GB2281926A - Mining machines - Google Patents

Abstract

A mining machine of the type comprising a rear assembly and a forward cutting assembly connected thereto is described. The forward cutting assembly includes a main frame 14 and at least one cutting device carried thereby the cutting device having at least one rotary cutter 34. The cutting assembly is arranged such that the cutting device is releasably attached to the cutting assembly frame. At least one adaptor 44 is provided which is releasably securable between the cutting assembly frame and the cutting device. The adaptor, when so secured, alters the position or orientation of the axis of rotation of the cutter of the cutting device relative the axis of the frame or, if the cutter can move relative the frame, the path followed by the cutter rotary axis relative the frame axis. By use of one or more adaptors, the rotary axis can be raised relative the frame axis. Alternatively, or additionally, the rotary axis can be set at an acute angle to the frame axis or at a 90 DEG angle thereto. <IMAGE>

Description

IMPROVEMENTS IN AND RELATING TO MINING MACHINES This invention relates to machines for mining of coal and other materials in underground mine conditions and, in particular, to continuous mining machines.

Continuous mining machines remove coal by engaging the solid coal in the seam with a power driven cutting mechanism. Continuous mining machines generally comprise a cutter assembly which is movable forwardly with respect to a mine face and generally also transversely across and/or vertically up and down the mine face. The cutting assembly may be connected to a mobile rearward assembly which effects the forward movement of the cutter assembly.

A common form of rearward assembly is one provided with endless tracks as the means to achieve the necessary mobility. Alternatives to the provision of endless tracks include cable and drum assemblies, movement of the mining machine being effected by anchoring one end of the cable an anchoring jack assembly fixed between the mine roof and the floor, and a hydraulic piston and cylinder unit which acts in a similar fashion.

If the cutter assembly is to move across the mine face relative the rear assembly, then the two are generally connected by a yoke which allows pivoting of the cutter assembly with respect to the rearward assembly about a generally vertically extending axis and/or about a horizontal axis under the control of hydraulic rams connected between the two assemblies.

Many types of cutting assembly are known. One form consists of a single cutting head mounted on an arm which is pivotally connected to the rearward assembly to enable the cutting head to be moved both horizontally and vertically. Such a cutting assembly can be employed for both high and low seams. However, the amount of coal which can be cut by use of a single cutter is obviously limited and, at least in low seams, the use of a pair of cutters is more efficient.

A particularly common type of two-cutter assembly is a dual auger machine in which a pair of oppositely pitched and oppositely rotated augers are carried on either side of the central frame with their axes extending generally horizontally forwardly. Each auger includes a pair of helical blades having a series of cutting teeth at the forward end thereof and a series of teeth extending outwardly of the periphery thereof in longitudinally spaced relation therealong. The augers may be pivoted to the central frame and be independently vertically moveable under the action of a hydraulic ram unit connected between each auger and the central frame which effects a swinging movement of the former relative the latter.

One problem with known mining machines, which was touched upon above, is that a compromise has to be reached between the efficiency of the mining operation and the capability of cutting coal from high seams. This is particularly acute in the case of dual auger-type cutting machines. Such machines are highly favoured because of their efficiency of operation but, to date, they have not been successfully utilised for high seam cutting.

One solution which has been proposed to this problem, and is particular to dual auger-type cutting machines, is to provide a mount for the cutting head which enables the cutters to be moved from a horizontal orientation to a vertical orientation, the former being employed for low seam operations and the latter for high seam operations.

The provision of such a mount, however, increases the complexity of the machine design and adds to the cost of production thereof.

The above-discussed problem is really the result of the limited area of a cut which can be produced with known cutting assemblies, even with maximum lateral and vertical movement thereof. The profile of the cutting area is known as the cutting envelope. With a single drum cutter, the cutting envelope is rectangular. With a dual auger-type cutting machine, the cutting envelope is generally oval but the ends are constituted by circular arcs rather than full semi-circles. Clearly it is desirable to maximise the cutting envelope produced by a cutting machine but hitherto it has not been possible fully to achieve this.

