GB1564707A

GB1564707A - Mining machine

Info

Publication number: GB1564707A
Application number: GB5018475A
Authority: GB
Original assignee: Dosco Overseas Engineering Ltd
Current assignee: Dosco Overseas Engineering Ltd
Priority date: 1976-11-22
Filing date: 1976-11-22
Publication date: 1980-04-10

Description

(54) MINING MACHINE (71) We, DOSCO OVERSEAS EN GINEERING LIMITED, a Company organised under the laws of Great Britain, of Planar House, Walton Street, Aylesbury, Bucking- hamshire, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to mining machines.

Minerals such as coal occur naturally in seams which are relatively shallow, for example from one to two metres in depth. In order to allow men and machines to be brought to the working face of the seam, tunnels or roadways of a height greater than the thickness of the ssm are driven through the coal and the surrounding materiaL Coal is then removed from those parts of the seam immediately adjacent the roadway leaving a recess known as a 'pack hole" to one side of the roadway.

These pack holes are filled with unwanted material removed from the face of the roadway as the roadway is advanced, the coal from the face of the roadway being conveyed away from the working face together with that removed from the pack hole.

Pack holes are usually filled by a machine which is separate from the cutting machine used to work the face of the roadway. Both these machines and their associated power packs occupy considerable space and require separate supervision and can therefore be difficult to operate in the limited space which is available in a mine roadway. Moreover, the conveyor which is used to carry coal away from the working face normally extends across the front of the pack hole, and it can often be difficult to manoeuvre the packing machine over this conveyor in order to operate the machine within the pack hole.

Broadly in accordance with the present invention we provide a mining machine which may be advanced forwards towards a working face from which material it to be removed comprising a cutting tool for removing material from the working face, a laterally extendable packing ram which is arranged to direct material removed from the working face into a pack hole adjacent one side of the machine, and a conveyor for delivering material removed from the working face to the ram.

The ram may be mounted for extension to either one of the sides of the machine.

Preferably, the machine includes a platform projecting outwardly from one side of the machine and the ram is arranged to push material over the platform. When the machine is being used adjacent to a conveyor, the platform will extend from the machine to the mouth of the pack hole over the roadway conveyor, thereby preventing material from falling onto the roadway conveyor or on to the floor of the roadway.

The ram itself will generally comprise two or more, for example, four, telescopic sections.

Although the total length of the ram when extended may be selected to conform with any operating requirements, in general it will be sufficiently long to penetrate from four to twelve feet into a pack hole adjacent a roadway.

Any one of a number of mechanisms may be used to extend the ram. In one embodiment of the invention, the ram is extendable by a chain which may be unwound from a drum.

In order to permit extension of the ram, as the chain is unwound the links of the chain are constrained against deflection from a linear configuration by the compressive forces exerted by the drum. For example the individual links of the chain may be connected for relatively pivotal movement about parallel transverse axes and provided with stops which allow the relative pivotal movement of adjacent links out of a common plane in one one direction only. By extending the chain from the drum along a supporting surface, kinking of the chain as it unwinds from the drum is prevented.

Alternatively (or additionally), the chain may be fed from the drum into a conduit which retains the chain in a linear configuration.

In a further alternative construction, the ram is extendable by means of an hydraulically actuated piston cylinder assembly. Although it would be possible to use a double acting hydraulically actuated piston cylinder assembly for this purpose, where the cylinder includes more than one extendable section, the required hydraulic circuits would become undesirably complicated. In these cases it is preferred to use a single acting hydraulically actuated piston cylinder assembly, the ram being extended under hydraulic pressure and re tracted by hauling using, for example, a suitable flexible connection, such as a rope or chain, and a winch.

In order to enable the ram to direct material into a pack hole at different vertical levels, the ram is preferably mounted on the machine for pivotal movement about a horizontal axis, for example by 150 above and below a hori zontal plane. The ram may also be mounted for rotation about a vertical axis so that it can be used to direct material to either side of the pack hole.

