A CUTTING HEAD ASSEMBLY

Abstract

A cutting head assembly for excavating rock fragments from a mine wall is disclosed. In an embodiment, the cutting head assembly comprises a primary breakage mechanism actuable to apply, to the mine wall, a breakage force for breaking rock fragments from the mine wall. A surface of the cutting head assembly catches the rock fragments broken from the mine wall and has one or more ports associated therewith. A secondary breakage mechanism is operatively associated with the surface and actuable to apply a force for reducing the size of at least some of the rock fragments caught by the surface so as to allow at least the reduced size rock fragments to pass through a respective port for transportation to downstream processing.

Claims

1. A cutting head assembly for excavating rock fragments from a mine wall, the cutting head assembly comprising: a primary breakage mechanism actuable to apply, to the mine wall, a breakage force for breaking rock fragments from the mine wall; a surface for catching the rock fragments broken from the mine wall, the surface having one or more ports associated therewith; and a secondary breakage mechanism operatively associated with the surface, the secondary breakage mechanism actuable to apply a force for reducing the size of at least some of the rock fragments caught by the surface so as to allow at least the reduced size rock fragments to pass through a respective port for transportation to downstream processing.

2. The cutting head assembly of claim 1, wherein the primary breakage mechanism comprises one or more primary cutters for breaking rock fragments from the mine wall.

3. (canceled)

4. The cutting head assembly of claim 1, wherein the breakage force is a percussive force applied by actuation of the primary breakage mechanism.

5. The cutting head assembly of claim 4, wherein the percussive force of the primary breakage mechanism provides between 50 to 1000 J of impact energy at 20 to 400 Hz to break rock fragments from the mine wall.

6. (canceled)

7. The cutting head assembly of claim 1, wherein the secondary breakage mechanism comprises one or more secondary cutters.

8. The cutting head assembly of claim 5, wherein the one or more secondary cutters comprises one or more blades reducing the size of at least some of the rock fragments caught by the surface and wherein the one or more blades are proximally associated with the one or more ports.

9-10. (canceled)

11. The cutting head assembly of claim 7, wherein the one or more secondary cutters of the secondary breakage mechanism is are associated with at least one of the primary cutters of the primary breakage mechanism.

12. The cutting head assembly of claim 1, wherein the primary breakage mechanism is actuated by a primary actuator and the secondary breakage mechanism is actuated by a secondary actuator.

13. The cutting head assembly of claim 12, wherein the primary and secondary actuators are independently operable.

14. The cutting head assembly of claim 12, wherein the secondary actuator actuates the secondary breakage mechanism subsequent to the primary actuator actuating the primary breakage mechanism.

15. The cutting head assembly of claim 1, wherein the assembly further comprises a fluid passageway concealed within a housing and a drive gear mounted on a top of the housing, the fluid passageway extending between the one or more ports and an outlet.

16. The cutting head assembly of claim 15, wherein the fluid passageway is sealed between the one or more ports and the outlet so as to permit transportation of the reduced size rock fragments therebetween on application of a negative pressure or a suction pressure.

17. The cutting head assembly of claim 15, wherein the outlet is proximal to the drive gear on the top of the housing and configured to connect to a suction pump of a miner body.

18. The cutting head assembly of claim 15, wherein the drive gear is configured to engage a connecting gear of the miner body to thereby connect the cutting head assembly to a mining system via the miner body.

19. (canceled)

20. The cutting head assembly of claim 17, wherein the drive gear transmits a feed force from the miner body to the cutting head assembly.

21. The cutting head assembly of claim 20, wherein the feed force is proportional to an applied weight of the miner body.

22. The cutting head assembly of claim 20, wherein combination of the feed force and the breakage force of the primary breakage mechanism permit the cutting head assembly to engage and maintain engagement with the mine wall.

23. A cutting head assembly for excavating rock fragments from a mine wall, the cutting head assembly comprising: a primary breakage mechanism actuable to apply, to the mine wall, a breakage force for breaking rock fragments from the mine wall; a housing comprising a fluid passageway and a surface for catching the rock fragments broken from the mine wall, the surface having one or more ports associated therewith, wherein the fluid passageway extends between the one or more ports and an outlet; a secondary breakage mechanism operatively associated with the surface and proximal to the one or more ports, the secondary breakage mechanism actuable to apply a force for reducing the size of at least some of the rock fragments caught by the surface so as to allow at least the reduced size rock fragments to pass through a respective port; and wherein, in use, the secondary breakage mechanism actuates subsequent to the primary breakage mechanism and a suction pressure applied to the outlet transports the reduced sized rock fragments via the one or more ports to the outlet for downstream processing.

24. A method for excavating rock fragments from a mine wall, the method comprising: providing a cutting head assembly according to claim 1; and operating the cutting head assembly to excavate the rock fragments from the mine wall.