Some attempts to increase the amount of coal which can be cut by a machine have centred on increasing the manoeuvrability of the whole machine. The problem with this is that relatively heavy equipment is required due to the weight of the mining machine. Other attempts have centred on increasing the possible movements of the cutting assembly relative the rearward assembly. These have generally resulted in increased overall machine weight and expense of manufacture.

A further problem with known machines is the form of the profile of the cut which they produce. In plan view, the sides of the cut generally appear as zig-zag lines.

The fluted sides produced by known machines mean that, if a narrow cut is required, for example, in the driving out of roadways, to produce is given minimum tunnel width, extra material has to be cut.

It is an object of this invention to provide a mining machine in which one or more of the above problems is obviated.

A mining machine in accordance with the invention comprises a rear assembly and a forward cutting assembly connected thereto, the cutting assembly including a main frame and at least one cutting device carried thereby, the cutting device having at least one rotary cutter, wherein the cutting device is releasably attached to the cutting assembly frame and wherein at least one adaptor is provided which is releasably securable between the cutting assembly frame and the cutting device and which, when so secured, alters the position or orientation of the axis of rotation of the cutter of the cutting device relative the axis of the frame or, if the cutter can move relative the frame, the path followed by the cutter rotary axis relative the frame axis.

The advantage of this is that to vary the action of the cutting device or cutting devices, for example, to increase the cutting envelope, all that is required is the connection of a suitable adaptor between the cutting device and the frame on which it is carried. Neither the connection between the cutting assembly and the rear assembly nor the manoeuvrability of the machine as a whole needs to be varied so that the problems associated with these approaches are avoided. Furthermore, the provision of an adaptor which can be inserted between the cutting assembly frame and the cutting device or devices carried thereby makes the cutting assembly design simpler and, accordingly, less expensive than, for example, that of an assembly in which the cutter mount is to be capable of holding the cutters in two different orientations.

Furthermore, and as is discussed below, with suitably arranged adapters, multiple variations in the cut produced by the machine are made possible. To further increase the possible variations, two or more interconnectible adaptors are preferably provided whereby the adapters may be secured together and between the frame and the cutting device produce a different effect on the cut, a still further, third, variation of the cut is made possible by connecting the two adapters together and then securing them between the frame and cutting device.

A first adapter may be provided, referred to hereinafter as a "lift" adapter, which, when secured, raises the rotary axis or at least part of its path relative the frame axis. The enables a cut of greater height to be made.

A second adapter may be provided, hereinafter termed an "angled" adapter, which, when secured, alters the angle between the rotary axis and frame axis. Suitably, the angled adapter is a "parallel angled" adapter and, when secured, sets the rotary axis at an acute angle to the frame axis. This has the very significant advantage that it allows tunnels to be produced with straight sides.

Instead of, or in addition to, the parallel angled adaptor, a "transverse angled" adaptor may be provided which, when secured, alters the angle between the rotary axis and frame axis by 90 . The transverse angled adaptor may be used, therefore, the change the cutter or cutters from a horizontal orientation to a vertical orientation.

Alternatively, it may be employed to move a cutter horizontally from a position extending generally parallel to the forward direction in which mining is proceeding, to a position transverse thereto. In the particular case of a dual auger-type cutting machine, the transverse angled adaptor allows the augers to be positioned so that they extend out from the sides of the machine transversely to the forward direction in which mining is proceeding.

Therefore a tunnel can be driven out with the augers in their normal position parallel to the direction of tunnel formation, the transverse angled adaptor can be added and the machine reversed out of the tunnel with the augers expanding the width thereof on either side.

In a particularly preferred embodiment, the adaptor(s) comprises a base member and at least one upper member, the base member being releasably securable to the frame and the upper member(s) being releasably securable between either the base member or another upper member and either another upper member or at least one cutting device. Accordingly, when multiple adaptors are provided, the weight and size thereof will be minimised by the use of a common base member therefor. The interconnectible upper members permit wide variation of cutting profile as has already been discussed above.

Alternatively, if the cutting device(s) is carried on the frame by a separate intermediate mount, the or each adaptor may comprise an adaptor block releasably securable between either the frame or another such block and either another such block and the intermediate mount. With this embodiment, the degree of variation of cut is more limited but adaptor design can be simplified.

The mining machine is preferably of the type in which the cutting device(s) is pivotally carried on the frame and the adaptor(s), when secured, then serve to alter the relative positions of the pivot axis and the frame axis.

