Mining lacing pattern

Abstract

A continuous miner drum (10) comprises a cylindrical body (11) having an outer cylindrical surface (12). Extending from the surface (12) are “start” vanes (13), with each vane extending angularly and longitudinally with respect to the longitudinal axis (15) of the drum. Positioned on each vane is a plurality of picks (16), each pick having a leading face, a trailing face and side faces between which the leading and trailing faces extend. Upon rotation of the drum each pick follows a cutting path with picks of adjacent paths being spaced by a longitudinal distance of between 30 mm and 100 mm measured between adjacent side faces of the picks of adjacent cutting paths.

Description

TECHNICAL FIELD

The present invention relates to the lacing pattern of picks on miner drums and more particularly but not exclusively to the lacing patterns on continuous miner drums.

BACKGROUND OF THE INVENTION

Continuous miners are used to mine coal. However, they are also used in earth layers containing hard rock.

A continuous miner drum includes a generally cylindrical body (web) from which there extends start vanes. Each vane has attached to it a plurality of picks. The picks can be of a point configuration or alternatively a chisel configuration. For example, disclosed in International Application PCT/AU01/00960 (International Publication WO 02/12677 A2) is the drum of a continuous miner, with the picks thereof having a “chisel” configuration. That is, they have a leading face and a trailing face that converge to a cutting edge.

The arrangement of the picks on the vanes is called a lacing pattern. When the drum is rotated each pick follows a cutting line.

Previously known lacing patterns have a number of disadvantages including not minimising wear of the picks and not minimising dust production.

OBJECT OF THE INVENTION

It is the object of the present invention to overcome or substantially ameliorate at least one of the above disadvantages.

SUMMARY OF THE INVENTION

There is disclosed herein a continuous miner drum including:

a generally cylindrical body having a longitudinal axis about which the drum rotates in a predetermined direction;

a plurality of start vanes fixed to the body so as to extend outwardly therefrom away from said axis, each vane also extending longitudinally and angularly with respect to said axis;

a plurality of picks fixed to each vane so as to be stationary with respect thereto, each pick having a leading face, a trailing face and side faces between which the leading and trailing faces extend, the leading and trailing faces converge away from said axis to a cutting edge, and wherein upon rotation of the drum each pick follows a cutting path with picks of adjacent paths being spaced by a longitudinal distance of between 30 mm and 100 mm measured between adjacent side faces of the picks of adjacent cutting paths.

In a first preferred form, the continuous miner drum is configured to mine coal, with the picks having a spacing of 50 mm to 90 mm.

In a further preferred form, each pick has a cutting edge of a length of about 30 mm.

In a further preferred form, there is only one pick per cutting line.

In a further preferred form, there is at least two picks per cutting line.

In a still further preferred form, the vanes extend angularly about said axis at an angle between 10° and 30°.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings wherein:

FIG. 1 is a schematic perspective view of the drum of a continuous miner;

FIG. 2 is a schematic front elevation of a pick employed in the drum of FIG. 1;

FIG. 3 is a schematic side elevation of the pick of FIG. 2;

FIG. 4 is a schematic illustration showing a pick lacing pattern to be employed with the drum of FIG. 1; and

FIG. 5 is a schematic illustration of an alternative pick lacing pattern.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1 of the accompanying drawings there is schematically depicted a continuous miner drum 10. The drum 10 includes a generally cylindrical body (web) 11 having an outer cylindrical surface 12. Extending from the surface 12 are “start” vanes 13 and an end (clearance) vane 14. Each vane 13 extends both angularly and longitudinally with respect to the longitudinal axis 15 of the drum 10. Still further each vane 13 extends radially outwardly from the surface 12 with respect the axis 15.

Positioned on each vane 13 is a plurality of picks 16 at an angle of attack of between 40° and 55°. The picks 16 are fixed with respect to their respective vane 13 and extend outwardly there from relative to the axis 15. The clearance ring also has picks 16 which also extend outwardly relative to the axis 15.

