GB2079346A - Shaft sinking apparatus - Google Patents

Abstract

Apparatus for sinking vertical shafts, for example for coal mines, comprising a support frame 9 for location within the shaft and means 11, 13 for supporting the frame adjacent the lower part of the shaft being excavated, a slewing ring 15 supported on the support frame and a swivelling cross beam 23 suspended from the slewing part of the slewing ring and wherein at least one cutting device 27 and preferably a pair of such devices are supported on the cross beam, the cutting devices being equally spaced from the centre of the beam which is in line with the rotational axis of the slewing ring, the cutting devices 27 facing in opposite directions and being mounted on cutting booms 25 such as that used on a road header, the cutting booms 25 themselves being mounted for rotation about further vertical axes and being capable of pivoting from a generally horizontal orientation to a position beneath the horizontal so that material can be mined from the bottom of the shaft beneath the beam. Preferably, conveying and load equipment is associated with the cutting devices so that mined material can be collected from the bottom of the shaft and lifted to the surface. The frame may be supported on hydraulic extendable legs 11 which rest on the floor of the shaft and by means of extendable peripheral arms 13 which engage in an anchor ring used for lining the shaft. <IMAGE>

Description

SPECIFICATION Shaft sinking apparatus This invention relates to apparatus for sinking vertical shafts, e.g. for coal mines.

Every time a new mine is opened, one or more access shafts are required, and these can vary in diameter from 26-33ft. or thereabouts, and can be as deep as about 3000ft. or thereabouts. Furthermore, shafts sometimes have to be dug for other purposes, e.g. hydro-electric projects, ventilation shafts, e.g.

for tunnels, and in other instances. Traditionally, shafts of this type are dug largely by hand, using drilling and blasting techniques as necessary. This is dangerous and time-consuming and therefore expensive.

Normally, when digging a shaft, a scaffold is supported from the surface, and this has three levels, the top one for stores, the central one from which the shaft lining is built, and the bottom one from which actual excavation takes place. Obviously, when blasting occurs, the scaffold has to be evacuated until the dust and fumes have cleared, and this has a considerable bearing on the time taken to dig, and hence the cost of building the shaft.

The present invention seeks to provide shaft sinking apparatus which helps to reduce some of the above problems, and which, at least to some extent, can operate automatically.

According to the present invention, we provide shaft sinking apparatus comprising a support frame, means to support the frame adjacent the bottom of the shaft being sunk, a slewing ring supported on the frame, a swivelling cross beam suspended from the slewing part of the slewing ring, and at least one cutting device supported on the cross beam.

Preferably, the cutting device is mounted on a cutting boom, such as that used on a road header, and two are provided on the cross beam, equally spaced from the centre of the beam, which coincides with the rotational axis of the slewing ring, and facing in opposite directions so that each will lead the beam when it is rotated in a cutting direction.

Preferably, each cutting boom is supported on the beam for rotation about a vertical axis through at least about 200 , and is capable of pivoting from a generally horizontal orientation to around 500 below the horizontal so as to be able to mine material beneath the beam.

Each cutting boom is preferably associated with an apron and gathering means, e.g. arms or star wheels, and a central conveyor so as automatically to collect material cut by the cutting device on the end of each boom, and deliver it rearwardly, where it can be loaded into buckets for lifting to the surface.

Preferably, the support means for the frame comprises a plurality of hydraulically extendable legs which rest on the floor of the shaft. It is also preferred that the frame is supported around its periphery, e.g. by means of extendable arms engaging in sockets in a two-part extendable and expandable anchor ring used to line the lower part of the shaft. Preferably also, safety supporting ropes extend upwardly from the frame to the surface, e.g. a Capstan engine.

One embodiment of shaft sinking apparatus is now described by way of example only with reference to the accompanying schematic drawings, in which FIGURE lisa side elevation ofthe apparatus, and FIGURE 2 is a section on the line A-A of Figure 1.

Referring to the drawings, a partially sunk shaft is indicated at 1, and adjacent its bottom, the shaft is temporarily lined with hydraulically adjustable lining segments which together make up two expanding anchor rings 5 and 7, one above the other, and which can be lowered into the shaft as it is sunk, one at a time.