Desirably, the ram is movable relative to the machine in the direction of movement of the machine so that the machine may be advanced whilst the ram continues to deliver material into the same pack hole. For example, the conveyor may be mounted on a main frame of the machine and the ram may be mounted for forward and rearward movement on the main frame. As the machine advances, the ram may be moved rearwardly along the main frame so that it continues to deposit material into the same pack hole. In this arrangement it may be necessary to provide for adjustment of the position at which the conveyor mechanism deposits material.

Alternatively, the ram may be mounted on the main frame of the machine and the cutting tool and conveyor may be mounted on a sub frame which is itself mounted for forward and rearward movement on the main frame.

Since the main frame of the machine normally comprises a tracked vehicle which is moved forward into a cutting position, the latter arrangement has the additional advantage of allowmg the tracked vehicle to remain station ary while the cutting tool is advanced on the sub-frame. This arrangement tends to reduce the risk of the vehicle becoming bogged down, as can happen when the drive of the main frame (i.e. the tracked drive) is used for force cutting against the working face.

Although the cutting tool may be of any conventional type, it preferably comprises a cutting head mounted on a boom for rotation about the axis of the boom. The boom itself is desirably mounted for pivotal movement about vertical and horizontal axis so that the cutting head can be used to tunnel out a road way as the machine advances.

The conveyor mechanism may also be con structed in any one of a number of forms. For example the mechanism may include gather ing arms for sweeping material in front of the machine to an endless conveyor which carried the mined material rearwardly of the machine to the ram. Normally, a gathering apron is provided in front of the machine for collecting mined material from the floor of the roadway, and the gathering arms are arranged to sweep the mined material to a central position on the apron.

In an alternative arrangement the conveyor mechanism carries the mined material trans versely across the front of the machine and subsequently rearwardly of the machine to the ram. This arrangement may make use of two endless conveyors, one of which directs the material transversely, the other of which directs the material rearwardly. Conveniently however this arrangement is achieved by providing a single endless conveyor which encircles the front part of the machine.

A preferred embodiment of a mining machine in accordance with the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which : - Figure 1 is a side elevation of the mining machine; Figure 2 is a front elevation of the machine partly broken away; Figure 3 is a plan of the machine; Figure 4 is a side view of a ram suitable for use in the machine of Figures 1 to 3; and Figure 5 is a perspective view of part of a suitable chain for use in the machine of Figures 1 to 3.

The mining machine illustrated in the drawings comprises a main frame 1 which may be advanced towards a working face 2 in a tunnel 3 by means of crawler tracks 4, 5.

A cutting tool 6 comprises a cutting head 7 mounted on a boom 8 for rotation about the axis of the boom 8. The boom is mounted in bearings 9 for pivotal movement about a horizontal axis, and the bearings are themselves mounted on a slewing ring 10 so that the boom may be rotated about a vertical axis relative to the main frame of the machine.

An extendable ram 12 is mounted on the main frame 1 of the machine immediately to the rear of the cutting tool. The extendable ram comprises four telescopic sections 12a, b, c and d, the innermost section, 12a, carrying a blade 13. The outermost section, 12d, is mounted transversely on the main frame of the machine so that the ram may be extended laterally relative to the machine frame between an extended position, illustrated in full lines in Figure 2 (and in broken lines in Figure 3), and a retracted position indicated in broken lines in Figure 2 (and in full lines in Figure 3).

The ram 12 is extendable by a chain 14 one end of which is secured to the inner end of the innermost section 12a of the ram and the other end of which is fixed to a winding drum 15 mounted on one end of the outermost section 12d of the ram. Adjacent links of the chain 14 are pivotably connected for movement about axes transverse to the length of the chain, but are pivotable from a coplanar configuration in one direction only. As a result the chain 14 may be wound on the drum 15 but, on unwinding from the drum 15 the chain 14 retains a linear configuration and transmits a thrust to the innermost section 12a of the ram 12.

