AU2021221597A1

AU2021221597A1 - Bore plug assembly

Info

Publication number: AU2021221597A1
Application number: AU2021221597A
Authority: AU
Inventors: Joseph O'connor; William O'Shea; Brett Pettitt
Original assignee: Far West Primary Ind Pty Ltd
Current assignee: Far West Primary Industries Pty Ltd
Priority date: 2020-09-24
Filing date: 2021-08-25
Publication date: 2022-04-07

Abstract

A bore plug assembly 20 comprises a proximal part 30, a distal part 40 and shear pins 50. The proximal part 30 is attached or mounted to the distal part 40 via the shear pins 50. In use, the bore plug assembly 20 is pushed up behind or into a broken rod 110 in a drill hole 112, via a drill rod 11Ob having a distal end thereof received in the engagement cavity 32. When the distal part 40 engages the broken rod 110, the proximal part 30 is continued to be pushed by the drill machine 100, at which the shear pins 50 are adapted to be sheared which releases the proximal part 40 from the distal part 30. The wedge surfaces 34 and 44 ramp up against each other causing the proximal part 30 to deviate from the longitudinal axis of the distal part 40. 40V 20 fi 11 30 [if110 ~20 100 -116 114 106 102 104 FIGURE 1 50 40 30 (a) 40 40__ _ 30 ()(b) 503 FIGURE 2

Description

40V fi 11

30 [if110

~20

100 -116

114

106 102 104 FIGURE 1 50

40

30

(a)

40

40__ _

30

()(b) 503

FIGURE 2

BOREPLUGASSEMBLY

Field of the Invention

[1] The present invention relates to a bore plug assembly for a drilled hole. The invention is primarily intended for the mining industry, but is not limited to this use.

Background of the Invention

[2] A long hole drill rig is an underground drilling machine, an example of which is illustratively shown in Figure 1 as machine 100. Drill rig machine 100 comprises a vehicle power unit with operator cabin 102, a telescopic boom 104 and a drilling unit 106. From an underground drive 114, they tend to drill upwards into an ore body 116 above them.

[3] In circumstances where drill rods 110 break in a drill hole 112, the drill rods are sometimes left in the drill hole 112. With no access to these broken rods 110, after some time, they can dislodge and then proceed to charge down the hole 112, entering the underground drive 114 where the drill rig was and with considerable force. This can potentially harm persons or damage equipment.

[4] The present invention seeks to overcome or substantially ameliorate at least some of the deficiencies of the prior art, or to at least provide an alternative.

[5] It is to be understood that, if any prior art information is referred to herein, such reference does not constitute an admission that the information forms part of the common general knowledge in the art, in Australia or any other country.

Summary of the Invention

[6] According to a first aspect, the present invention provides a bore plug assembly for a drilled hole, the assembly comprising a proximal part and a distal part connected to each other via a releasable connection means, wherein forcing the distal part against an object in a drilled hole via the proximal part releases the connection means which causes the proximal part to move relative to the distal part which effectively expands the bore plug assembly within the drilled hole.

[7] In a preferred embodiment, the releasable connection means are shear pins.

[8] In another preferred embodiment, the proximal part comprises a wedge shaped front end which engages a corresponding wedge shaped rear end of the distal part.

[9] In another preferred embodiment, the proximal part and the distal part each have a generally cylindrical body.

[10] In another preferred embodiment, the proximal part has a rod engagement cavity at a rear end thereof.

[11] In another preferred embodiment, the body has a diameter slightly smaller than the diameter of the drill hole.

[12] In another preferred embodiment, the wedge shaped ends are formed by the end portions thereof being cut at an angle of about 30° relative to the longitudinal axis of the body.

[13] In another preferred embodiment, the wedge shaped ends each comprise an engagement surface having ratchet teeth formations formed therein which will engage and lock with each other in use.

[14] In another preferred embodiment, the distal part comprises a rounded front end

[15] In another preferred embodiment, spaced pin apertures are formed in the second end portions, the pin apertures of the proximal part and the distal part being respectively aligned when assembled.

[16] In another preferred embodiment, each shear pin comprises a cylindrical body which is dimensioned for interference fit into the aligned apertures of the proximal part and the distal part.

[17] In another preferred embodiment, the length of each shear pin is substantially equal to the diameter of the proximal part and the distal part.

[18] In another preferred embodiment, wherein when assembled, the wedge surfaces face and abut each other at which the apertures of the proximal part and the distal part are aligned, and the longitudinal axes of the proximal part and the distal part are generally aligned.