In the case where pivotal movement of a cutting device relative the frame is effected by a ram, this is suitably releasably connected between the frame and the cutting device and a mount is provided between which and the cutting device the ram may be releasably connected. The mount may include a link member releasably connectible to one end of an auxiliary ram, the other end of the auxiliary ram and the link member being pivotally connectible to the frame. If the cutting assembly does not include an intermediate mount, both the auxiliary ram and the link member will, in use, be pivotally connected to the adaptor.

If there is an intermediate mount then either or both may alternatively be, in use, pivotally connected thereto instead of the adaptor. This arrangement provides a movable anchorage point for the existent ram and thereby increases the possible extent of the cutting device swing.

In the particular case of a dual auger-type cutting machine, it significantly increases the possible height of the cutting envelope with consequent maximisation of the amount of coal which may be mined.

The link member includes at least two connection points, one by which it is connected to the rams and a second, offset from the first, by which if is connected to the frame. The second may be at the pivotal mount of the cutting device. The link could alternatively include separate connection points for each of the rams.

The link member may have two arms at right angles to each other, the connection to the two rams being at the end of one arm and the connection to the frame being at the end of the other arm.

In one known form of mining machine, the cutting device(s) and the frame are both provided with lugs and are connected by pinning the lugs in an interdigitated relationship via apertures therein. This arrangement is particularly used for dual auger-type cutting machines.

With such machines and with the first adaptor embodiment, the base member of the adaptor(s) includes apertured lugs for pinning to the frame lugs and the upper member(s) includes apertured lugs for interdigitation and pinning to the cutting device(s) lugs. This provides a particularly simple and efficient way of connecting the adaptor or adaptors to the cutting assembly since the existent connection points of the cutting assembly are employed.

With this embodiment, the lift adaptor upper member will be provided with lugs, the axis of the apertures of which, when the adaptor is secured, is parallel to the axis of the apertures of the frame lugs, but is offset laterally and vertically upwards therefrom. The angled adaptor upper member will have lugs, the axis of the apertures of which, when the adaptor is secured, is at an angle to the axis of the apertures of the frame lugs: an acute angle defining a parallel angled adaptor and a 90" angle defining a transverse angled adaptor.

The adaptor base member may comprise two sections, each of which is securable to the frame on opposite sides thereof and a tapered wedge which, when the adaptor base member is assembled, is located therebetween. The wedge will allow accommodation of any misalignment of the base member lug apertured and the frame lug apertures.

With the alternative adaptor embodiment, each adaptor block simply includes appropriate means for connection thereof to the frame and the intermediate mount on to other such blocks. For example, if the intermediate mount is bolted to the frame, each adaptor block will include suitable apertures whereby it may be bolted therebetween either alone or with one more other adaptor blocks.

It will be appreciated that the invention is applicable to many different types of mining machine and is not dependent on how the cutting assembly is connected to the rear assembly or how the machine, as a whole, is moved.

Preferably the mining machine is of the type in which the rear assembly is provided with means for advancing the machine, such as endless tracks, and the cutting assembly is horizontally and/or vertically pivotal relative the rear assembly.

It is very particularly suitable for a dual auger-type mining machine where two cutting devices are provided, one on either side of the frame, each of which comprises a side frame independently pivotally mountable to the main frame, a shaft carried on the side frame and an auger cutter carried on the shaft forwardly of the side frame in the direction in which mining is proceeding. With such a device, the provision of one or more adaptors allows variations in cut, in particular in the possible cut height, which hitherto it has not been thought possible to achieve.

The invention will now be further described by way of example with reference to the accompanying drawings in which:- Figure 1 is a side elevation of a typical known dual auger-type mining machine; Figure 2 is a plan view of the mining machine of Figure 1; Figure 3 is a view from the front of the mining machine of Figure 1; Figure 4 is a side elevation of the cutting assembly of a mining machine in accordance with the invention; Figures 5A, 5B and 5C are front view of the cutting assembly of Figure 4 at different positions thereof; Figure 6 is a front view of an adaptor which forms part of the assembly of Figure 4; Figure 7 is a side view of the adaptor of Figure 6; Figure 8 is a front view of a link member forming part of the assembly of Figure 4; Figure 9 is a side view of the link member of Figure 8;; Figure 10 is a plan view showing the connection produced by the link member of Figure 8; Figure 11 is a plan view of an alternative embodiment of the mining machine of Figure 4; Figure 12 is a front view of part of an adaptor forming part of the cutting assembly; and Figure 13 is a front view of a still further embodiment of the mining machine of Figure 4.