25. (canceled)

26. A system for mining excavating rock fragments from a mine wall, the system including: a cutting head assembly according to claim 1; means controlling operation of the cutting head assembly to excavate rock fragments from the mine wall to provide a supply of rock fragments for processing; and processing means for processing the supply of rock fragments.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0057] Embodiments of the present disclosure will be discussed with reference to the accompanying drawings wherein:

[0058] FIG. 1 is a perspective view of a cutting head assembly according to an embodiment;

[0059] FIG. 2 is a side cross-sectional view of the cutting head assembly of FIG. 1:

[0060] FIG. 3 is a bottom view of the cutting head assembly of FIGS. 1 and 2:

[0061] FIG. 4 is a schematic view of a primary breakage mechanism according to an embodiment:

[0062] FIG. 5 is a front view of the primary breakage mechanism of FIG. 4:

[0063] FIG. 6 is a side view of the primary breakage mechanism of FIGS. 4 and 5:

[0064] FIG. 7 is a perspective detail view of a secondary breakage mechanism of the cutting head assembly:

[0065] FIG. 8 is a perspective detail view of the secondary breakage mechanism of FIG. 7 illustrating one or more ports and an excavated rock fragment:

[0066] FIG. 9 is a side sectional view detailing a port, a fluid passageway, the primary and secondary breakage mechanisms of the cutting head assembly:

[0067] FIG. 10 is a detailed view of the primary breakage mechanism engaging a mine wall:

[0068] FIG. 11 is a perspective view of a cutting head assembly according to an alternative embodiment:

[0069] FIG. 12 is a perspective view of a mining system comprising a miner body and the cutting head assembly according to an embodiment:

[0070] FIG. 13 is a perspective alternate view of the mining system of FIG. 12 illustrating the mining system, the miner body and the cutting head assembly:

[0071] FIG. 14 is a perspective view detailing the mining system of FIGS. 12 and 13;

[0072] FIG. 15 is a schematic view illustrating the miner body and the cutting head assembly in operation:

[0073] FIG. 16 is a perspective view of the miner body of FIG. 15:

[0074] FIG. 17 is a side detail view of a cutting head assembly, according to certain embodiments, illustrating a primary breakage mechanism actuating to apply to a mine wall a breakage force for breaking rock fragments from the mine wall;

[0075] FIG. 18 is a side sectional view of the cutting head assembly of FIG. 17, illustrating a surface catching the rock fragments broken from the mine wall; and

[0076] FIG. 19 is a side sectional view of the cutting head assembly of FIG. 18, illustrating a secondary breakage mechanism actuating to apply a force for reducing the size f at least some of the rock fragments caught by the surface.

[0077] In the following description, like reference characters designate like or corresponding parts throughout the figures.

DESCRIPTION OF EMBODIMENTS

[0078] Referring to any one of FIGS. 1 to 10, there is illustrated a cutting head assembly (100) according to an embodiment of the present disclosure, for excavating rock fragments from a mine wall.

[0079] In the present case, the cutting head assembly (100) engages a mine wall (1000, ref. FIG. 10) to cause a primary mode of failure of the mine wall (1000) due to tension resultant of percussive forces generated by the cutting head assembly (100). Using a percussive force to generate tension allows the cutting head assembly (100) to excavate a mine wall (1000) comprising rock which is susceptible to breaking into rock fragments under tensile failure. In this respect, certain embodiments of the present disclosure involve transmitting energy into the rock as wave energy which causes tensional spalling and explosive rock failure. An advantage of this approach is that it allows for improved control of energy projection into rock compared to approaches which involve drilling and blasting.

[0080] In the illustrated embodiment, and with reference initially to FIG. 1, a cutting head assembly (100) according to one embodiment comprises a primary breakage mechanism (10) actuable to apply, to the mine wall (1000), a breakage force for breaking rock fragments from the mine wall (1000). The depicted cutting head assembly (100) also comprises a surface (20) for catching the rock fragments broken from the mine wall (1000) by primary breakage mechanism (10), the surface (20) itself having one or more ports (21) associated therewith. The function of, and interaction between, the surface (20) and the ports (21) of the cutting head assembly (100) will be described in more detail below.

[0081] The cutting head assembly (100) additionally comprises a secondary breakage mechanism (30) which is operatively associated with the surface (20). As will be described in more detail below, in use the secondary breakage mechanism (30) is actuable to apply a force for reducing the size of at least some of the rock fragments caught by the surface (20) so as to allow at least the reduced size rock fragments to move off of the surface (20) through the one or more ports (21) for downstream processing.

[0082] In embodiments, the surface (20) of the cutting head assembly (100) catches the rock fragments broken, resultant of the breakage force applied by the primary breakage mechanism (10) from the mine wall (1000). The surface (20) shown here comprises a substantially flat surface. However, it will be appreciated that the surface (20) may have any suitable configuration or form. Examples of suitable configurations and/or forms include a surface of any one of a tray, platform, ledge, catch, trap or the like which is configured to function so as to catch the rock fragments broken as a result of the breakage force applied by the primary breakage mechanism (10).

[0083] Referring now to FIG. 7 and FIG. 8, in the present case the one or more ports (21) are sized and shaped so as to permit at least the reduced size rock fragments to pass therethrough. In this way, the one or more ports (21) advantageously ensure that only rock fragments having at least one geometric dimension which is less than a certain size are passed via a port (21) for downstream processing, noting that it is possible that not all rock fragments caught by the surface will require a size reduction in order to pass through a port (21) since some of the rock fragments caught by the surface (20) may be able to pass through a port (21) without requiring a size reduction. Furthermore, it is also possible that rock fragments caught by the surface (20) which do not require a size reduction in order to pass through a port (21) will nevertheless be reduced in size by the secondary breakage mechanism (30).