[19] In another preferred embodiment, when assembled, the proximal part and the distal part form a generally whole cylinder.

[20] The invention also provides a method of plugging a bore hole, the method comprising pushing an assembly as per any of the above behind or into an object in a drill hole, and when the distal part engages the object, the proximal part is continued to be pushed at which the shear pins are adapted to be sheared which releases the proximal part from the distal part causing the proximal part to deviate from the longitudinal axis of the distal part

[21] Other aspects of the invention are also disclosed.

Brief Description of the Drawings

[22] Notwithstanding any other forms which may fall within the scope of the present invention, preferred embodiments of the present invention will now be described, by way of examples only, with reference to the accompanying drawings in which:

[23] Figure 1 shows an illustration of an underground mining assembly in use, with a broken drill rod in a drill hole, and use of the bore plug assembly according to a preferred embodiment of the present invention;

[24] Figure 2 shows (a) front perspective view, (b) side view and (c) end view of the bore plug assembly;

[25] Figure 3 shows (a) top perspective view, (b) top view, (c) side view and (d) end view of the proximal part of the bore plug assembly,

[26] Figure 4 shows (a) top perspective view, (b) top view, (c) side view and (d) end view of the distal part of the bore plug assembly, and

[27] Figure 5 shows (a) front perspective view, (b) side view and (c) end view of a shear pin of the bore plug assembly

Description of Embodiments

[28] It should be noted in the following description that like or the same reference numerals in different embodiments denote the same or similar features.

[29] Figures 1 and 2 show a bore plug assembly 20 according to a preferred embodiment of the present invention. The bore plug assembly 20 comprises a proximal part 30, a distal part 40 and shear pins 50. The proximal part 30 is attached or mounted to the distal part 40 via the shear pins 50.

[30] Referring to Figures 2 and 3, the proximal part 30 comprises a generally cylindrical body 31 having a rod engagement cavity 32 at a first (rear) end 33 thereof and a wedge surface 34 at a second (front) end portion 35 thereof. The body 31 has a diameter slightly smaller than the diameter of the drill hole 112 with the engagement cavity 32 being sized to receive the distal end of a drill rod 11Ob therein. The wedge surface 34 is formed by the second end portion 35 being cut at an angle of between 30° to 50°, preferably 30° relative to the longitudinal axis of the body 31. The second end portion 35 is thus a generally pointed end. The wedge surface 34 comprises ratchet teeth formations 36 formed therein. Theformations 36 are formed perpendicular to the longitudinal axis of the body 31, being across the wedge surface 34. Two spaced pin apertures 37 are formed in the second end portion 35, the pin apertures 37 extending perpendicularly to the longitudinal axis of the body 31 and extending from the wedge surface 34 and through to the opposite side of the body 31.

[31] Referring to Figures 2 and 4, the distal part 40 is similarly shaped and comprises a generally cylindrical body 41 with a generally conically shaped or rounded first (front) end 43 and a wedge surface 44 at a second (rear) end portion 45 thereof. The body 41 has the same diameter as the body 31. The wedge surface 44 is also formed by the second end portion 45 being cut at an angle of about 30° relative to the longitudinal axis of the body 31. Thesecond end portion 45 is thus also a generally pointed end. The wedge surface 44 comprises ratchet teeth formations 46 formed therein which correspond to the ratchet teeth formations 36, in that the ratchet teeth formations 36 and 46 will engage and lock with each other in use. The formations 46 are thus also formed perpendicular to the longitudinal axis of the body 41, being across the wedge surface 44. Two spaced pin apertures 47 are also formed in the second end portion 45, the pin apertures 47 extending perpendicularly to the longitudinal axis of the body 41 and extending from the wedge surface 44 and through to the opposite side of the body 41.

[32] Referring to Figures 2 and 5, each shear pin 50 comprises a cylindrical body 51 which is dimensioned for interference fit into aligned apertures 37 and 47 of the proximal part 30 and the distal part 40. The length of each shear pin 50 is substantially equal to the diameter of the proximal part 30 and the distal part 40.

[33] To assemble the bore plug assembly 20, the wedge surfaces 34 and 44 face and abut each other at which the apertures 37 and 47 of the proximal part 30 and the distal part 40 are aligned. The longitudinal axes of the proximal part 30 and the distal part 40 are also generally aligned. Two shear pins 50 are inserted into the aligned apertures 37 and 47. This retains the distal part 40 to the proximal part 30. When assembled, the proximal part 30 and the distal part 40 form a generally whole cylinder as the second end portions 35 and 45 thereof match.

