GB2370295A - A cutting and drilling machine - Google Patents

Abstract

A mining or tunnelling machine includes a shield (12) which supports a boom (13) having at the forward end a cutting head (14). There is a drive arrangement (16) and a control mechanism (17, fig 2) which allows the cutting head (14) to operate at a rock cutting speed and a drill positioning speed. When it is required to drill the rock, the drill (22) is moved from a position remote from the cutting head (14) on a track (21). Once adjacent the cutting head (14) the drill (22) is attached to the cutting head (14) by attachment members (23, 24) and the cutting head (14) is operated at a speed to allow positioning of the drill (22, fig 4).

Description

A MINING OR TUNNELLING MACHINE AND METHOD

This invention relates to a mining or tunnelling machine ; and to a method of using such a machine for drilling a rock face.

In the mining and tunnelling industries various techniques are used in the creation of underground roadways, tunnels, cross cuts and other cavities, referred to herein collectively as"cross cuts".

In general such cross cuts extend inclinedly or horizontally from a generally downwardly extending service shaft.

Typically the creation of cross cuts involves the use of a mining or tunnelling machine including a forward end having a cutting head whose purpose is to cut the rock face terminating the cross cut.

The cutting head includes a rotatable member having secured therein a plurality of bits. The cutting head typically is rotatable at a comparatively high speed to cut the rock face. For example some tunnelling machines have two speed heads capable of rotating at eg. 25 rpm and 50 rpm, depending on the ground conditions.

The various types of tunnelling machines in common usage include but are not limited to so-called"road headers", "twin boom miners"and tunnelling shields. Such machines are referred to collectively herein as"tunnelling or mining machines".

It is characteristic of such a tunnelling or mining machine that its components occupy almost the entire cross section of the tunnel that the machine cuts.

As the cutting head rotates to cut the rock face, the tunnelling or mining machine advances forwardly. A typical tunnelling or mining machine includes a conveyor mechanism for conveying cut rock (that may be spoil, won minerals and/or other matter) to the rear of the machine for removal and/or subsequent processing. Such conveying occurs while the machine advances as aforesaid.

Frequently mining and tunnelling techniques involve the setting of charges to blast the rock face, before commencement of a period of operation of the tunnelling or mining machine. Such blasting facilitates operation of the tunnelling or mining machine, especially when the machine encounters a formation that is harder than the predominant formations in which the machine operates.

Typically the setting of charges involves drilling a plurality of bores into the rock face, and packing a cylindrical, explosive charge into each bore.

The cutting head of a tunnelling or mining machine is designed to cut and break up the material of the rock face in bulk. It is incapable of drilling the rock face for the purpose of setting explosive charges.

Consequently it is known to employ a rock drill for the purpose of drilling cylindrical bores in the rock face ahead of the tunnelling or mining machine in order to set charges.

Typically the drill used for drilling the rock face is a heavy item that may require two or more men to lift it.

Since the tunnelling or mining machine occupies substantially the entire cross section of the cross cut ; and since the drill cannot be stored ready for use in front of the tunnelling or mining machine, hitherto it has been possible only to use a comparatively small (eg. hand held) rock drill that is small enough to be carried past the cutting, to the rock face, for the purpose of drilling the latter. Consequently the operation of drilling the rock face is slow and inefficient.

Therefore drilling of the rock face is a time consuming operation that affects the economics of mining and tunnelling.

It has in the past been common practice for tunnelling machine operators to climb onto the tunnelling shield, carrying the rock drill, in order to gain access to all parts of the rock face for the purpose of drilling the cylindrical bores. This practice is potentially dangerous.

According to a first aspect of the invention there is provided a mining or tunnelling machine comprising a machine frame supporting: a boom having secured at a forward end thereof a rotatable cutting head; a drive arrangement for selectively rotating the cutting head at a rock cutting speed and moving the cutting head at a drill positioning speed; a control mechanism for selectively switching the drive arrangement between rotation of the cutting head at the said cutting speed and movement of the cutting head at a said drill positioning speed; and a track, extending between a location on the machine adjacent the cutting head and a further location remote therefrom; the machine including, releasably supported on the track, a drill that is moveable between a location remote from the cutting head and a position adjacent thereto; and the drill and cutting head including mutually securable

attachment members ; whereby when the drill occupies its location on the track remote from the cutter head the drive arrangement is operable to rotate the cutting head at the rock cutting speed; and when the drill occupies its position adjacent the cutting head the mutually securable attachment members are operable to support the drill on the cutting head on releasing of the drill from the track, the drive arrangement being operable during such supporting to move the cutting head at a said drill positioning speed.

The presence of the track supporting a drill permits the drill to be carried forwardly, in a fixed location on the mining or tunnelling machine as it advances. When it is necessary to drill the rock face, the drill may be advanced on the track relative to the mining or tunnelling machine and attached to the cutting head using the mutually securable attachment members.

The presence of a drive arrangement capable of selectively rotating the cutting head at a rock cutting speed and moving the cutting head at a drill positioning speed allows the cutting head to perform a drill positioning function that is additional to its normal function, of cutting mineral material.

