Mining machine

Abstract

 A roadheader type mining machine comprises a self-propelled chassis, an elongate boom (9) having a longitudinal axis (10), the boom (9) being supported by the chassis for powered positioned adjustment with respect to the chassis, a terminal end (13) of the boom (9) provided with a rotary cutting head (14) having a plurality of nozzles (20) each to emit a water spray or jet (41), water conveying conduits (22) connectable between the nozzles (20) and a source of pressurised water, and an on/off water flow control valve (24) associated with each conduit (22), and a collar (34) surrounding at least a portion of the boom (9) about an axis co-axial with the boom longitudinal axis (10) and being rotatable about this axis by power means (36) to a selected position, the collar (34) carrying, and/or positionally controlling, valve actuation means (30) whereby periodic water supply to the nozzles (20), due to head rotation, within a selected radial sector is controllable by the valves (24), phased activation of which is controlled by positioned adjustment of the collar (34) to provide appropriate positional adjustment of the valve actuation means (30).

Description

[0001] This invention relates to a mining machine of the kind adapted to drive underground roadways, tunnels or headings, commonly known as a roadheader machine.

[0002] Basically, such a machine comprises a self-propelled, crawler or wheel-mounted chassis carrying a displaceable boom, a terminal end of which is provided with a rotary cutting head, the latter being driven from a power unit carried by the chassis, via a transmission including a final drive shaft extending longitudinally of the boom and rotatably supported in bearings carried by a stationary, outer casing of the boom. The boom is power-displaced e.g. hydraulically, by the machine operator so that the boom follows the profile required for the roadway etc. Apart from the cutting heads being provided with replaceable cutter picks, they are also provided with a plurality of nozzles to emit a water spray or jet, while the nozzles may, in practice be mounted on the heads and/or on the picks. The water spray or jet may be for purposes such as pre-start warning, dust suppression, pick face flushing, incendive sparking elimination and, at higher pressures, water jet assisted cutting. It will be appreciated however that only a certain sector of the periphery of the cutting head is in the cut at any one time and consequently, and if as is usually the case, water is emitted over 360° a substantial proportion of the water e.g. 50%, has no beneficial effect but represent a waste, not only of water, but of power consumed in generating the pressure (which, in the case of water jet assisted cutting, may be of the order of 30,000 p.s.i.), apart from creating unnecessarily wet floor conditions. Attempts have been made to provide valving arrangements to achieve phased emission, but such systems have yet to be proved and are relatively complex to instal, maintain and adjust.

[0003] The object of the present invention is to provide a roadheader type mining machine in which the emission of water sprays or jets may be readily phased in a desired radially extending sector by simple control of valving arrangements.

[0004] According to the present invention, there is provided a roadheader type mining machine comprising a self-propelled chassis, an elongate boom having a longitudinal axis, the boom being supported by the chassis for powered positional adjustment with respect to the chassis, a terminal end of the boom provided with a rotary cutting head having a plurality of nozzles each to emit a water spray or jet, water conveying conduits connectable between the nozzles and a source of pressurised water and an on/off water flow control valve associated with each conduit, and a collar surrounding at least a portion of the boom about an axis co-axial with the boom longitudinal axis and being rotatable about this axis by power means to a selected position, the collar carrying, and/or positionally controlling, valve actuation means whereby periodic water supply to the nozzles, due to head rotation, within a selected radial sector is controllable by the valves, phased activation of which is controlled by positional adjustment of the collar to provide appropriate positional adjustment of the valve actuation means.

[0005] Thus, the invention provides a roadheader type mining machine in which water phasing only to a selected radial sector (normally the cutting sector) of the cutting head, is readily attained simply by appropriate re-positioning of the collar, by rotation, from a previous angular position (appropriate to a previously selected sector) to a new, static, position that results in phased water emission over only the selected sector, thereby maximising the efficient use of water.

[0006] Conveniently, the head is attached to one end of a drive shaft extending longitudinally of the boom and rotatably supported in bearings carried by a stationary outer casing of the boom, the drive shaft forming part of a power transmission from a power unit of the chassis to the cutting head.

