GB2196666A - A roadheader with drilling assembly - Google Patents

Abstract

A roadheader comprises: a first rail 14 mounted axially on its chassis 3, a second rail 15 mounted axially on its boom 11; the first and second rails being axially alignable by movement of the boom; a carriage 17 movable along the rails, when they are substantially aligned, from a stowed position at the rear of the roadheader, whereat it is supported only by the first rail, to an operative position at the front of the roadheader, whereat it is supported only by the second rail; and a drilling machine 43 mounted on the carriage for pivotal movement in a vertical plane and for rotary movement orthogonal to its pivot axis; the pivot axis of the drilling machine when the carriage is in its operative position being axially beyond the cutting head of the roadheader. The present invention also includes a hydraulic system and mounting for use in such a roadheader. <IMAGE>

Description

SPECIFICATION Roadheader with drilling assembly The present invention relates to a roadheader on which is mounted a drilling assembly.

In many mining operations, it is necessary to drive roadways underground in the mine to obtain access to the mineral being mined and to allow mined mineral to be transported to the surface. Nowadays, such roadways are often constructed using machines known as roadheaders.

Roadheaders are also used in other tunnelling operations, for instance in the formation of road, rail or waterway tunnels. In the present specification, for convenience, reference is only made to roadways. However, it should be understood that "roadway" is used to designate any roadway or tunnel formed by a roadheader, whether or not in a mining operation.

Roadheaders have been known and used for some time. They generally comprise a chassis movable, for instance, on caterpillar tracks, and a boom turret mounted on the chassis.

The chassis may include stelling jacks to fix it in a desired position.

The boom turret is rotatable about a vertical axis on the chassis, generally by use of hydraulic rams. This rotation is normally referred to as slewing. A boom is mounted on the turret for pivotal movement, again generally by hydraulic rams, in a vertical plane. This movement-is generally referred to as elevating. By combination of the slewing and elevating movements, the boom can be moved through a complete 360" arc. (Some roadheaders have two booms, mounted on the chassis via a double turret, each of which can be slewed and elevated).

A cutting head is mounted on the end of the boom and rotates about the axis of the boom so that, as the boom is slewed and elevated, rock is won from the face of the roadway.

It is necessary to support the roadway as it is constructed to prevent it collapsing under the strains imposed on it by surrounding strata. Conventionally, this is achieved by setting steel arches along the roadway, generally at about metre intervals. This is relatively expensive since it requires a large quantity of steel to support the roadway. Moreover, setting arches will not prevent the floor of the roadway becoming distorted by stresses acting on it from underlyning strata.

Alternatively, the roadway may be supported by lining it with concrete sections which are set in place around the roadway to provide a complete concrete lining. However, this does not always provide sufficient support for the roadway, particularly in highly stressed strata.

It is therefore becoming the practice to reinforce the roadway before setting arches or lining the roadway. This is achieved by drilling a number of holes radially into the roadway walls, floor and roof and securing therein reinforcing bolts, for instance using resins or cement. After the reinforcing bolts have been secured in place, the arches are set or the roadway is lined as before.

The advantages of this system is that it is cheaper, in that it allows the arches to be set further apart (generally at 1.3 metre intervals), quicker and safer (since it reinforces the roadway before the arches are set).

It is also useful to be able to drill holes in the roadway face. For instance, if the operation is to be shut down over a weekend or a holiday, it is advisable to reinforce the face to prevent distortion of the face occurring. Alternatively, the face can be drilled when very strong strata, which cannot be cut by the roadheader, is encountered, so that the strong strata can be blasted.

Clearly, where such drilling operations are to be carried out, it is necessary to provide a drilling machine. This can present problems.

Most roadheaders are large enough to occupy substantially the whole cross-section of the roadway, making it difficult or impossible to move a drilling machine easily from behind the roadheader to the position in front of the roadheader where it is needed tQ drill the holes.

A known roadheader, designed to obviate this difficulty, has a drilling machine mounted on its chassis. The drilling machine is normally in a retracted position, where it does not interfere with the operation of the boom, but can be extended on a telescopic mounting to a drilling position in front of the cutting head.

The drilling machine has its own slewing and elevating rams.

The known drilling machine has a large number of hoses or cables for supplying power to its various moving parts. Since there are telescopic, pivoting and rotating parts in the machines, these hoses or cables need to be long and to be able to loop and unloop as necessary. The constant looping and unlooping can damage the cables or hoses, which are also readily susceptible to accidential damage.

In its retracted position, the drilling machine interferes with the operator's view of the roadheader cutting head, thus making its operation difficult. The drilling machine can fulfil all the required drilling operations, but this requires the machine to have a large number of functions which complicates manoeuvring and adds to the cycle time.