[0084] Before proceeding further, it is to be noted that throughout this specification reference will be made to rock fragments which are reduced in size by the secondary breakage mechanism (30). It will be appreciated that, in the context of this specification, a rock fragment may be reduced in size by any suitable secondary breakage mechanism (30).

[0085] In certain embodiments, the reduction in size of an original rock fragment involves the use of a secondary breakage mechanism (30) which applies a shearing force to the original rock fragment so as to cut the original rock fragment into two or more smaller rock fragments of a reduced size compared to the original rock fragment. In other embodiments, the secondary breakage mechanism (30) may involve a crushing pulverising, or impact type force which breaks the original rock fragment into two or more smaller rock fragments of a reduced size compared to the original rock.

[0086] In still other embodiments, a pressurised jet of gas or fluid may be used to erode or cut an original rock fragment into two or more smaller rock fragments. In certain embodiments, the secondary breakage mechanism (30) may involve a combination of forces generated by different means.

[0087] In embodiments, the size and shape of the one or more ports (21) may be configured to allow rock fragments which are sufficiently small in size to be easily transported and processed downstream. In this way, the size and shape of the one or more ports (21) enables the rock fragments which pass through a port (21) to have at least one geometric dimension of a predictable size and thus to provide rock fragments having a predictable fragment size for at least that geometric dimension, with the predictable fragment size being one whereby the rock fragments have a size and shape which permits them to pass through the one or more ports (21).

[0088] As shown in FIGS. 3 to 6, in the present case the primary breakage mechanism (10) comprises one or more primary cutters (11) for breaking rock fragments from the mine wall (1000). In the present case, each primary cutter (11) is positioned to engage the mine wall (1000) when the primary breakage mechanism (10) is actuated to apply the primary breakage force to break rock fragments from the mine wall (1000).

[0089] In certain embodiments, the or each primary cutter (11) may be manufactured of a sufficiently hardened material comprising high tensile strength, capable of applying large tensile forces in use to the mine wall (1000).

[0090] As shown in FIG. 4, the or each primary cutter (11) comprises one or more cutting elements (12) for excavating the rock fragments from the mine wall (1000). As shown in FIG. 10, the one or more cutting elements (12) of the or each primary cutter (11) engage the mine wall (1000) when the primary breakage mechanism (10) is actuated to apply the breakage force.

[0091] The depicted one or more cutting elements (12) are positioned and arranged to engage the mine wall (1000) and excavate the mine wall (1000) by application of the breakage force on actuation of the primary breakage mechanism (10). In the present case, the one or more cutting elements (12) are selected to cause a failure of the mine wall (1000), and its geology, via tensile failure of the mine wall (1000). In this respect, hard rock is known to have a high compressive strength. However, the tensile strength of hard rock is typically 10% of the compressive strength. Given this, the primary breakage mechanism (10), and subsequently the or each of the primary cutters (11) and the one or more cutting elements (12), are selected to exploit this weakness of hard rock. That is to say, in embodiments, the primary breakage mechanism (10) and subsequently the or each of the primary cutters (11) and the one or more cutting elements (12) are manufactured and designed so as to advantageously apply the breakage force to the mine wall (1000) such that the broken rock fragments are resultant of tensile failure of the mine wall (1000). Tensile failure of hard rock typically results from tension cracks forming at a point of contact between either one of the or each primary cutter (11) or the one or more cutting elements (12) and the mine wall (1000).

[0092] In embodiments, the primary cutters (11) and/or the one or more cutting elements (12) are manufactured from a material or materials according to the geology and rock expected to be excavated in the mine wall (1000) by the cutting head assembly (100). Suitable materials would be well understood by a person skilled in the art.

[0093] In certain embodiments, the one or more cutting elements (12) provide up to an 80 mm depth of cut in the mine wall (1000), with the actual depth depending on various factors, including the geology of the rock. Furthermore, the one or more cutting elements (12) may be designed and/or arranged to provide an angle of attack, being the angle at which the cutting element (12) engages the mine wall (100). The combination of the angle of attack and percussive force results in lower temperatures generated at the one or more cutting elements (12) compared to conventional drilling based techniques, advantageously improving the life of the cutting elements (12). In contradistinction, the use of conventional percussion or tri-cone/drag bit drilling applications results in the generation of high temperatures, resulting in de-lamination of cutting elements used in these applications.

[0094] Continuing now with reference to FIG. 4, in certain embodiments, the one or more cutting elements (12) are Polycrystalline Diamond (PCD) inserts, as are well known for their use in mining and drilling operations, particularly in those applications involving hard rock or ore bodies. In this way, the one or more cutting elements (12) and their associated angle of attack, effectively excavates the mine wall (1000) in a manner such as to plane off the rock fragments, as opposed to drilling or boring into the mine wall (1000), using the percussive force applied by the primary breakage mechanism (10) to cause a tensile failure of the mine wall (1000).

