GB2077325A - Mining unit - Google Patents
Mining unit Download PDFInfo
- Publication number
- GB2077325A GB2077325A GB8115822A GB8115822A GB2077325A GB 2077325 A GB2077325 A GB 2077325A GB 8115822 A GB8115822 A GB 8115822A GB 8115822 A GB8115822 A GB 8115822A GB 2077325 A GB2077325 A GB 2077325A
- Authority
- GB
- United Kingdom
- Prior art keywords
- hub
- mining unit
- mining
- frontal
- unit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000005065 mining Methods 0.000 title claims abstract description 48
- 239000003245 coal Substances 0.000 claims abstract description 34
- 230000010006 flight Effects 0.000 claims description 43
- 230000005540 biological transmission Effects 0.000 claims description 3
- 230000033001 locomotion Effects 0.000 description 7
- 230000003292 diminished effect Effects 0.000 description 1
- 239000012634 fragment Substances 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000003313 weakening effect Effects 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21C—MINING OR QUARRYING
- E21C25/00—Cutting machines, i.e. for making slits approximately parallel or perpendicular to the seam
- E21C25/06—Machines slitting solely by one or more cutting rods or cutting drums which rotate, move through the seam, and may or may not reciprocate
- E21C25/10—Rods; Drums
Landscapes
- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Mechanical Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Drilling And Exploitation, And Mining Machines And Methods (AREA)
- Crushing And Pulverization Processes (AREA)
Abstract
The mining unit for coal mining combines, according to the invention, has a frontal disc which is cup-shaped and its longitudinal section consists of a flat ring (13) on the periphery and an arcuate area (25) narrowing towards a hub (1) in the direction towards the rear edge of the unit. The disclosed invention can be applied especially for mining of a wet coal bed in coal mines. <IMAGE>
Description
SPECIFICATION
Mining unit
The present invention relates to a mining unit for a mining coal combine, comprising a hub for
mounting the unit on the transmission shaft of the cbmbine, on which there are at least two coaxially arranged screw flights whose outer edges
are provided with coal mining cutters, and having
a frontal disc with cutters fixed on its perimeter.
The mining unit known from the Polish Patent
No. 56,286 has screw flights arranged on a
cylindrical hub, said panels being armed with
mining cutters on its perimeter. Thus, the mining
unit has, in principle, the outline of a cylinder.
From the side facing the coal being mined it is
provided with a frontal disc having a circular
profile and provided with mining cutters on its
perimeter. in the frontal disc it has cut-outs
connecting the space in front of said disc with
spaces between the screw flights. Through the cut-outs the winning from in front of the frontal disc passes to spaces between the screw flights
and is transported by the flights along the axis of the mining unit towards the body of the combine wherein it is poured onto a longwall conveyor.
The mining unit known from the German Patent
Specification No. 1,349,873 is a worm-type unit.
It has a frontal plate in the form of a cone whose base is directed towards the body of coal. On the periphery of the conical base of the frontal plate
mining cutters are arranged. Screw flights which are also armed on their periphery with mining cutters, are spread along the whole hub of the unit only to the conical surface of the frontal plate.
Thus, the interior of the frontal plate, as seen from the front i.e. the nearer side of the body of coal and looking towards the combine, is hollow, and during mining it is filled with crushed coal.
The mining unit known from Polish Patent
Specification No. 93,244 has, iike the unit known from the cited German Patent Specification No.
1,349,873, a hub with screw flights on it.
Moreover, it has frontal panels arranged between screw flights. The frontal panels form a circular profile on the perimeter, whereas along the axis of the unit they form a conical surface directed with its base end (the larger diameter end) towards the body of coal. The peripheries of the frontal panel and screw flights are provided with mining cutters. The screw flights do not partition completely the section of the space between adjacent screw flights but they leave free a part of said section closer to the axis of rotation of the unit. This achieves communication between the interior of the cone formed of frontal panels and the spaces between the screw flights, and in this way the winning from the face of the unit arrives between the screw flights.The flights reach as far as the front of the unit, in other words they penetrate the conical frontal plate, which is conducive to transporting of the winning from the front of the unit to behind the conical plate and then towards the longwall conveyor.
The drawback of the mining unit according to
Polish Patent No. 56,285 resides in the high
frictional resistances of the mining unit against the
body of coal, which is caused by the flat frontal
plate. Besides, lumps of mined coal get in between
the body of coal and the frontal plate, which
increases frictional resistance by the operation of
crushing the coal lumps. Although the frontal plate
has holes or recesses through which the winning
passes to arrive between transporting flights of
the unit, the dimensions of these holes are too
small to remove the winning effectively from in
front of the frontal plate. Increasing the size of said
holes is impossible over their determined area,
since this would cause weakening of the structure
of the mining unit.
The mining unit according to the German
Patent No. 1,349,873 does not rub its frontal
plate against the body of coal, due to the conical form of said plate. However, during mining, the
interior of the cone is filled with lumps of coal,
which as a result of the rotary motion of the unit
and rubbing of the winning are crushed to small
pieces. This drawback is caused by a lack of holes
in the frontal conical plate, through which the winning could pass to arrive between the screw flights to be transported onto a longwall conveyor.