Figure 1 is a side elevation of a dual auger continuous mining machine 2. The mining machine 2 comprises a forward cutter assembly 4, a rearward assembly 6 and a yoke 8 connecting the two assemblies 4 and 6. The rearward assembly 6 is provided with an endless track assembly 10 on either side thereof for movement of that assembly together with the cutter assembly 4 longitudinally forwardly and rearwardly. The yoke 8 permits horizontal swinging movement of the forward cutter assembly 4 with respect to the rearward assembly 6 under the action of two hydraulic piston and cylinder units 12 connected between the forward and rear assemblies 4 and 6.

The forward cutter assembly 4 may thus be moved forwardly and rearwardly with respect to a mine face by operation of the endless track assemblies 10 and horizontally across the mine face by swinging movement thereof with respect to the rear assembly 6.

The cutter assembly 4 includes a main frame 14 provided with lugs 16. A side frame 18 is secured on either side of the main frame 14. Each side frame 18 includes lugs 20 which interdigitate with the lugs 16 of the main frame 14, the interdigitated lugs 16 and 20 then being connected by passing a pivot pin through apertures therein. Each side frame 18 is therefore capable of pivotal movement about the longitudinal access of the pivot pin 22 by which it is connected to the main frame 14 of the cutting assembly 4.

Pivoting of each side frame 18 relative the main frame 4 is effected by a hydraulic ram 24. Each hydraulic ram 24 is pivotally connected at one end to the main frame 14 by a pivot pin 26 carried by a pair of lugs fixed to the lower forward portion of main frame 14. The other end of the hydraulic ram 24 is connected to the associated side frame 18 again by a pivot pin 28 carried by a pair of lugs 30.

Each side frame 18 serves to rotatably mount an elongate shaft 32 such that a portion thereof extends forwardly of the side frame 18. A motor may be provided on each side frame 18 for driving the shaft 32 thereof together with suitable gearing or a single motor may be provided on the main frame 14 with suitable gearing in the side frames 18.

An auger cutter 34 is fixed to the projecting forward end portion of each shaft 32. The pair of auger cutters 34 are similar in construction but they are oppositely pitched and oppositely rotated. Each auger cutter 34 includes at least one helical blade mounted on the tip of which are spaced cutting teeth. Cutting teeth are also mounted at the forward ends of the blade so that each auger cutter 34 is capable both of a forwards movement into a seam and a lateral movement across the face of a seam in cutting relation to the material forming the seam.

The machine 2 shown in Figures 1 to 3 and described generally above is known. Particular forms thereof are described, for example in U.S. Patent 4887868, U.S. Patent 4256343 and U.S. Patent 4341424.

Coal, or other mineral, cut by the auger cutters 34 is directed thereby into a tunnel 35 along which it is conveyed in a rearwards direction by endless conveyor 36 which is mounted in conjunction with both the cutting assembly 4 and the rearward assembly 6. Coal, or other mineral, is additionally fed to the conveyor by clean-up scrolls 37 which, for the purposes of clarity, are shown only in the front views.

The operation of the machine 2 of Figures 1 to 3 will now be briefly described. The machine 2 is advanced to a coal face by the track assemblies 10 with the cutters 34 extending forwardly therefrom and generally parallel to the direction of movement. The cutters 34 are operated in conjunction with the rams 24 to clear a central section of coal, the outline of which is shown by dotted line 36 in Figure 3. The cutting envelope 38 produced by this operation is shown in Figure 3. The.maximum height H1 thereof is approximately twice the diameter D1 of the auger cutter 34. The cutting envelope 38 is generally oval but does not have truly semicircular ends due to the limited path though which the auger cutters 34 can move under the action of the rams 24.The hydraulic rams 12 are activated to cause the cutting assembly 4 to slew to the right and left and in each position the cutters 34 and rams 24 are operated to remove a section of coal. The profile 40 of the tunnel produced by the cutting operation is fluted. A result of this is that extra material has to be cut to produce a tunnel of a certain minimum width.