[0007] The power means to rotate the collar to its desired angular position with respect to non-rotational portions of the boom may for example be an hydraulic motor or an e- ctric motor, and either type of motor may drive the collar through a gearbox, which may be of a speed reduction kind. For medium pressures e.g. 1,000-1,500 p.s.i., suitable for example for pick face flushing, journal bearings may be interposed between the collar and a portion of the outer casing of the boom, while for higher loadings/pressures e.g. 30,000 p.s.i., roller bearings may be provided.

[0008] Collar re-positioning (by rotation of collar about the boom axis), to result in sector selection variations, to suit positional variations of the boom and hence the cutting head, may be controlled by any of several alternative procedures. Thus, in its simplest form, collar rotation may be controlled directly by activation of hand controls by the machine operator, provided the machine operator has sight of the cutting head and/or the boom. Alternatively, automatic collar rotational control may be effected by attaching transducers to the boom (to register directionally, load or stresses within the boom) and/or the cutting head and/or the cutting picks and/or the conventional hydraulic control circuitry of the boom (to register flow and/or pressure changes) to sense the sector of the head that is effecting cutting, the transducers being connected to electrical and/or hydraulic control circuitry to instigate collar rotation. In detail, the transducers may be of a pressure sensing kind and/or a movement sensing kind. As a further alternative, the boom may be provided with a trailing arm or a link mechanism in contact with the cut, to sense the location of the cut and hence the sector of the drum that is effecting cutting, with collar rotation, to achieve its desired re-positioning, being controlled through suitable control circuitry by movements of the arm or link mechanism. Finally, if the machine is of a kind provided with a micro-processor which retains a profile cutting pattern program, then this program may be modified to control additionally collar positioning, as the sector in the cut is pre-determined.

[0009] The valve actuating means preferably comprises an operating lever attached to each valve, the levers, in a first embodiment, being positionally controlled by a cam track of the collar. The cam track may be machined into the collar, or releasably attached to the collar so as to be readily changeable when a change in the angles of the water emitting, or non-emitting, segments is reuired. In detail, the cam track may be provided in an inwardly extending, annular flange of the collar located adjacent the cutting head. In a second embodiment, the valve operating levers are engagable by two angularly spaced-apart protrusions on the collar, in the form of lobes or pins, such that upon striking one protrusion, the valves are rotated to their "on" position, and upon striking the other protrusion are rotated to their "off" position. The protrusions are preferably adjustable in position (e.g., by being screwed into selected tapped holes provided around a circumference of an end face of the collar adjacent the rotary cutting head) so that the water emitting segment may be readily increased or decreased to suit particular operating conditions.

[0010] Each valve may comprise a stationary valve body with a through bore aligned with its conduit, the valve body housing -a rotatable valve member to which its operating lever is attached, which member also has a through bore which is alignable with the valve body bore to perm it water flow, and is non-alignable to prevent water flow.

[0011] It may be arranged for a 180° sector (the "cutting" sector) to be water emitting and the remaining 180⁰ sector to be non-emitting.

[0012] Conveniently, water from a pressure supply source (e.g. at 1000 - 10,000 p.s.i. or higher), is conveyed along a supply conduit drilled along the longitudinal axis of the drive shaft, the supply conduit terminating within the cutting head and being intersected by a plurality of radial supply conduits, one for each nozzle or group of nozzles. Thus, the valves may be located in the radial supply conduits, so that as these conduits and hence their nozzle(s), upon rotation of the head, temporarily enter the "spraying" sector, the cam path change, or the protrusions being struck, displacing the operating levers and hence rotating the valve members to align the bores of the valve members to permit water delivery to the nozzle(s), while cessation of water delivery occurs as the conduits amd their valves exit the "spraying" sector.