Figure 5 illustrates a suitable form of chain linkage which is composed of links having two different constructions, alternate links having a similar construction. The link of the first construction, illustrated at 60, comprises two parallel plates 61, 62 connected together by pivot pins 63, 63. The ends of each plate 61, 62 are shaped to define stops 64, 65 each of which has a cylindrical bearing surface 66, 67. The links of the second construction also comprises two parallel plates 68, 69 pivotally mounted on the pivot pins 63 of the adjacent links, the ends of the plates 68, 69 being received between the plates 61, 62 of the adjacent links. Each plate 68, 69 carries a stop in the form of a cylindrical projection 70 which each engage with the bearing surfaces 66, 67 of an adjacent link when the links lie in a common plane, as illustrated in the drawing.In this position the links can pivot relative to each other only in the direction of the arrow A. Thus, provided that the chain is supported on a flat surface, such as illus trated at P, a compressive force applied along the chain in the direction of the arm B cannot bend the chain. The chain can however be wound onto a drum by causing the links to pivot relative to each other in the opposite direction to the arrow A.

The outermost section 12d of ram 12 is mounted in a slideway on the main frame 1 of the machine for forward and rearward movement relative to the main frame 1 by means of hydraulically actuated piston cylinder units. The ram 12 and winch 15 are mounted in bearings 28 on the slideway for pivotal movement about a horizontal axis by means of hydraulically actuated piston cylinder units.

A reuactable platform 16 is mounted on the main frame 1 immediately beneath the ram 12 and is movable from a retracted position, in which it overlies the main frame 1, to an extended position, in which it projects from the side of the machine beneath the ram 12 to form a surface over which the blade 13 of the ram sweeps when the ram 12 is extended.

The mining machine includes a gathering apron 18 which gathers material removed from the working face 2 of the machine as the machine advances and directs the material to a central position from which it is removed by a chain conveyor 19. The conveyor 19 directs the material rearwardly from the apron 18 and delivers it to a point immediately in front of the blade 13 of the ram 12 when the ram is retracted.

The movement of the conveyor 19, the ram 12, the platform 16, the cutting tool 6, and the crawler tracks 4, 5 are all powered from a power pack 30 which is controlled from an operating platform 31 above the ram 12.

The use of the machine in a coal mine is illustrated in Figure 3. The mine comprises a working face 2 which extends between two parallel roadways, one of which is illustrated at 3, the roadways being of greater height than the seam itself. Material removed from the part of the face between the roadways is delivered to a conveyor 21 alongside which the mining machine operates.

As the working face is advanced, the roofs of the roadways are shored by supports 22 which are erected at intervals of about one metre. The excavated area 23 adjacent each roadway is known as the packing area or pack hole, and is filled with the waste rock removed during the excavation of each roadway.

Thus, in the position illustrated in Figure 3, with the ram 12 retracted, the mining machine advances the working face of a particular roadway by about one metre. The waste rock removed from the face is gathered onto the gathering apron 18 as the machine advances and is delivered by the conveyor 19 to a point immediately in front of the blade 13 of the ram 12. The platform 16 is then extended over the conveyor 21 to the side of the roadway 3. The ram 12 is then extended to push the waste material over the platform 16 into the pack hole 23. This operation is repeated until all the waste material from the face of the roadway has been deposited in the pack hole.

The platform 16 is then withdrawn and the ram is used to direct coal from the working face onto the conveyor 21.

When all the waste material removed from the face of the roadway being worked has been cleared, the working face is excavated, and coal transferred onto the conveyor 21 by a further conveyor 25 which extends parallel to the working face. The sequence of operations is then repeated.

If insufficient waste material is excavated in one cycle of operation to fill the pack hole, the ram 12 may be moved rearwardly relative to the machine as the machine itself advances.

As a result, the ram 12 may be held in alignment with the same region of the packing area thereby enabling filling of the pack hole to be completed using material excavated during a subsequent cycle of operations.

During this packing process it may be desirable to direct successive batches of waste material into the pack hole at different levels, in which case the inclination of the ram 12 may be adjusted.

Figure 4 shows an alternative construction for the extendable ram 12. The ram comprises six cylindrical telescopic sections 41 to 46 the innermost of which, 41, carries a blade 48.

The ram may be extended from its collapsed condition to its expanded condition by means of a single-acting hydraulically actuated piston cylinder assembly having a cylinder 49, which comprises four telescopic sections 49a, b, c, and d. One end of the innermost section 49a of the cylinder 49 is secured to the innermost section 41 of the ram immediately below the blade 48.