It is an object of the present invention to provide a roadheader which at least in part overcomes the disadvantages of the prior art roadheader with a chassis-mounted drilling machine.

According to the first aspect of the present invention, there is provided a roadheader having: a first rail mounted axially on its chassis; a second rail mounted axially on its boom; the first and second rails being axially alignable by movement of the boom; a carriage movable along the rails, when they are substantially aligned, from a stowed position at the rear of the roadheader, whereat it is supported only by the first rail, to an operative position at the front of the roadheader, whereat it is supported only by the second rail; and a drilling machine mounted on the carriage for pivotal movement in a vertical plane and for rotary movement orthogonal to its pivot axis; the pivot axis of the drilling machine when the carriage is in its operative position being axially beyond the cutting head of the roadheader.

Preferably, the end of the carriage on which the drilling machine is mounted is cranked so that the pivotal axis of the drilling machine is displaced off the axis of the second rail away from the boom. This allows a greater degree of pivotal movement of the drilling machine.

Conveniently, pivotal movement of the drilling machine is effected by use of a hydraulic ram pivotally attached to one end of a lever, the other end of the lever being fixedly attached to the drilling machine about its pivotal axis.

Advantageously, the drilling machine has on its end remote from its drilling end a fixture for receiving an assembled arch, a junction girder or a concrete segment. Preferably, the fixture is removably located on the drilling machine so that it can be changed for a fixture having a different function.

Preferably, the drilling machine is arranged so that, by suitable pivotal and rotary movement, it can be moved to a stowed position wherein it is parallel with the second rail with its drilling end pointing towards the rear of the roadheader. Advantageously, the carriage can only be moved to its stowed position when the drilling machine is in its stowed position.

Preferably, the rails each comprise a boxtype girder, optionally having a flat plate on top, the edges of the plate protruding symmetrically beyond the edges of the girder. Advantageously, the end of each girder adjacent the other rail reduces in width towards its end. This ensures that, even if the rails are slightly misaligned, the carriage will still be able to pass between them.

Alternatively, any other type of rail, such a T-section or I-section rail, could be used.

Preferably, the carriage is movable on the rails by means of at least two driving wheels mounted on the carriage. The driving wheels must be spaced apart an amount sufficient to ensure that at all times at least one driving wheel is in contact with at least one of the rails. Conveniently, the driving wheels ride on a vertical surface of the rails.

Advantageously, each driving wheel is opposed by a biased idler wheel which is arranged to ensure that the rail is firmly gripped between the driving wheels and their respective idler wheels. The idler wheels are prefera bly arranged so that a minimum gap is maintained between them and their respective driving wheels so that there is no hindrance to the passage of the carriage as each pair of driving and idler wheels crosses the gap between the rails.

Advantageously, the carriage is also provided with further wheels or rollers adapted to ride on other surfaces of the rails to ensure that the carriage cannot become dislodged from the rails. The further wheels or rollers may be biased to enable them to grip the rails.

Preferably, each driving wheel is driven by a hydraulic, pneumatic or electric motor mounted on the carriage.

In the roadheader of the present invention, it is desirable that the drilling machine should be as compact as possible so that it is readily manoeuvrable. preferably, therefore, the drilling machines comprises; a motor for receiving and rotating the drill bit; a frame on which the motor is axially (i.e. in the direction in which the drill bit extends) movable; and a support on which the frame is axially movable.

Drilling machines of this type are commercially available.

Preferably, the drilling machine includes a drive motor, fixed on the support, which drives an endless chain, mounted in the frame, to which the drilling motor is attached. When the drive motor begins to operate, the movement of the chain will move the drilling motor along the frame. When the drilling motor reaches the end of its movement, it will jam the chain, which will then act as a rack moving on the drive motor pinion, thus causing the frame to move relative to the support.

Conveniently, the drilling machine includes a guide which is movable axially relative to the support, preferably by hydraulic rams, to fix the position of the drilling machine relative to the roadway.

Preferably, the drilling motor and the drive motor are both hydraulically powered so that the whole operation of the drilling machine is hydraulically powered.

Advantageously, the hydraulic system includes a number of sequence valves so that only one manually operated valve is required to control the operation of the drilling machine. Such a hydraullic system is arranged, according to a second aspect of the present invention, such that on operating the manually operated valve to allow flow in one direction, the hydraulic rams extend the guide until it encounters the roadway surface, whereupon pressure will build up in the system, causing a sequence valve to operate. The drilling motor and the drive motor will then be activated, causing the drill to be driven into the roadway until the frame has extended as far as possible.