[0013] The invention will now be described, in greater detail, by way of example, with reference to the accompanying drawings, in which:-

Figure 1 is a side elevation of a roadheader type machine in accordance with the invention;

Figure 2 is a plan view of Figure;

Figure 3 is an enlarged, part axial sectional view of a cam track embodiment;

Figures 4 and 5 are diagrammatic end views on the cam track of Figure 3, showing the on and off positions, respectively;

Figures 6 and 7 are, respectively, enlarged sectional portions of Figures 4 and 5, showing the "on" and "off" valve positions;

Figure 8 is an enlarged, sectional view through an on/off valve of Figures 3 to 5; and

Figure 9 is a plan view of Figure 6. In the drawings, a roadheader type mining machine 1 is shown seated on a mine floor 2 over which the machine is manoueverable on crawler tracks 3 under the control of a machine operator, an operator's seat being indicated at 4 and a bank of control valves at 5.

[0014] The machine 1 comprises a chassis 6 provided with a spoil gathering/loading conveyor 7 and carrying one end 8 of an elongate boom 9 having a longitudinal axis 10, the boom 9 being mounted on a turn-table arrangement 11 for swinging movements about a vertical axis, and on pivot pins 12 for swinging movements about a horizontal axis, such movements being controlled in the known manner by hydraulic rams 11A. At the other end 13 of the boom 9 is provided a cutting head 14 rotatable about the boom axis 10 and provided with a plurality of replaceable cutter picks 15 as shown in Figure 3. The chassis 6 also carries a power unit in the form of an electric motor (not shown) to power not only the cutting head 14 via a transmission which includes a final drive shaft 16 (see Figure 3) but also a hydraulic pump(s) for various hydraulic functions of the machine 1, including drive to the tracks 3.

[0015] As best seen in Figure 3, the boom 9 comprises an outer casing 17 which carries spaced-apart bearings 18 for rotational support of the drive shaft 16, with the cutting head 14 drivably attached to, and supported from, the drive shaft 16 at a flanged joint 19. Associated with each pick 15 is a nozzle 20 from emitting a water spray or jet. Water is conveyed to the nozzles 20 from a water pressurisation source e.g., a pump (not shown) along a plurality of conveying conduits comprising a supply conduit 21 drilled along the longitudinal axis of the drive shaft 16 and cutting head 14, which conduit 21 is in fluid flow communication with a plurality of radial conduits 22 drilled into the cutting head 14, which conduits 22 are in fluid flow communication with delivery conduits 23, which deliver water to the nozzles 20. Associated with each conduit 22 is a valve 24 comprising a stationary valve body 25 mounted in a rearward end 26 of the cutting head 14, the valve body 25 having a through bore 27 permanently aligned with its conduit 22. The valve body 25 also houses a rotatable valve member 28 having a through bore 29 which is alignable with the bore 27 to permit water flow, and non-alignable to prevent water flow. To each valve member 28 is attached a an operating lever 30 having a roller or pin 31 located in a cam track 32 machined into an inwardly extending, annular flange 33 of a collar 34, which flange 33 is located adjacent the cutting head 14. The collar 34 surrounds a portion of the outer casing 17 of the boom 9, and is rotatable about such casing on interposed journal bearings 35. Rotation is effected by an hydraulic or electric motor 36 attached to a flange 37 of the outer casing 17, and having a drive pinion 38 in drivable engagement with a toothed outer portion 39 of the collar 34.

[0016] As best seen in Figures 4 and 5, the cam track 32 has an inner diameter sector 40 over which each bore 29 is aligned with its associated bore 27 to permit water flow, as indicated both in Figure 6 and at the lower valve 24 of Figure 3, so that a water spray 41 is emitted from each lower nozzle 20 of Figure 3. Similarly, the cam track 32 has an outer diameter sector 42 over which the bores 27 and 29 are not aligned to prevent water flow, as indicated both in Figure 7 and at the upper valve 24 of Figure 3. The transition from sector 40 to sector 42 occurs at areas 43 and 44 of the cam track 32, at which areas the mode of each valve 24 is altered, as the valves 24 are rotated through areas 43 and 44 by rotation of the cutting head 14. In the alternative embodiment with protrusions to cause valve activation, such protrusions would likewise be located at areas 43 and 44, which areas result in the nozzles (20) spraying over approximately 180°, being the cutting sector.