The arrangement of the invention also advantageously allows remote controlling of a rock drill, thereby obviating the need for tunnelling machine operators to climb onto the tunnelling shield in order to drill the cylindrical bores.

In addition the ability to mount a rock drill on the cutting head allows the rock drill to access all parts of the rock face, including those which would otherwise be obscured by the cutting boom, as was the case in the prior art

arrangements.

Yet a further advantage of the invention is that the ability to mount the rock drill on the cutting head allows use of a higher torque drill than previously, since the cutting head can brace the drill torque between than a human operator.

Preferably the drive arrangement includes a first motor for rotating the cutting head at a said rock cutting speed; and a second motor for rotating the cutting head at a said drill positioning speed; and the cutting head includes a drive shaft selectively drivingly engageable with a first output shaft of the first motor and a second output shaft of the second motor respectively.

Advantageously the use of discrete motors to provide both rock cutting and drill positioning speeds of rotation of the cutting head simplifies construction of the machine of the invention. This follows from the fact that the primary drive motor for driving the cutting head of a mining or tunnelling machine typically is an electric motor capable of developing its full torque at 0 rpm.

The armature of such a motor is permanently and rigidly coupled to the main, rotatable shaft of the cutter head. Consequently it is not easily possible in a known cutting head to interpose eg. a reduction gearbox in the drive train, for the purpose of providing a drill positioning speed of rotation of the cutting head.

In preferred embodiments of the invention the second output shaft is spaced from the said drive shaft and the control mechanism includes a clutch member slideably mounted on the drive shaft for selective movement between a first position, in which the drive shaft and the second output shaft

are drivingly engaged with one another ; and a second position in which the drive shaft and the second output shaft are disengaged from one another. This arrangement advantageously permits the second motor to lie at the rear end of the drive shaft of the cutting head, remote from the rock face; and for the machine of the invention to employ a simple, sliding clutch for selectively engaging the second motor to drive the drive shaft.

When as is common in the art of mining and tunnelling machines the first output shaft (of the first motor) is permanently coupled to the drive shaft as described hereinabove, the mining or tunnelling machine preferably includes a switchable power supply for the first motor, the control mechanism including an actuator member for moving the clutch member between its first and second positions and the actuator member including an interlock switch that switches off the power supply for the first motor when the clutch member occupies its first position.

This arrangement advantageously ensures that the power supply to the first motor is disconnected when an operator of the machine of the invention selects engagement of the drive from the second motor for the purpose of positioning a drill. Consequently when positioning the drill for drilling of the rock face there is no danger of the first motor becoming energised.

More specifically the control mechanism preferably includes respective locks for locking the actuator member in its first and second positions. In a particularly preferred embodiment of the invention there is provided a single key for the respective locks.

In such embodiments of the invention the interlock switch forming part of the control mechanism may be activatable by insertion of the key into one

of the locks.

The foregoing features assure that only one of the two motors of the machine of the invention may be energised at a time.

In particularly preferred embodiments of the invention the first motor is an electric motor and the second motor is an hydraulic motor.

As noted hereinabove, the use of an electric motor as the first motor is preferred because of the torque characteristic that may be achieved.

On the other hand the use of an hydraulic motor as the second motor is preferable since an hydraulic motor when operating under the control of a per se known control valve may accurately position the cutting head and hence any drill attached thereto relative to the rock face.

In a particularly preferred embodiment of the invention the rock cutting speed is greater than the drill positioning speed. It is however possible within the scope of the invention to include an arrangement capable of plural drill positioning speeds one or more of which may be greater than the rock cutting speed. For example, a control arrangement for the preferred hydraulic second motor may permit movement of the cutting head at two positioning speeds, ie. a fast positioning speed used to move the drill approximately to the desired drilling position; and a slow positioning speed, for final positioning of the drill.

The control arrangement, that may be of per se known design, for the second motor may optionally include a switchable power supply for the second motor. Such a switchable power supply may be interlocked with the power supply to the first motor to prevent simultaneous connection of both

the power supplies.

Preferably the boom includes a flexible joint interconnecting respective boom portions and the machine includes a powered actuator for powering motion of the flexible joint to adjust the angle subtended at the flexible joint by the boom portions.

The presence of the flexible joint and powered actuator (that in preferred embodiments is an hydraulic actuator) advantageously provides a second kind of positioning movement of the cutting head.

More preferably, the machine of the invention may include a slewing ring interconnecting the boom and the machine frame; and a motor operatively connected to cause selective, powered rotation of the boom about the slewing ring.

This arrangement provides a third possible positioning movement of the cutter head.

The axis of rotation of the slewing ring preferably is skewed relative to the axis of rotation of the drive shaft of the cutting head; and the axis of rotation of the flexible joint is skewed relative to the two aforesaid axes of rotation. Consequently the machine of the invention permits at least three degrees of freedom of positioning movement of the cutting head, and hence of a drill secured thereto.

Conveniently the mutually securable attachment members include brackets secured respectively on the cutting head and the drill, the respective brackets including mutually alignable, through going apertures and the machine including one or more securing pins each insertable through an

aligned pair of the said apertures to secure the drill and the cutting head together.

The use of the brackets, alignable apertures and securing pins confers simplicity and robustness on the attachment mechanism for the drill.