[0095] Suitable alternative cutting elements (12) such as tungsten carbide inserts, titanium carbide inserts and others may also be selected for use, and the selection of cutting elements (12) would be well within the knowledge of a skilled person. The person skilled in the art will also appreciate that the selection of cutting elements (12) involves consideration of the friction forces and temperatures during excavation/engagement of the mine wall at high contact pressures, commonly greater than 2 GPa pressure waves (as often encountered in percussion drilling).

[0096] In the embodiment of the cutting head (100) illustrated in any one of FIGS. 1 to 11, the breakage force is a percussive force applied by actuation of the primary breakage mechanism (10). In certain embodiments, the percussive force of applied by the primary breakage mechanism (10) provides up to 1000 J of impact energy at 20 to 400 Hz. However, it will of course be appreciated that the impact energy and frequency of the percussive force applied by the primary breakage mechanism (10) may vary according to the geology and rock expected to be excavated in the mine wall (1000) by the cutting head assembly (100). Suitable impact energy and frequency parameters would be well within the knowledge of a skilled person.

[0097] In terms of the effect of the percussive force applied by the primary breakage mechanism (10), the primary breakage mechanism (10), when actuated, causes a pressure wave at the speed of sound to penetrate through the mine wall (1000) (via reciprocating motion) when engaged by the or each primary cutters (11), and thus by the one or more cutting elements (12). Engagement of cutting elements (12) with the mine wall (1000) applies sufficient percussive force such that the mine wall (1000) fails in tension. In one embodiment, in which the cutting elements (12) have an angle of attack, the combination of the angle of attack and the percussive force applied by actuation of the primary breakage mechanism effectively excavates the mine wall (1000) by causing rock fragmentation.

[0098] In certain embodiments, and as is illustrated in FIGS. 3 to 4 and 6, the primary breakage mechanism (10) comprises a shank (14) and a head (15), the head (15) being at one end of the shank (14). The head (15) comprises the primary cutter (11), which itself comprises or supports the one or more cutting elements (12). In these embodiments, the one or more cutting elements (12) are positioned and/or arranged to engage the mine wall (1000) to impart the breakage force thereupon.

[0099] With reference now to FIG. 4, in the illustrated embodiment the shank (14) comprises a receptacle (16) which is sized and shaped to receive a portion of a retaining mechanism (13) therein (ref. FIG. 3). In this embodiment, the or each primary cutter (11) is removably securable to the primary breakage mechanism (10). In a particular embodiment, and as is illustrated in FIG. 3, the retaining mechanism (13) comprises a retaining pin which removably secures the or each primary cutter (11) to the primary breakage mechanism (10). In the present case, the or each primary cutter (11) may be removed from the primary breakage mechanism (10) by removing the retaining pin (13), a portion of which is received within the receptacle (16) of the shank (14). In this way, the or each primary cutter (11), and subsequently the one or more cutting elements (12), may be easily removed from the primary breakage mechanism (10) after use for repair, inspection or replacement with another primary cutter (11).

[0100] In one embodiment, and referring now to any one of FIGS. 1 to 2 and 7 to 9, the secondary breakage mechanism (30) comprises one or more secondary cutters (31). The or each secondary cutter (31) may be designed such that on actuation of the secondary breakage mechanism (30), the or each secondary cutter (31) applies the force for reducing the size of at least some of the rock fragments caught by the surface (20) to allow at least the reduced size rock fragments to move off the surface (20) through the one or more ports (21).

[0101] In the above embodiment, and referring now to FIGS. 7 and 8 in particular, the or each secondary cutter (31) comprises one or more surfaces or edges for reducing the size of at least some of the rock fragments caught by the surface (20). The one or more surfaces or edges may be designed to shear the rock fragments broken from the mine wall (1000) caught on the surface (20) and reduce the size of at least some of those rock fragments on actuation of the secondary breakage mechanism (30).

[0102] In the present case, the or each secondary cutter (31) is proximally associated with a respective one or more ports (21). In this way, actuation of the secondary breakage mechanism (30) involves moving the or each secondary cutter (31) so as to shear rock fragments at least partially located within a port (21) associated with the surface (20) to thereby allow at least reduced size rock fragments to pass through the proximally associated port (21). In other words, in embodiments, rock fragments caught by the surface which would otherwise not be able to move off the surface (20) via a port (21), as a result of their size relative to the port (21), may be effectively reduced in size by the secondary cutter (31), resulting in one more rock fragments of a reduced size passing through the port (21) for downstream processing.

[0103] In certain embodiments, and as is illustrated in any one of FIGS. 1, 2, 7 and 8, the or each secondary cutter (31) of the secondary breakage mechanism (30) is associated with at least one of the primary cutters (11) of the primary breakage mechanism (10). In this way, for every secondary cutter (31) of the secondary breakage mechanism (30) there is an associated at least one primary cutter (11) of the primary breakage mechanism (10). Accordingly, in some embodiments it is possible that there may be more than one primary cutters (11) associated with a single secondary cutter (31), such that the primary breakage mechanism (10) on actuation applies the breakage force to break rock fragments from the mine wall via the primary cutters (11), the rock fragments broken caught by the surface (20), and subsequently the secondary breakage mechanism (30) is actuated to apply the force to reduce the size of at least some of the rock fragments caught by the surface (20) via the secondary cutter (31).