Referring now to Figures 4 and 5, the mining machine 42 shown therein differs from that of Figures 1 to 3 in that an adaptor 44 has been added thereto. Those parts of the machine 42 which are also present in the machine 2 will be identified by the same reference numerals as employed in the description of the machine 2.

The adaptor 44 is positioned between and removably secured to the main frame 14 and the side frames 18. The adaptor 44 includes apertured lugs 46 which interdigitate and are pinable to the lugs 20 of the side frames 18. The side frames 18 are therefore still capable of pivotal movement but the effect of the adaptor 44 is to move the pivotal axis outwardly and upwardly of its original position. The pivot pins 45 employed to connect the side frames 18 and the adaptor are of a length such that a portion thereof extends forwardly of the adaptor 44 for reasons discussed below.

The adaptor 44 includes a second pair of lugs 48 which are pinned to the lugs 16 of the main frame 14. It will be noted that whilst the axis of the apertures 50 of the lugs 46 and that of the apertures 52 of the lugs 48 are parallel, the lugs 46 and 48 extend transversely to each other. The lugs 48, therefore, do not strictly interdigitate with the lugs 16 but rather they are moved downwards into an interlocking relationship therewith.

In addition to the lugs 46 and 48 the adaptor 44 has two pairs of spaced apertured lugs 54 at the front face thereof the purpose of which will be discussed below. The lugs 54 are carried on a pair of flanges 56 which extend forwardly of the adaptor 44.

The adaptor 44 includes an upper member 58 and a lower member constituted by two half sections 60. The upper member 58 bears the lugs 46 whilst the two half lower sections 60 bear the lugs 48. The upper member 58 is bolted to the two half lower sections 60 by bolts 62. The upper member 58 includes a keyhole slot 64 which locates with a correspondingly shaped protrusion on a wedge member 66 which is held between the two lower half sections 60. By splitting the lower member, the manufacturing tolerances thereof do not have to be so high.

Each half section 60 is independently pinned to the frame 14 and the wedge member 66 accommodates any misalignment between the half sections 60.

The rams 24 are still connected at one end to the side frames 18 by the pivot pins 28 and associated lugs. The other end of each ram 24 is connected to a link member 70 via a pivot pin 72. The link member 70 comprises a pair of plates 74 connected and spaced by a web 76. Each plate 74 has two arms at right angles to each other, at the ends of which an aperture 78, 80 is provided. The web 76 also defines an aperture aligned with the apertures 80.

The pivot pin 72 passes through the aperture 78 of the link member 70 and through the end fitting of hydraulic ram 24. In addition it passes through a split-end fitting 82 of an auxiliary ram 84, which split-end fitting 82 locates either side of the end fitting of ram 24. The other end of auxiliary ram 84 is connected to the adaptor 44 between the lugs 54 by a pivot pin 86.

The link member 70 is also secured via apertures 80 to the associated side frame 18 and the adaptor 44 by elongate pivot pin 45.

The machine 42 is operated in the same way as the machine 2. A completely different cutting envelope 88 is however produced. This is the result of the new location of the pivot axis of the side frames 18 produced by the adaptor 44. It is further the result of the semicircular cutting path 90 which the auger cutters 34 can follow around the new pivot axis under the action of the dual cylinder 24 and 8. The cutting envelope 88 is a full oval and has a height H2 which is over two and half times the diameter D2 of the auger cutters 34.

The adaptor 44 is termed a lift adaptor since it serves to raise the axes of rotation of the auger cutters 34 relative the axis of the frame 14 when employed.

The result of use of the lift adaptor 44, as discussed above, is the production of a cutting envelope 88 the height H2 of which is a greater multiple of the diameter D2 of the auger cutters 34 then is achieved when the adaptor 44 is not used.

The lift adaptor 44 will still produce a tunnel profile 40 is fluted. Figure 11 illustrates the production of a straight tunnel profile which is achieved by use of a different adaptor 92. The adaptor 92 is termed a parallel angled adaptor since it produces a tunnel with parallel walls. The parallel angled adaptor 92 sets the rotary axes of the auger cutters 34, and the pivot axes of the side frames 18, at an acute angle to the axes 94 of the main frame 14.