In practical embodiments of the invention each bracket includes at least two said through going apertures, whereby to provide a plurality of pairs of mutually alignable apertures.

Preferably the bracket secured on the cutting head is releasable therefrom.

This ensures that the bracket does not interfere with or become damaged by rock cutting operations of the cutting head.

Preferably the machine of the invention includes a won mineral conveyor extending between a location on the machine adjacent the cutting head and a further location remote therefrom, and wherein the track includes a pair of rails extending generally parallel to the won mineral conveyor on either side thereof.

The won mineral conveyor advantageously occupies a central space, extending from the front to the rear of the mining or tunnelling machine, that advantageously is suitable for moving the drill from a storage location, at the rear of the machine, to a drilling position secured on the cutting head.

More preferably the machine includes respective rail extension members that are releasably securable to the ends of the pair of rails adjacent the cutting head, whereby temporarily to extend the track beyond the end of the spoil conveyor in the vicinity of the cutting head. Preferably the track when

extended by the rail extension members permits the drill to underlie the cutting head. The use of such rail extension members advantageously permits temporary extension of the rail defining the track, to a location closely adjacent the cutting head. This in turn allows for spacing of the components of the won mineral conveyor a distance away from the cutting head, without reducing the ease with which the drill may be moved to and secured on the cutting head.

More preferably still the machine may include an optional winch and cable assembly for controllably moving the drill supported by the track.

The track preferably is inclined to the horizontal, whereby in one direction of movement of the drill (in preferred embodiments towards the forward end of the machine) the winch and cable assembly operates to pay out cable and control descent of the drill towards one end of the track; and in the opposite direction of movement of the drill (preferably away from the forward end of the machine), the winch and cable assembly may operate positively to draw the drill upwardly away from the cutting head against the gravitational force.

Movement of the drill relative to the remainder of the machine, and transfer of the drill to a position supported on the cutting head, are facilitated by the presence in preferred embodiments of the invention of a rigid basket that is movably supported on the track, the drill being releasably securable in the basket.

The basket advantageously serves as a sled or carrier for the drill, thereby obviating the need for modification of a standard drill for the purpose of

moving it along the track forming part of the machine of the invention. Preferably the machine includes a control panel for the drill, the said panel having at least one control and/or indicator member and being releasably securable in the basket, the control panel and the drill being interconnected by at least one flexible control line whereby the control panel is positionable on the machine independently of the drill while being operatively connected thereto.

In one embodiment of the invention there is a single said control panel. In an alternative arrangement the control panel may include a control panel for the drill, the said panel having at least one control and/or indicator member and being releasably securable in the basket, the control panel and the drill being interconnected by at least one flexible control line whereby the control panel is positionable on the machine independently of the drill while being operatively connected thereto.

The arrangements advantageously allow an operator of the machine to position the drill control panel at any convenient location on the machine and/or as dictated by local rock formations, thereby enhancing the potential usability and safety of the machine of the invention.

According to a second aspect of the invention there is provided a method of drilling a rock face using a machine as defined herein, the method comprising : (i) as necessary, deselecing operation of the drive arrangement for rotating the cutting head at a rock cutting speed; (ii) moving the drill along the track from the remote location to the location adjacent the cutting head; (iii) securing the drill to the cutting head using the mutually

securable attachment members ; (iv) selecting operation of the drive arrangement to cause movement of the cutting head at a drill positioning speed, whereby to release the drill from the track and position the drill for drilling of a rock face; and (v) drilling the rock face using the drill.

The method of the invention may optionally include the further steps of, after drilling of the rock face, (vi) selecting operation of the drive arrangement to move the drill, at the said drill positioning speed, onto the track; (vii) disconnecting the mutually securable attachment members to permit the track to support the drill; (viii) moving the drill along the track from the location adjacent the cutting head to the remote location; and (ix) selecting operation of the drive arrangement for rotating the cutting head at a rock cutting speed.

The method steps of the invention permit the rapid, effective drilling of a rock face eg. for the purpose of setting charges. The drill may also be used for probe drilling, eg. for the purpose of assessing whether there is a liquid formation ahead of the tunnelling machine.

When the mining or tunnelling machine includes a first motor for rotating the cutting head at a rock cutting speed and a second motor for rotating the cutting head at the drill positioning speed, step (iv) of the method of the invention includes rotating the cutting head at the said drill positioning speed.

When the boom of the mining or tunnelling machine includes a flexible

joint as aforesaid, the step (iv) preferably includes operating the powered actuator. When the mining or tunnelling machine includes a slewing ring as aforesaid, the step (iv) preferably includes operating the powered actuator to cause slewing of the boom about the axis of rotation of the slewing ring.

When the track includes releasably securable rail extension members as defined herein, the method of the invention may include the sub-step of : (i a) attaching the rail extension members before step (ii).

Optionally the method may also include the sub-step of : (vii a) removing the rail extension members before carrying out step (viii).

When the mining or tunnelling machine includes the winch and cable assembly, the method preferably includes using the winch and cable assembly to move the drill supported by the track.

When the mining or tunnelling machine includes a basket as defined herein, the method of the invention may optionally include the sub-step of : (iv a) moving the basket to a location on the track remote from the cutting head, before carrying out step (v).