[0104] In certain embodiments, and referring now to FIGS. 2, 3 and 7 to 9 in particular, the primary breakage mechanism (10) is actuated by a primary actuator (40) and the secondary breakage mechanism (30) is actuated by a secondary actuator (50).

[0105] In embodiments, the primary (40) and secondary (50) actuators may be independently operable. That is to say, that the primary actuator (40) may actuate the primary breakage mechanism (10) so as to apply the breakage force to the mine wall (1000) without actuation of the secondary breakage mechanism (30). In this way, the cutting head assembly (100) may, as a first action, excavate rock fragments from the mine wall (1000) without processing and extraction of said rock fragments caught by the surface (20) via the one or more ports (21) for downstream processing. This first action may be used, for example, to test the primary breakage mechanism (10) to ensure that the primary cutters (11) and any cutting elements (12) are suitable for the mine wall (1000).

[0106] In certain embodiments, in alternative to the above, the secondary actuator (50) actuates the secondary breakage mechanism (30) subsequent to the primary actuator (40) actuating the primary breakage mechanism (10). That is to say, following actuation of the primary breakage mechanism (10) by the primary actuator (40), the secondary breakage mechanism (30) is actuated by the secondary actuator (50). In this way, first the primary breakage mechanism (10) is actuated to apply the breakage force to the mine wall (1000) and break rock fragments therefrom, and the secondary breakage mechanism (30) is actuated to apply the force for reducing the size of at least some of the rock fragments of the mine wall (1000) caught by the surface (20). In other words, in some embodiments, actuation of the primary (40) and secondary (50) actuators may be synchronised so that the primary (10) and secondary (30) breakage mechanisms interoperate to move rock fragments off of the surface (20) through the one or more ports (21) for downstream processing. As described above, this may involve reducing the size of rock fragments caught by the surface (20) to allow at least the reduced size to pass through a port (21).

[0107] In any one of the above embodiments comprising the primary (40) and secondary (50) actuators, the primary (40) and/or secondary (50) actuators may be hydraulic actuators of a type well known in the art.

[0108] In the embodiment illustrated in FIG. 3, the primary actuator (40) is configured to receive at least a portion of the shank (14) of the primary breakage mechanism (10) therein. In this way, the primary actuator (40) is able to reciprocate or actuate the primary breakage mechanism (10) to transmit the breakage force to break the rock fragments from the mine wall (1000).

[0109] In certain embodiments, as illustrated by FIG. 1, 2 or 9, the cutting head assembly (100) includes a fluid passageway (22) located within a housing (23) which extends between the or each port (21) and an outlet (26).

[0110] Continuing now with reference to FIG. 9, there is shown a sectional view of one of the ports (21) and the fluid passageway (22). As shown, the port (21) shown here is shaped to assist with guiding at least the reduced size rock fragments through the port (21) and into the fluid passageway (22). In the present case, the shape of the port (21) is such that it narrows as it depends towards the fluid passageway (22).

[0111] In the above embodiment, and with reference now to FIG. 2, the fluid passageway (22) is sealed between the or each port (21) and the outlet (26) so as to permit transportation of the reduced size rock fragments therebetween on application of a negative pressure or a suction pressure by suitable means. In this way, a suction pressure may be applied via the outlet (26) to the one or more ports (21) and the fluid passageway (22) therebetween to create a vacuum which effectively transports at least the reduced size rock fragments received within the one or more ports (21) to the outlet (26) via the fluid passageway (22) for downstream processing. It will be appreciated, that in this embodiment, at least the reduced size rock fragments are sized and shaped to be transported through the one or more ports (21) via the fluid passageway (22) to the outlet (26).

[0112] In certain embodiments, and as is illustrated by FIGS. 1, 15 and 16, the outlet (26) is proximal to a drive gear (24) located on the housing (23). In the present case, the drive gear (24) is a swing gear located on or near a top portion (25) of the housing (23). However, it will be appreciated that other mounting arrangements may be possible.

[0113] In the present case, and with reference now to FIG. 15, the suction pump (210) of the miner body (200) shown here comprises a conduit (230) which is connected to the suction pump (210) at one end, and connected to the outlet (26) of the cutting head assembly (100) at an opposite end. In this way, the suction pump (210) of the miner body (200) can apply a suction pressure to transport at least the reduced size rock fragments from the or each port (21) to the outlet (26) and subsequently to the miner body (200) via the conduit (230).

[0114] The conduit (230) may have any suitable form. For example, the conduit may comprise a flexible conduit, such as a hose or the like, sized and shaped so as to be able to apply the suction pressure to the outlet (26) and subsequently the or each port (21), and to be able to transport the reduced size rock fragments therein for downstream processing. It will also be appreciated that the conduit (230) must be sealed at both ends connecting at the suction pump (210) and the outlet (26), to allow for the maintenance of a suction pressure which is sufficient to transport rock fragments which for downstream processing whilst suspended in a fluid or slurry.