For example if the drum 10 was adapted to mine coal, the drum 10 would be rotated about the axis 15 and moved into the coal seam. The picks 16 engage the coal and remove it from the seam from where the material is delivered to conveying apparatus. Each pick 16 upon rotation of the drum 10 moves along a cutting path.

It should be appreciated that the drum 10 depicted in FIG. 1 is also illustrated in the previously mentioned International Patent Application.

Each pick 16 includes a shank 17 via which the pick 16 is attached to its associated vane 13. The outer extremity of the shank 17 is provided with a cutting head 18 that includes a leading face 19 and a trailing face 20. The faces 19 and 20 converge away from the axis 15 to a cutting edge 21. The faces 19 and 20 extend between side faces 22.

The extremity 23 of the shank 17 is received within a sleeve and a holder fixed to irrespective vane 13.

The picks 16 are arranged in a lacing pattern. Two lacing patterns are shown in FIGS. 4 and 5.

The lacing pattern of FIG. 4 would be a lacing pattern employed in a drum 10 adapted to mine coal. The lacing pattern of FIG. 5 would be used on a drum 10 to mine in hard rock conditions.

The lacing pattern illustrated in FIG. 4 is the developed cylindrical surface 12 of a continuous miner drum. The drum would rotate about its longitudinal axis in the direction of the arrow 24. This particular drum would have end vanes (clearance) 25 and 26 with picks 16 arranged along to start vanes 13. The drum would also have a left hand web section 27, a central web section 28 and a right hand web section 29. Each section 27, 28 and 29 would have a series of start vanes 30, each start vane 30 having a plurality of picks 16.

In respect of the left hand section 27, central section 28 and right hand section 29, the picks 16 have a lacing pattern such that the picks 16 have a predetermined spacing in the direction of the longitudinal axis 15. More particularly each pick 18 passes along a cutting path 31. Each pick 16 on a respective path 31 is spaced from the pick 16 of the next adjacent path 31 by a spacing “S”.

The spacing “S” is the distance between the adjacent side faces 22 of the picks 16 of adjacent cutting paths 31. In the embodiment of FIG. 4, the lacing pattern would be such that the spacing “S” is a distance of 50 mm to 90 mm. In this instance, the picks 16 would have a cutting edge of 21 of approximately 30 mm in length. Typically, the drum would have a rotational speed between 30 and 60 revolutions per minute. This would provide each pick 16 with approximately a tip speed between 1.76 and 3.52 metres per second.

The lacing pattern of FIG. 5 is intended for a drum that is to engage hard rock. In this embodiment, the spacing “S” is 40 mm to 50 mm. Each pick 16 would have a cutting edge 21 with a length of about 10 mm.

The sections 25 and 26 would have picks 16 passing along cutting lines 32.

Claims

1. A continuous miner drum including:

a generally cylindrical body having a longitudinal axis which the drum rotates in a predetermined direction;

a plurality of start vanes fixed to the body so as to extend outwardly therefrom away from said axis, each vane also extending longitudinally and angularly with respect to said axis;

a plurality of picks fixed to each vane so as to be stationary with respect thereto, each pick having a leading face, a trailing face and said faces between which the leading and trailing faces extend, the leading and trailing faces converge away from said axis to a cutting edge, and wherein upon rotation of the drum each pick follows a cutting path which picks of adjacent paths being spaced by a longitudinal distance of between 30 mm and 100 mm measured between adjacent side faces of the picks of adjacent cutting paths.

2. The continuous miner drum of claim 1, where in the drum is configured to mine coal, with the picks having a spacing of 50 mm to 90 mm.

3. The continuous miner drum of claims 1 or 2, wherein each pick has a cutting edge of a length of about 30 mm.

4. The continuous miner drum of claim 1, wherein there is only one pick per cutting line.

5. The continuous miner drum of claim 1 wherein there is at least two picks per cutting line.

6. The continuous miner drum of claim 1, wherein the vanes extend angularly about said axis at an angle between 10° and 30°.

7. (canceled)