There now follows a description of a preferred embodiment of the invention, by way of non-limiting example, with reference being made to the accompanying drawings in which: Figure 1 is a side elevational, partly sectioned view of a mining or tunnelling machine according to the invention, in its configuration shortly before commencement of a rock face drilling operation;

Figure 2 is an enlarged, side elevational, partly sectioned view of the circled portion"2"of Figure 1 ; Figure 3 is a view, similar to the Figure 1 view, showing the mining or tunnelling machine during transfer of a rock drill to the cutting head thereof but before commencement of drilling operations; Figure 4 is a view, similar to the views of Figures 1 and 3, showing schematically the range of movement of the drill during drill positioning operations; and Figure 5 is an end elevational view of a rock face, showing some of the possible patterns of drilling achievable through use of the apparatus and method of the invention.

Referring to the drawings there is shown a mining or tunnelling machine 10 shown located in a rock cutting/removing position in a subterranean cross cut 11.

Cross cut 11 may extend laterally from a downwardly extending shaft; or may terminate at its open end at a hillside or cliff. The precise details of the mine or tunnel workings are not relevant to the principles of the invention.

Machine 10 includes a shield 12 shown partly in section in the drawings. In practice shield 12 is constituted by a network of rigidly interconnected members extending on either side of the main, functional components of the machine 10 described in more detail below.

At its forwardmost end, to the left of Figures 1,3 and 4, machine 10 includes a boom 13 (described in more detail below) supporting a cutting head 14 of per se known design.

Cutting head 14 may include eg. a plurality of annular series of cutting bits

made from or faced with a hard material such as a tungsten carbide mixture or diamond.

Machine 10 includes a drive arrangement indicated in Figure 1 schematically by reference numeral 16 and by chain lines, that is capable of selectively rotating the cutting head at a rock cutting speed; and moving the cutting head at a drill positioning speed.

The drive arrangement is described in more detail hereinbelow.

The machine 10 also includes a control mechanism the main components of which are signified in general by reference numeral 17 and are most easily visible in Figure 2. The function of control mechanism 17 is to provide selective switching of drive arrangement 16 between rotation of the cutting head at the said cutting speed; and movement of the cutting head at a said drill positioning speed.

Machine 10 includes a central cavity 18 extending rearwardly from cutting head 14. Cavity 18 contains a won material conveyor 19 described in more detail below; and a track 21 extending between a location 21a generally

adjacent the cutting head and a further location 21b remote therefrom.

A drill 22 is releasably moveably supported on the track 21. In the configuration shown in Figure 1, drill 22 and cutting head 14 include mutually securable attachment members in the form of respective brackets 23,24.

The drill is moveable between the location illustrated in Figure 1, that is remote from the cutting head; and a position adjacent to the cutting head as

shown in Figure 3.

When the drill occupies the remote position shown in Figure 1 the drive arrangement 16 is operable to rotate the cutting head at a said rock cutting speed. When the drill occupies the position shown in Figure 3, the mutually securable attachment members 23,24 are operable to support the drill 22 on the cutter head 14 on releasing of the drill from the track 21. During such supporting of the drill the drive arrangement 16 is operable to move the cutter head at a said drill positioning speed.

The drive arrangement 16 includes a first motor 26, for rotating the cutting head 14 at a said rock cutting speed; a second motor illustrated schematically by reference numeral 27, for rotating the cutting head at a said drill positioning speed; a flexible joint 28 in the boom 13 together with a powered actuator 29 for powering movement of the flexible joint in a manner described hereinbelow; a slewing ring 31 interconnecting the boom 13 and the shield 12; and a motor (not visible in the drawings) operatively connected to cause selective, powered rotation of the boom 13 relative to the slewing ring 31.

Drive arrangement 16 also includes longitudinally extendable and retractible sumping cylinder 30, whose purpose is the advancement of the cutting head in eg. 300 mm increments, in order completely to cut the rock face.

The cutting head 14 is mounted on a rotatable drive shaft 32 that is joumalled in the free end 13a of boom 13, whereby to permit rotation of cutting head 14 relative to boom 13.

Drive shaft 32 is selectively drivingly coupleable with a first output shaft 33

of first motor 26 ; and with a second output shaft 34 of second motor 27. First motor 26 is an electric motor such as a squirrel cage induction motor, whose armature is rigidly, permanently connected to drive shaft 32, in a manner known per se in the art of mining and tunnelling machines.

Second motor 27 is supported in boom 13 rearwardly of first motor 26. The free end of second output shaft 34 is spaced from the end of drive shaft 32.

The control mechanism 17 includes a clutch member 36, that in the embodiment shown is a slidable sleeve forming part of a sliding dog clutch.

Clutch member 36 is slideably mounted on drive shaft 32 encircling two toothed drive collars, 47,48 selectively rigidly secured respectively to the free end of drive shaft 32 protruding rearwardly of first motor 26; and second output shaft 34 protruding from motor 27. Clutch member 36 is moveable between a first position as shown, in which the drive shaft 32 and the second output shaft 34 are drivingly engaged with one another; and a second position (described below) in which the drive shaft 32 and the second output shaft 34 are mutually disengaged.

