Rock Bolt Tension Indicator With Visual Torque Confirmation
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Solution Overview
Problem
Existing rock bolt installation methods often result in inadequate tensioning due to low torque output from installation equipment, leading to suboptimal reinforcement of formations and potential safety hazards from faulty installations.
Innovation Solution
A tension indication device for rock bolts featuring a deformable circumferential wall with slits or weakened portions surrounding an indicator substance, which becomes visible upon proper tensioning, ensuring correct torque application and easy visual confirmation of proper installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual inspection and tightening of rock bolts is performed, then installation accuracy can be improved, but installation time and labor cost increase significantly
Solution Approach 1:
The rock bolt system performs self-inspection through the indicator substance that automatically displays whether the bolt has been properly tensioned. The indicator substance changes position or appearance based on the tensioning state, eliminating the need for manual inspection and allowing workers to quickly identify properly installed bolts without time-consuming checks.
Solution Approach 2:
The indicator substance utilizes color changes or positional changes to visually indicate the tensioning status of the rock bolt. When the bolt is properly tensioned, the indicator substance moves to a visible position or changes color, providing immediate visual confirmation of correct installation without requiring manual measurement or inspection.
2Device complexity
If low torque output installation equipment is used, then equipment cost and complexity are reduced, but bolt tensioning adequacy deteriorates
Solution Approach 1:
The indicator substance provides immediate visual feedback on the tensioning status of the rock bolt. This feedback mechanism allows workers to know instantly whether the bolt has been properly tensioned, enabling them to apply additional torque if needed without complex measurement equipment or procedures.
Solution Approach 2:
The system performs self-verification of proper installation through the indicator substance, which automatically indicates whether adequate tension has been applied. This eliminates the need for complex tensioning equipment or procedures while ensuring reliable installation through simple visual confirmation.
3Reliability
If blind nut with thread-locking fluid is used to prevent co-rotation, then connection reliability is improved, but installation complexity and time increase
Solution Approach 1:
The patent extracts the thread-locking function from a complex blind nut mechanism and implements it through a simple shear pin that breaks at a predetermined torque. This removes the need for blind nuts, thread-locking fluids, and complex prevention mechanisms, while maintaining reliable torque transmission and co-rotation prevention through the simpler shear pin design.
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 tension indication device ensures accurate and consistent tensioning of rock bolts, enhancing formation reinforcement and reducing the risk of accidental collapses by providing a clear visual indication of proper installation.
Implementation Method 1
The circumferential wall portion (9) is configured such that it is deformable by the nut (4) upon tensioning of the central rod (3) at rotation of the nut (4) such that the nut (4) at least partly enters the first space (8)
Implementation Method 2
the indicator substance (7) is forced radially outwards by the expanding circumferential wall portion (9), providing visual indication of proper tensioning
Data Source
Figure 1~4
AI summary
A tension indication device 1 for a rock bolt 2 wherein the tension indication device 1 comprises a support washer 5, a cover member 6 with a central hole for receiving a trailing portion of the rock bolt 2, and an indicator substance 7 provided in a first space 8. The first space 8 is provided in the cover member 6 or in a recess in the support washer 5 for facing the nut 4. Upon rotation of the nut 4, indicator substance 7 is forced out of the first space 8 such that the indicator substance 7 is visible at inspection of the rock bolt 3, thereby indicating the rock bolt 3 has been tensioned.