MINING MACHINE GATHERING HEAD

Abstract

A gathering head for a mining machine is positionable at a forward end of the machine. The gathering head includes a base, a back plate and sidewalls. The sidewalls are both tapered inwardly in the widthwise direction of the head from a forward end to a rearward end and outwardly relative to the base from a lowermost region to an uppermost region. Accordingly, the requirement for additional gathering arms at a base region of the head is avoided.

Description

FIELD OF INVENTION

The present invention relates to a mining machine gathering head positionable at a forward end of a mining machine, and in particular, although not exclusively, to a gathering head having a pair of end walls positioned at the lengthwise ends of the head being shaped and configured to guide a flow of extracted material into and from the gathering head.

BACKGROUND ART

A variety of different methods and machines have been developed to extract minerals and other valuable materials at and below the Earth's surface. Such machines typically operate in mines at great depths.

In order to maximise excavation and mineral recovery efficiency, mining machines have been developed for specific purposes. Whilst some machines are configured exclusively to cut the mineral from a deposit or seam, other machines are configured to tunnel within the subterranean depth to effectively create the mine and provide passageways for the mineral cutters. In particular, mobile mining machines have emerged as successful apparatus to both provide direct cutting at the seam and as a means of rapid entry roadway development. Typically a mobile mining machine comprises a rotatable cutting or mining head having cutting bits provided on rotating drums to contact the mineral face. The cutting head is conventionally mounted at a moveable boom so as to be adjustable in height relative to the mine floor. As the cutting head is rotated and advanced into the seam, the extracted mineral is gathered by a gathering head and then conveyed rearwardly by the mobile machine via conveying apparatus to create discharged stock piles for subsequent extraction from the mine. Example gathering heads are described in DE 3015319 and DE 880576.

The gathering head (alternatively termed a loading shield) is forced into the material extracted from the deposit by the forward motion of the mining machine. There are two general approaches to facilitate rearward transport of the extracted material from the leading edge of the loading shield rearwardly onto the travel conveyor. Firstly, the rotating cutting head boom may comprise helical discs extending lengthwise along the boom to form an auger optionally coupled with a secondary helical conveying device that transports the material rearwardly of the head. Example gathering heads configured with helical augers are disclosed in U.S. Pat. No. 3,860,291 and U.S. Pat. No. 4,277,105 and with secondary helical augers as disclosed in WO 2011/040806 and U.S. Pat. No. 4,952,000. An alternative approach to material transport involves gathering arms or rotating discs provided at the loading shield that require separate drive components. Such arms or discs are mounted at a base of the gathering head and operate continuously and independently of the cutting head. This gathering mechanism is preferred over the helical cutting head configuration as the latter approach hinders the torque force of the cutting teeth due to the frictional contact with the extracted material that is driven between the helical plates. A gathering head comprising rotating spinning arms is disclosed in WO 98/03770 and U.S. Pat. No. 4,296,856. However, as will be appreciated the associated components and operation of rotating gathering arms increases the number of moving parts and weight of the machine generally ,which is disadvantageous for maintenance and transport reasons. Accordingly, what is required is a gathering head effective to receive and transport rearwardly material extracted from a deposit that addresses the above problems.

SUMMARY OF THE INVENTION

It is an objective of the present invention to provide a gathering head for a continuous mining machine that obviates the need for additional gathering or spinner arms drivably mounted at a base region of the head and that is effective to receive and facilitate rearward transport of the extracted material onto a conveyor or rearward transport assembly to convey the extracted material away from the cutting face. It is a further objective to provide a gathering head that requires little or no maintenance and is generally lighter than conventional loading shield assemblies.