[0115] In certain embodiments, as is illustrated by any one of FIGS. 12 to 16, the drive gear (24) is configured to engage a connecting gear (220) of the miner body (200) to thereby connect the cutting head assembly (100) to a mining system (300) via the miner body (200). As described above, the drive gear may comprise a swing gear (27) capable of rotating the cutting head assembly (100) about an axis of the connecting gear (220) of the miner body (200).

[0116] In certain embodiments, the swing gear (27) allows for rotation of the cutting head assembly (100) over about 190 degrees about the axis of the connecting gear (220). In this way, advantageously the cutting head assembly (100) may be rotated about the axis of the connecting gear (220) so as to maintain engagement with the mine wall (1000) as illustrated by FIG. 15. It will be appreciated that the degree to which the cutting head assembly (100) may be rotated about the axis of the connecting gear (220) is dependent on the cutter head assembly (100) size relative to the miner body (200).

[0117] In the above embodiment, the drive gear (24) transmits a feed force from the miner body (200) to the cutting head assembly (100) which is intended to drive progression of the cutting head assembly (100) and the miner body (200) through a mine shaft created in the mine wall (1000) as illustrated by FIG. 15. It will be appreciated that the feed force is resultant of a mass of the miner body (200) applied to the cutting head assembly (100). It will also be appreciated that a maximum feed force that may be applied is roughly equal to the maximum weight of the miner body (200). That is to say, the feed force applied to the mine wall (1000) via the cutting head assembly (100) may depend on the weight of the miner body (200) being picked up or slacked off via an arrangement of pulleys, drawworks and the like connected and controlled by the mining system (300) in order to engage the mine wall (1000) and progress the cutting head assembly (100) through the created mine shaft. A person skilled in the art will appreciate that the term feed force may be interchangeable with other terms such as slack off force or drive force, so as the term references the force applied to drive/progress the cutting head assembly (100). Also in the above embodiment, the feed force drives the cutting head assembly (100) to engage the mine wall (1000) and subsequently permit the primary breakage mechanism (10) to engage the mine wall (1000) by actuation. In this embodiment, the combination of the feed force and the percussive force of the primary breakage mechanism (10) permit the cutting head assembly (100) to engage and maintain engagement with the mine wall (1000).

[0118] Although the above described embodiment involves the miner body (200) applying the feed force to the mine wall (1000) via the cutting head assembly (100), it will be appreciated that the miner body (200) may not necessarily be required to apply the feed force if the mine wall (1000) is not initially engaged with the cutting head assembly (100) at a horizontal position, as is illustrated by FIGS. 12, 13 and 17 to 19. By way of example, if the cutting head assembly (100) is engaged with or in contact with the mine wall (1000) without the application of the feed force, the primary breakage mechanism (10) is actuated to apply to the mine wall (1000) the breakage force to break rock fragments from and excavate the mine wall (1000).

[0119] Additionally, as the primary breakage mechanism (10) actuates so as to excavate the mine wall (1000) via percussive forces, these percussive forces combined with the feed force may generate p-wave energy exiting at the or each primary cutters (11) or the one or more cutting elements (12) to further induce tensile failure of the mine wall (1000). Furthermore, the feed force from the miner body (200) to the cutting head assembly (100) may be up to a total weight of the miner body (200) at the primary breakage mechanism (10). That is to say, for example, if the miner body (200) has a weight of up to 2 tonnes, then the feed force that may be slacked off and imparted via the cutting head assembly (100) at the primary breakage mechanism (10) is up to 2 tonnes.

[0120] In certain embodiments, the housing (23) of the cutting head assembly (100) is scaled such that the cutting head assembly (100) is operable when submerged in a fluid or slurry. By way of example only, sealed areas of the cutting head assembly (100) may include any one or more of the housing (23), the fluid passageway (22), and the primary (10) and the secondary (30) breakage mechanisms. In this way, the cutting head assembly (100) is operable in an environment where the mine wall (1000) and the subsequently resultant mine shaft is filled with the fluid or slurry. It will be appreciated by those skilled in the art, that the fluid or slurry in which the cutting head assembly (100) may operate could be, for example, water or a bentonite clay/water mix depending on the geology of the mine wall (1000) and water table conditions of the environment of the mine wall (1000).

[0121] In certain embodiments, not illustrated, the cutting head assembly communicates with a control system which actuates and monitors the primary (40) and secondary (50) actuators of the primary (10) and secondary (30) breakage mechanisms. For example, the cutting head assembly may communicate with a control system which monitor the hydraulic pressures and flows in each of the primary (40) and secondary (50) actuator.

[0122] In certain embodiments, the control system comprises a remote control interface supporting remote monitoring and control of the primary (40) and secondary (50) actuators of the primary (10) and secondary (30) breakage mechanisms. The control system may be programmable so as to automate the actuation of the primary (40) and secondary (50) actuators reactive of their monitored activity. It will be appreciated that the control system, and subsequently the remote control interface, could be located at surface level and outside of the resultant mine shaft created during excavation of the mine wall (1000) and include communication infrastructure and equipment to support communication with one or more communication interface modules on board the cutting head assembly. Suitable communication infrastructure and equipment would be known to a person skilled in the art.