The above mentioned drawbacks are not
present in the mining unit known from Polish
Patent No. 93,244; nevertheless, its operation shows an imperfection resulting from a rather small space between flights, as said space is reduced in the front part of the unit by the conical frontal plate penetrating said space. In the region where the screw flights meet the surface of the
conical frontal plate a small space is formed
between a flight into which space two streams of
winning fall. One stream is that of the coal mined
by the cutters arranged on the outer edges of the flights; the other stream of the winning comes from the space from in front of the frontal plate through holes in said plate in between the flights.
This hinders the transport of coal towards the longwall conveyor and results in crushing the winning into excessively small lumps.
Transporting the coal away from these diminished spaces is performed so ineffecfively that after a certain time of operation of the unit, especially in wet coal, the winning is totally immobilized by clogging of said space. Efficiency of operation of the mining unit is subject to further and considerable change for the worse.
The object of the present invention is to avoid the drawbacks discussed in the presentation of the known solutions.
Accordingly, the present invention provides a mining unit for a coal mining combine, comprising a hub for mounting the unit on the transmission shaft of the combine, at least two co-axially arranged screw flights on the hub and provided on their outer edges with cutters, the hub including a frontal disc with cutters on its perimeter, wherein the frontal disc has a cup-shaped longitudinal section, and consists of a flat ring at the rim of the cup periphery and an arcuate region behind the rim narrowing towards the hub in the rearward direction along the mining unit.The cup-shape of the frontal disc is achieved due to the fact that the disc is made of panels attached between screw flights and bent backwards arcuately with the convexity directed to the axis of rotation of the unit, whereby particular panels of the frontal plate are attached to one of the screw panels only on its
part, so that from the side of the hub an opening is
left which connects the space between screw flights and the interior of the cup-shaped frontal disc.
The invention is shown by way of example with
reference to the accompanying drawings in which FIGURE 1 is the view of the unit from the side
of the frontal plate;
FIGURE 2 is a sectional view of the unit taken
on section line A-A in Figure 1;
FIGURE 3 is a perspective view of the unit seen
in the direction shown by the arrow W of Figure 1;
FIGURE 4 is a schematic illustration of a
longitudinal sectional view (i.e. taken on a
longitudinal plane passing through the axis of
rotation of the unit);
FIGURE 5 is a perspective view of a form of the unit having panels of the frontal plate which do not reach the hub;
FIGURE 6 is a longitudinal section through the
unit shown in Figure 5; and FIGURE 7 is a longitudinal section of a form of the unit having an inverted cup-shaped frontal plate.
The mining unit has a hub 1 directed with its front end 19 towards the body of coal 20 being
mined. On the hub 1 are helical flights 2 which are spread over the whole length of the hub 1. In one embodiment of the invention the unit has three
helical flights 2 whose front edges 1 5 reach the frant base 19 of the hub 1. The outer edges 21 of
helical flights 2 form a cylindrical profile of the unit
and are armed with cutters 22 fixed in holders 23 which are coupled to the flights 2 by means of, for
example, welds. The drawing shows only one
holder 23 and one cutter 22 on a helical flight 2
but there is in fact a bigger number of cutters 22
on each helical flight 2. The flights are directed in
accordance with the direction of working rotation
of the mining unit.
The frontal disc 3 is divided by the helical flights 2 into parts 3a situated between flights 2
so that the number of parts 3a of the frontal disc 3
corresponds to the number of flights 2. A part 3a
is formed of a fragment of a flat ring 1 3 which forms a circular edge 12. The holders 23 are
attached to the ring 13 and have the cutters 22
fixed thereto. Figures 1 and 2 show one of many
holders 23 and its cutter 22 on a flight 2. The
holders 23 are mounted so that particular cutters
22 are inclined in relation to one another, due to
which they cut out in the body of coal a groove wider than the width of the edge 12 (Figure 5). A
part 3a has an area 25 or 25a having a radius of
curvature R and directed with the convexity
inwards towards the hub 1 of the unit.The ring 1 3
and area 25, 25a form an integral whole, and the ring 13 is tangent to the area 25 or 25a. The part 3a is fixed to the slight 2 along its whole inner edge 11 (Figure 3) on the side of the flight 2, which is opposite to the direction of rotation of the unit. To the neighbouring flight 2 the part 3a is fixed on the side of the flight 2 turned in the direction of rotation of the unit. The part 3a is connected to the flight 2 along the edge 6 only in the upper part in the region of the ring 13 and in a part of the area 25 or 25a because a part of the area 25 or 25a is cut away to leave an opening 10 which is limited by an edge 9 passing in the space 8 between flights 2. Through openings 10 mined coal from the interior of the frontal disc 3 gets into the space 8 between flights 2. Parts 3a of the frontal disc 3 are limited by an edge 5 from the side of the combine.The edge 5 meets the hub 1 when the area 25a is provided or is situated above the hub 1, if the part 3a has the area 25. The latter solution is applied in working units having larger outer diameters. The mining unit can be complete with scrapers 4 situated inside the frontal disc 3 and connected with the hub 1 along the edge 16, with the part 3a along the edge 17, and with the flight 2 along the edge 1 5. The scrapers 4 are situated so that they do not cover up openings 10 and are inclined towards the openings 10 so that from the side of flights 2 they are fixed in the region of the edge 1 5. In mining units designed for especially brittle coals, the parts 3A are bent with a radius R and turned with the convexity in the direction of the axis of rotation of the unit. In this embodiment the hub 1 reaches only the edge 5 of the part 3a, as shown in Figure 7.Due to this an enlarged space for crushed winning is formed at the front of the mining unit.
