AU2007203613A1 - Resin Cartridge Insertion Method & Apparatus - Google Patents

Description

02 Aug 2007 10:23 FRASER OLD AND SOHN 0299552700 p. 3 0"- 0 0

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant(s): Actual Inventor(s): Address for Service: Invention Title: Details of Associated Provisional Applications: Industrial Roll Formers Pty Lid David James FERGUSSON FRASER OLD SOHN Patent Attorneys PO Box 560 MILSONS POINT NSW 1565 Resin Cartridge Insertion Method Apparatus 2006 904 184 Dated 2 August 2006 The following statement is a full description of this invention, including the best method of performing it known to us: COMS ID No: ARCS-155351 Received by 1P Australia: Time 10:32 Date 2007-08-02 02 nug 2007 10:23 FRASER OLD AND SOHN 02 lu 20710:3 RAEROLDAN SHN0299552700 p.4 2 O Field of the Invention The present invention relates to rock bolts and, in particular, to a tubular rock ;Z bolt in which a resin cartridge is able to be inserted into the interior of a blind hole in a rock or mineral face through the interior of the tubular rock bolt.

O B3ackyround Art M Australian Patent Application No. 2004 201 693 (to which US Patent No. 6, IND 033, 153 corresponds) discloses the use of wadding located in a tubular rock bolt and Mn O to the rear of a resin cartridge or sausage. Fluid pressure is applied to the rear of toe 1.0 wadding to force the wadding and the cartridge along the length of the hollow rock O bolt.

The above described arrangement suffers from a number of problems, one of which is that although the cartridge contents are driven clean out of the end of the rock bolt, the fluid (nornally either air or water) under pressure also exits from the end of the tubular rock bolt. This can disrupt the mixing of the resin constituents and the form of the set resin. i particular, bubbles of air or drops of water can form in the set resin thereby reducing its strength.

Genesis of the Invention The genesis of the present invention is a desire to substantially overcome or at least reduce the abovemnentioned difficulty by the provision of an improved resin insertion arrangement SuMM of the Invention in accordance with the first aspect of the present invention there is disclosed a rock bolt -utilizing fluid pressure for resin insertion, said bolt comprising a tube having a leading and a trailing end, an annular seal located at, or adjacent, said tailing end, a piston stop means located at, or adjacent said leading end, and a piston slidably and sealingly mounted within said tube intermediate said seal and stop means.

In accordance with a second aspect of the present invention there is disclosed a driver attachment for a mine drilling machine, said attachment comprising a central body, a generally conical protrusion extending from said body, a plurality of drive 2945DP-AU COMS ID No: ARCS-155351 Received by IP Australia: Time (I-tm) 10:32 Date 2007-08-02 02 Aug 2007 10:23 FRASER OLD AND SOHN 02 ug200 1:23 FRSEROL AN SHN0299552700 3 o recesses in said body and extending around the base of said body to engage with a like plurality of lugs on the trailing end of a rock bolt and said central body being ;Z connectable to a drilling armn of said drilling machine, wherein a fluid passage extends through said central body and conical protrusion to connect a supply of fluid under o) 5 pressure on said drilling arm to said rock bolt trailing end.

In accordance with a third aspect of the present invention there is disclosed a en method of utilizing fluid pressure to insert a resin cartridge into a blind hole in a -rock IND or mineral face via a tubular rock bolt having a leading end and a trailing end, said o) method comprising the steps of, in any order, 10 forming a piston stop means at, or adjacent, said leading end, o(ii) inserting a piston into the hollow interior of said rock bolt, said piston being slidingly and sealingly engaged with the interior of said tube, (iii) locating an annular seal at, or adjacent, the trailing end of said rock bolt, and (iv) inserting said resin cartridge into said rock bolt interior and intermediate said piston and said stop means, and thereafter carrying out the steps of: inserting said bolt leading end into said hole, (vi) applying fluid pressure to said bolt trailing end to accelerate said piston and cartridge towards said leading end, (vii) retaining said piston within said bolt by engagement thereof with said stop means, and (viii) permitting said accelerated ca rtridge to pass said piston stop means and exit said leading end.

