WO2020047562A1

WO2020047562A1 - An integrated bolt rotator and grout nozzle device for use in a mechanised bolting application

Info

Publication number: WO2020047562A1
Application number: PCT/ZA2019/050053
Authority: WO
Inventors: Greig KNOX; Paolo Ettore Pastorino; James William Sheppard
Original assignee: Epiroc Holdings South Africa (Pty) Ltd
Priority date: 2018-08-28
Filing date: 2019-08-27
Publication date: 2020-03-05
Also published as: ZA201905641B

Abstract

The invention provides an integrated bolt rotating and a grout delivery device for use in a mechanised rock bolting application which includes a bolt rotator (28) which has a shaft (30) with a first end, adapted for engagement to a drill rig drive means, and a second end (34) in which a rock bolt engaging socket (36) is defined; and a grout delivery nozzle which has a body (38), a grout duct (46) formed through the body adapted to channel a grout material from an exterior to an interior of the body; wherein the body (38) is adapted to engage the shaft (30) to move reciprocally along the shaft between a forward position, in which the body at least partially overlaps the second end of the shaft, and a retracted position in which the body is spaced from the second end.

Description

AN INTEGRATED BOLT ROTATOR AND GROUT NOZZLE DEVICE FOR USE IN

FIELD OF THE INVENTION

[0001] The invention relates to an integrated bolt rotator and pumping nozzle device for use in a mechanised rock bolting application.

BACKGROUND OF INVENTION

[0002] In a typical mechanised rock bolting procedure, a rock hole is drilled into a rock face, a rock bolt is inserted into the rock hole and the rock bolt is mechanically anchored and tensioned therein. Then an adhesive material, such as a resin or grout, is pumped into rock hole to fix the bolt in the rock hole.

[0003] A drill rig is employed to achieve this mechanised procedure. A typical drill rig for this process has a boom with a carousel. The carousel is pivotally movable and rotatable relatively to the boom. On the carousel, a drill is engaged. The drill is actuated to drill the rock hole.

[0004] The carousel can also support a rock bolt, in a holder, and includes a drive means which after axial alignment, drives the rock bolt into the rock hole. In doing so, the drive means engages a trailing end of the rock bolt. To achieve this, a leading end of the drive means often is adapted not only to provide a driving force, to insert the rock bolt, but also, to spin the rock bolt, once the bolt is inserted, to place the bolt in tension. [0005] In a grouted rock bolt application, the carousel additionally supports an adhesive material input means, such as a nozzle or injection pipe, connected to a feed hose and pump.

[0006] For each installation, the carousel must rotate to index the relevant tool (i.e. drill, drive means, nozzle) with the rode hole and/or the rock bolt. So, for example, once the rock hole has been drilled by the drill, the carousel is rotated to bring the rock bolt in register with the rock hole, so that it may be driven into the rock hole by the drive means, as the drill rotates away. Once the rock bolt has been driven into the rock hole and tensioned, the drive means rotates away as the nozzle rotates into alignment with the trailing end of the roc* bolt.

[0007] Aligning the nozzle with the trailing end of the rock bolt and engaging the nozzle with the trailing end, so that the nozzle ports with grout input apertures on the trailing end of the bolt, requires time-consuming precision.

[0008] The invention at least partially solves the aforementioned problems.

SUMMARY OF INVENTION

[0009] Hereinafter, the term “grout" is used to refer to any adhesive material, whether a resin based adhesive or a cementious adhesive.

[0010] The invention provides an integrated bolt rotating and a grout delivery device for use in a mechanised rock bolting application which includes a bolt rotator which has a shaft with a first end, adapted for engagement to a drill rig drive means, and a second end in which a rock bolt engaging socket is defined; and a grout delivery nozzle which has a body, a grout duct formed through the body adapted to channel a grout material from an exterior to an interior of the body; wherein the body is adapted to engage the shaft to move reciprocally along the shaft between a forward position, in which the body at least partially overlaps the second end of the shaft, and a retracted position in which the body is spaced from the second end.

[0011] The nozzle body may be engageable to a pneumatic or hydraulic moving means to move the body between the retracted position and the forward position.

[0012] The nozzle body may include a first inlet port into the grout duct engageable to a grout source.

[0013] The nozzle body may include a second inlet port which communicates the exterior of the body with the conduit. The second inlet port may be connectable to a water source for flushing of the grout conduit.

[0014] The nozzle body may have a passage through which the shaft is received in engagement of the body to the shaft to circumscribe the shaft.

[0015] The grout conduit may terminate in a distributing channel formed in a wall of the passage and the grout conduit terminates in the distributing channel formed in a wall of the passage.

[0016] The invention further provides a method of introducing a grout into a rock hole, post installation of a rock bolt, which rock bolt includes, on a threaded projecting section of the bolt, a docking member which has a grout conduit which communicates an exterior surface of the member with a grout tube which extends into an interior of the rock hole, and a tensioning nut between the docking member and a projecting end of the bolt, using the device described above, the method includes the steps of:

(a) engaging the socket with the nut when the nozzle body is in the retracted position;

(b) spinning the bolt rotator to turn the nut along the threaded section of the bolt into load supportive abutment with the docking member;

(c) moving the nozzle body from the retracted position to the forward position to receive at least part of the docking member within the passage of the body engage with the docking member in a position in which the grout conduit of member sealingly docks with the grout duct of the nozzle body;

(d) pumping a grout into the rock hole via the first inlet port, the grout duct, the grout conduit and the grout tube.

[0017] The method may include the additional step, after step (d), of retracting the nozzle body and pumping water through the grout duct, via the second inlet port, to flush the grout duct of residual grout.

£0018] A grouted rock bolt installation method in accordance with another aspect of the invention is provided, which method includes the steps of (a) providing a rock bolt which includes, on a threaded projecting section of the bolt, a docking member which has a grout conduit which communicates an exterior surface of the member with a grout tube which extends into an interior of the rock hole, and a tensioning nut between the docking member and a projecting end of the bolt; (b) inserting the rock bolt into a predrilled rock hole; (c) providing a device in accordance with the preceding statemens; (d) engaging the socket with the nut when the nozzle body is in the retracted position; (e) spinning the bolt rotator to turn the nut along the threaded section of the bolt into load supportive abutment with the docking member; (f) moving the nozzle body from the retracted position to the forward position to receive at least part of the docking member within the passage of the body engage with the docking member in a position in which the grout conduit of member sealingly docks with the grout duct of the nozzle body; and (g) pumping a grout into the rock hole via the first inlet port, the grout duct, the grout conduit and the grout tube.

[0019] The method may include the additional step, after step (e), of retracting the nozzle body and pumping water through the grout duct, via the second inlet port, to flush the grout duct of residual grout

[0020] The invention extends to an integrated bolt rotating and a grout delivery device for use in a mechanised rock bolting application which includes a bolt rotator which has a shaft with a first end, adapted for engagement to a drill rig drive means, a second end which has a rock bolt engaging socket, a bore which extends at least partially through the shaft opening at the socket and an aperture opening through a wall of the shaft into bore; and a grout delivery terminal which has a body with a grout duct and a first inlet port and which body engages the shaft over the aperture to communicate an exterior of the body with the bore.

[0021] The shaft may include an opening which opens into the bore and through which a flushing fluid, such as water, may be passed to flush the bore of residual grout.

[0022] The device may include a check valve in the bore between the aperture and the opening which is configured to close when grout flows in a back direction towards the first end of the shaft and to open when a flushing fluid flows in a forward direction towards the second end of the shaft.

[0023] The grout delivery terminal may have a circular body which circumscribes the shaft.

[0024] The shaft may include a radial plurality of apertures formed through the wall.

[0025] The grout delivery terminal may include a distributing channel formed in a wall of the body which leads from the grout duct and which distributes grout around the shaft to access the plurality of apertures.

[0026] The invention provides a method of introducing a grout into a rock hole, post installation of a rock bolt, which rock bolt is hollow, defining a tube which opens at each end of the bolt, and which bolt has a tensioning nut on a threaded projecting section of the bolt, using the device described above, the method includes the steps of: (a) engaging the socket with the nut and spinning the bolt rotator to turn the nut along the threaded section of the bolt into load supportive abutment with a faceplate on the bolt; and

(b) pumping a grout into the rock hole via the aperture, the bore of the shaft and the tube of the rock bolt.

[0027] The method may include the additional step of pumping water through the hole and along the bore, via the check valve, to flush the bore of residual grout.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The invention is described with reference to the following drawings in which:

Figure 1 diagrammatically represents a drill rig to which a which an integrated bolt rotating and a grout delivery device in accordance with the invention is engaged;

Figure 2 - 6 is a chronological series of drawings showing a first embodiment of the device of the invention in operation; and

Figures 7 - 10 is a chronological series of drawings showing a second embodiment of the device of the invention in operation.

[0029] Figure 1 illustrates a drill rig 10 that is used in a mechanised rock hole drilling and rock bolt installation process. [0030] The drill rig 10 has a boom 12 that is pivotally connected to the body 14 of the rig to bring a carousel 16 to a rock face 18 within which the installation is to take place.

[0031] The carousel is pivotally and rotationai!y moveable relatively to the boom. The carousel comprises a plurality of functional components including a rock drill 20, a rock bolt holder 22, supporting a rock bolt 24, and grout delivery device 26 which is in accordance with the invention.

[0032] In a first embodiment, illustrated in Figure 2, the device 26A includes a bolt engaging component 28 and a grout delivery component 32. The bolt engaging component comprises a shaft 30 with a first end (not shown) and an opposed second end 34. The first end is adapted for attachment to a drill rig, preferably to the drive means 35 of the drill rig. The second end 34 of the shaft is adapted with a socket 36.

[0033] The drive means can be hydraulically or pneumatically actuated and can impart both axial and rotational drive to the shaft. The axial drive not only brings the shaft into guiding engagement with the rock bolt but it can also drive the rock bolt into a predrilled rock hole.

[0034] The grout delivery component comprises a hemispherical nozzle body 38 with a forward end 40 and a back end 42. The body defines and circumscribes a central cylindrical passage 44 (see Figures 6) which opens onto each of these ends. The shaft 30 passes through the passage to slidably mount the body on the shaft.

[0035] The passage 30 has a first section 43 of a first diameter, which opens onto the back end 42, and a second section 45 of a second diameter, which is larger than the first diameter, and which opens onto the forward face 40. The first diameter is slightly larger than the diameter of the shaft. With a small tolerance, the nozzle body rides smoothly on the shaft, with little lateral rock. The increased tolerance between the second section 45 of the passage 30 and the shaft provides a docking space 44 which opens on the forward face 40.

[0036] A circular distribution channel 46 is formed in a surface of the wall of the second section 45 of the passage 30.

[0037] The grout delivery component 32 further includes a grout port 48 connectable to a grout source (not shown) and a flushing port 50 connectable to a water source (not shown). Each port is laterally extensive of the nozzle body 38 and each port opens into the circular distribution channel 46.

[0038] The nozzle body 38 is axially moveable along the shaft between a retracted position, as illustrated in Figure 3, and a forward position, as illustrated in Figure 5. The nozzle body is moved between these two positions by a pneumatic or hydraulic moving means (not illustrated).

[0039] Although mention is made above that the device 26 can be capacitated to impart axial drive to drive a bolt into a rock hole, this step is not an essential function of the device. This step can be just as well facilitated by a separate functional component on the carousel. Therefore, a rock bolt insertion step is not explained further. In Figure 3, the rock bolt 24 is already functionally fully inserted into a rock hole 49.

[0040] The rock bolt 24, in this specific example, is of a type that is described in South African patent number 2012/07431. This bolt includes an elongate shank 52, with a threaded end section 54, which terminates at a proximal end 56. Part of this threaded end-section projects from the rock hole as illustrated in Figure 3. On this section the bolt has a barrel 58 which has a central bore 60 for receiving the shank, A pair of grout openings 62.1 and 62.2 is formed in the side wall of the barrel, communicating the exterior of the barrel with the bore. The bolt also has a sleeve 64 over the shank. One end of the sleeve is received in the bore of the barrel. A tensioning nut 66 is threaded onto the threaded portion, behind a load indicator 68 or, in the absence of which, the barrel 58.

[0041] In a first step, in the use of the grout delivery device 26A, post installation of the rock bolt, the shaft 30 is moved axially forward for the socket 36, which is compiementariiy shaped, to receive the hex-shaped nut 66. This steps is illustrated in Figure 3.

[0042] The shaft 30 is then actuated to spin, as illustrated in Figure 4, to turn the nut along the threaded portion 54 of the bolt into load bearing connection with the barrel 58 which, in turn, is forced against a faceplate 69 (only illustrated in Figure 3). The faceplate bears against the rock face 18 in load support.

[0043] Once the rock bolt is loaded in tension as described, the nozzle body 38 is driven forward along the shaft, from its retracted position to the forward position, at which point a trailing portion 70 of the barrel, which includes the openings to the grout openings 62, is received in the docking space 44 of the body 38. A step 72, between the first section 43 and the second section 45 of the passage 30, abuts the barrel, preventing further ingress of the barrel beyond the trailing portion. The depth of the docking space positions the grout conduits 62 adjacent the distribution channel 44. Sealing formations (not shown) seal the docking engagement of the grout openings of the barrel with the distribution channel of the nozzle body 38 of the device 26.

[0044] Grout now can be pumped into the rock hole via the grout port 48, the distribution channel 46, the grout openings 62, the bore 60 and finally into the annular space between the rock bolt shank 52 and the sleeve 64. The grout percolates along the length of the sleeve to cascade into the rock hole from a distal open end of the sleeve (not shown).

[0045] When the grouting step is complete, the nozzle body 38 is retracted away from the barrel 58 and water is pumped through the flushing port 50 to flush both the ports and the distributing channel 44 of residual grout, readying the grout delivery component 32 for re-use. This last step is illustrated in Figure 6.