The control mechanism 17 also includes an actuator member in the form of a lever 37 for moving the clutch member 36 between its first and second positions.

Lever 37 is pivotably secured at a lowermost end 37a to clutch member 36; and at a location 37b spaced from end 37a to a bracket 38 protruding on an upper side of a housing 39 enclosing clutch member 36 and second output shaft 34.

Housing 39 includes an elongate aperture 41 through which lever 37 protrudes. The free end 37c of member 37 remote from clutch member 36 terminates in the vicinity of a pair of lever locks 42,43.

In Figure 2 clutch member 36 is shown occupying its first position, in which it is engaged with second output shaft 34. This is achieved by virtue of the hollow interior of sleeve 36 including protruding radially inwardly a series of dogs 44 that are engageable with the teeth on the respective collars 47,48.

When occupying the first position shown, the dogs are engaged with the teeth of both the collars 47,48, whereby drive from motor 27 is transferred to shaft 32 to drive the head 14 at a drill positioning speed.

On movement in the direction of arrow A in Figure 2, lever 37 pivots about pivot point 37b and drives clutch member 36 to the right, whereby the dogs 44 disengage from the complementary set of dogs or teeth protruding from collar 47 attached to the free end of output shaft 32. Consequently the drive train between motor 27 and shaft 32 is broken. During such motion of lever 37 its end 37a pivots about the pivot point securing it to clutch member 36.

In practice lever 37 is bifurcated a short distance below pivot point 37b, whereby the free end of lever 37 defines a yoke that embraces either side of clutch member 36 with a pivot/driving pin riding in a groove 45 defined on the outer surface of a cylindrical clutch member 36. By this means clutch member 36 may be moved to the left and the right as a result of pivoting movement of lever 37; yet clutch member 36 remains rotatable relative to the yoke defined by the free end 37a of lever 37, by virtue of the presence of groove 45.

In the embodiment shown movement of lever 37 away from the direction of arrow A causes operation of an interlock switch that switches off the power supply to the first motor 26 when the clutch member 36 occupies its first position, drivingly engaged with the second output shaft 34.

This may be achieved eg. through the use of a per se known"Castell"key, that may be employed to lock lever 37 at one or other of the lever locks 42, 43.

As is well known a Castell key may if desired be configured to actuate a relay on its insertion into a lock such as lever locks 42,43. If as in preferred embodiments of the invention lever lock 43 is operatively connected to a relay that provides power to the first motor 26; and lever lock 42 is operatively connected to a relay that provides power to the second motor 27, if the machine is supplied with only a single Castell key it is possible to provide power to the respective first and second motors 26,27 on a mutually exclusive basis. This is an inherent safety feature whereby it is impossible to energise the first motor 26 when it is desired to energise the second motor 27 for the purpose of positioning the drill 22.

As noted herein, first motor 26 is an electric motor, whose torque characteristic is suitable for rock cutting operations.

Preferably second motor 27 is an hydraulic motor since such motors can if appropriately specified and designed provide a high degree of precision to the positioning of the drill by virtue of rotation of the drill head 14.

The hydraulic motor 27 also includes a"powered off'brake to lock the motor 27 and hence the head against rotation during drilling. The powered off brake automatically locks on at the end of a drill positioning movement,

in order to prevent movement of the head 14 during rock drilling.

It follows from the choice of motors in the embodiment shown that the speed of rotation of the cutting head during rock cutting operations, that may be eg. 25 or 52 rpm (at the option of the operator) in a preferred embodiment, is greater than the speed of rotation of the cutting head 14 when powered by the second motor 27 for drill positioning operations.

In practice the hydraulic second motor 27 may be operated under the control of a per se known control valve and proportional controller, whereby the speed of rotation of the cutting head 14 during drill positioning operations is finely controllable down to a slow speed corresponding to fractions of a revolution per minute.

Flexible joint 28 is defined between respective portions 49,51 of boom 13.

Hydraulic actuator 29 interconnects boom portions 49,51 across the elbow defined at flexible joint 28.

Hydraulic actuator 29 is pivotably secured at either end to a respective boom portion 49,51 whereby on extension of actuator 29 boom portion 49 rotates upwardly relative to boom portion 51 ; and whereby on contraction of actuator 29 boom portion 49 rotates downwardly relative to boom portion 51, about flexible joint 28.

The upper face of boom portion 51 remote from cutting head 14 is secured to machine frame 12 via a slewing ring 31.

Slewing ring 31 may include eg. a pair of slewing cylinders; or a per se known ring gear drivingly engaged with the pinion of a motor (not visible in

the drawings) that is fixed relative to machine frame 12. Operation of the slewing cylinders or motor (if present) causes selective slewing of boom 13 about a vertical axis perpendicular to the plane of slewing ring 31.

In addition sumping cylinder 30 is useable to advance the drill 22 relative to the rock face, during drilling.

It will thus be apparent that drive shaft 32, flexible joint 28, sumping cylinder 30 and slewing ring 31 between them provide four degrees of freedom of movement of cutting head 14. Consequently when drill 22 is secured to cutting head 14, drill 22 is positionable according to four degrees of freedom of movement.