Brief Description of the Drawings Two preferred embodiments of the present invention will now be described with reference to the accompanying drawings in which: Fig. I is a truncated longitudinal cross sectional view through the leading end of a tubular rock bolt in accordance with a first embodiment of the present invention, Fig. 2 is a similar cross sectional view through the Wrailing end of the rock bolt of Fig. 1 and also illustrating the leading end of the driver tool used to -rotate the rock bolt of Figs. I and 2, Fig. 3 is a perspective view of the driver tool of Fig. 2 looking from the front thereof, 2945DP-AU COMS ID No: ARCS-155351 Received by IP Australia: Time 10:32 Date 2007-08-02 02 Rug 2007 10:23 FRnSER OLD nND SOHN 02 ug200 1:23 FRSEROL AN SHN0299552700 P.

6 4 o Fig. 4 is a perspective view of the driver tool of Figs. 2 and 3 looking from the rear thereof, ;Z Figs. 5, 6 and 7 are respectively a rear view, a side view and a front view of the driver tool of Figs. 3 and 4, and o Fig. 8 is a longitudinal cross-section through a second embodiment.

~Detailed Descrito INC As seen in Figs. 1 and 2, a tubular rock bolt 1 has a leading end 2 and a trailing Mn oend 3. The leading end 2 preferably includes a number of serrated deformations r- 10 which act to shred a resin sausage or cartridge 40 (illustrated in phantom in Fig. 1).

o In some circumstances, the deformations 5 can also form cutting teeth which enable the rock bolt 1 to be self drilling in soft minerals such as coal or shale. However, normally in hard rock mining applications the rock bolt 1 is inserted into a previously drilled hole which is drilled in conventional fashion using drill steels.

Also formed at, or adjacent to, the leading end 3, is a stop mechanism in the form of one or more inwardly directed crimps 7, each of which extend by a small distance into the smooth bore 8 of the rock bolt 1.

A piston 10 is slidingly located within the bore 8 and includes an annular slot 11 into which an 0-ring 12 is inserted in order to provide a robust seal between the piston 10 and the bore 8. In addition, the piston 10 includes a circumferential inclined groove 14 which undercuts and forms a circumferential lip 15 having a triangular or ramp shaped cross sectional form.

As seen in Fig. 2, at the trailing end 3 of the rock bolt I a castellated ring 17 is welded to the tube forming the rock bolt I thereby permitting the rock bolt 1 to be rotatably driven by means of a driver attachment or tool 20. The rock bolt I includes an annular flat 18 formed from the end of the tube which comprises the body of the rock boltl1.

A sealing sleeve 30 is able to be inserted into the trailing end 3 of the rock bolt 1 as illustrated in Fig. 2. The sleeve 30 has an internal taper 3 1, an annular flange 3 2 and a circumferential step 33. The sealing sleeve 30 is preferably made from a soft 2945DP-AUL COMS ID No: ARCS-155351 Received by P1 Australia: Time 10:32 Date 2007-08-02 02 Aug 2007 10:23 FRASER OLD AND SOHN 02 ug200 1:23 FRSEROL AN SHM0299552700 p.7 o plastic material (typically 45-SOD) and is able to be inserted into the trailing end 3 of the rock bolt I with the annular flange 32 flush with the castellated ring 17 and the ;Z circumferential step 33 engaged with the annular flat 18. A conventional strata plate (or load distributing washer) 9 is provided to engage with the castellated ring 17.

As seen in Figs. 2-7, the driver tool 20 is substantially the same as that en illustrated in Australian Design Registration No. 147, 14 8 (to which US Design Patent IND ~No. 46 8, 753 corresponds) and has a main body 2 1, a conical protrusion 22 and o castellated recesses 23. The driver tool 20 differs from conventional driver tools in having an interior passage 25 and helical grooves 26 on the conical projection 22.