The mining unit is set in rotary motion, and at the same time it advances along the heading together with the combine. In arm-type combines the mining unit can perform movements transverse in relation to the floor; however, these transverse movements are not, in principle, working movements but only movements serving for setting the unit at an appropriate height depending on the height of the coal bed. The rotary and translatory motions of the working unit cause the cutters 22 t6 cut into the body of coal 20 and to break off the coal therefrom. Coal mined by those cutters 22 situated on edges 21 of the flights 2 falls down to the space 8 and is transported away therefrom in the direction of a longwall conveyor due to the helical arrangement of the flights 2.
Coal mined by the cutters 22 arranged on the edge 12 of the frontal plate 3 also falls into the space 8, such that the direction of falling is that of the coal mined by cutters 22 deflected towards the spaces 8. On the other hand, the coal mined by those cutters 22 fixed on the edge 12, but deflected towards the body of coal 20, falls into the space between the body of coal 20 and the frontal disc 3. In this space the winning is displaced by scrapers 4 towards the openings 10 through which it gets to the space 8 between flights 2 and is transported onto a longwall conveyor.
Claims (8)
1. A mining unit for coal mining combine, comprising a hub for mounting the unit on the transmission shaft of the combine, at least two coaxially arranged screw flights on the hub and provided on their outer edges with cutters, the hub including a frontal disc with cutters on its perimeter, wherein the frontal disc has a cupshaped longitudinal section, and consists of a flat ring at the rim of the cup periphery and an arcuate region behind the rim narrowing towards the hub in the rearward direction along the mining unit.
2. A mining unit according to claim 1, wherein the frontal disc consists of a number of parts equal to the number of screw flights whereby one such part partially covers a space between two
adjacent flights and partially forms an opening
connecting the region behind the frontal disc with
the said space between the screw flights.
3. A mining unit according to claim 2, wherein
the said parts of the frontal disc are fixed to the
screw flights along side edges, and from their side nearer the rear edge of the mining unit they leave a free space above the hub along a skew edge.
4. A mining unit according to claim 2, wherein said parts of the frontal disc have side edges fixed to the screw flights and another edge fixed to the hub.
5. A mining unit according to claim 3 or 4, including scrapers extending from the front of the mining unit, which are fixed between an associated hub and screw flight and to the associated said part of the frontal disc.
6. A mining unit according to claim 2 or 3, wherein the arcuate area of the said part of the frontal disc has its concave side facing radially inwardly towards the hub, and is connected to the hub along an edge of the said part.
7. A mining unit according to any one of the preceding claims wherein the said arcuate region of the longitudinal cross-section of the frontal disc has a constant radius of curvature.
8. A mining unit constructed and adapted to operate substantially as hereinbefore described with reference to, and as illustrated in, Figures 1 to 4, or Figures 5 and 6, or Figure 7 of the accompanying drawings.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
PL22475180A PL128042B1 (en) | 1980-06-04 | 1980-06-04 | Mining head |
Publications (1)
Publication Number | Publication Date |
---|---|
GB2077325A true GB2077325A (en) | 1981-12-16 |
Family
ID=20003490
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB8115822A Withdrawn GB2077325A (en) | 1980-06-04 | 1981-05-22 | Mining unit |
Country Status (4)
Country | Link |
---|---|
AT (1) | ATA219081A (en) |
DE (1) | DE3121533A1 (en) |
GB (1) | GB2077325A (en) |
PL (1) | PL128042B1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2538850A1 (en) * | 1983-01-04 | 1984-07-06 | Krampe & Co | Rock cutting drum for coal mining machine |
-
1980
- 1980-06-04 PL PL22475180A patent/PL128042B1/en unknown
-
1981
- 1981-05-15 AT AT219081A patent/ATA219081A/en not_active IP Right Cessation
- 1981-05-22 GB GB8115822A patent/GB2077325A/en not_active Withdrawn
- 1981-05-29 DE DE19813121533 patent/DE3121533A1/en not_active Withdrawn
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2538850A1 (en) * | 1983-01-04 | 1984-07-06 | Krampe & Co | Rock cutting drum for coal mining machine |
Also Published As
Publication number | Publication date |
---|---|
PL224751A1 (en) | 1981-12-11 |
DE3121533A1 (en) | 1982-05-19 |
ATA219081A (en) | 1983-05-15 |
PL128042B1 (en) | 1983-12-31 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |