FIELD

[0001] The present invention relates to bolters employed in the mining industry and more particularly but not exclusively to roof bolts.

BACKGROUND

[0002] A roof bolter is a pneumatically or hydraulically driven piece of mining equipment. Bolters are used to install bolts in a mine roof, however in some instances roof bolts are also equipped with a drill bit to form the hole in which the bolt is to be inserted.

[0003] A disadvantage of known roof bolters is that they are generally adapted to suit a particular drill bit and/or bolt. Accordingly a variety of bolters need to be manufactured to suit the drill bits and various bolts.

OBJECT

[0004] It is the object of the present invention to overcome or substantially ameliorate the above disadvantage.

SUMMARY

[0005] There is disclosed herein a bolter to receive a driving fluid under pressure and a flushing fluid under pressure, the bolter including:

a base

a telescopic leg having a longitudinal axis, a lower portion to engage a floor surface, and an upper portion supporting the base, with the driving fluid causing telescopic extension of the leg to raise the base;

a chuck mounted on the base and to engage a drill bit or bolt, the chuck being rotatable a chuck axis to drive the bit or bolt, the chuck axis being generally parallel to the leg axis; a motor mounted on the base and drivingly coupled to the chuck to cause rotation thereof, with the motor being driven by said driving fluid; a control assembly manipulated by an operator to control delivery of the driving fluid to the motor and leg; and wherein

said base includes a fluid delivery face to which ducting to receive the driving fluid extends, with the ducting being connectable so that the driving fluid flows past said face to be delivered to the motor.

[0006] Preferably, the face is adapted to receive a flow directing member to provide for the flow of said drive fluid to said motor.

[0007] Preferably, the bolter includes an arm pivotally attached to the base for angular movement about an axis generally normal to said longitudinal axis, with the arm including the control assembly so that an operator may control the bolter by manipulating the arm.

[0008] There is further disclosed herein, in combination the above bolter and flow direction member.

[0009] Preferably, said flow direction member includes ducting to provide for the flow of the driving fluid to and from the motor.

[0010] Preferably, the flow direction member includes a muffler through which driving fluid leaving the motor is exhausted to atmosphere.

[001 1 ] Preferably, said flow direction member includes a valve assembly to provide for the delivery of the driving fluid to said motor so that the motor may be driven in a first direction or a direction opposite said first direction.

[0012] Preferably, said valve assembly includes a casing and a rotary valve member located in the casing and moved angularly to provide for delivery of the driving fluid to said motor so that said motor can be selectively driven in either direction.

[0013] Preferably, said valve includes a movable valve member, said member valve has a drive first position providing for the delivery of driving fluid to drive the motor in said first direction, and a drive second position providing for the delivery of the drive fluid to drive the motor in said opposite direction. [0014] Preferably, the movable valve member is movable to a third position at which the drive fluid provides for the injection of a resin by the bolter.

[0015] Preferably, a lock assembly operable to engage the chuck preventing rotation thereof relative to the base.

[0016] Preferably, the flow direction member includes a valve operable to activate the motor to rotate the chuck, in a predetermined direction, and also operable to cause engagement of the lock member to prevent rotation of the chuck relative to the base.

[0017] Preferably, the valve is operable to activate the motor to rotate the chuck in a direction opposite to said predetermined direction.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings wherein:

[0019] Figure 1 is a schematic isometric view of a roof bolt assembly;

[0020] Figure 2 is a schematic side elevation of the bolter of Figure 1;

[0021] Figure 3 is a schematic a side elevation of the roof bolter of Figure 1 in an extended configuration;

[0022] Figure 4 is a schematic parts exploded isometric view of the bolter of Figure 1 ;

[0023] Figure 5 is a schematic sectioned side elevation of the bolter of Figure 1 ;

[0024] Figure 6 is a schematic sectioned plan view of the bolter of Figure 1 ;

[0025] Figure 7 is a schematic isometric view of a modification of the bolter of Figure 1;

[0026] Figure 8 is a schematic side elevation of the bolter of Figure 7;

[0027] Figure 9 is a schematic parts exploded isometric view of the bolter of Figure 7; [0028] Figure 10 is a schematic sectioned side elevation of the bolter of Figure 7;

[0029] Figure 1 1 is a schematic plan view of the bolter of Figure 7;

[0030] Figure 12 is a schematic isometric view of a modification of the bolter of Figure I ;

[0031] Figure 13 is a schematic side elevation of the bolter of Figure 12;

[0032] Figure 14 is a schematic parts exploded isometric view of the bolter of Figure 12;

[0033] Figure 15 is a schematic sectioned side elevation of the bolter of Figure 12;

[0034] Figure 16 is a schematic sectioned plan view of the bolter of Figure 12; and

[0035] Figure 17 is a schematic sectioned plan view of a valve employed in the bolter of Figure 7 and the bolter of Figure 12.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] In Figures 1 to 6, there is schematically depicted a roof bolter 10. The roof bolter 10 is intended to receive a drill bit for the purposes of drilling a hole in a surrounding rock structure, with the drill bit then being removed and a roof bolt engaged and inserted in the hole by the roof bolter 10. In some instances a cartridge is to be inserted in the hole and then the roof bolt inserted thereafter and rotated to cause the cartridge to rupture so that the resin surrounds the roof bolt. Upon setting of the resin the bolt is then anchored to the surrounding rock structure.

[0037] The bolter 10 includes a base 11 that is supported by a telescopic leg 12. The telescopic leg 12 has a plurality of sections 13 that are telescopically received within each other and that are extendable to the configuration as shown in Figure 3. The lowermost section 13 has a floor engaging part 14 that aids in securely engaging the floor surface of a mine. The uppermost section 13 is attached to the base 1 1 so that upon telescopic extension and retraction of the leg 12, the base 1 1 is raised and lowered.

[0038] Pivotally attached to the base 11 is a control arm 15 having a pair of handles 16 that are gripped by an operator. The operator, by manipulation of the arm 15, controls and operates the bolter 10. Typically adjacent one of the handles 16 is trigger 17 that is caused to move by the operator, which in turn causes operation of the bolter 10, in particular the leg 12. Typically the bolter 10 would receive hydraulic fluid or air under pressure which acts as a driving fluid for the bolter 10. The bolter 10 would also receive a flushing fluid (a liquid such as water) that would be delivered to the interior of the drill bit and used to flush the hole being drilled by the drill bit. The driving fluid and flushing fluid would be connected to the bolter 10 by couplings 18. The trigger 17 operates valves, at the operators end of the control arm 15, that provide for the flow of the driving fluid and flushing fluid to the base 1 1 and leg 12. The valves are operated by levers 41 and 42.

[0039] The arm 12 is pivotally attached to the base 1 1 for angular movement about an axis 20 provided by a pivot member 21. The pivot member 21 also connects various ducting in the arm 15 to ducting in the base 11 for the transfer of the driving fluid and flushing fluid thereto.

[0040] Attached to the base 1 1 is a further handle 19.

[0041 ] Mounted on the base 1 1 is a chuck 22 that is rotatably driven about an axis 23 that is also the longitudinal axis of the leg 12. Fixed to the base 1 1 and surrounding the chuck 12 is a guard (shield) 24. The axis 23 is generally normal relative to the axis 20.

[0042] The chuck 22 is turned by a shaft 25 engaged within the centre spline 26 of a ring gear 27. The gear 27 is driven by a further gear 28 which in turn is driven by a motor 29. The motor 29 is operated by the driving fluid. Upon the driving fluid under pressure being delivered to the motor 29, the motor 29 drives the gears 28 and 27 and therefore the chuck 22 angularly about the axis 23.

[0043] The base 1 1 provides exhaust ducting for the motor 29, with the ducting extending to a face 30 of the base 1 1. Attached to the base 1 1 so as to abut the face 30 is a duct member 31 that communicates with ducting extending from the arm 15 to direct the driving fluid to the motor 29, and to receive exhaust fluid from the motor 29. In this embodiment, the member 31 also acts as a muffler as exhaust from the motor 29 is vented to atmosphere.

[0044] In the above described embodiment, the driving fluid is compressed air. The motor 29 is a gear motor including a pair of rotatable meshingly engaged gears 32 which are caused to rotate in a predetermined direction upon the compressed air being delivered thereto. The above described preferred embodiment has the chuck 22 driven in one rotational direction only, with a flushing fluid (typically water) being delivered to a passage 33 in the chuck 22 for delivery to the longitudinal passage of the drill bit engaged with the chuck 22.

[0045] In the embodiment of Figures 7 to 1 1, the bolter 10 is provided with a valve 34 (further duct member). The valve 34 is bolted to the face 30 so as to communicate with ducting extending from the handle 15 so that the compressed air is delivered to the valve 34. The valve 34 includes a body 35 within which there is supported for angular movement a movable valve element that is caused to move angularly about an axis 36. The movable valve element has a number of passages that provide for the delivery of compressed air to the motor 29, and the ducting of exhaust air from the motor 29 to a muffler incorporated in the valve 34. The valve 34 is described more fully with reference to Figure 17.

[0046] The valve 34 provides for the delivery of compressed air to the motor 29 so that the motor 29 can be driven in either rotational direction. Accordingly in the embodiment of Figures 9 to 1 1, the chuck 22 can be driven rotationally in either direction and again a flushing fluid such as water is delivered to the chuck.

[0047] Further in respect to this embodiment, there is attached to the base 1 1 a pump 37 that receives the driving fluid (air) and delivers water (flushing fluid) to the interior passage 32 at a higher pressure to provide for the injection of resin to the internal longitudinal passage in a bolt mounted in the chuck 22.

[0048] In this embodiment, the bolter 10 receives a self drilling roof bolt. The bolter 10 has the chuck 22 rotated in a first direction for the self drilling bolt to drill into the rock layer. Once the rock bolt has penetrated a desired depth, resin is injected through the bolt and allowed to set to secure the bolt to the surrounding rock layer. Thereafter the chuck 22 is caused to rotate in the opposite angular direction to tension the bolt. During the drilling operation water is pumped longitudinally through the bolt to flush the hole being drilled. The rock bolt employed with this embodiment includes a first longitudinal passage that has a flexible closed tube of resin, with an annular passage surrounding the central passage, with the annular passage receiving the flushing fluid. When the pump 37 is activated, water under pressure is delivered to the central passage and ruptures the tube of resin and forces the resin out of the bolt and into the area surrounding the bolt adjacent the rock surface. The resin is then allowed to set.

[0049] The pump 37 receives the water under an initial pressure, and delivers the water to the chuck 22 and a higher pressure. This enables injection of the resin longitudinally through the bolt. It should further be appreciated that in respect of this embodiment, the bolt is inserted using the bolter 10 and the resin injected, with the bolt then being tensioned once the resin has set.

[0050] In the embodiment of Figures 14 to 17, the bolter 10 includes the chuck 22 of the embodiment of Figure 1 and the valve 34 of the embodiment of Figure 7. However in this embodiment, there is mounted in the base 1 1 a lock member 38 that is selectively moved into engagement with the gear 27 to prevent movement thereof and therefore to prevent movement of the chuck 22. Accordingly the bolter 10 may be employed to perform a final tensioning of the roof bolt.

[0051] In Figure 17, there is schematically depicted the valve 34. The valve 34 includes an angularly movable valve element 39 that is movable angularly about the axis 36 between a first position, a second position and a third position. This is achieved by a pair of cables 40 that extend to adjacent the handle 16 at which there is located levers-41 and 42 that cause movement of the cables 40 and therefore rotation of the element 39.

[0052] In the embodiment of Figure 7, the valve element 39 (as shown in Figure 17) is moved into a position (first position - drive first position) at which ducting is connected to deliver compressed air to the motor 29 to cause rotation thereof in a predetermined direction to rotate the self drilling bolt to drill the hole, a further position (second position - resin injection position) at which air is delivered to the pump 37 to cause injection of the resin, and a still further position (third position - drive second position) at which the self drilling bolt is rotated in the reverse direction to tension the bolt once the resin has cured. In the embodiment of Figure 12, the valve element 39 (as shown in Figure 17) is movable between a position (first position) at which the chuck 22 is rotated in a predetermined direction to rotate the drill bit to drill the hole, a further position (second position) at which compressed air is delivered to an actuator to cause engagement (and disengagement) of the lock member 38, and a still further position (third position) to rotate the chuck 22 to tension the bolt. [0053] In use of the bolter 10 of Figures 12 to 17, a drill bit is inserted in the chuck 22, and a passage formed in the adjacent rock layer. Once the passage is formed, the drill bit is removed and a tube of resin inserted in the passage. The rock bolt is then inserted so as to move the tube of resin to the remote end of the passage, with the rock bolt then being operated to rupture the tube. The rock bolt is mounted in the chuck 22 and rotated to cause distribution of the resin. The rock bolt 10 is then rotated in the opposite direction to the drilling direction to tension the bolt once the resin sets. Final tensioning is achieved by manually angularly moving the roof bolter 10 about the axis 23 once the lock member 38 is engaged with the gear 27.

[0054] An advantage of the bolter 10 of the above described preferred embodiments, is that the bolter 10 is adapted, by interchanging the duct member 31 with the further duct member (in the form of the valve 34), and by adding or removing the pump 37 to be used with a variety of rock bolt systems.