Following fabrication of the rock bolt I. at a factory, and prior to the rock bolt 1 leaving the factory, the piston 10 is manually inserted into the trailing end 3 of the rock bolt 1. Then the sealing sleeve 30 is also positioned into the trailing end 3 in the configuration illustrated in Fig. 2. In this position the piston 10 is either abutting, or is closely spaced fr-om, the sealing sleeve 30. In this condition the rock bolts I are dispatched from the factory to the mine.

At the mine, the blind hole into which the rock bolt I is to be inserted is drilled using the conventional drilling drifter of a JUMBO. The rock bolt I is then "loaded" by passing a strata plate 9 over the leading end 2 and inserting one or more resin cartridges 40 (Fig. 1) into the leading end 2 of the rock bolt 1. The cartridge(s) 40 are permitted to slide downwardly under the influence of gravity towards the trailing end 3. Thus the cartridge, or the lower most cartridge, 40 abuts the piston 10. This loading procedure can be carried out by an assistant whilst the drill operator is drilling the rock face to the correct diameter and depth to suit the rock bolt 1. When the drill operator has completed drilling the required hole, the driver tool 20 is then fitted to the drilling drifter and the loaded rock bolt 1 is then lightly engaged with the driver tool 20 by placing the sealing sleeve 30 of the rock bolt 1 over the conical protrusion 22 and rotating slightly so as to inter-engage the helical grooves 26 and the internal taper 31 of the sleeve 30. With this "self tapping" threaded inter-engagement, the loaded rock bolt I can be moved with the boom and drifter of the JUMBO without dislodging the bolt I from the driver tool 2945DP-AU COMS ID No: ARCS-155351 Received by IP Australia: Time 10:32 Date 2007-08-02 02 Aug 2007 10:24 FRnSER OLD nND SOHN 02 ug207 0:2 FFIEROLDRH SHH0299552700 P- 8 6 o The leading end 2 of the bolt 1 is then positioned in the vicinity of the opening tb of the drilled hole. The drill feed is then engaged by the drill operator so as to extend ;Z the leading end 2 of the bolt 1 to touch the rock or mineral into which the hole is tilled and simultaneously drive the sealing sleeve 30 further into the trailing end 3 so o 5 that the circumferential step 3 3 passes beyond the annular flat 18 and the annular flange 32 abuts the annular flat 18S. The plastic deformation of the sealing sleeve 30 in this configuration results in an excellent fluid tight seal between the rock bolt 1 and the driver tool 20. In addition, the castellations on the castellated ring 17 are also o inter-engaged with the castellated recesses 23 on the driver tool 20. The bolt is then h- 10 positioned by the drill operator to engage the previously drilled hole and insert the o rock bolt I by approximately one third of its length into that hole.

The drill operator then activates a pressure source available to the boom which is communicated via the interior passage 25 of the driver tool 20 to the interior of the rock bolt 1. This pressure source, which is either compressed air or water under pressure, drives the piston 10 forwardly towards the leading end 2 of the rock bolt 1 and thereby carries the resin cartridge(s) 40 along the bore 8. As the lip 15 of the piston 10 passes over the crimp(s) 7 of the rock bolt 1, the lip deforms thereby permitting the crimp(s) 7 to be positively located in the inclined groove 14. This arrests the movement of the piston 10 and stops the piston 10 due to this interengagement. The cessation of movement of piston 10 causes a change in the pressure gauge of the drilling rig which therefore indicates to the drill operator that the piston has reached and engaged with the leading end 2 of the rock bolt 1. This provides a signal to reduce or remove the fluid pressure. At this time, the drill operator then commences to rotate the rock bolt 1 and feed the JUMBO arm thereby causing the resin cartridges 40 to be mixed by the serrated formations 5. Simultaneously the bolt 1 is pressed home so that the castellated ring 17 abuts the strata plate 9 which in turn abuts the rock or mineral surface into which the hole has been drilled. The feed pressure is held to maintain the rock bolt 1 in this position for the recommended resin setting time, thereby allowing the mixed resin to set and secure the rock bolt 1 Because of the good seal between the piston 10 and bore 8, the pressurised fluid does not escape from the rock bolt 1 and thereby become entrained in the mixed resin constituents. The result is a. desirable strong bond between the resin, bolt and 2945DP-AU COMS ID No: ARCS-155351 Received by IP Australia: Time 10:32 Date 2007-08-02 02 Aug 2007 10:24 FRASER OLD AND SOHN 02 ug200 1:24 FRSEROL Ar SHM0299552700 P.9 7 o hole. In addition, the piston 10 and sleeve 30 can be inexpensively fabricated from plastics thereby giving rise to a low-cost arragement The embodiment described in Figs. 1 and 2 can, under extreme circumstances, suffer from two potential problems. Firstly, if the resin cartridge(s) 40 should rapture within the bore 8, it is possible for the material of the cartridge to become jammed between the head of the piston 10 and the bore 8. Secondly, the sealing sleeve 30 may INC become attached to the conical protrusion 22 of the driver tool 20 and therefore pull o out of the rock bolt I when the driver tool 20 is retracted at the conclusion of the installation process. This means that it is necessary for the sealing sleeve 30 to be o manually twisted off the protrusion 22 before the next bolt I can be installed.