The objectives are achieved by providing a material gathering shield comprising a plate-like construction in which the plates are arranged specifically to direct the flow of extracted material from a forwardmost or leading edge region of the head rearwardly towards a rearward exit region from which material is then conveyed from the head. In particular, the present gathering head comprises a base extending lengthwise along the head with a pair of sidewalls positioned at the lengthwise ends of the base. Each sidewall comprises a side surface to contact the extracted material where these side surfaces are both tapered inwardly in a widthwise direction of the head from the forward end to the rearward end and are tapered outwardly relative to the base from a lowermost region to an uppermost region of each side surface. Accordingly, extracted material contacts the side surfaces and is guided and deflected onto the base surface of the head and at least one back plate that extends upwardly from a rearward region of the base. Importantly, a width of the base of the head in a direction between the forward and rearward ends of the head is minimised, to reduce as far as possible, the travel distance by which material must flow from the leading edge (of the head) to the exit region (conveyor). The declined and inwardly tapering configuration of the sidewalls eliminates regions of the head that would otherwise represent ‘entrapment zones’ where extracted material could collect and represent an obstruction to the continuous flow of material through the gathering head.

The present gathering head also comprises a plurality of additional sets of conveyor feed plates that are also tapered and inclined to facilitate further the rearward transport of material along the loading shield.

According to a specific implementation of the present invention there is provided a mining machine gathering head positionable at a forward end of a mining machine, the head having a forward end and a rearward end, the rearward end intended to be positioned adjacent the mining machine, the head comprising: at least one base extending lengthwise along the head, the base having a base surface to contact material gathered by the head; a pair of sidewalls positioned at the lengthwise ends of the base, the sidewalls each having a side surface to contact the material and being tapered inwardly in the widthwise direction of the head from the forward end to the rearward end; at least one back plate having a material contact surface extending upwardly from a rearward region of the base surface and extending in the lengthwise direction of the gathering head between the sidewalls; a ramp extending lengthwise along the head and being declined to project forward and downward from the base to provide a leading edge at the head; characterised in that: each side surface is tapered outwardly relative to the base surface from a lowermost region to an uppermost region of each side surface to guide the flow of material onto the base surface and the material contact surface.

Preferably, the head further comprises a pair of side flanges each flange being moveably mounted at an outer region of a respective sidewall and capable of projecting forwardly of the respective sidewall to increase the inlet area of the gathering head when extended and to facilitate manoeuvrability of the mining machine when retracted. Optionally, each flange is mounted at the respective sidewall via at least one pivot mounting and at least one guide member to hold and guide the pivoting movement of each flange relative to each sidewall. Preferably, each flange is pivotally driven by a power operated linear actuator such as a hydraulic or pneumatic cylinder to provide a simple and reliable movement mechanism. Optionally, the guide member comprises an elongate member slidably mounted within a guide bracket. Preferably, each flange is tapered inwardly and outwardly at substantially the same angle as the side surfaces such that a flange contact surface (to contact material gathered by the head) is substantially coplanar with each respective side surface. This is advantageous to provide a smooth transfer of material in the rearward direction over the head contact surfaces.

Preferably, the head further comprises a conveyor having a belt projecting rearwardly from the ramp, a forward end of the conveyor extending into a region of the base in the widthwise direction between the sidewalls. Accordingly, this minimises the distance by which material within the head must travel rearwardly to reach the conveyor. Optionally, the head may comprise a helical auger projecting rearwardly from the head to transport the extracted material rearwardly with such an auger arrangement also projecting into the head region.

Where the machine comprises a conveyor, preferably a height level of the base surface is positioned at a level above the belt to provide that material is configured to fall downwardly from the base surface onto the belt. As such, the rearward flow of material through the head is greatly facilitated without the need for independently powered conventional spinner or gathering arms.

Preferably, the head further comprises a first set of conveyor feed plates extending between and inclined downwardly from the base surface to the belt. Optionally, the head further comprises a second set of conveyor feed plates extending between and being tapered inwardly from the back plate towards the belt. According to the specific implementation, the first and second sets of feed plates comprise a shape configuration to match certain end edges of the base plate(s) and the back plate(s). Preferably, a front end of the conveyor is positioned substantially at a region of the leading edge of the base and/or a rearward edge of the ramp to facilitate the rearward travel of the extracted material through the head.