Supported within the rings 5 and 7 is a support frame 9, which would be a network of girders giving structural strength and rigidity, but having sufficient "windows" therein to provide plenty of vertical access to the floor F of the shaft. The frame 9 is supported on a plurality of hydraulically extendable legs 11, the length of which can be adjusted automatically to ensure that the frame 9 is maintained perfectly level in the shaft. Furthermore, extendable structural arms 13 are housed in the hollow ends of the members of the frame 9, for engagement in sockets (not shown) in the rings 5, 7. It will be noted that a second frame 10 is shown in the drawing, which is optional and can be similar to the frame 9, and if provided would be connected to the frame 9.Furthermore, the frame 9 (and 10) would also be connected by safety ropes (not shown) to a Capstan engine on the surface. It will be appreciated therefore that the support means for the frame 9 may be provided by the legs 1 1,the arms 13 or the ropes, or a combination of any two or more of these, or by other means. The advantage of using the legs, however, is that they can also be used to level the frame 9, just as the arms 13 can be used to centralise it. The arms 13 form a snug fit in the vertical plane in the sockets in the rings 5, 7, but a looser fit in the horizontal plane, to allow the ring to be expanded or retracted as needed.

A slewing ring 15 of known construction, but as small as practically possible, is supported at the centre of the frame 9, and on the outer periphery of the slewable part of the ring is a ring gear 17 engaging with one or more (three are shown) drive pinions 19 rotated by hydraulic motors 21. Supported centrally from the slewable part of the ring 15 is a swivelling cross beam 23, the length of which is such that when rotated about the vertical rotating axis of the ring 15, it will not foul the support legs 11. Hanging from the beam 23, adjacent each end, is a cutting boom 25 having a cutter head 27 thereon, of known construction, one boom facing in one direction and the other in the opposite direction.Each of the booms 25 is supported on the beam 23 for rotation through at least 1800 about a vertical axis, e.g. on a slewing ring having a ring gear 29 rotatable by a pinion 31 driven by a hydraulic motor 33. Each of the booms 25 is also pivotable from a substantially horizontal position, through about 50 downwardly, about a horizontal pivot 33.

It will thus be appreciated that by rotating the cross beam 23 through just over 1809 in increments and for each increment, rotating the booms through the arcs 35 (see Figure 2), a slice can be mined from the bottom of the shaft. Obviously, from time to time it will be necessary to lift a leg 11 to allow material to be mined beneath it.

Once a complete slice of rock has been mined, the beam is moved back to its original position, after mined material has been removed, as will be described hereinafter, and the two booms 25 are lowered through a few degrees, and the operation is completed, there being several such passes to mine material to a depth of several feet.

The mined material is collected largely in traditional manner, and for this purpose, each boom 25 has an apron 37 of known construction associated with it, each of which is provided with traditional gathering wheels or arms 39 for sweeping mined material onto a central conveyor 41, which conveys the material rearwardly. The apron is supported from the beam 23 by extendable struts 43. The conveyor41 preferably has a horizontal hinge (not shown) at its forward end, where it is supported on its apron 37, so that its rear end can be raised and lowered hydraulically, and a vertical hinge midway along its length, so that its rear end can be swung from side to side, and a swinging tail extension 45 is also provided, so that mined material can be loaded into a bucket 47.

Normally, the depth of one cut over an arc 35 is sufficient just to fill a bucket 47, which must then be raised to the surface in traditional manner, so that another can be located in place for the next cut (after rotation ofthe beam 23 through an increment).

Obviously, the buckets could be raised to a platform in the shaft, for subsequent passage to the surface.

Furthermore, it is envisaged that mined material could be moved from the bottom of the shaft in other ways, e.g. pneumatically. Obviously, however, when buckets are used, care has to be taken not to foul their support wires when the beams and booms are swung from one position to another.

The two gathering aprons 37 are designed to be advanced into a pile of mined material and normally therefore a mining operation would be started as follows. The initial cut of the two cutting heads would be at a depth of about 12" and this material would be cut from the floor of the proposed shaft over the two arcs 35 of the booms. The beam 23 would then be advanced say through 10 or 20 and a subsequent arc of material would be mined by each cutting head to a slightly greater depth, say 15", than the previous arc. In advancing the beam 23 so the aprons 37 would be advanced into the mined material.During each increment of the beam 23, so the booms are lowered a little so that the cutting heads 27 gradually cut deeper into the shaft so that eventually two semi-circular ramps are formed in the bottom of the shaft, the lower ends of which are, for example, 3ft. lower than the upper ends. As the booms are lowered and advanced, so the aprons 37 will also have to be lowered. Obviously, there will be a step at the upper end of each ramp where it joins the lower end of the other ramp.