The adaptor 92 comprises the same bottom half sections 60 and wedge member 66 as the adaptor 44 but it has a different upper member 96. The upper member 96 of the adaptor 92 has, as with upper member 58 of adaptor 44, lugs 98 for interdigitation and pinning with the lugs 20 of the side frames 18 but the apertures 100 of the lugs 98 have an axis which is at an acute angle to the central axis of the upper member 96. The effect of this, as is illustrated by Figure 11, is that when the cutting assembly 4 is swung to the left or the right, the appropriate auger cutter 34 will follow a cutting path which will result in a straight line tunnel profile 40.

The upper member 96, as with upper member 58, has bolt apertures 102 whereby it maybe bolted to the two lower half sections 60. Alternatively however the upper member 96 could be bolted to the two lower half sections 60 with the upper member 58 interposed therebetween. The mining machine 42 would therefore effectively be provided with two adaptors. The cut produced thereby would have straight sides in plan and a very high cutting envelope.

The main frame 14 of the cutting assembly 4 shown in Figures 1 to 12 is directly connected to the side frames 18. However an intermediate mount could be secured e.g. by bolting between the frame 14 and the side 18 with the lugs 16 then being provided on the intermediate mount.

In such a case, in place of double lugged adaptor 44, an adaptor block 104 would be employed as shown in Figure 13.

The adaptor block 104 has apertures therein whereby it may be bolted, see 106, both to the frame 14 and the intermediate mount 108. The adaptor block 104 comprises two half sections which are mounted in spaced relationship to thereby define conveying tunnel 35 therebetween. The adaptor block 104 is a lift adaptor since it raises the rotary axes of the cutters 34 but, in contrast to lift adaptor 44, there is no transverse movement of the rotary axes.

In the illustrated form, the intermediate mount 108 includes lugs for connection of both the side frames 18 and the rams 24. Alternatively however the lugs for connection of rams 24 could be provided on the main frame 14. In either case, a movable anchorage may be provided for the rams 24 in a similar fashion to that described above with reference to Figures 5 to 10. The auxiliary rams 84 would be connected between the link members 70 and the lugs to which, in the unadapted machine, the rams 24 are connected.

The link members 70 would then be attached by elongate pivot pins at the connection between the intermediate mount 108 and the side frames 18. Alternatively special mounting lugs for the auxiliary rams could be provided on the main frame 14 or adaptor block 104.

It will be appreciated that other forms of adaptor could be provided. In particular the upper plate could have lugs which extend forwardly in the direction in which mining is proceeding. The side frames 18 when attached thereto would then extend outward on either side of the mining machine 42. Such an adaptor might be employed when a tunnel has been driven out. The adaptor would be added when the full length of the tunnel had been completed.

Withdrawal of the machine from the tunnel with the auger cutters 34 rotating would then cause expansion of the width of the tunnel.

Whatever form of adaptors are provided, it will be appreciated that with the embodiment illustrated in Figures 3 to 10 only a single base member, constituted by the two half members 60 and the wedge 66, is required even when multiple adaptors are to be attached to a machine.

This arrangement is very economical in terms of weight and expense. The alternative adaptor embodiment has the advantage of simplicity of design and fitting to a machine.

The provision of adaptors allows the cutting profile produced by a mining machine to be varied in a simple and effective manner. The necessary equipment need not be heavy since only the cutting assembly is modified. Addition of an adaptor or a plurality of adaptors can be effected rapidly and easily.

The above description has been concerned with a particular type of mining machine namely a dual auger continuous mining machine. It will be readily appreciated.

that the invention has wider applicability and can be employed in any mining machine with a cutting assembly in which the or each cutting device is reasonably attached to the assembly main frame.

Claims (21)

1. A mining machine comprising a rear assembly and a forward cutting assembly connected thereto, the cutting assembly including a main frame and at least one cutting device carried thereby, the cutting device having at least one rotary cutter, wherein the cutting device is releasably attached to the cutting assembly frame and wherein at least one adaptor is provided which is releasably securable between the cutting assembly frame and the cutting device and which, when so secured, alters the position or orientation of the axis of rotation of the cutter of the cutting device relative the axis of the frame or, if the cutter can move relative the frame, the path followed by the cutter rotary axis relative the frame axis.