Optionally, the base comprises two base plates extending inwardly from each respective sidewall. Each base plate extends in the lengthwise direction between a respective side wall and a region of the conveyor. Optionally, each base plate comprises a trapezium shaped profile where a longest edge of one of the parallel sides of the trapezium is positioned forwardmost to represent a leading edge of the base plate. That is, a width of the base plate decreases from the leading edge to the rearward edge of each plate. Such an arrangement functions to funnel the cut material through the head towards the conveyor. Preferably, a shape profile of the side surface immediately adjacent each back plate and each base plate comprises a generally triangular configuration to create the present contoured contact surface of the gathering head to guide material from the forward end to the rearward end of the gathering head.

Preferably, the back plate comprises two back plates extending inwardly from each respective sidewall and upwardly from each respective back plate. Optionally, each back plate comprises an upper shield plate projecting upwardly from an upper edge of each back plate and being inclined rearwardly and upwardly from each back plate. Accordingly, the contact surface area of the head is increased to avoid sideways loss of material whilst facilitating directing of the material onto the conveyor via the funnelling effect. Optionally, an approximate length of each upper shield plate is approximately equal to a maximum length of each back plate.

Preferably, the base surface is substantially planar and devoid of obstructions to allow the unhindered passage of material gathered by the head. Preferably, the head is devoid of rotatable spinner arms mounted at the base that would otherwise increase the weight, complexity and energy consumption of the machine.

Preferably, a distance by which the base extends widthwise between the forward and rearward ends is less than a height of the head between a lowermost to an uppermost region of the sidewalls. Such an arrangement further facilitates the funnelling of material rearwardly through the head to maximise the travel distance of material by the rearward drive action of the rotating cutting head.

According to a second aspect of the present invention there is provided a mining machine or a continuous mining machine comprising a gathering head as claimed herein.

BRIEF DESCRIPTION OF DRAWINGS

A specific implementation of the present invention will now be described, by way of example only, and with reference to the accompanying drawings in which:

FIG. 1 is a perspective view of a bolter mining machine configured for mineral cutting with simultaneous bolting and mineral conveying in which material extracted from a deposit is initially gathered and transported rearwardly by a forwardmost gathering head according to a specific implementation of the present invention;

FIG. 2 is an external side elevation view of the mining machine of FIG. 1;

FIG. 3 is an external front elevation view of the machine of FIG. 2;

FIG. 4 is a perspective view of the gathering head of the machine of FIG. 3;

FIG. 5 illustrates schematically a side view of the gathering head of FIG. 4 and the rotating cutting head of FIGS. 1 to 3 positioned at a material seam.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION

The present gathering head will now be described with reference to a preferred embodiment by way of example mounted upon a bolter miner being an electrically powered, track-mounted continuous mining machine designed to excavate roadways and install roof bolts simultaneously. Such mining machines comprise a series of cutter drums mounted on a hydraulically actuated frame to enable independent movement of the drums relative to a main frame and tracks. The machine also comprises roof bolters mounted on a stationary part of the main frame that can be operated throughout the cutting cycle.

Referring to FIG. 1, the mining machine 100 comprises a main frame 101 that provides support for an undercarriage or chassis 109 that supports a pair of endless driven tracks 113 for propelling the machine 100 over the ground and along a tunnel to advance forwardly through a material deposit seam. Main frame 101 comprises a generally forward end 102 and a generally rearward end 103. A conveyor 104 extends substantially from forward end 102 to rearward end 103 and is adapted to carry material dislodged from the cutting face for subsequent discharge and stock piling at a remote location optionally using additional conveying and mining apparatus. A movable cutting boom 105 is pivotally mounted at one end 112 to main frame 101 via a pivoting bracket 110 and comprises a second end 106 mounting a cutting head 115 that in turn mounts a plurality of rotatable drums 107. Cutting bits 108 project radially from each drum 107 and are specifically adapted to cut into and dislodge the mineral material to be mined from the seam. Boom 105 and in particular end 106 is capable of being raised or lowered relative to main frame 101 and endless tracks 113 to enable machine 100 to cut the seam face over a varying height range above the ground of the mine tunnel. Boom 105 is operated by hydraulic rams 202 (referring to FIG. 2) and other associated components as will be appreciated by those skilled in the art.