[0046] Figures 7 to 10 illustrate a second embodiment of the grout delivery device, designated 26B. In describing this embodiment, like features bear like designations.

[0047) The shaft 30B is a hollow shaft, with a cylindrical bore 74 that extends along the length of the shaft, opening at the socket 36 and the first end (not shown). A radial array of apertures (76.1 and 76.2 are illustrated) penetrate the wall of the shaft to open the bore to the exterior. The apertures are spaced from the second end 34 of the shaft.

[0048] The device 26B has a nozzle body 38B which circumscribes the shaft, over the apertures 76 and is immovably fixed to the shaft in this position. The body has a single port, a grout port 48, which laterally and backwardly extends from the body. [0049] A check valve 78 is placed in the bore 74, behind the apertures 76, between the apertures and the first end. A grout passage section 80 of the bore is defined between the valve and the socket 36.

[0050] This embodiment is used with a rock bolt 24B which has a hollow shank 52B which defines a tube 82. The tube opens at each end of the bolt.

[0051] In Figure 9, the bolt 24B is engaged with the shaft 30B, with the tensioning nut 66 received in the socket 36. Spinning the shaft spins the nut along the threaded section 54 of the bolt into load bearing abutment with a faceplate (not shown).

[0052] Once the bolt is loaded in tension, grout is pumped through the grout port 48, into the distributing channel 46. The channel distributes the grout around the shaft that the channel circumscribes to allow the grout access to the radially spaced apertures 76 through which the grout flows into the grout passage section 80 of the shaft bore 70. The grout is prevented from backflow by the check valve 74. The grout moves into the tube 82 of the bolt’s shank and ultimately into the rock hole as the grout cascades from a leading open end of the tube (not shown).

[0053] Retracting the shaft 30B from engagement with the rock bolt 24B, once the rock hole is fully grouted, the grout passage section 80 of the bore 70 is flushed with water that is pumped into the bore from the open first end of the shaft. The water lifts the valve from the valve seat of the check valve allowing passage into the bore’s grout passage section 80 to flush residual grout. This step is illustrated in Figure 10.

Claims

1. An integrated bolt rotating and a grout delivery device for use in a mechanised rock bolting application which Includes a bolt rotator which has a shaft with a first end, adapted for engagement to a drill rig drive means, and a second end in which a rock bolt engaging socket is defined; and a grout delivery nozzle which has a body, a grout duct formed through the body adapted to channel a grout material from an exterior of the body to an interior of the body, wherein the body is adapted to engage the shaft to move reciprocally along the shaft between a forward position, in which the body at least partially overlaps the second end of the shaft, and a retracted position in which the body is spaced from the second end.

2. An integrated bolt rotating and a grout delivery device according to claim 1 wherein the body is engageable to a pneumatic or hydraulic moving apparatus to enable movement of the body between the retracted position and the forward position.

3. An integrated bolt rotating and a grout delivery device according to claim 1 or 2 wherein the body includes a first inlet port into the grout duct which port is engageable to a grout source.

4. An integrated bolt rotating and a grout delivery device according to any one of claims 1 to 3 wherein the body includes a second inlet port into the grout duct which port is engageable to a flushing medium source.

5. An integrated bolt rotating and a grout delivery device according to any one of claims 1 to 4 wherein the body has a passage through which the shaft is received in engagement of the body to the shaft.

6. An integrated bolt rotating and a grout delivery device according to any one of claims 1 to 5 wherein the body has a distributing channel formed in a wall of the passage and the grout conduit terminates in a distributing channel formed ih a wall of the passage.

7. An integrated bolt rotating and a grout delivery device for use in a mechanised rock bolting application which includes a bolt rotator which has a shaft with a first end, adapted for engagement to a drill rig drive means, a second end which has a rock bolt engaging socket, a bore which extends at least partially through the shaft opening at the socket and an aperture opening through a wall of the shaft into bore; and a grout delivery terminal which has a body with a grout duct and a first inlet port and which body engages the shaft over the aperture to communicate an exterior of the body with a bore.

8. An integrated bolt rotating and a grout delivery device according to claim 7 wherein the shaft includes an opening which opens into the bore and through which a flushing fluid, may be passed to flush the bore of residual grout.

9. An integrated bolt rotating and a grout delivery device according to claim 7 or 8 wherein the device includes a check valve in the bore between the aperture and the opening which is configured to close when grout flows in a back direction towards the first end of the shaft and to open when a flushinhg fluid flows in a forward direction towards the second end of the shaft.

10. An integrated bolt rotating and a grout delivery device according to any one of claims 7 to 9 wherein the grout delivery terminal has a circular body which circumscribes the shaft.

11. An integrated bolt rotating and a grout delivery device according to any one of claims 7 to 10 wherein the shaft includes a radial plurality of apertures formed through the wall.