Machine 10 includes a control apparatus such as a microprocessor together with hydraulic and electric control elements, for providing precise positional control of the motors employed during drill positioning.

As is evident from the drawing figures, the mutually securable attachment members include a bracket 23 protruding upwardly from an upper member forming part of drill 22; and a bracket 24 of complementary shape secured relative to cutting head 14.

Each bracket 23,24 includes a pair of through going apertures 52,53, 54, 56.

On alignment of bracket 23 adjacent bracket 24 the respective bracket pairs 52,54 and 53,56 are mutually aligned.

Each aperture of a said pair of apertures is of the same diameter, whereby a respective retention pin is insertable into each pair of aligned apertures in

order to retain the drill 22 relative to the cutting head 14.

In the embodiment shown the bracket 24 is releasably secured on cutting head 14, whereby during rock cutting operations bracket 24 is removed so as not to interfere with or become damaged by operation of the cutting head 14. Bracket 24 may be stored on the shield 12 away from cutting head 14 during cutting operations.

Releasable retention of bracket 24 may be achieved by means of eg. pin, set screws, lockable clips or similar means. The bracket is securable so as to be non-rotatable relative to head 14.

Central cavity 18 of machine 10 contains a won material conveyor 19, extending from a location adjacent and behind cutting head 14 to the rear of machine 10.

Won material conveyor 19 is inclined, whereby its rear end is higher than its forwardmost end. This facilitates collection of won materials for conveying, during rock cutting operation of the machine 10.

Track 21 is defined by a pair of parallel, mutually spaced rails of which one, 57, is visible in the drawing figures.

Each rail 57 is secured to and overlies conveyor 19.

As shown in the drawings, each rail includes an uppermost portion 57a that extends substantially parallel to conveyor 19 and defines a parking location for drill 22 when the latter is not in use.

Disposed forwardly of portion 57a, each rail is inclined towards conveyor

19 over a portion 57b ; and the remaining portion 57c of each rail is inclined towards conveyor 19 at a lesser angle than that of portion 57b. The machine 10 additionally includes a pair of rail extensions 58 that are releasably securable extending from the free end of each rail portion 57c, whereby to define a temporary extension of track 21 thereby permitting positioning of drill 22 under cutting head 14.

At the end 57a of track 21 remote from cutting head 14 there is provided a powered winch 59 for winching the drill 22 up and down on track 21 relative to the remainder of machine 10.

Such winching is achieved by virtue of the presence of a rigid basket 61 best seen in Figure 4, that is moveably secured, eg. by means of rollers 62, 63 that extend laterally on either side of basket 61 and are rotatably captive relative to the adjacent rail 57. Instead of rollers, skids or any other equivalent means could be employed.

Basket 61 and winch 59 are interconnected by a flexible cable (not visible in the drawings), whereby on operation of winch 59 in a first direction basket 61 and drill 22 carried thereby are let down the incline defined by the rail 57, towards cutting head 14. On operation of winch 59 in the opposite direction basket 61 is drawn in the opposition direction, up the incline defined by rail 57 and away from cutting head 14.

Drill 22 is of a per se known design, and includes a flexible elbow 64 providing a pivotable connection of bracket 23 to an upper face of drill 22.

A hydraulic or pneumatic actuator 66 is operable under control of a control mechanism whereby to alter the angle of the drilling axis of drill 22 relative

to bracket 23, as desired, during operation of the drill for drilling of a rock face.

Drill 22 includes a control panel 67 that is releasably securable in basket 61 for conveyance thereby on rails 57.

Control panel 67 is attached to drill 22 by one of more flexible control lines, whereby on use of drill 22 for drilling of a rock face control panel 67 may be positioned remotely, eg. at any preferred location on the remainder of machine 10, to facilitate controlling of drill 22 at a location safely removed from the rock face.

In another arrangement not shown in the drawings, control panel 67 may have connected thereto eg. by a flexible control line or any equivalent means a lightweight mimic panel that is light enough to be carried manually by an operator. Such a mimic panel may include control buttons or similar controls; and, optionally eg. shoulder straps or a stand.

One way of constructing the mimic panel is for the control buttons to be connected to operate relays in the mimic panel that are connected to operate solenoid valves forming part of control panel 67.

Figure 4 shows drill 22 in use in a variety of exemplary positions, and control panel 67 removed from basket 61 and located at one preferred location on the rails 57.

In use of the machine 10 for drilling a rock face 71 terminating a cross cut 11, any rock cutting operations employing cutting head 14 are initially ceased, by virtue of an appropriate series of commands. At this time basket 61 occupies the position shown in Figure 1, at the right hand (upper) end of

track 21 remote from cutting head 14.

Once movement of cutting head 14 ceases, the Castell key securing lever 37 in the position shown in Figure 2 is removed. This switches off the power supply to first motor 26, thereby eliminating the possibility of cutting head 14 rotating at rock cutting speeds during drill positioning operations.

Bracket 24 is then secured to cutting head 14 to provide an attachment point for supporting drill 22.

The rail extensions 58 are then attached to the ends 57c of the rails 57 to extend the track 21 to permit drill 22 to underlie cutting head 14.

