Tensionable Cable Anchor Assembly With Integrated Wedge Tensioning

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Solution Overview

Problem

Existing cable anchor installation processes in mining and tunnelling are cumbersome due to the need for multiple heavy devices, lack of control over cable length, and potential for inadequate rock support by manipulating the protruding end section.

Innovation Solution

A tensioning device comprising an outer barrel-like member and an inner cylindrical member with a tapered bore, which, when rotated relative to each other, wedges the cable anchor within the rock hole, allowing for precise tensioning and anchoring, and includes a locking mechanism to ensure synchronized rotation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple heavy devices are used for tensioning and cropping cable anchors, then the cable anchor can be installed and tensioned, but the equipment becomes difficult and cumbersome to elevate to the hanging wall of an excavation

Engineering Contradiction:
Improvecable anchor installation reliabilityVSAvoidtensioning and cropping equipment weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent combines the tensioning device and cropping device into a single integrated unit that attaches to the cable anchor. The tensioning device includes a barrel and wedge assembly for tensioning, while the cropping device includes a circular blade for cropping the protruding end section. This merging eliminates the need to handle separate heavy devices for each operation, directly resolving the contradiction between installation reliability and equipment weight/mobility.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single integrated device performs multiple functions: it tensions the cable anchor using the barrel and wedge assembly, crops the protruding end section using the circular blade, and provides a faceplate for support. This multi-functionality allows one device to replace multiple separate devices, reducing overall equipment weight and improving ease of elevation to the hanging wall while maintaining complete installation capability.

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

2Ease of manufacture

If the protruding end section is cropped after tensioning, then the cable anchor can be secured, but control over the length of cable anchor body is lost

Engineering Contradiction:
Improvecable anchor installation simplicityVSAvoidcable anchor length control
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The cropping device is designed with an adjustable positioning mechanism that allows the operator to set the desired crop length before cropping occurs. The circular blade can be positioned at specific distances from the faceplate, providing visual and mechanical feedback to ensure the protruding end section is cropped to the correct length. This feedback mechanism ensures proper cable installation length is maintained while still allowing the anchor to be secured.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The cropping operation is performed immediately after tensioning while the device is still attached to the cable anchor, rather than as a separate subsequent step. The positioning mechanisms for both the tensioning and cropping functions are established before the cropping action, ensuring that the correct length is determined in advance of the actual crop, thereby maintaining length control throughout the process.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If the protruding end section is cropped to cover insufficient hole depth, then the appearance can be improved, but the rock support adequacy is compromised

Engineering Contradiction:
Improveinstallation defect concealmentVSAvoidrock support adequacy
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The integrated device includes a faceplate that serves as an intermediary element between the cable anchor and the rock surface. The faceplate provides a bearing surface for the wedge assembly and distributes the tension load across a larger area of the rock face. This intermediary structure ensures that even if the hole depth is insufficient, the rock support adequacy is maintained through proper load distribution, preventing the need to crop the anchor to conceal the problem.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Facilitates efficient and controlled tensioning of cable anchors, ensuring proper rock support by allowing precise adjustment and preventing manipulation of the anchor length for inadequate support.

Implementation Method 1

an inner cylindrical member (14) with a tapered bore, which, when rotated relative to each other, wedges the cable anchor within the rock hole

Methodology Applied
Scientific EffectWedge: Wedge

Data Source

PatentEP3259448B1Tensionable cable anchor assembly and a tensioning device for tensioning same
Publication Date: 2019.12.04 NCM INNOVATIONS (PTY) LTD
  • EP3259448B1 patent drawingFigure 1~2
  • EP3259448B1 patent drawingFigure 3~4
  • EP3259448B1 patent drawingFigure 5

AI summary

The invention provides a cable anchor assembly which includes: a cable anchor body which longitudinally extends between a leading end and a trailing end; a tensioning device which Includes an outer member having a first end and s second end and a threaded passage which extends through the member between the ends and an inner member which threadedly engages with the threaded passage of the outer member and which Is fixedly attached to the cable anchor body at or towards the trailing end; a faceplate engaged with the cable anchor body between the leading end and the tensioning device; wherein, in use, with the cable anchor body inserted in a borehole and anchored therein, the faceplate positioned against a rock face and the first end of the outer member abutting the faceplate, the outer member is rotatable relatively to the inner member to cause the Inner member to move within the passage towards the second end of the outer member, drawing on the cable anchor body to place the body in tension.