Hydraulic systems of this type are not provided on presently available drilling machines, which will therefore need to be adapted to be able to operate in this fashion.

The manual valve may then be reversed to retract the drill, or this may- be achieved by use of another sequence valve. At this stage, the drill bit may be replaced by a reinforcing bolt which is put in place using the drilling machine. The drilling motor is then again retracted, and finaily the guide is retracted either under control of the manual valve or under control of a further sequence valve.

Advantageously, the drilling machine, the means for causing its pivotal and rotary movement, and the means for moving the carriage on the rails are hydraulically powered. For any hydraulic powered machinery including a hydraulic motor, it is necessary to have three hydraulic lines, being the pressure, return and drain lines. It would be advantageous if the roadheader of the present invention required only these three hydraulic lines for operation of the drilling machine, with as few manually operated controls and as little looped hose as possible.

According to a third aspect of the present invention there is provided a mounting for connecting a hydraullically operated drilling machine to a carriage, comprises: a housing which is pivotally mountable on the carriage; a shaft mounted for roation about an axis orthogonal to the pivot axis of the housing, with one end of the shaft protruding beyond the housing; and driving meaning for rotating the shaft, wherein: the protruding end of the shaft is adapted to receive thereon the drilling machine and has in its face three fluid connections; the housing includes a cap which fits snugly over the other end of the shaft, the cap having therein three axially spaced fluid connectors; the shaft or the cap has two or three circumferentially grooves aligned with two or three respectively of the fluid connectors in the cap, and the shaft includes three fluid conduits connecting the fluid connectors in the cap to the fluid connections in the protruding end of the shaft.

Where there are only two circumferential grooves, the base of the cap should be spaced from the other end of the shaft so that fluid from the outermost cap connector flows into this space and thence through one of the conduits to its respective connection.

Where there are three circumferential grooves, each groove will be aligned with one cap connector and fluid will be led from this connector, through its respective groove, into its respective conduit, to its respective shaft connection.

Preferably, the grooves are formed in the shaft, and conveniently they are separated from one another by circumferential seals.

Advantageously, the cap is bolted onto the remainder of the housing by means of shouldered bolts, whereby the shaft is allowed a minimum amount of axial movement relative to the cap, thereby increasing the life of any seals present.

Preferably, the driving means comprises a gear wheel fixed onto the shaft and a worm gear meshed with the gear wheel. Conveniently, the worm gear is driven by a hydraulic motor.

In a roadheader including all the aspects of the present invention, and wherein all power is hydraulic power, it is possible to have very few hoses which need to be looped. These will include three hoses connected from the main power supply for the roadheader to the carriage, and three hoses connecting the drilling motor to the base of the drilling machine.

Even these hoses will not be subject to much stress, as they only execute longitudinal movement, and in the case of the hoses on the drilling machine, this is only of small amplitude.

The system of the present invention could readily be adapted for use with a twin boom roadheader merely by making the first rail movable, in the manner of points on a railway, between two positions, each position being aligned with one of the booms respectively.

Preferably, the drilling machine is controlled by use of a controll panel mounted on the rear end of the carriage so that the operator, while still being in a safe area, can readily see the machine as its operates.

It will be readily apparent to the skilled person that it will be necessary to interlock the controls of the roadheader including the drilling machine to ensure that it can be operated safely. The interlocks may include mechanical, hydraulic and/or electrial interlocks, as will be apparent to those skilled in the art.

Some embodiments of the roadheader of the present invention are now described, by way of examples only, with reference to the accompanying drawings, in which; Figure 1 is a side view of a first embodiment of the roadheader; Figure 2 is a side view of a second embodiment of the roadheader; Figures 3A and 3B are views along line A-A of Figure 2; Figure 4 is a front view of part of the road header of Figure 2; Figure 5 is a view along line C-C of Figure 6, showing a detail of the roadheader of Figure 2; Figure 6 is a view along line B-B of Figure 5; Figure 7 is a side view of a third embodiment of the roadheader; Figure 8 is a side view of a fourth embodiment of the roadheader; and Figure 9 is a hydraulic circuit diagram.

In all the Figures like reference numerals have been used for like parts, and description of one Figure applies, except as specifically noted, to the other Figures. In some of the Figures parts have been removed or sectioned for the sake of clarity.

Referring now to Figure 1, there is shown a roadheader 1 comprising a chassis 3 mounted on catapillar tracks 5. A boom turret 7 is mounted for rotation about a vertical axis by means of slewing rams 9 on the chassis 3. A boom 11 is mounted for pivotal movement about a horizontal axis by elevating rams (not shown) on the turret 7. The boom 11 supports a cutting head 12 which is rotated about its longitudinal axis by an electric motor (not shown).

