GB2079624A - Mineral or rock breaking equipment - Google Patents

Abstract

Mineral breaking equipment for installation within the length of a flight chain conveyor, for instance a stage loader in a coal mining operation comprises a first conveyor pan (7) for leading the conveyor chain (5) to a raised horizontally mounted reaction roller (10). A slideably mounted driven breaker roller (18) is located downstream of the reaction roller (10) and spaced therefrom at such a distance that in use mineral above a preselected size is broken between the rollers (10, 18). The broken mineral is fed onto a second conveyor pan (11) from which it is removed by the conveyor chain (5). Preferably the second conveyor pan (11) is coplanar with the conveyor (1a) and an idler roller (14) is located lower than and upstream of the reaction roller (10) in order to guide the chain (5) onto the second conveyor pan (11). <IMAGE>

Description

SPECIFICATION Mineral or rock breaking equipment This invention relates to mineral or rock breaking equipment, and in particular, but not exclusively, to equipment for breaking coal on a stage loader conveyor.

In many mining operations, particularly coal mining operations, the mineral won immediately from a seam may comprise large pieces which will give rise to handling problems in the outbye transportation system. To prevent such problems, it has been proposed to mount mineral breaking equipment within the length of an armoured conveyor to reduce 'the size of the large pieces.

Presently proposed mineral breaking equipment comprises either a pair of opposed driven breaker rollers mounted on vertical axes above the conveyor, or a single driven breaker roller mounted on a horizontal axis above the pan of the conveyor. In the former case the large pieces are broken in the nip of the rollers, and in the latter case the large pieces are broken between the roller and the conveyor pan.

Such mineral breaking equipment is able to reduce in size most of the large pieces of mineral. However, long thin pieces of mineral which are able to lie flat on the conveyor are able to pass through the equipment without being broken, thereby given rise to problems in the outbye transportation system.

In our co-pending application No. 04729/79, we describe mineral or rock breaker equipment in which the path of the conveyor through the equipment is non-linear so that long thin pieces of mineral are forced to project above the plane of the conveyor and can therefore be broken.

However, even though this design is an improve ment over previously used equipment, it still presents some disadvantages, which are also shown by previously used equipment. If a horizontal breaker roller is used, the breaking action takes place between the roller and the conveyor pan. High forces can be generated during a breaking operation, and these forces can cause deformation of the conveyor pan.

Another problem, which is associated with both horizontally and vertically mounted breaker rollers, is that large or hard pieces of mineral are retarded by the rollers while they are being broken. Such pieces tend to become wedged in front of the flight bars of the conveyor, causing the flight bars to bend, and in extreme cases causing breakage of the conveyor chain.

It is an aim of the present invention to provide mineral breaking equipment which at least in part overcomes these disadvantages.

According to the present invention there is provided mineral or rock bearing equipment for fitting within the length of a flight chain conveyor, comprising a first conveyor pan for leading the conveyor chain to a raised horizontally mounted reaction roller, and a horizontally mounted driven breaker roller located downstream of the reaction roller and spaced therefrom at such a distance that in use mineral I nr rnek shnve S nreRelected size is broken between the rollers, the broken mineral or rock being fed onto a second conveyor pan from which it is removed by the conveyor chain.

Preferably, the second conveyor pan is co-planar with the conveyor and a chain guide is mounted between the reaction roller and the second conveyor pan to lead the conveyor chain onto the second conveyor pan. Conveniently, the chain guide ensures that the chain leaves the reaction roller either vertically downwardly or in a direction againstthe direction of travel of the conveyor. In this way it is ensured that the mineral or rock falls off the reaction roller directly onto the second conveyor pan. The mineral or rock is thus quickly cleared from the mineral or rock, breaking equipment. The chain guide may comprise a slipper guide, but is preferably an idler roller mounted upstream of and lower than the reaction roller.

The breaker roller may comprise either a barred roller or a series of picks mounted on a central shaft, and is preferably mounted with its axis of rotation above that of the reaction roller. Advantageously, the breaker roller is rotated in a direction tending to urge the broken mineral or rock between the breaker roller and the reaction roller.

Conveniently, the reaction roller is an idler roller, and preferably has on it a series of radially extending teeth which, in use, project beyond the conveyor flight bars, thus preventing mineral or rock becoming jammed between the flight bars and the breaker roller. The spacing of the teeth should be arranged such that the flight bars are able to fit therebetween.

Conveniently the teeth comprise bars extending axially substantially along the whole length of the reaction roller.

Preferably, the breaker roller is movably mounted so that the gap between it and the reaction roller is variable. This is of advantage where it is desired to tailor the mineral or rock for different outbye transportation systems. Conveniently the breaker roller and its drive mechanism are mounted on a base which is slidable relative to the reaction roller mounting. Sliding of the base may be achieved for instance by hydraulic or pneumatic rams, or mechanical means such as screw threads.

It is envisaged that the present equipment will find especial use in the coal mining industry where it will advantageously be fitted within the length of a stage loader conveyor. However the equipment will also be useful in other mining and mineral handling industries.

The present invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 shows a sectional side view of mineral or rock breaking equipment according to the present invention fitted within the length of a stage loader; Figure 2 is a plan view of Figure 1; and Figure 3 is a view along line A-A of Figure 2.

Referring now to the drawings, there is shown a stage loader having fitted within its length mineral or rock breaking equipment according to the invention.