Winch 59 is then operated to pay out the cable and permit basket 64 (and hence drill 22 and control panel 67 carried thereby) to advance down the inclines defined by the rails 57,58 towards cutting head 14.

When basket 61 reaches the end of its travel, actuators 28,29 and 30; and slewing ring 31 are operated as necessary to bring bracket 24 into alignment with bracket 23 disposed on top of drill 22.

Securing pins are then inserted into the mutually aligned aperture pairs 52, 54; 53,56 to secure the drill 22 relative to cutting head 14.

Control panel 67 may then be removed from basket 61 to a convenient location for controlling drill 22.

At this time actuator 29 may be extended under control of control elements 28, 29, 30 and 31 as necessary to raise boom portion 49 relative to track 57 and thereby lift drill 22 clear of basket 61 to permit withdrawal of basket 61 to the upper end of track 21 as described.

Winch 59 is then operated to wind in the cable and withdraw basket 64 to the position visible in Figure 4. Thereafter lever 37 is locked in position adjacent lever lock 42 as shown in Figure 2, by means of the Castell key. This energises motor 27 and optionally transfers control of rotation of cutting head 14 to control elements forming part of control panel 67.

Drill 22 may then be operated, at the option of a human operator, to drill a pattern of bores in the rock face 71.

Typically the pattern may be achieved through a combination of actuation of slewing ring 31, actuators 29 and 30, motor 27 and actuator 66.

Such operations are represented schematically by the differing positions of drilling head 14 and drill 22 shown in Figure 4.

One possible pattern of bores is shown in Figure 5. In this pattern drill 22 is rotated about each of four pitch circles (one, 72, of which is marked in Figure 5), to cause a series of four circular bore patterns in a cruciform arrangement.

Other drilling patterns are of course possible, depending on the precise blasting operation required. Furthermore, by virtue of the ability to alter the angle of incidence of bit 73 of drill 22 (by operation, in turn, of actuators 29 and 66 as necessary) it is possible to drill bores in the rock face at angles that are skewed relative to the general longitudinal axis of cross cut 11.

Following completion of drilling operations winch 59 is again operated to

allow basket 61 to occupy is forwardmost position. Operation of the various motors and actuators of the drive arrangement 16 then follows to replace the drill 22 in the basket.

The operator of the machine 10 at around the same time places the control panel 67 into basket 61.

Once drill 22 is secured in basket 61 the securing pins are removed thereby releasing bracket 23 from engagement with bracket 24. Winch 58 is then again operated to draw the basket and the drill and control panel carried thereby to the uppermost position on track 21 (at the right hand end of the drawing figures).

Following removal of bracket 24 from cutting head 14; and removal of the rail extensions 58 from the ends of rails 57, the Castell key may be removed from lever lock 42 to permit return of lever 37 from the position shown in Figure 2. This disengages dog clutch member 36 from the shaft 32.

On reinsertion of the Castell key into lever lock 43 the power supply to first motor 26 is re-established, thereby permitting continuation of rock cutting operations following detonation of charges placed in the bores drilled by drill 22.

Although the preferred embodiment of the invention has been described as having only a single cutting head 14, it is of course possible within the scope of the invention to devise a mining or tunnelling machine 10 having plural cutting heads.

Also although one preferred embodiment of the invention has been described herein, the invention embraces within its scope all functional equivalents to the specific realisations disclosed herein. Thus, for example, the winch 58 could in alternative embodiments be replaced by eg. a worm and peg drive or a lead screw and nut drive operatively connected to drive the basket 61 up and down on the track 21.

Claims (32)

1. A mining or tunnelling machine comprising a shield supporting : a boom having secured at a forward end thereof a rotatable cutting head; a drive arrangement for selectively rotating the cutting head at a rock cutting speed and moving the cutting head at a drill positioning speed; a control mechanism for selectively switching the drive arrangement between rotation of the cutting head at the said cutting speed and movement of the cutting head at a said drill positioning speed; and a track, extending between a location on the machine adjacent the cutting head and a further location remote therefrom; the machine including, releasably supported on the track, a drill that is moveable between a location remote from the cutting head and a position adjacent thereto; and the drill and cutting head including mutually securable attachment members whereby when the drill occupies its location on the track remote from the cutter head the drive arrangement is operable to rotate the cutting head at the rock cutting speed; and when the drill occupies its position adjacent the cutting head the mutually securable attachment members are operable to support the drill on the cutter head on releasing of the drill from the track, the drive arrangement being operable during such supporting to move the cutting head at a said drill positioning speed.

2. A machine according to Claim 1 wherein the drive arrangement includes a first motor for rotating the cutting head at a said rock cutting speed; and a second motor for rotating the cutting head at a said drill positioning speed; and the cutting head includes a drive shaft selectively drivingly engageable with a first output shaft of the first motor and a second output shaft of the second motor respectively.

3. A machine according to Claim 2 wherein the second output shaft is spaced from the said drive shaft and the control mechanism includes a clutch member slideably mounted on the drive shaft for selective movement between a first position, in which the drive shaft and the second output shaft are drivingly engaged with one another; and a second position in which the drive shaft and the second output shaft are disengaged from one another.