A first rail 14 is fixedly mounted on top of the chassis 3 and is aligned with the central longitudinal axis of the roadheader 1. A second rail 15 is fixedly mounted on the boom 11 and is aligned with the central longitudinal axis of the boom 11.

The roadheader 1 is arranged so that the boom 11 can be mechanically immobilised when its axis is horizontal and aligned with the longitudinal axis of the roadheader 1. The second rail 15 is so mounted on the boom 11 that, when the boom 11 is aligned the first and second rails 14,15 are substantially coaxial.

Moreover, as can be seen from the fragmentary drawing in Figure 1, the second rail 1 5 is so mounted on the boom 11 that, whatever position the boom 11 is moved to, the rail 1 5 does not abut the roadway or any arches set therein.

A carriage (not shown in Figure 1), on which is mounted a drilling machine, is arranged to be movable on the rails 14,15 and is mounted in a stowed position on the first rail 14 to the rear of the roadheader 1.

Referring now also to Figure 2, there is shown a similar roadheader 1 in which the carriage 1 7 is in its operative position at the front of the roadheader 1 on the second rail 15.

Referring now also to Figure 3, the rail 15 comprises a box girder 19 to the top of which has been welded a plate 21, the edges of the plate 21 extend beyond the edges of the box girder 19. The widths W of the box grider 19 decreases towards the rear of the second rail 15.

The first rail 14 is identical in construction to the second rail 15 except that its less wide end is its forward end.

The carriage 1 7 comprises two box girder sections 23,25 welded to the inside of the bottom of a U-cross-section metal member 27. Mounted between the box girder section 23,25 are three equally spaced horizontal rollers 29 adapted to roll along the top surface of the plate 21. Mounted between the sides of the U section member 27 and below the rearmost horizontal roller 29 are two further horizontal rollers 31 adapted to bear on the lower surface on the plate 21 to prevent the carriage 17 tipping off the rail 15.

Mounted on carriage 17 are a pair of spaced apart driving wheels 33 provided with polyurethane tyres 35 to assist in driving the carriage on the rails 14,15. The distance between the driving wheels 33 is greater than the gap between the adjacent ends of the rails 14,15 when the boom is in its immobilised position. The driving wheels 33 are driven directly by hydraulic motors 37.

Depending from the U-section member 27 and directly opposite the driving wheels 33 are a pair of biased idler wheels 39, also provided with polyurethane tyres 35. These are biased so that the respective pairs of driving 33 and idler 39 wheels pinch the rail with a force of about 5 kN. However, the bias is arranged so that a gap will be maintained between each pair even if there is no rail present.

At the forward end of the carriage 1 7 are bushings 45 mounted inside the box girder sections 23,25, for receiving a mounting 41 for a drilling machine 43. The mounting 41 is shown in Figure 6, to which reference is now also made, and comprises a housing 47 to which is attached to stub shafts 49 which are received in the bushings 45. One end of lever 51 is bolted and keyed into housing 47 and the other end of each lever 51 is pivotally connected to one end of a pivoting ram 53.

The other end of the pivoting ram 53 is pivotally connected to the carriage 17.

The drilling machine 43 has on it an abutment 55 to ensure that when the mounting is pivoted to its fullest extent clockwise (as viewed in Figure 2), the drilling machine 43 lies parallel to the carriage 17.

The mounting means 41 allows the drilling machine 43 to rotate continuously in either direction about an axis orthogonal to the axis of the stub shafts 49, as shown in Figures 5 and 6, to which reference is now also made.

A shaft 57 is rotatably mounted in the housing 47 by means of bearings 59. The shaft 57 has on one end a flange 61 to which the drilling machine 43 can be bolted. Bolts 63 also retain a seal cover 65 in place. A gear wheel 67 is keyed onto the shaft 57 and meshes with a worm gear 69 driven by hydraulic rotation motor 71. Thus, the drilling machine is rotatable in either direction on shaft 57.

Further details of the mounting means 41 are described below in relation to the hydraulic system.

The drilling machine 43 is shown in detail in Figure 4, and comprises a base plate 72 which is bolted onto the flange 61. A pair of runners 73 is fixed onto the base plate 72, and a pair of guide members 75 are slidably mounted on the runners 73. The guide members 75 can be retracted longitudinally relative to the runners 73 by use of hydraulic guide rams (not shown) located inside the runners 73.

A frame member 77 is slidably mounted on each of the guide members 75. Mounted on sprockets on each frame member 77 is an endless chain 79. The chains 79 mesh with pinions (not shown) on a hydraulic drive motor 81. A hydraulic motor 83 is fixedly attached to the endless chains 79 so that it spans the frame members 77.