Claims

1. A roadheader type mining machine 1 comprising a self-propelled chassis 6, an elongate boom 9 having a longitudinal axis 10, the boom 9 being supported by the chassis 6 for powered positional adjustment with respect to the chassis 6, a terminal end 13 of the boom 9 provided with a rotary cutting head 14 having a plurality of nozzles 20 each to emit a water spray or jet 41, water conveying conduits 22 connectable between the nozzles 20 and a source of pressurised water, and an on/off water flow control valve 24 associated with each conduit 22, and a collar 34 surrounding at least a portion of the boom 9 about an axis co-axial with the boom longitudinal axis 10 and being rotatable about this axis by power means 36 to a selected position, the collar 34 carrying, and/or positionally controlling, valve actuation means 30 whereby periodic water supply to the nozzles 20, due to head rotation, within a selected radial sector is controllable by the valves 24, phased activation of which is controlled by positional adjustment of the collar 34 to provide appropriate positional adjustment of the valve actuation means 30.

2. A machine as claimed in Claim 1, wherein the head 14 is attached to one end of a drive shaft 16 extending longitudinally of the boom 9 and rotatably supported in bearings 18 carried by a stationary outer casing 17 of the boom 9, the drive shaft 16 forming part of a power transmission from a power unit of the chassis 6 to the cutting head 14.

3. A machine as claimed in Claim 1 or Claim 2, wherein the power means 36 to rotate the collar 34 to its desired angular position with respect to non-rotational portions of the boom 9 is an hydraulic or electric motor 36.

4. A machine as claimed in any preceding Claim, wherein collar re-positioning is controlled by hand controls 5 activated by the machine operator.

5. A machine as claimed in any one of Claims 1 to 3, wherein collar re-positioning is controlled automatically by attaching transducers to the boon, (to register directionally, load or stresses within the boom 9) and/or the cutting head 14 and/or the cutting picks 15 and/or the conventional hydraulic control circuitry of the boom 9 (to register flow and/or pressure changes) to sense the sector of the head 14 that is effecting cutting, the transducers being connected to electrical and/or hydraulic control circuitry to instigate collar rotation.

6. A machine as claimed in any one of Claims 1 to 3, wherein collar re-positioning is effected by a micro-processor provided on the machine 1, which processor retains a profile cutting pattern program, with the program modified to control additionally collar positioning, as the sector in the cut is pre-determined.

7. A machine as claimed in any preceding Claim, wherein the valve actuating means comprises an operating lever 30 attached to each valve 24, with the levers 30 positionally controlled by a cam track 32 of the collar 34.

8. A machine as claimed in Claim 7, wherein the cam track 32 is provided in or at an inwardly extending, annular flange 33 of the collar 34 located adjacent the cutting head 14.

9. A machine as claimed in any one of Claims 1 to 6, wherein the valve operating means comprises an operating lever 30 attached to each valve 24, the levers 30 being positionally controlled by engagement with two angularly spaced-apart protrusions on the collar.

10. A machine as claimed in Claim 7 and any Claim appendant thereto, wherein each valve 24 comprises a stationary valve body 25 with a through bore 27 aligned with its conduit 22, the valve body 25 housing a rotatable valve member 28 to which its operating lever 30 is attached, which member 28 also has a through bore 29 which is alignable with the valve body bore 27 to permit water flow, and is non-alignable to prevent water flow.

11. A machine as claimed in any preceding Claim, wherein water from a pressure supply source (e.g. at 1000 - 10,000 p.s.i. or higher), is conveyed along a supply conduit 21 drilled along the longitudinal axis of the drive shaft 16, the supply conduit 21 terminating within the cutting head 14 and being intersected by a plurality of radial supply conduits 22, one for each nozzle 20 or group of nozzles 20.

Drawing