The stage loader comprises a series of conveyor pans 1 defining a deck 2 and two pairs of chain quides 3 and 4 for guiding the conveyor chains 5 on their forward and return runs respectively. Flight bars 6 are attached to the chains 5 and are drawn across the deck 2 to convey mineral matter along the stage loader from right to left as shown in Figure 1.

The mineral or rock breaking equipment comprises a first conveyor pan 7 which has an inclined deck 8 and one pair of chain guides 9 for guiding the chains 5 up to a reaction roller 10 mounted above the general level of the stage loader deck 2. The lower end of the first pan 7 is engageable with the normal conveyor pans 1. The reaction roller 10 has on each of its ends a sprocket 15 for engaging with the chains 5.

Below the reaction roller 10 is a second conveyor pan 11 which is co-planar with the conveyor pans 1 and engageable at its end remote from the reaction roller 10 with a normal conveyor pan 1. The second pan 11 includes two pairs of chain guides 12 and 13 which, in use, align with the guides 3 and 4 respectively in the normal pans 1.

An idler roller 14 is mounted on the flat pan 11 beneath the upper end of the first pan 7 and below and upstream of the reaction roller 10. In use, the chains 5 are led through the guides 3a and 9, over the sprockets 15 of the reaction roller 10 around the idler roller 14 and into the guides 12 and 3b, 3c etc.

The chains 5 act on the idler roller 14to cause itto rotate.

The reaction roller 70 is provided between the sprockets 15 with axially extending bars 16 which project radially beyond the flight bars 6 on the chains 5.

A base 17 is slidably mounted on the stage loader and supports a breaker roller assembly 18 and its drive mechanism (in this case an N.C.B. specification gearbox, fluid coupling and an electric motor) 19.

The drive causes the roller assembly 18 to rotate clockwise as shown in Figure 1. The base 17 is slidable to and fro longitudinally of the stage loader by means of hydraulic rams 20. The breaker roller assembly 18 is mounted on the base 17 such that its axis is parallel to but above that of the reaction roller 10. The breaker rollerassembly 18 comprises a number of star wheels 23 mounted on a central shaft 22. The star wheels 23 include on their outer ends a series of picks 21.

In use mineral or rock is dragged along the conveyor deck 2a and up the inclined deck 8 by the flight bars 6. It is then conveyed over the reactionroller 10, which is caused to rotate by the chains 5 acting on the sprockets 15. If the mineral or rock is of a small enough size it will fall offthe reaction roller 10 onto the second pan 11 from which it will be conveyed by the flight bars 6 onto the deck 2b.

If the mineral or rock is too large it will be broken by the action of the picks 21 acting on the mineral or rock and reacting against the reaction roller 10. The mineral or rock will not be able to jam against the flight bars 6 because of the bars 16 and will not cause a blockage in the flow of mineral or rock. Once the mineral or rock has been broken it will fall onto the second pan 11 for further disposal.

The distance between the reaction roller 10 and breaker roller 18 may be varied by use of the rams 20 thereby enabling the size of the mineral or rock to be controlled.

The advantages of this arrangement are that there is no strain put on the conveyor pans due to the breaking action, the mineral or rock cannot jam the conveyor flights, and the mineral or rock is forced to project above the plane of the conveyor. It is this ensured that ail large pieces are broken in an efficient manner without damaging the conveyor itself.

Claims (15)

1. Mineral or rock breaking equipment for fitting within the length of a flight chain conveyor, comprising a first conveyor pan for leading the conveyor chain to a raised horizontally mounted reaction roller, and a horizontally mounted driven breaker roller located downstream of the reaction roller and spaced therefrom at such a distance that in use mineral or rock above a preselected size is broken between the rollers, the broken mineral or rock being fed onto a second conveyor pan from which it is removed by the conveyor chain.

2. Equipment according to chain 1, wherein the second conveyor pan is co-planar with the flight chain conveyor.

3. Equipment according to claim 2, and including a chain guide mounted between the reaction roller and the second conveyor pan to lead the conveyor chain onto the second conveyor pan.

4. Equipment according to claim 3, wherein the chain guide ensures that the chain leaves the reaction roller either vertically downwardly or in a direction against the direction of travel of the conveyor.

5. Equipment according to either of claims 3 and 4, in which the chain guide is a slipper guide.

6. Equipment according to either of claims 3 and 4, in which the chain guide comprises an idler roller mounted upstream of and lower than the reaction roller.

7. Equipment according to any one of the preceding claims, in which the breaker roller comprises a series of picks mounted on a central shaft.

8. Equipment according to any one of the preceding claims, in which the breaker roller is mounted with its axis of rotation is above that of the reaction roller.

9. Equipment according to any one of the preceding claims, in which the breaker roller is rotated in a direction tending to urge the broken mineral or rock between the breaker roller and the reaction roller.

10. Equipment according to any one of the preceding claims, in which the reaction roller is an idler roller.

11. Equipment according to any one of the preceding claims, in which the reaction roller has on it a series of radially extending teeth which, in use, project beyond the conveyor flight bars.

12. Equipment according to any one of the preceding claims, in which the breaker roller is movably mounted so that the gap between it and the reaction roller is variable.

13. Equipment according to claim 12, in which the breaker roller is mounted on a base which is slidable relative to the reaction roller mounting.

14. Mineral or rock breaking equipmentforfitting within the length of a flight chain conveyor, substantially as hereinbefore described with refer ence to the accompanying drawings.

15. A mineral mining installation comprising a flight chain conveyor having disposed within its length mineral or rock breaking equipment accord jng to any one of the preceding claims.