The drilling machine 43 may also be provided with resin boxes and reinforcing bolt storage boxes to facilitate its use. Such arrangements are well known in the art.

On the end of the base plate 72 is removably located a fixture 119 adapted to receive an arch section. This could by replaced by bracket for receiving a junction girder or a concrete tunnel lining section.

The hydraulic system of the roadheader 1 is now described, although in the drawings, many of the hydraulic connections and valves have been omitted for the sake of clarity.

The main hydraulic power supply is located to the rear of the roadheader 1 and three armoured flexible hoses (for the pressure, return and drain lines) will extend from the power supply to the rear of the carriage 17.

These three hoses will need to be long enough to extend from the power supply to the rear of the carriage (17) in its operative position, and to be flexible so that, on movement of the carriage 1 7 to its stowed position, they can loop out of the way.

The carriage 17 will include a number of fixed hydraulic hoses which will lead hydraulic fluid to the driving motors 37, the pivoting ram 53 and a control panel 85. It is envisaged that the control panel 85 could alternatively be mounted on the rear of the carriage 17 so that an operator could control the operation of the drilling machine 43 from the chassis 3.

This would not involve the use of any flexible hosing.

Three small lengths of flexible hosing are used to connect the rotation- motor 71 to the power supply via the conduits on the carriage 17. However, such hosing will only need to rotate through a very limited angle, for instance about 60 , on either side of a central position, and will therefore not need to be very long or very flexible.

Hydraulic power is supplied from the carriage 17 to the drilling machine 43 by the system shown in Figure 5. The shaft 57 to which the drilling machine is attached has in it three axial drillings 87,89,91 arranged syrri- metrically in the radial direction (as shown in Figure 6). The first drilling 87 extends completely through the shaft 57. The second and third drillings 89,91, are blind at their ends remote from the flange 61, and the second drilling 89 is longer than the third 91.

Two radial drillings 93,95 connect the blind ends of the axial drillings 89,91 with circumferential grooves 97,99 respectively in the cylindrical surface of the end of the shaft 57 remote from the flange 61. Seals 101,103,105 are located in further circumferential grooves on either side of and between the grooves 97,99.

The housing 47 includes an end cap 107 which fits snugly over the end of the shaft 57 remote from the flange 61. The cap 107 is bolted onto the remainder of the housing 47 by shouldered bolts 109, which allows it to float on the seals 101,103,105. The cap 107 is arranged so that its base is spaced from the end of the shaft 57. The space 111 thus formed connects with the first axial drilling 87.

The cap 107 is provided with three hydraulic connectors 113,115,117 which are aligned with the space 111 and the grooves 97,99 respectively. The hydraulic connectors are connected to the hydraulic power supply via three short lengths of flexible hosing which connect with fixed hydraulic supply hoses in the carriage 17.

The ends of the drillings 87,89,91 at the flanged end of the shaft 57 have screwthreaded sections for receiving hydraulic connectors for supplying hydraulic power to the drilling machine. From the flange end of the shaft, fixed hydraulic hoses provide hydraulic fluid to the guide rams and the drive motor 81 of the drilling machine 43. The only flexible hosing required connects the drilling motor 83 to the hydraulic power supply. The three lengths of hosing required will be relatively short and will only need to extend and retract in a longitudinal direction. They will not need to rotate.

A hydraulic circuit for controlling the operation of the drilling machine is shown in Figure 9, to which reference is now also made. The circuit comprises a carriage traverse control panel 151 which is under the control of a double diverter valve 153. The double diverter valve 153 allows the activation of the carriage traverse'motors 37 when the carriage lock key B is fitted in the diverter valve 153. The carriage lock key B is normally in place on the main control panel (not shown) of the roadheader 1 and, when in normal place, enables the movement of the boom. Thus, when removed, boom movement is disabled.

When the carriage lock key B is removed from the diverted valve 153, hydraulic fluid flows to control panel 155, which has four operating valves 157, 159, 161, 163. The first 157 controls the pivoting rams 53. The second valve 159 controls the rotation motor 71. These two valves 157, 159 operate in conventional fashion.

The third valve 161 controls the operation of the drilling machine 43. Hydraulic fluid passes from the control panel 155 through a distributer 165 and a second diverted valve 167 to the drilling machine 43. At first the fluid is fed only to the guide rams 169. Once the guide rams 169 have extended the guide members 75 to their fullest extent, a relief valve operates to connect the supply of hydraulic fluid to the drill motor 83 and the drive motor 81. Thus, these latter two motors can only operate once the guide members 75 are fully engaged.