A canopy 111 comprises a vertically uppermost region having a generally planar configuration and is adapted for being raised vertically upward from frame 101 in a manner similar to cutting boom 105 so as to contact the mine roof to provide structural support as necessary during the cutting and roof bolting operations. Additionally, a tail section 114 projects rearwardly from the rearward end 103 of frame 101 to carry rearwardly conveyor 104 to a discharge end 116 representing a rearwardmost part of the continuous miner 100.

Referring to FIGS. 1 to 4, the machine 100 further comprises a gathering head 117 mounted at forward end 102 via a head mounting bracket 203. Head 117 comprises a base 119 extending lengthwise along the head in a direction perpendicular to a main length of machine 100. Base 119 is terminated at each lengthwise end by a respective sidewall 120. A ramp 118 is inclined downwardly from a forwardmost end of base 119 to provide a leading and lowermost component of head 117. Ramp 118 extends lengthwise between sidewalls 120. Head 117 further comprises a back plate 124 projecting upwardly from a rearward region of base 119 that in combination with sidewalls 120, base 119 and ramp 118 represent the main components of gathering head 117.

A pair of side flanges 121 are pivotally mounted at an outboard side of each respective sidewall 120 via a pivot mounting 204 located at an upper region 322 of head 117. An elongate guide bar 200 is mounted at a lowermost region of each flange 121 at a lowermost end 323 of sidewalls 120. Each flange 121 comprises a contact surface 303 aligned substantially coplanar with side surface 304 to effectively represent an extension of each sidewall 120. Accordingly, each flange 121 is capable of pivoting about mount 204 to swing forwardly and laterally outward from the main components of shield 117 so as to effectively increase the cross sectional area of the mouth of head 117 that receives and gathers the extracted material. Pivoting extension of flanges 121 is controlled via a respective pair of power operated linear actuators 201 having a first end mounted at sidewall 120 and a second end mounted at flange 121.

Head 117 further comprises an initial transport conveyor 122 having a forwardmost end 310 located at a forwardmost region of head 117. That is, a region of conveyor 122 extends into base 119 and in a widthwise direction between sidewalls 120. Conveyor 122 comprises a transport belt that extends around a forward mounted guide and drive assembly 125 positioned within a region of ramp 118. Conveyor 122 interfaces at its rearward end with the main machine conveyor 104 that extends through frame 101 and tale section 114.

Ramp 118 is substantially elongate to extend between sidewalls 120 and comprises a leading edge 301 and a trailing edge 302. Ramp surface 300 is inclined upwardly from front edge 301 to rear edge 302. According to the specific implementation, base 119 comprise two base plates positioned to the left and right hand side of the conveyor 122 when head 117 is viewed from the front as shown in FIG. 3. Each base plate comprises a base surface 324 for contacting material gathered by head 117. The exposed base surface 324 comprises a generally trapezium shaped profile such that the longest edge 311 of the parallel sides is positioned forwardmost and immediately behind trailing edge 302 of ramp 118. Surface 324 is further defined by an inner edge 314 and an outer edge 313 that extend rearwardly from ramp 118 to back plate 124. Each edge 313, 314 tapers inwardly to a shortest rearward edge 312 aligned parallel with front edge 311. Outer tapering edge 313 is positioned in contact with a side surface 304 of side wall 120 whilst the second inward tapering edge 314 is positioned opposed to conveyor 122.

As illustrated in FIG. 3, back plate 124 is divided into two plates that extend upwardly from the rearward edge 312 of each respective base plate 119. That is, a lowermost edge 325 of each back plate 124 is positioned at the rearward edge 312 of each base plate 119. A side edge 326 of each back plate 124 is inclined upwardly from base edge 325 and is positioned in contact with side surface 304. An uppermost edge 327 of each back plate 124 forms a junction with a lowermost edge 319 of a respective upper shield plate 123 that is inclined upwardly and projects rearwardly from each back plate 124. A rearward edge 320 of each shield plate 123 represents a rearwardmost part of head 117 and acts to contact and further guide material flow onto the conveyor 122 that extends centrally between the corresponding pairs of base plates 119, back plates 124 and shield plates 123.