2. A mining machine as claimed in Claim 1, wherein two or more interconnectible adaptors are provided whereby the adaptors may be secured together and between the frame and the cutting device.

3. A mining machine as claimed in either Claim 1 or Claim 2, wherein the cutting device(s) is pivotally carried on the frame and the adaptor(s), when secured, alters the relative positions of the pivot axis and the frame axis.

4. A mining machine as claimed in Claim 3, wherein pivotal movement of a cutting device relative the frame is effected by a ram releasably connected therebetween and wherein the adaptor includes a mount between which and the cutting device, the ram may be releasably connected.

5. A mining machine as claimed in Claim 4, wherein the mount includes a link member releasably connectible to one end of an auxiliary ram, the other end of the auxiliary ram and the link member being pivotally connectible to the frame.

6. A mining machine as claimed in Claim 5, wherein the auxiliary ram and the link member are pivotally connectible to the frame via the adaptor.

7. A mining machine as claimed in either Claim 5 or Claim 6, wherein the link member has two arms at rightangles to each other, the connection to the rams being at the end of one arm and the connection to the frame being at the end of the other arm.

8. A mining machine as claimed in any preceding Claim, wherein the adaptor is a "lift" adaptor and, when secured, raises the rotary axis or at least part of its path relative the frame axis.

9. A mining machine as claimed in any preceding Claim, wherein the adaptor is an "angled" adaptor and, when secured, alters the angle between the rotary axis and the frame axis.

10. A mining machine as claimed in Claim 9, wherein the angled adaptor is a "parallel angled" adaptor and, when secured, sets the rotary axis at an acute angle to the frame axis.

11. A mining machine as claimed in Claim 9, wherein the "angled" adaptor is a "transverse angled" adaptor and, when secured, alters the angle between the rotary axis and the frame axis by 90 .

12. A mining machine as claimed in any preceding Claim, wherein the adaptor(s) comprises a base member and at least one upper member, the base member being releasably securable to the frame and the upper member(s) being releasably securable between either the base member or another upper member and either another upper member or at least one cutting device.

13. A mining machine as claimed in Claim 12, wherein the cutting device(s) and the frame are both provided with lugs and are connected by pinning the lugs in an interdigitated relationship via apertures therein and wherein the base member includes apertured lugs for pinning to the frame lugs and the upper member(s) includes apertured lugs for interdigitation and pinning to the cutting device(s) lugs.

14. A mining machine as claimed in Claim 13, when dependent on Claim 8, wherein the lift adaptor upper member has lugs, the axis of the apertures of which, when the adaptor is secured, is parallel to the axis of the apertures of the frame lugs but is off-set laterally and vertically upwards therefrom.

15. A mining machine as claimed in Claim 13, when dependent on Claim 9, wherein the angled adaptor upper member has lugs, the axis of the apertures of which, when the adaptor is secured, is at an angle to the axis of the apertures of the frame lugs.

16. A mining machine as claimed in any one of Claims 12 to 15, wherein the base member comprises two sections securable to opposite sides of the frame and a tapered wedge which is, on assembly of the base member, located therebetween.

17. A mining machine as claimed in any one of Claims 1 to 11, wherein the cutting device(s) is carried on the frame by a separate intermediate mount and wherein the adaptor(s) comprises an adaptor block releasable securable between either the frame or another such block and either another such block and the intermediate mount.

18. A mining machine as claimed in any preceding Claim, wherein the cutting assembly is horizontally and/or vertically pivotal relative the rear assembly.

19. A mining machine as claimed in any preceding Claim, wherein the rear assembly is provided with means for advancing the machine in the direction in which mining is proceeding.

20. A mining machine as claimed in any preceding Claim, wherein two cutting devices are provided, one either side of the frame, each of which comprises a side frame independently pivotally mountable to the main frame, a shaft carried on the side frame and an auger cutter carried on the shaft forwardly of the side frame in the direction in which mining is proceeding.

21. A mining machine substantially as hereinbefore described and illustrated in the accompanying drawings.