AU2021200885A1

AU2021200885A1 - Sleeve for a drill rod and related method and system

Info

Publication number: AU2021200885A1
Application number: AU2021200885A
Authority: AU
Inventors: Troy Evans; Dale Harper
Original assignee: Ezy Mining Solutions Pty Ltd
Current assignee: Ezy Mining Solutions Pty Ltd
Priority date: 2020-02-12
Filing date: 2021-02-11
Publication date: 2021-08-26

Abstract

P10279.AU Specification for filling - 11/02/2021 -8 ABSTRACT A sleeve for a drill rod for indicating a depth of a hole drilled into a wall by the drill rod, the sleeve being removably securable to the rod towards a drive end thereof, wherein in use, as the drill rod drills and advances into the wall to form the hole, the sleeve advances with 5 the drill rod towards the hole and indicates to a user to cease drilling when the sleeve advances proximate to or substantially reaches the level of the wall. 1/3 6 FIGURE 1

Description

1/3

6

FIGURE 1

P10279.AU Specification for filling - 11/02/2021

Sleeve for a drill rod and related method and system

Field of the invention The present invention relates to a sleeve for a drill rod used in mining applications, and a related method and system.

Background It is known to install rock bolts into rock walls and rooves to help stabilise rock excavations, such as in mining applications and the like. An example of a rock bolt 2 being installed in a predrilled hole formed in a roof 4 of a mine is shown in Figure 1. In this Figure, an elongate hole has been predrilled by a drill rod driven by a drilling machine. Resin containing retainers or capsules 6 are then inserted towards the rear of the hole, and the roof bolt 2 is then screwed into the hole, thereby bursting the resin capsules and unleashing resin therein to encapsulate a shaft 8 of the roof bolt 2.

To ensure adequate encapsulation of the roof bolt 2, it is important for the depth of the hole to correspond with the length of the roof bolt 2 to be installed. For example, if the hole is overdrilled (i.e. too deep), the roof bolt 2 may not extend to the rear of the hole and may even be too shallow to burst one or more resin capsules 6 and thus may not be adequately encapsulated by resin. This can result in inadequately secured rock bolts 2 and bolt corrosion.

It is common that for a specific rock excavation or mine site, rock bolts 2 of various lengths need to be installed, thereby requiring holes of various depths to be drilled. However, drill rods typically come in standard lengths and are relatively specialist pieces of equipment which are difficult, if not costly to customize, as are the drilling machines used to drive them. As such, even though holes of different depths need to be drilled, they are typically formed by drill rods of the same length. As such, drill operators often resort to eyeballing or guessing how far to drill into a rock wall or roof to reach a desired hole depth.

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In an attempt to take the guesswork out of drilling these holes, drill rods have been provided with simple visual markers painted on the drill to indicate to the drill operator how far the drill rod has been drilled into a rock wall. However, these indicators have not proven to be effective because the drill rod, and thus the visual indicator, often gets coated in dirt, mud or dust. This is not helped by the fact that such drilling usually occurs in low visibility environments.

There is a need to address the above, and/or at least provide a useful alternative.

Summary According to a first aspect of the present invention, there is provided a sleeve for a drill rod for indicating a depth of a hole drilled into a wall by the drill rod, the sleeve being removably securable to the rod towards a drive end thereof, wherein in use, as the drill rod drills and advances into the wall to form the hole, the sleeve advances with the drill rod towards the hole and indicates to a user to cease drilling when the sleeve advances proximate to or substantially reaches the level of the wall.

In embodiments of the invention, the sleeve comprises a substantially hexagonal inner for fitting over the drill rod.

In embodiments of the invention, the sleeve comprises a substantially cylindrical outer sized to fit within a drill guide of a drill machine to which the drill rod is engaged.

According to a second aspect of the present invention, there is provided a method of drilling a hole of a predefined depth into a wall, the method comprising: securing a sleeve to a drill rod towards a drive end thereof such that the sleeve advances with the drill rod as the drill rod drills the hole; drilling the drill rod into the wall and advancing it therein to form the hole; and ceasing drilling when the sleeve has advanced proximate to or substantially reaches the level of the wall.

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In embodiments of the invention, the sleeve comprises a sleeve according to the first aspect of the invention.

According to a third aspect of the invention, there is provided an assembly for drilling into a wall a hole of a predefined depth, the system comprising: a drill rod; a drilling machine for driving the drill rod into the wall; and a sleeve removably secured to the drill rod toward a drive end thereof and configured to advance with the drill rod toward the hole formed thereby.

Brief description of the drawings In order that the invention may be more easily understood, an embodiment will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a cross-sectional side view of a rock bolt being installed into a predrilled hole in a roof of a mine; Figure 2 is a rear perspective view of a drilling machine used to drive a drill rod; and Figure 3 is a cross-sectional top view of a sleeve according to an embodiment of the invention.