A chain (not shown) is secured to the inner end 51 of the innermost section 41 of the ram and extends along the length of the ram, emerging from the outer end 52 of the outermost section 46 of the ram. The ram can therefore be extended by pressurising the cylinder 49 and may be retracted by hauling in the chain by means of a winch.

The embodiments of the invention described above with reference to the accompanying drawings provide a single machine which may be used not only to excavate roadways in mines but also to fill adjacent pack holes with the waste excavated material. The use of these single machines therefore reduces the amount of equipment and the number of personnel in the region of the working face of the roadway and speeds up the mining operation.

WHAT WE CLAIM IS:- 1. A mining machine which may be advanced forwards towards a working face from which material is to be removed, and comprises a cutting tool for removing material from the working face, a laterally extendable packing ram which can be arranged to direct material removed from the working face into a pack hole ajdacent one side of the machine, and a conveyor for delivering material removed from the working face to the ram.

2. A mining machine according to claim 1 further including a platform projecting outwardly from one side of the machine over which material is pushed by the ram.

3. A mining machine according to daim 1 or claim 2 wherein the ram is extendable by means of a chain which may be extended and retracted by a winding drum, the links of the chain being constrained against deflection from a linear configuration under compressive forces exerted thereon by the drum.

4. A mining machine according to claim 3 wherein the individual links of the chain are connected for pivotal movement about parallel transverse axis and including stops which allow relative pivotal movement of the links out of a common plane in one direction only.

5. A mining machine according to claim 3 or claim 4 wherein the chain is fed from the drum into a conduit which retains the chain in a linear configuration.

6. A mining machine according to claim 1 or claim 2 wherein the ram is extendable by an hydraulically actuated piston cylinder assembly.

7. A mining machine according to claim 6 wherein the piston cylinder assembly is singleacting, the ram being extended under hydraulic pressure and retracted by hauling.

8. A mining machine according to any one claims 1 to 7 wherein the ram is mounted on the machine for pivotal movement about a horizontal axis.

9. A mining machine according to any one of claims 1 to 8 wherein the ram is mounted on the machine for rotation about a vertical axis.

10. A mining machine according to any one of claims 1 to 9 wherein the ram comprises a plurality of telescopic sections.

11. A mining machine according to any one of claims 1 to 10 wherein the ram is movable relative to the machine in the direction of movement of the machine.

12. A mining machine acording to claim 11 wherein the conveyor and cutting tool are mounted on a main frame of the machine and the ram is mounted for forward and rearward movement on the main frame.

13. A mining machine according to claim 12 Wherein the ram is mounted on a main frame of the machine and the cutting tool and conveyor are mounted on a sub-frame which is itself mounted for forward and rearward movement on the main frame.

14. A mining machine according to any one of the preceding claims wherein the cutting tool is mounted on a boom and is rotatable about the axis of the boom.

15. A mining machine substantially as hereinbefore described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. six cylindrical telescopic sections 41 to 46 the innermost of which, 41, carries a blade 48. The ram may be extended from its collapsed condition to its expanded condition by means of a single-acting hydraulically actuated piston cylinder assembly having a cylinder 49, which comprises four telescopic sections 49a, b, c, and d. One end of the innermost section 49a of the cylinder 49 is secured to the innermost section 41 of the ram immediately below the blade 48. A chain (not shown) is secured to the inner end 51 of the innermost section 41 of the ram and extends along the length of the ram, emerging from the outer end 52 of the outermost section 46 of the ram. The ram can therefore be extended by pressurising the cylinder 49 and may be retracted by hauling in the chain by means of a winch. The embodiments of the invention described above with reference to the accompanying drawings provide a single machine which may be used not only to excavate roadways in mines but also to fill adjacent pack holes with the waste excavated material. The use of these single machines therefore reduces the amount of equipment and the number of personnel in the region of the working face of the roadway and speeds up the mining operation. WHAT WE CLAIM IS:-

1. A mining machine which may be advanced forwards towards a working face from which material is to be removed, and comprises a cutting tool for removing material from the working face, a laterally extendable packing ram which can be arranged to direct material removed from the working face into a pack hole ajdacent one side of the machine, and a conveyor for delivering material removed from the working face to the ram.