[34] In use, the bore plug assembly 20 is pushed up behind or into a broken rod 110 in a drill hole 112, via a drill rod 11Ob having a distal end thereof received in the engagement cavity 32. The assembled bore plug assembly 20 provides a generally smooth outer surface from the conical front end 43 thereof to the engagement cavity 32 which assists with insertion of the bore plug assembly 20 through the drill hole 112 via the drill machine 100. When the distal part 40 engages the broken rod 110, the proximal part 30 is continued to be pushed by the drill machine 100, at which the shear pins 50 are adapted to be sheared which releases the proximal part 40 from the distal part 30. The wedge surfaces 34 and 44 ramp up against each other causing the proximal part 30 to deviate from the longitudinal axis of the distal part 40. The bore plug assembly 20 thus effectively expands in diameter inside the drill hole 112 at which both the proximal part 30 and the distal part 40 engage the walls of the drill hole 112 and/or the broken drill rod 110. The ratchet teeth formations 36 and 46 can remain engaged and locked with each other, which retains the bore plug assembly 20 in its'expanded' position within the drill hole 112 which plugs the drill hole 112 and wedges the broken drill rod to remain in place.

[35] The bore plug assembly 20 thus comprises two main components and utilises shear pins that hold the assembly together until activated by force provided from the long hole rig, and by coming into contact with the rods still stuck in the drill hole. the shear pins break off and the main components effectively expand, wedge in place and are locked to each other. The assembly expands and locks inside the hole and prevents harm to persons and damage to equipment from uncontrolled movement of drill rods used underground.

[36] Although a preferred embodiment of the present invention has been described, it will be apparent to skilled persons that modifications can be made to the embodiment shown.

[37] For example, the wedge surfaces can include guide means to ensure they remain in contact in use. The expansion means of the bore plug assembly 20 can also be embodied in other forms such as by the distal part expanding radially via force from the proximal part.

[38] The distal part can comprise two or more separate components, each respectively engaging the proximal part. The proximal part in this case can have respective two or more wedge surfaces.

[39] Another possible modification includes the omission of the ratchet/serration formations 36 and 46, and to have smooth faces for the wedge surfaces 34 and 44. This will provide a smooth face/friction lock method.

Claims

Claims The claims defining the invention are as follows:

1. A bore plug assembly for a drilled hole, the assembly comprising a proximal part and a distal part connected to each other via a releasable connection means, wherein forcing the distal part against an object in a drilled hole via the proximal part releases the connection means which causes the proximal part to move relative to the distal part which effectively expands the bore plug assembly within the drilled hole.

2. The assembly of claim 1 wherein the releasable connection means are shear pins.

3. The assembly of claim 1 wherein the proximal part comprises a wedge shaped front end which engages a corresponding wedge shaped rear end of the distal part.

4. The assembly of claim 1 wherein the proximal part and the distal part each have a generally cylindrical body.

5. The assembly of claim 1 wherein the proximal part has rod engagement cavity at a rear end thereof.

6. The assembly of claim 4 wherein the body has a diameter slightly smaller than the diameter of the drill hole.

7. The assembly of claim 3 wherein the wedge shaped ends are formed by the end portions thereof being cut at an angle of about 30° relative to the longitudinal axis of the body.

8. The assembly of claim 3 wherein the wedge shaped ends each comprise an engagement surface having ratchet teeth formations formed therein which will engage and lock with each other in use.

9. The assembly of claim 3 wherein the distal part comprises a rounded front end.

10. The assembly of claim 3 wherein spaced pin apertures are formed in the second end portions, the pin apertures of the proximal part and the distal part being respectively aligned when assembled.

11. The assembly of claim 10 wherein each shear pin comprises a cylindrical body which is dimensioned for interference fit into the aligned apertures of the proximal part and the distal part.

12. The assembly of claim 11 wherein the length of each shear pin is substantially equal to the diameter of the proximal part and the distal part.

13. The assembly of claim 10 wherein when assembled, the wedge surfaces face and abut each other at which the apertures of the proximal part and the distal part are aligned, and the longitudinal axes of the proximal part and the distal part are generally aligned.

14. The assembly of claim 13 wherein when assembled, the proximal part and the distal part form a generally whole cylinder.

15. A method of plugging a bore hole, the method comprising pushing an assembly as per any of claims 1 to 14 above behind or into an object in a drill hole, and when the distal part engages the object, the proximal part is continued to be pushed at which the shear pins are adapted to be sheared which releases the proximal part from the distal part causing the proximal part to deviate from the longitudinal axis of the distal part.