The arrangement of the second embodiment illustrated in Fig. 8 substantially overcomes both of these problems. Firstly, as seen in Fig. 8, the leading end of the piston I110 is provided with a concavity 1ll having a thin flexible annular seal 112.

As a consequence, the trailing end of the resin cartridge 40 is cradled in, and better supported by, the concavity Ill I. Thus if the resin cartridge 40 should rupture, the cartridge material and the resin constituents are pushed clear of the bore 8 by the annular seal 112 which flexibly expands to seal against the interior cylindrical. surface of the bore 8.

Furthermore, the trailing end 3 of the rock bolt 1 in addition to being provided with the castellated ring 17 (not illustrated in Fig. 8) is also provided with two machined conical surfaces 114 and 115 respectively.

The sealing sleeve 30, instead of being provided inside the rock bolt 1, is now positioned on the conical protrusion 22 of the driver tool 20. During the installation procedure the tip of the conical protrusion 22 enters the trailing end 3 thereby causing the sealing sleeve 30 to bear against the conical surface 114. Thus the plastic sleeve 3 0 conforms tothe shape of the surfaces 114 and 115 and therefore provides a fluid tight seal with the trailing end 3. At this stage fluid pressure is applied to move the piston 1 10 along the bore 8 towards the leading end 2 as before. Because the sleeve conforms to the shape of the trailing end 3, the sleeve 30 engages with the barb 1 18 between the two conical surfaces 114 and 115. Thus the barb 118 retains the 2945DP-AU COMS ID No: ARCS-155351 Received by IP Australia: Time 10:32 Date 2007-08-02 02 Aug 2007 10:25 FRASER OLD AND SOHN 0299552700 8 osleeve 30 within the rock bolt 1. As a consequence, the sleeve 30 therefore does not pull out of the rock bolt 1 and thus does not need to be rotated off the conical ;protrusion 22. As a result, the second abovementioned problem is avoided.

oThe foregoing describes only two embodiments of the present invention and modifications, obvious to those skilled in the rock bolting arts, can be made thereto en without departing from the scope of the present invention.

oThe term "comprising" (and its grammatical variations) as used herein is used 10 in the inclusive sense of "including" or "having" and not in the exclusive sense of o"consisting only of".

2945DP-AU COMS ID No: ARCS-155351 Received by IP Australia: Time 10:32 Date 2007-08-02

Claims (12)

1. A rock bolt utilizing fluid pressure for resin insertion, said bolt comprising a ;Z tube having a leading and a trailing end, an annular seal located at, or adjacent, said tailing end, a piston stop means located at, or adjacent, said leading end, o and a piston slidably and sealingly mounted within said tube intermediate said seal and stop means. The bolt as claimed in claim I wherein said stop means comprises an IND indentation formed in said tube and extending a short distance into the tube o interior, and said piston includes a circumferential groove having a depth sufficient to mate with said indentation. o3. The bolt as claimed in claim I or 2 wherein said tube is cylindrical said piston includes a circumferential seal which mates with the cylindrical interior of said tube.