When the drive motor 8 1 has extended the drill to its greatest extent, the flow can be reversed to retract the drill.

If it is required to lock a segment for setting onto the drilling machine 43, the fourth valve 163 is operated to switch second diverter valve 167 to cause locking cylinder 173 to operate.

At all times during the operation of the drilling machine 43, the roadheader's boom cutter motor, scraper conveyor and gathering arms are all disabled by removal of key A from position A shown on the carriage traverse control panel 151.

The roadheader 1 as a whole will use its normal controls, but modified to include the necessary interlocks. Since these will be known or obvious to the person skilled in the art they are not further shown or described.

The roadheader 1 is operated as follows. At the beginning of its operation, the carriage 1 7 is maintained in its stowed position and the boom 11 and cutting head 12 are operated in conventional fashion to excavate material from the face of the roadway. Once sufficient excavation has taken place, it is necessary either to insert reinforcing bolts around the roadway or to set a further arch.

In order to achieve the insertion of reinforcing bolts, the boom is moved to its immobilisation position and is held in that position by a mechanical interlock according to conventional procedures. In this position, the two rails 14,15 are substantially aligned. The key A is removed from position A and the key B is inserted in position B. The driving motor 37 is activated to move the carriage 17 from its stowed position across the gap between the rails 14,15 to its operative position.

Once the carriage 17 is in its operative position, key B is removed and reinserted in its normal position to reactivate the boom slewing and elevating mechanisms. The mechanical interlock is removed and the boom is slewed and/or elevated. At the same time the drilling machine is pivoted by means of the pivoting ram 53 and rotated by means of the rotating motor 71. The movements of the boom 11 and the drilling machine 43 are coordinated so as to position the drilling machine at a desired location.

Desirably, the various movements are coordinated such that the axis of rotation of the drilling machine 43 is coaxial with the axis of the curved portion of the roadway. This is shown in Figures 2 and 4 for a D-shaped roadway. The drilling machine 43 is also arranged so that it can drill in any direction orthogonally to the axis of the roadway. In this position, the drilling machine can be moved so that it can drill a number of radial holes for receiving reinforcing bolts merely by rotation using the rotation motor 71.

It will, of course, be appreciated that where the roadway is not circular in cross-section, for instance at the lower parts of the walls and at the floor of a D-section roadway, the boom 11 will also need to be moved to position the drilling machine 43 correctly.

Once the drilling machine 43 is in position, it is activated. This causes the guide members 75 to extend until they abut the roadway wall, whereupon the drilling motor 83 and the drive motor 81 are activated. The drive motor causes the drilling motor 83 to be moved towards the wall on the chains 79. When the drilling motor 83 reaches the end of the frame members 77, the chain jams and acts as a rack which meshes with the motor pinions and causes the frame members 77 to move towards the wall.

When the frame members reach the wall, the sequence is reversed, whereby the drilling motor 83 is moved back to its originally position. However, the guide members 75 are not retracted so as to ensure that a reinforcing bolt can be inserted correctly into the newly drilled hole.

The drill bit is then replaced by a reinforcing bolt, the hole is filled with resin, and the machine 43 is activated to move the reinforcing bolt into the holes as if it were a drill bit. The reinforcing bolt is held in the hole for a time sufficient for the resin to begin setting and the sequence is then reversed. This time the guide members 75 are also retracted. The drilling machine 43 can then be rotated by rotation motor 7 1 so that a further reinforcing bolt can be inserted.

In order to set a further arch, the carriage 1 7 is located at its stowed position as shown in phantom in Figure 7 to which reference is now also made. An arch section 121 is assembled at the rear of roadheader 1 and located on the bracket 119. This entire operation can be carried out in a safe area, in a portion of the roadway which has already been supported and away from the prop free front.

The boom 11 is then put in its immobilised position and the carriage 17 is moved to its operative position, dragging with it- the arch section 121. This is the position shown in full in Figure 7. The boom 11 is then remobilsed and elevated to position the arch section 121 in the desired position. The arch section 121 is then fixed in place. Thus, the minimum amount of work needs to be done in dangerous areas.

If the bracket 119 is changed, similar operations can be carried out to set junction beams or concrete segments.

If desired, as shown in Figure 8, to which reference is now also made, the roadheader 1 may be used to drill the roadway face.

It will be noted that the forward end of the carriage 17 shown in Figure 8 is cranked so that the pivot axis of the mounting 41 is above the axis of the second rail 1 5. This allows the mounting 41 to pivot through a greater arc than is possible with the arrangement shown in Figure 2. This has the advantage that it becomes more easy to drill holes below the level of the base of the roadheader in the face of the roadway.

Once the carriage 1 7 has been moved to its operative position, the motor 7 1 is activated to rotate the drilling machine 43. Then, by combinations of slewing and elevating movements of the boom 11 and rotating and pivoting movements of the drilling machine 43 it is possible to align the drilling machine in any desired orientation relative to the face to enable drilling for reinforcement or blasting to take place.

It can be seen that the roadheader of the present invention has considerable advantages over the nearest roadheader known from the prior art. In particular: the roadheader has on it a drilling machine which can be readily moved into an operative position when needed and to a stowed position when not needed; in the stowed position, the drilling machine does not obstruct the view of the operator controlling the operation of the roadheader; the roadheader does not require a separate set of slewing and elevating rams for the drilling machine; the drilling machine has on it only the minimum amount of flexible loop hosing for power supply, thus reducing the possibility of wear and damage to the hosing; the drilling machine can rotate through 360" or further, in either direction, as desired by the operator; ; the drilling machine is compact and can be operated by use of a single control handle; the roadheader can be used to set arches, junctions beams and concrete sections safely and easily; and the whole operation of the drilling machine and the roadheader can be controlled using a minimum number of control levers from a position which is away from the prop free front.

Use of the roadheader of the present invention will therefore speed up and make more cost efficient roadheading operations, and will make them considerably safer.

It will of course be understood that the present invention has been described above purely by way of example, and modification of detail can be made within the scope of the invention.

Claims (33)

1. A roadheader having: a first rail (14) mounted axially on its chassis (3); a second rail (15) mounted axially on its boom (11); the first and second rails (14, 15) being axis ally alignable by movement of the boom (11); a carriage (17) movable along the rails (14,15), when they are substantially aligned, from a stowed position at the rear of the roadheader, whereat it is supported only by the first rail (14), to an operative position at the front of the roadheader, whereat it is supported only by the second rail (15); and a drilling machine (43) mounted on the carriage (17) for pivotal movement in a vertical plane and for rotary movement orthogonal to its pivot axis; the pivot axis of the drilling machine (43) when the carriage (17) is in its operative position being axially beyond the cutting head (12) of the roadheader.

2. The roadheader of claim 1, wherein the end of the carriage (17) on which the drilling machine (43) is mounted is cranked so that the pivotal axis of the drilling machine (43) is displaced off the axis of the second rail (15) away from the boom (11).

3. The roadheader of claim 1 or claim 2, wherein pivotal movement of the drilling machine (43) is effected by use of a hydraulic ram (53) pivotally attached to one end of a lever (51), the other end of the lever (51) being fixedly attached to the drilling machine about its pivotal axis.

4. The roadheader of any one of claims 1 to 3, wherein the drilling machine (43) has on its end remote from its drilling end a fixture (119) for receiving an assembled arch, a junction girder or a concrete segment.

5. The roadheader of claim 4, wherein the fixture (119) is removably located on the drilling machine (43) so that it can be changed for a fixture having different function.

6. The roadheader of any one of claims 1 to 5, wherein the drilling machine (43) is arranged so that, by suitable pivotal and rotary movement, it can be moved to a stowed position wherein it is parallel with the second rail (15) with its drilling end pointing towards the rear of the roadheader.

7. The roadheader of claim 6, wherein the carriage (17) can only be moved to its stowed position when the drilling machine (43) is in its stowed position.

8. The roadheader of any one of claims 1 to 7, wherein the rails (14, 15) each comprise a box-type girder (19) having a flat plate (21) on top, the edges of the plate (21) protruding symmetrically beyond the edges of the girder (19).

9. The roadheader of claim 8, wherein the end of each girder (19) adjacent the other rail reduces in width towards its end.

10. The roadheader of any one of claims 1 to 9, wherein the carriage (17) is movable on the rails (14, 15) by means of at least two driving wheels (33) mounted on the carriage (17), the driving wheels (33) being spaced apart an amount sufficient to ensure that at all times at least one driving wheel (33) is in contact with at least one of the rails (14, 15).

11. The roadheader of claim 10, wherein the driving wheels (33) ride on a vertical surface of the rails (14, 15).

12. The roadheader of claim 10 or claim 11, wherein each driving wheel (33) is opposed by a biased idler wheel (39) which is arranged to ensure that the rail (14, 15) is firmly gripped between the driving wheels (33) and their respective idler wheels (39).

13. The roadheader of claim 12, wherein the idler wheels (39) are arranged so that a minimum gap is maintained between them and their respective driving wheels (33) so that there is no hindrance to the passage of the carriage (17) as each pair of driving (33) and idler (39) wheels crosses the gap between the rails (14, 15).

14. The roadheader of any one of claims 10 to 13, wherein the carriage (17) is also provided with further wheels or rollers adapted to ride on other surfaces of the rails (14, 15) to ensure that the carriage cannot become dislodged from the rails.

15. The roadheader of claim 14, wherein the further wheels or rollers are biased to enable them to grip the rails (14, 15).

16. The roadheader of any one of claims 1 to 15, wherein the drilling machine comprises; a motor (83) for receiving and rotating the drill bit; a frame (77) on which the motor (83) is axially (i.e. in the direction in which the drill bit extends) movable; and a support (73) on which the frame (77) is axially movable.

17. The roadheader of claim 16, wherein the drilling machine (43) includes a drive motor (81) fixed on the support, which motor drives an endless chain (79) mounted in the frame (77), to which the drilling motor (83) is attached, whereby when the drive motor (81) begins to operate, the movement of the chain (79) will move the drilling motor (83) along the frame (77) and when the drilling motor (83) reaches the end of its movement, it will jam the chain (79), which will then act as a rack moving on the drive motor pinion, thus causing the frame (77) to move relative to the support (73).

18. The roadheader of claim 16 or claim 17, wherein the drilling machine (43) includes a guide (75) which is movable axially relative to the support (73), to fix the position of the drilling machine (43) relative to the roadway.

19. The roadheader of any one of claims 16 to 18, wherein the drilling motor (43) and the drive motor (81) are both hydraulically powered so that the whole operation of the drilling machine is hydraulically powered.

20. The roadheader of claim 19, wherein the hydraulic system includes a number of sequence valves so that only one manually operated valve (161) is required to control the operation of the drilling machine.

21. A hydraulic system for operating a roadheader according to claim 20, which system is arranged such that on operating the manually operated valve (161) to allow flow in one direction, hydraulic rams (169) extend the guide (75) until it encounters the roadway surface, whereupon pressure will build up in the system, causing a sequence valve to operate so that the drilling motor (83) and the drive motor (21) are then activated, causing the drill to be driven into the roadway until the frame (77) has extended as far as possible.

22. The hydraulic system of claim 21, wherein on reversal of the manual valve (161), the drill is retracted.

23. The hydraulic system of claim 21, wherein the drill is retracted by use of another sequence valve.

24. A mounting for connecting a hydraulically operated drilling machine (43) to a carriage, said mounting comprising: a housing (47) which is pivotally mountable on the carriage (17); a shaft (57) mounted for roation about an axis orthogonal to the pivot axis of the housing (47) with one end of the shaft protruding beyond the housing (47); and driving means (67, 69, 71) for rotating the shaft (57), wherein: the protruding end of the shaft (57) is adapted to receive thereon the drilling machine and has in its face three fluid connections; the housing (47) includes a cap (107) which fits snugly over the other end of the shaft (47), the cap (107) having therein three axially spaced fluid connectors (113, 115, 117,); the shaft (57) or the cap (107) has two or three circumferential.grooves (97, 99) aligned with two or three respectively of the fluid connectors (113, 115, 117) in the cap, and the shaft (57) includes three fluid conduits (87; 89 and 93; 91 and 95) connecting the fluid connectors (113, 115, 117) in the cap (107) to the fluid connections in the protruding end of the shaft (57).

25. The mounting of claim 24, wherein there are only two circumferential grooves (97, 99) and the base of the cap (107) is spaced from the other end of the shaft (57) so that fluid from the outermost cap connector (113) flows into this space and thence through one of the conduits (87) to its respective connection.

26. The mounting of claim 24, wherein there are three circumferential grooves and each groove is aligned with one cap connector and fluid is led from this connector, through its respective groove, into its respective conduit, to its respective shaft connection.

27. The mounting of any one of claims 24 to 26, wherein the grooves are formed in the shaft and are separated from one another by circumferential seals (101, 103, 105).

28. The mounting of any one of claims 24 to 27, wherein the cap (107) is bolted onto the remainder of the housing (47) by means of shouldered bolts (109), whereby the shaft (57) is allowed a minimum amount of axial movement relative to the cap (107), thereby increasing the life of any seals present.

29. The mounting of any one of claims 24 to 28, wherein the driving means comprises a gear wheel (63) fixed onto the shaft and a worm gear (69) meshed with the gear wheel (67).

30. The mounting of claim 29, wherein the worm gear (69) is driven by a hydraulic motor.

31. A roadheader substantially as hereinbefore described with reference to the accompanying drawings.

32. A hydraulic system substantiantially as hereinbefore described with reference to the accompanying drawings.

33. A mounting substantially as hereinbefore described with reference to the accompanying drawings.