GB2104129A - Improvements in mining equipment - Google Patents

Abstract

A face conveyor (2) is spaced from a mineral face (29) by a stop member (1) which serves to maintain the face conveyor at an optimum distance from the face. The stop member may be a rotatable star wheel. <IMAGE>

Description

SPECIFICATION Improvements in mining equipment The present invention relates to mining equipment and more particularly relates to a device for use with armoured flexible conveyors.

In continuous mining operations the armoured face conveyor (AFC), which carries the power loader or power loaders, is 'snaked' forward in step with the advance of the face being mined, for example a coal face. Normally the AFC is pushed forwards by means of hydraulic rams which are connected to some part on the goaf side of the AFC, for example to ramming bars on the spill plates. Thus, as the power loader moves along the face and cuts a strip of the material being mined, the AFC is moved forward behind it. This advance will be a distance equal to the depth of the cut, which cut is generally made by a shearer drum, and is usually between 0.45 m and 0.70 m (18 to 28 ins) in coal mining. The powered supports are also advanced to support the newly exposed roof.

When this has happened along the full length of the face being worked, the whole cycle of operations is repeated as the power loader returns along the AFC and takes off another strip of material being mined.

Heretofore there has been no convenient means available to ensure that the AFC is at the distance from the face to be mined which is such that the cutting tool carried by the power loader is working at its peak of efficiency, i.e. the depth of cut is an optimum. Ordinarily the AFC is at a distance from the coal face which is greater than that distance required for peak efficiency. This is because if the hydraulic rams move the AFC too close to the face to be mined then it has to be moved back manually to a position where work can commence and accordingly the AFC is not moved as far as the optimum distance to remove the change of any need for any manual handling.

Thus the cutting tool which as aforementioned is normally a shearing drum mounted on the power loader, is not cutting at maximum efficiency.

According to one aspect of the invention there is provided a stop member for spacing a face conveyor from a mineral face comprising a star wheel. Preferably the star wheel is formed by symmetrical concave arcuate sections joined to symmetrical convex arcuate sections and advantageously has six arms.

According to another aspect of the invention there is provided a face cutting system comprising a face conveyor for use in cutting a mineral face, and a stop member, wherein the face conveyor can be maintained at an optimum distance from the face by the interposition of at least one stop member between the conveyor and the face. Preferably the stop member is mounted on a ramp plate provided on the conveyor. It is desirable that the stop member is mounted on the ramp plate by an axle about which the stop member is rotatable.

The stop member is so mounted that when the hydraulic ram moves the section of AFC associated therewith towards the face to be worked, at least part of the stop member abuts the face when the AFC is at an optimum distance from the face, as regards cutting efficiency, and further advancement of the AFC section is thereby prohibited. If a star wheel is used as the stop member then it is preferred that two "arms" of the star abut the face when the optimum distance is achieved.

The present invention will now be further illustrated with reference to the accompanying drawings in which: Figure 1 is a plan view of a preferred stop member of the present invention; Figure 2 is a side view of the member shown in Figure 1; Figure 3 shows on a reduced scale the member of Figures 1 and 2 fixed in position on the ramp plate of an AFC; and Figure 4 is a schematic side view on a further reduced scale showing the general layout of an AFC having the member of Figures 1 and 2 mounted thereon in a mining operation.

Referring now to Figures 1 and 2, the stop member generally designated 1 is in the form of a star wheel having a hole 2 for receiving an axle upon which the star wheel 1 is to be rotatably mounted. The hole 2 has a raised rim 3. As may be seen clearly from Figure 1, the star wheel has six symmetrically spaced concave arcuate surfaces 4 which are joined in end-to-end fashion to form tips 5 which are themselves of convex arcuate shape. When the star wheel 1 abuts the face being worked two of the tips 5 engage said face when the aforementioned optimum distance is achieved.

Referring now to Figure 3, the stop member 1 is rotatably mounted on an axle 10 and is held in place thereon by means of the stud 11 which engages the rim 3 of the member 1. The axle 10 is itself mounted on an angle bar 12 which is attached to the ramp plate 1 3 by means of welds 1 4a and 1 4b. The ramp plate 13 is attached to part of the AFC 15 (the rest of the AFC not being shown), and has a slot (chain lines) 16 for receiving a part of the stop member 1 whereby rotation of the latter is permitted.

Referring now to Figure 4, the stop member 1 is rotatably mounted on an axle 10 which is attached to an angle bar 12 attached to the ramp plate 1 3. The ramp plate 1 3 is attached to the remainder of the AFC which is generally designated 20. A power loader 21 which carries the shearing drum or other cutting tool is mounted on the AFC 20, a part thereof 22 (which is part of the underframe 22a) being received in the AFC shoe 23. The power loader 21 is also slidably held in place on the AFC 20 by means of the trapping over guide 24. Attached to the goaf side of the AFC 20 is a spill plate 25 which carries a ramming bar 26 to which is attached a hydraulic ram 27.

The face to be worked is shown at 29 and the ceiling formed 30 is held up by supporting members 31 which are themselves supported by a hydraulic support 32.

In Figure 4, the AFC 20 is at the optimum distance from the face 29 for peak efficiency of the cutting tool to be achieved. As the power loader 21 and its associated cutting tool move across the face 29 to be cut, the face 29 and the material M therebehind will be removed to a distance equal to the cutting depth of the cutting tool.

Normally, as the cutting tool passes by the stop member 1 there will be no contact therebetween but should there by chance be contact, the ability of the member 1 to rotate removes the possibility of damage thereto. After the power loader 21 and its associated cutting tool have passed by, the AFC 20 has to be moved in the direction of arrow A to the new face which has been formed in order that cutting may occur when the power loader 21 returns on its next cycle. This is performed by activating the ram 27 whereby the whole apparatus on the face side thereof is moved in the direction of arrow A. Movement is continued until the face side of stop member 1 abuts the fresh face whereby the position shown in Figure 4 is again achieved. As aforementioned, when this position is achieved the stop member 1 spaces the AFC 20 at such a distance from the face 29 that maximum efficiency of the cutting tool will be appreciated.

It will be understood that even only an additional depth of cut of say 25 mm (1") which can be achieved by using the present invention will represent an extremely large amount of material over the length of the face being mined thereby leading to a much greater amount of material being gained per unit time from the face.

This is particuiarly so in coal mining where seams are comparatively large as opposed to other types of mining.

Claims (11)

Claims

1. A stop member for spacing a face conveyor from a mineral face comprising a star wheel.

2. A stop member according to Claim 1 in which the star wheel is formed by symmetrical concave arctuate sections joined to symmetrical convex arctuate sections.

3. A stop member according to Claims 1 or 2 in which the starwheel has six arms.

4. A stop member according to Claim 3, in which two arms of the starwheel abut the mineral face.

5. A stop member according to any of the preceding claims which is made from a material which will not spark when struck.

6. A face cutting system comprising a face conveyor, for use in cutting a mineral face, and a stop member, wherein the face conveyor can be maintained at an optimum distance from the face by the interposition of at least one stop member between the conveyor and the face.

7. A face cutting system according to Claim 6 in which the stop member is mounted on a ramp plate provided on the conveyor.

8. A face cutting system according to Claim 7 in which the stop member is mounted on the ramp plate by an axle.

9. A face cutting system according to Claim 8 in which the stop member is rotatable about the axis of the axle.

10. A stop member substantially as herein described with reference to and as shown in the accompanying drawings.

11. A face cutting system substantially as herein described with reference to and as shown in the accompanying drawings.