4. The bolt as claimed in claim 3 wherein said circumferential seal comprises an 0-ring. The bolt as claimed in any one of claims 1-4 wherein said annular seal comprises a sleeve of resilient material dimensioned to be retained within said trailing end by means of a frictional fit.

6. The bolt as claimed in claim 5 wherein said wrailing end includes an annular lip and said sleeve includes an annular step engageable with said lip.

7. A driver attachment for a mine drilling machine, said attachment comprising a central body, a generally conical protrusion extending from said body, a plurality of drive recesses in said body and extending around the base of said body to engage with a like plurality of lugs on the trailing end of a rock bolt, and said central body being connectable to a drilling arm of said drilling machine, wherein a fluid passage extends through said central body and conical protrusion to connect a supply of fluid under pressure on said drilling ann to said rock bolt trailing end.

8. The attachnment as claimed in claim 7 wherein said central body is annular and said fluid passage is centrally located therein.

9. The attachment as claimed in claim 7 or 8 wherein said conical protrusion includes at least one spiral surface undulation which is able to inter-engage with a seal in the wrailing end of said rock bolt. 2945DP-AUJ COMS ID No: ARCS-155351 Received by IP Australia: Time 10:32 Date 2007-08-02 02 Aug 2007 10:25 FRASER OLD AND SOHN 02 ug200 1:25 FRSEROL AN SHN0299552700 P.12 o 10. A method of utilizing fluid pressure to insert a resin cartridge into a blind hole in a rock or mineral face via a tubular rock bolt having a leading end and a ;Z trailing end, said method comprising the steps of, in any order, forming a piston stop means at, or adjacent, said leading end, o(ii) inserting a piston into the hollow interior of said rock bolt, said piston being slidingly and sealingly engaged with the interior of said tube, en(iii) locating an annular seal at, or adjacent, the trailing end of said rock IND bolt, and o(iv) inserting said resin cartridge into said rock bolt interior and intermediate said piston and said stop means, and thereafter carrying out the steps of: inserting said bolt leading end into said bole, (vi) applying fluid pressure to said bolt trailing end to accelerate said piston and cartridge towards said leading end, (vii) retaining said piston within said bolt by engagement thereof with said stop means, and (viii) permitting said accelerated cartridge to pass said piston stop means and exit said leading end.

11. The method as claimed in claim 10 wherein step (vi) is carried out after said rock bolt is driven substantially fuilly into said hole.

12. The method as claimed in claim 10 wherein step (vii) is carried out whilst said rock bolt is driven substantially fully into said hole.

13. The method as claimed in any one of claims 10- 12 wherein any or all of steps (vi) (viii) are carried out whilst rotating said rock bolt about its longitudinal axis.

14. The method claimed in any one of claims 10-13 including the step of (ix) locating said annular seal on a driver tool used to rotate said bolt A method of utilizing fluid pressure to insert a resin cartridge into a blind hole in a rock or mineral face, said method being substantially as herein described with reference to the drawings.

16. A rock bolt utilizing fluid pressure for resin insertion, said bolt being substantially as herein described with reference to Figs. 1 and 2 or Fig. 8 of the drawings. 2945DP-AU COMS ID No: ARCS-i 55351 Received by IP Australia: Time 10:32 Date 2007-08-02 02 Aug 2007 10:2G FRASER OLD AND SOHN 0299552700 p.13 0 0 ci ci 0 11

17. A driver attachment for a mine drilling machine, said attachment being substantially as herein described with reference to Figs. 2-7 of the drawings. Dated this 1 st day of August 2007 INDUSTRIAL ROLL FORMERS PTY LTD By FRASER OLD SOHN Patent Attorneys for the Applicants 2945DP-AU COMS ID No: ARCS-155351 Received by IP Australia: Time 10:32 Date 2007-08-02