As illustrated in FIGS. 3 and 4, a relative height of each base surface 324 is vertically above a height of the belt of conveyor 122 such that as material is gathered by head 117 it falls or is guided downwardly from surface 324 onto conveyor 122. This flow is facilitated by a first set of conveyor feed plates 306 that extend between the lengthwise sides of conveyor 122 and the inner tapering edges 314 of each base plates 119. Each feed plate 306 comprises a guide surface 307 that is defined, in part, by a lengthwise edge 317 that is positioned in contact with the inner tapered edge 314. Feed plate surface 306 terminates at its innermost side by edge 318 positioned immediately adjacent the side edges of conveyor 122. Due to the relative height difference between base surface 324 and conveyor 122, each feed surface 307 is declined downwardly from outer edge 317 towards inner edge 318. Material is therefore capable of sliding downwardly over surface 307 and onto conveyor 122. The flow of extracted material onto conveyor 122 is further assisted by a second set of conveyor feed plates 308. In particular, a pair of second feed plates 308 are positioned inboard of each back plate 124 and a lower region of each shield plate 123. In particular, an outer edge 328 of each feed plate 308 is positioned in contact with the upstanding innermost edge 315 of each back plate 124 adjacent each side of conveyor 122. Each feed plate 308 tapers inward from its leading edge 328 to a rearwardmost edge 316 such that edge 316 is positioned closest to conveyor 122 relative to leading edge 328. Accordingly, a feed surface 309 of each plate 308 provides a tapered guide surface from each back plate 124 to conveyor 122. The combination of the first and second set of conveyor feed plates 306, 308 provide a guide mouth for conveyor 122 that tapers outwardly and upwardly to facilitate transfer of material from the forwardmost edge 301 of ramp 118 towards the main conveyor 104.

Each sidewall side surface 304 is inward facing towards back plates 124 and base plates 119. Each side surface 304 is defined at its outermost region by an outermost lengthwise edge 321 that extends upwardly from lowermost region 323 to uppermost region 322. Each side surface 304 and in particular each sidewall 120 is tapered inwardly in the widthwise direction of head 117 between a forwardmost region corresponding to leading edge 301 and a rearwardmost region corresponding to mount 205 at a rearward end of conveyor 122. That is, a width of head 117 decreases generally in a direction from end 301 to end 205. Each side surface 304 and sidewall 120 is also inclined rearwardly relative to a vertical plane and in particular a material contact surface 305 of each back plate 124. That is, each side surface 304 is inclined outwardly relative to each base plate 119 and inclined rearwardly relative to each back plate 124. This configuration is advantageous to provide a guided material flow path as material flows over ramp 118 and into the main collection area of head 117 in contact with each base plate 119, each side wall 120 and each back plate 124. In particular, the material is both deflected laterally inward towards conveyor 122 and upward onto back plate 124 where it is subsequently directed onto conveyor 122 via respective feed plates 306, 308.

As illustrated in FIG. 5, the present head 117 is configured such that a surface area of each base surface 324 is minimised as far as possible to avoid creation of ‘entrapment zones’ where the material flow would otherwise become static and disrupt the feed and gathering of head 117. This reduced surface area is achieved, in part, by the outwardly and rearwardly tapered sidewalls 120 that effectively project into the base region of head 117.

The surface area of each base surface 324 is further reduced via the first set of conveyor feed plates 306 being inclined downwardly relative to each surface 324. Present head 117 therefore provides a greatly contoured internal material contact surface formed from the plurality of plate sections that are specifically angled relative to one another to optimise the material flow. The need for independently powered gathering or spinner arms is avoided due to this specific shape configuration of head 117 and in particular by minimising the distance between the front and rear edges 311, 312 of each base plate 119. Accordingly, as illustrated in FIG. 5, a width of head 117 between leading edge 301 and a rearward side 501 of head 117 is less than a corresponding height between lowermost and uppermost regions 323, 322. Accordingly, as cutting head 115 extracts material from seam 500, the fractured material is capable of being transported over the respective surfaces 300, 324, 304, 305, and 309 onto conveyor 122 by the action of the rotating head 115. The present gathering head therefore is optimised for reduced weight and robustness by eliminating the additional components associated with gathering or spinner arms conventional to existing continuous mining machines.

