bolting washers, characterised in that bolting washers (5) have a dome shape, are at the same time the components of the anchor plate, and are superimposed one after another on the rod (1) of the bolting protruding from the hole (2), and are secured by the head (4a) of the bolting or the nut (4b), with the domed convexities of the bolting washers (5) are located on opposite sides, while between the bolting washers (5) there is thin-walled container (6) of known compressive strength filled with a liquid colouring agent.