Detailed description Figure 2 shows a drilling machine 10 with a drill rod 12 used to drill holes in which rock bolts are installed. The drill rod 12 has a hexagonal cross-section and extends through

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two drilling guides 14 of the drilling machine 10 which help to guide the drill rod 12 as it advances forward to drill a hole.

Figure 3 shows a cross-sectional top view of a sleeve 16 according to an embodiment of the present invention. From the exterior, the sleeve 16 has the appearance of a longitudinal cylinder that may be formed in a range of lengths to suit different drill rod 12 lengths and different hole depth requirements. The sleeve 16 has a hollow hexagonal inner 18 which corresponds with the hexagonal cross-section of the drill rod 12. As such, the sleeve 16 can readily slide onto and be rotationally engaged with the drill rod 12. The sleeve 16 has a cylindrical outer 19 to allow the sleeve 16 to fit in and advance through the corresponding cylindrical drill guides 14 of the drilling machine 10. The sleeve 16 may be formed from hardened steel.

In use, a sleeve 16 of a desired length is slid onto the drill rod 12 towards a drive end thereof (in Figure 3, the drive end is also indicated by reference numeral 12). As the drill rod 12 is advanced forward during the drilling of a hole, the sleeve 16 also advances forward toward the hole being drilled. When the front of the sleeve 16, that is, the end of the sleeve furthest from the drive end 12, advances proximate to or is substantially at the level of the wall or roof being drilled, the operator can visually tell that he or she should stop drilling and that the required depth of the hole has been reached. Additionally, even if the operator cannot visually tell that the sleeve 16 has reached the level of the wall or roof being drilled, impact between the sleeve 16 and the rock wall can help provide feedback to the operator to stop drilling.

By selecting sleeves 16 of an appropriate length, the operator can easily drill holes of the desired depth without relying on guesswork. The following is a crude but illustrative example of how the present sleeves 16 can be fitted to drill rods 12 to enable the accurate drilling of holes of a desired depth. Suppose a hole two metres in depth is required to be drilled and suppose the drill rod 12 is 2.5 metres long. The operator can thus fit a 50 cm sleeve 16 to the drill rod 12 such that when the sleeve 16 reaches the level of the surface being drilled, the operator can tell that the hole being drilled has reached 2 metres in depth.

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Then, suppose the next hole is required to be 2.2 metres in depth. The operator can thus easily slide the 50 cm sleeve off the drill rod 12 and replace it with a 30 cm sleeve 16. In this way, neither the drill rod 16 nor the drilling machine 10 requires any expensive or difficult modification, and yet they can be used to accurately drill holes of different depths simply with the addition of removable and retrofittable sleeves 16.

Many modifications of the above embodiments will be apparent to those skilled in the art without departing from the scope of the present invention. For example, the sleeve 16 may be coated in a bright or otherwise easy to see colour so that it is easy to see in underlit environments. The inner and outer of the sleeve 16 need not necessarily have hexagonal or cylindrical profiles, respectively, and could have other profiles which allow the sleeve 16 to slide over the drill rod 12 and advance through any drilling guides 14 of the drilling machine 10.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Claims

P10279.AU Specification for filling - 11/02/2021 -6 CLAIMS:

1. A sleeve for a drill rod for indicating a depth of a hole drilled into a wall by the drill rod, the sleeve being removably securable to the rod towards a drive end thereof, wherein in use, as the drill rod drills and advances into the wall to form the hole, the sleeve advances with the drill rod towards the hole and indicates to a user to cease drilling when the sleeve advances proximate to or substantially reaches the level of the wall.

2. The sleeve of claim 1, wherein the sleeve comprises a substantially hexagonal inner for fitting over the drill rod.

3. The sleeve of claim 1 or 2, wherein the sleeve comprises a substantially cylindrical outer sized to fit within a drill guide of a drill machine to which the drill rod is engaged.

4. A method of drilling a hole of a predefined depth into a wall, the method comprising: securing a sleeve to a drill rod towards a drive end thereof such that the sleeve advances with the drill rod as the drill rod drills the hole; drilling the drill rod into the wall and advancing it therein to form the hole; and ceasing drilling when the sleeve has advanced proximate to or substantially reaches the level of the wall.

5. The method of claim 4, wherein the sleeve comprises the sleeve of any one of claims 1 to 3.

6. An assembly for drilling into a wall a hole of a predefined depth, the system comprising: a drill rod; a drilling machine for driving the drill rod into the wall; and a sleeve removably secured to the drill rod toward a drive end thereof and configured to advance with the drill rod toward the hole formed thereby.

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7. The system of claim 6, wherein the sleeve comprises the sleeve of any one of claims 1 to 3.

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FIGURE 1

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FIGURE

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FIGURE 3