[0123] In this way, advantageously, the cutting head assembly (100) may be operated and monitored at a safe distance from the mine wall (1000) without placing an operator in any hazardous situation resultant of excavating the mine wall (1000).

[0124] In certain embodiments, with particular reference to FIG. 11, the cutting head assembly (100) may further comprise an adapter plate (60) configured to be removably attachable to the housing (23). In the present case, the adapter plate (60) comprises one or more lifting means (61) enabling handling and transportation of the cutting head assembly (100). It will be appreciated, although not illustrated, that the adapter plate (60) may cover and protect the outlet (26) so as to prevent ingress of any unwanted particles of substances or debris during handling or transportation of the cutting head assembly (100).

[0125] In certain embodiments, the mining system (300) (referring to any one of FIGS. 12 to 14) is downstream of the cutting head assembly (100) to receive rock fragments from the cutting head assembly (100).

[0126] In the present case, and as is illustrated in the Figures, the mining system (300) is a vertical mining system which creates a vertical to sub vertical mine shaft by utilising the above described cutting head assembly (100) to excavate the mine wall (1000). A vertical mining system (300), when used with the cutting head assembly (100), may permit access to smaller scale mineral deposits without the need for expansive excavation such as those employed in either of explosive excavation or mechanical rock fragmentation excavation. In an alternative case, not illustrated in the Figures, the mining system (300) is a mining system capable of creating a near-horizontal, sub-horizontal or angled mine shafts or tunnels by utilising the above described cutting head assembly (100) to excavate the mine wall (100). The described cutting head assembly (100), in this alternative case, may permit access to mineral deposits that largely span in a horizontal or near-horizontal orientation. As will be appreciated by the disclosure of the above two cases, the cutting head assembly (100) may be utilised to create an angled mine shaft.

[0127] The vertical mining system (300) illustrated in any one of FIGS. 12 to 16 may be a closed loop mining system comprising a base carrier (310) such as a hydromill or trench cutter (illustrated), a solid separation and sorting unit (320), a mineral processing unit (not shown), tailings and waste integration unit (not shown) and a filling system (not shown). The composition of the closed loop mining system is preferentially modular such that the system is easy to commission and decommission, and is easily transported to and from a site.

[0128] It will be appreciated that although, in some embodiments, the base carrier (310) may comprise a hydromill or trench cutter, it is possible that other types of base carrier (310) may be used. For example, the base carrier (310) may be a duty cycle crane (not shown) configured for use in the vertical mining system (300). Indeed, the base carrier (310) may be any suitable type of base carrier which is selected to excavate rock fragments from the mine wall (1000) to create the resultant mine shaft in a vertical, sub-vertical or near-vertical orientation. Suitable types of base carrier (310) would be readily available and typically used in the foundation industry. One example of a suitable base carrier (310) is a base carrier (310) having a capacity to reach depths of, for example, 250 m.

[0129] The base carrier (310) comprises control lines, hoses and the drawworks cables necessary to supply the hydraulics, electrical power and the fluids utilised to operate the miner body (200) and subsequently the cutter head assembly (100). The drawworks cables may be spooled in drums located on the base carrier (310) and is used to support the weight of the miner body (200) and subsequently the cutter head assembly (100). In such embodiments, the above described feed force may be a force which results from slacking off or picking up the miner body (200) as is imparted by the drawworks cables of the base carrier (310).

[0130] The control system and the remote control interface may be located at the base carrier (310) for actuating and monitoring the primary (40) and secondary (50) actuators of the primary (10) and secondary (30) breakage mechanisms.

[0131] With reference now to FIGS. 15 and 16, in certain embodiments, the miner body (200) operates in conjunction with the cutting head assembly (100). In the present case, the miner body (200) includes the suction pump (210) centrally disposed between one or more pairs of steering plates (240) and one or more crawler tracks (250), the connecting gear (220) disposed on an underside of the miner body (200) concealing the conduit (230), and a hoist mechanism (260) disposed on a topside of the miner body (200).

[0132] The one or more pairs of steering plates (240) operate in combination with the one or more crawler tracks (250) and the hoist mechanism (260) to follow the excavation of the mine wall (1000).

[0133] The hoist mechanism (260) connects the miner body (200) to the base carrier (310) via the drawworks cables, the control lines and hoses of the base carrier (310). It will be appreciated that the hoist mechanism (260) coupled with the drawworks cables act so as to provide the feed force from the miner body (200) to the cutter head assembly (100). The hoist mechanism (260), in one embodiment, comprises a level wind system to help maintain spooling of wire into a hoist drum.

[0134] The steering plates (240), in one embodiment, may comprise one or more steering actuators for moving the steering plates (240) about an axis so as to enable the steering plates (240) to contact walls of the excavated mine shaft. In certain embodiments, the actuators are able to retract the steering plates (240) away from the walls of the excavated mine shaft to assist in retrieval of the miner body (200) and thus the cutting head assembly (100) from the excavated mine shaft.