Claims

1. A mining machine gathering head positionable at a forward end of a mining machine, the head having a forward end and a rearward end, the rearward end arranged to be positioned adjacent the mining machine, the head comprising: at least one base 0494 extending lengthwise along the head, the base having a base surface arranged to contact material gathered by the head;a pair of sidewalls positioned at the lengthwise ends of the base, the sidewalls each having a side surface to contact the material and being tapered inwardly in the widthwise direction of the head from the forward end to the rearward end;at least one back plate having a material contact surface extending upwardly from a rearward region of the base surface and extending in the lengthwise direction of the gathering head between the sidewalls; anda ramp extending lengthwise along the head and being declined to project forward and downward from the base to provide a leading edge at the head; wherein each side surface is tapered outwardly relative to the base surface from a lowermost region to an uppermost region of each side surface to guide the flow of material onto the base surface and the material contact surface.

2. The gathering head as claimed in claim h further comprising a pair of side flanges each flange being moveably mounted at an outer region of a respective sidewall and capable of projecting forwardly of the respective sidewall.

3. The gathering head as claimed in claim 2 wherein each flange is mounted at the respective sidewall via at least one pivot mounting and at least one guide member to hold and guide the pivoting movement of each flange relative to each sidewall.

4. The gathering head as claimed in claim 2, wherein each flange is tapered inwardly and outwardly at substantially the same angle as the side surfaces, such that a flange contact surface to contact material gathered by the head is substantially coplanar with each respective side surface.

5. The gathering head as claimed in claim 1, further comprising a conveyor having a belt projecting rearwardly from the ramp, a forward end of the conveyor extending into a region of the base in the widthwise direction between the sidewalls.

6. The gathering head as claimed in claim 5, wherein a height level of the base surface is positioned at a level above the belt to provide that material is configured to fall downwardly from the base surface onto the belt.

7. The gathering head as claimed in claim 5, further comprising a first set of conveyor feed plates extending between and inclined downwardly from the base surface to the belt.

8. The gathering head as claimed in claim 5, further comprising a second set of conveyor feed plates extending between and being tapered inwardly from the back plate towards the belt.

9. The gathering head as claimed in claim 5, wherein a front end of the conveyor is positioned substantially at a region of the leading edge of the base and/or a rearward edge of the ramp.

10. The gathering head as claimed in claim 1, wherein the base includes two base plates extending inwardly from each respective sidewall.

11. The gathering head as claimed in claim 10, wherein the back plate includes two back plates extending inwardly from each respective sidewall and upwardly from each respective back plate.

12. The gathering head as claimed in claim 1, wherein the base surface is substantially planar and devoid of obstructions to allow the unhindered passage of material gathered by the head.

13. The gathering head as claimed in claim 1, being devoid of rotatable spinner arms mounted at the base.

14. The gathering head as claimed in claim 1, wherein a distance by which the base extends widthwise between the forward and rearward ends is less than a height of the head between a lowermost to an uppermost region of the sidewalls.

15. A mining machine comprising: a forward end; anda gathering head positioned at the forward end, the gathering head having a forward end and a rearward end, the rearward end arranged to be positioned adjacent the mining machine, the gathering head including at least one base extending lengthwise along the head, the base having a base surface arranged to contact material gathered by the gathering head, a pair of sidewalls positioned at the lengthwise ends of the base, the sidewalls each having a side surface to contact the material and being tapered inwardly in the widthwise direction of the gathering head from the forward end to the rearward end, at least one back plate having a material contact surface extending upwardly from a rearward region of the base surface and extending in the lengthwise direction of the gathering head between the sidewalls, and a ramp extending lengthwise along the gathering head and being declined to project forward and downward from the base to provide a leading edge at the gathering head, wherein each side surface is tapered outwardly relative to the base surface from a lowermost region to an uppermost region of each side surface to guide the flow of material onto the base surface and the material contact surface.

16. The mining machine of claim 15, wherein the mining machine is a continuous mining machine.