4. A machine according to Claim 3 wherein the first output shaft is permanently coupled to the drive shaft and the machine includes a switchable power supply for the first motor, the control mechanism including an actuator member for moving the clutch member between its first and second positions and the actuator member including an interlock switch that switches off the power supply for the first motor when the clutch member occupies its first position.

5. A machine according to Claim 4 wherein the control mechanism includes respective locks for locking the actuator member in its first and second positions.

6. A machine according to Claim 5 including a single key for the respective locks.

7. A machine according to Claim 2 or any claim dependent therefrom, wherein the first motor is an electric motor and the second motor is an hydraulic motor.

8. A machine according to any preceding claim wherein the rock cutting speed is greater than the drill positioning speed.

9. A machine according to Claim 8 including a switchable power supply for the second motor.

10. A machine according to any preceding claim wherein the boom includes a flexible joint interconnecting respective boom portions and the machine includes a powered actuator for powering motion of the flexible joint to adjust the angle subtended at the flexible joint by the boom portions.

11. A machine according to Claim 10 including a slewing ring interconnecting the boom and the machine frame; and a motor operatively connected to cause selective, powered rotation of the boom about the slewing ring.

12. A machine according to any preceding claim including a sumping cylinder operatively connected incrementally to advance the boom relative to the shield.

13. A machine according to any preceding claim wherein the mutually securable attachment members include brackets secured respectively on the cutting head and the drill, the respective brackets including mutually alignable, through going apertures and the machine including one or more securing pins each insertable through an aligned pair of the said apertures to secure the drill and the cutting head together.

14. A machine according to Claim 13 wherein the bracket secured on the cutting head is releasable therefrom.

15. A machine according to any preceding claim including a won mineral conveyor extending between a location on the machine adjacent the cutting head and a further location remote therefrom, and wherein the track

includes a pair of rails extending generally parallel to the won mineral conveyor on either side thereof.

16. A machine according to Claim 15 including respective rail extension members that are releasably securable to the ends of the pair of rails adjacent the cutting head, whereby temporarily to extend the track beyond the end of the spoil conveyor in the vicinity of the cutting head.

17. A machine according to Claim 16 wherein the track when extended by the rail extension members permits the drill to underlie the cutting head.

18. A machine according to any preceding claim including a winch and cable assembly for controllably moving the drill supported by the track.

19. A machine according to any preceding claim including a rigid basket that is moveably supportable on the track, the drill being releasably securable in the basket.

20. A machine according to Claim 19 including a control panel for the drill, the said panel having at least one control and/or indicator member and being releasably securable in the basket, the control panel and the drill being interconnected by at least one flexible control line whereby the control panel is positionable on the machine independently of the drill while being operatively connected thereto.

21. A machine according to Claim 20 wherein the control panel includes one or more solenoid valves; and wherein the machine includes a mimic panel having a respective relay actuator for each said solenoid valve, whereby the mimic panel is sufficiently light to allow it to be manually carried; the mimic panel and the control panel being operatively

interconnected whereby the mimic panel is moveable relative to the control panel.

22. A method of drilling a rock face using a machine according to any preceding claim, the method comprising: (i) as necessary, deselecting operation of the drive arrangement for rotating the cutting head at a rock cutting speed; (ii) moving the drill along the track from the remote location to the location adjacent the cutting head; (iii) securing the drill to the cutting head using the mutually securable attachment members; (iv) selecting operation of the drive arrangement to cause movement of the cutting head at a drill positioning speed, whereby to release the drill from the track and position the drill for drilling of a rock face; and (v) drilling the rock face using the drill.

23. A method according to Claim 22 including the further steps of, after drilling of the rock face, (vi) selecting operation of the drive arrangement to move the drill, at the said drill positioning speed, onto the track; (vii) disconnecting the mutually securable attachment members to permit the track to support the drill; (viii) moving the drill along the track from the location adjacent the cutting head to the remote location; and (ix) selecting operation of the drive arrangement for rotating the cutting head at a rock cutting speed.

24. A method according to Claim 22 or Claim 23, when the machine is as claimed in Claim 2, wherein the step (iv) includes rotating the cutting

head at the said drill positioning speed.

25. A method according to any of Claims 22 to 24 when the machine is as claimed in Claim 10, wherein the step (iv) includes operating the powered actuator.

26. A method according to any of Claims 22 to 25 when the machine is as claimed in Claim 11, wherein the step (iv) includes operating the powered actuator.

27. A method according to any of Claims 22 to 26 when the machine is as claimed in Claim 16 or Claim 17, including the sub-step of : (i a) attaching the rail extension members before step (ii).

28. A method according to Claim 23 when the machine is as claimed in Claim 16 or Claim 17, including the sub-step of : (vii a) removing the rail extension members before step (viii).

29. A method according to any of Claims 22 to 28 when the machine is as claimed in Claim 18, including using the winch and cable assembly to move the drill supported by the track.

30. A method according to any of Claims 22 to 29 when the machine is

as claimed in Claim 19, including the sub-step of : (iv a) moving the basket to a location on the track remote from the cutting head, before carrying out step (v).

31. A machine generally as herein described, with reference to and/or as illustrated in the accompanying drawings.

32. A method generally as herein described, with reference to and/or as illustrated in the accompanying drawings.