[0135] Retracting the steering plates (240) via the one or more actuators also assist in positioning the steering plates (240) to best absorb reactive forces created by the percussive force of the primary breakage mechanism (10). The steering plates (240) may also function so as to lock the miner body (200) at a position in the mine shaft, and thus position the cutter head assembly (100) allowing the feed force from the drive (24) and/or swing (27) gears to engage/excavate the mine wall (1000) by actuation of the primary rock breakage mechanism (10). It will be appreciated that with the steering plates (240) locked and engagement of the mine wall (1000) for excavation, the steering plates (240) advantageously absorb reactive forces created by the percussive force of the primary breakage mechanism (10). It will be appreciated that in sub-horizontal or near-horizontal mine shafts or tunnels, the steering plates (240) operate in sub-horizontal positions to drive the miner body (200) and thus the cutting head assembly (100) forward, via the feed force, in the required direction.

[0136] The connecting gear (220), in one embodiment, may comprise a drive motor for the connecting gear (220) so as to impart drive on the gear (220) and subsequently rotate the cutting head assembly (100) about the axis of the connecting gear (220) via the swing gear (27). In certain embodiments, with particular reference to FIG. 15, the drive motor rotates the cutting head assembly (100) about the axis of the connecting gear (220) illustrated by dashed lines X-X. Rotation of the cutting head assembly (100) about the axis as shown allows the actuation of the primary (10) and secondary (30) breakage mechanisms to mine the mine wall (1000) so as to permit drive of the cutting head assembly (100) and subsequently the miner body (200) through the resultant mine shaft. It will be appreciated that in this way, the rotation of the cutting head assembly (100) about the axis of the connecting gear (220) clears the mine shaft so as to allow progression of the cutting head assembly (100) via the feed force applied by the miner body (200).

[0137] An exemplary method by which the cutting head assembly (100) of any one of the above embodiments excavates rock fragments from the mine wall (1000), may include the steps of: [0138] 1. Slacking off the miner body (200) so as to apply the feed force at the primary breakage mechanism (10) of the cutting head assembly (100) and engage the mine wall (1000); [0139] 2. Actuating the primary breakage mechanism (10) to apply, to the mine wall (1000), the breakage force (the percussive force) for breaking rock fragments from the mine wall (1000) via tensile failure; [0140] 3. Catching the resultant rock fragments on the surface (20); [0141] 4. Actuation of the secondary breakage mechanism (30) to apply the force (the shear force) for reducing the size of at least some of the rock fragments caught by the surface (20) so as to allow at least the reduced size rock fragments to move off of the surface (20) through the one or more ports (21); [0142] 5. Application of the suction pressure via the suction pump (210) of the miner body (200) to transport the reduced size rock fragments from the one or more ports (21) through the fluid passageway (22) and subsequently the outlet (26) for downstream processing; [0143] 6. Subsequent to above steps 1 to 5, as the mine wall (1000) is sufficiently excavated and is creating the mine shaft, the miner body (200) is slacked off further to force the cutting head assembly (100) and the miner body (200) into the created mine shaft to continue excavation of the mine wall (1000).

[0144] It will be appreciated in any one of the above embodiments, and as illustrated in any one of the Figures, that the cutting head assembly (100) is also particularly designed such that it can be detached from the miner body (200) in a modular manner. That is to say, one or more cutting head assemblies (100) with various primary cutters (11), cutting elements (12) and/or secondary cutters (31) may easily be attached and detached from the miner body (200) during excavation of the mine wall (1000). This is particularly advantageous if the cutting head assembly (100) or any one of the primary cutters (11), cutting elements (12) and/or secondary cutters (31), require replacement or exchange in response to the mine wall (1000) geology or due to damage.

[0145] It will be appreciated in a number of the embodiments described above, that the cutting head assembly (100) may exploit a number of factors in order to achieve effective rock breakage in the mine wall (1000). In particular, the combination of the primary (10) and secondary (30) breakage mechanisms applying both percussive and shear forces to target both tensile and shear stresses in the rock.

[0146] Additionally, the arrangement of the primary cutters (11) and/or the cutting elements (12) of the primary breakage mechanism (10) may advantageously allow the cutting head assembly (100) to combine the feed force supplied by the miner body (200) and the percussive force applied by the primary breakage mechanism (10) to exploit weaknesses of hard rock and ore bodies whilst minimising wastage whilst mining the wall (1000) due to the predictable size of the resultant reduced size rock fragments for improved downstream rock fragment processing.

[0147] A further advantage of the cutting head assembly (100) is that it suits use in a vertical mining system (300). In this way the mine wall (1000) and the resultant mine shaft is excavated vertically to sub vertically (i.e. sub horizontally), depending on geological conditions of the mine wall (1000), thus advantageously being economical when targeting smaller scale mineral deposits and minimising environmental footprint.

[0148] Throughout the specification and the claims that follow, unless the context requires otherwise, the words comprise and include and variations such as comprising and including will be understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers.

[0149] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement of any form of suggestion that such prior art forms part of the common general knowledge.

[0150] It will be appreciated by those skilled in the art that the disclosure is not restricted in its use to the particular application described. Neither is the present disclosure restricted in its preferred embodiment with regard to the particular elements and/or features described or depicted herein. It will be appreciated that the disclosure is not limited to the embodiment or embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the scope of the disclosure as set forth and defined by the following claims.