Normally, after the beam 23 has been rotated through 180"to form the two semi-circular ramps, it will be moved back through those 1809 whereupon the booms (and aprons) would be lowered to the bottom of the steps so that in the next sweeping movement of the beam 23 material could be mined from the bottom of the shaft to the total depth of the ramps. The maximum depth to which the booms can be swung would be approximately 12ft.-15ft. and it will thus be appreciated that after three or four sweeps of the beam 23, the booms will be operating at their maximum depth.

As an alternative, it is envisaged that instead of swinging the beam 23 back through 180" after every 1800 mining sweep, the beam could be further advanced so that after 180"the cutting heads would be mining material from the rear end of the ramp formed by the other cutting head. After about two complete revolutions ofthe beam 23, during which time the booms and aprons would slowly be lowered, the depth of the shaft would have been increased by about 1 2ft., i.e. to the maximum.

It will thus be appreciated that the two cutter heads thus effectively spiral their way down into the bottom oftheshaftratherafterthefashion of a two start auger bit.

Of course, when the shaft is mined by rotating the beam continuously by as much as at least 720', any power supply lines extending between the frame 9 and the beam 23 will have become twisted. To untwist these lines the beam must either be turned back through the amount by which it has been rotated, or, alternatively, the power lines must be disconnected, untwisted and re-connected.

Once a complete circle of material has been mined from the bottom of the shaft, to the maximum possible depth, i.e. the booms are pivoted to their lowest position (and of course, the legs 11 will then be at full extension), the whole apparatus must be lowered further into the shaft. It can of course be let down simply by shortening the legs 11 but before this, the arms 13 must be disengaged from the sockets in the rings 5,7 and the safety ropes must be lowered.

Once the frame 9 is located at its new level, the ring 7 can be contracted, and can then be jacked down (using the ring 5 as a reaction member) and expanded back into engagement with the shaft wall.

The arms 13 can then be re-located in their sockets.

Alternatively, the frame 9 and associated equipment," can be let down together, after contracting the ring.

Subsequently, the ring 5 can be lowered in a similar manner.

It will be appreciated that the apparatus is preferably operated hydraulically, and that many, if not all, the operations can be controlled at least largely automatically.

Claims (1)

1. Shaft sinking apparatus comprising a support frame, means to support the frame adjacent the bottom of the shaft being sunk, a slewing ring supported on the frame, a swivelling cross beam suspended from the slewing part of the slewing ring, and at least one cutting device supported on the cross beam.

2. Shaft sinking apparatus according to claim 1 wherein two cutting devices are provided on the cross beam, equally spaced from the centre of the beam, which centre coincides with the rotational axis of the slewing ring, the cutting devices facing in opposite directions so that each will lead the beam when it is rotated in a cutting direction.

3. Shaft sinking apparatus according to claim 1 or 2 wherein the or each cutting device is mounted on a cutting boom.

4. Shaft sinking apparatus according to claim 3 wherein the or each cutting boom is supported on the beam for rotation about a vertical axis through at least about 200 and is capable of pivoting from a generally horizontal orientation to around 50 below the horizontal so as to be able to mine material beneath the beam.

5. Shaft sinking apparatus according to claim 3 or 4 wherein the or each cutting boom is associated with an apron and gathering means, and a central conveyor so as automatically to collect material cut by the cutting device on the end of each boom, and to deliver it rearwardly, where it can be loaded into buckets for lifting to the surface.

6. Shaft sinking apparatus according to any one of the preceding claims wherein the support means for the frame comprises a plurality of hydraulically extendable legs which rest on the floor of the shaft.

7. Shaft sinking apparatus according to any one of the preceding claims wherein the frame is supported around its periphery.

8. Shaft sinking apparatus according to claim 7 wherein the frame is supported by means of extendable arms engaging in sockets in a two-part extendable and expandable anchor ring used to line the lower part of the shaft.

9. Shaft sinking apparatus according to claim 7 or 8 wherein safety supporting ropes extend upwardly from the frame to the surface, e.g. a Capstan engine.

10. Shaft sinking apparatus substantially as hereinbefore described with reference to the accompanying drawings.

New claims or amendments to claims filed on 2nd October 1981.

Superseded claims 1 and 3.

New or amended claims: Original claims 4 to 10 renumbered as 3 to 9 respectively and appendancies corrected.

1. Shaft sinking apparatus comprising a support frame, means to support the frame adjacent the bottom of the shaft being sunk, a slewing ring supported on the frame, a swivelling cross beam suspended from the slewing part of the slewing ring, and two boom mounted cutting devices supported on the cross beam.