| 1. | A movable support device for use in supporting the roof of an underground tunnel or the like, said support device including: a lower portion adapted to rest on the floor of said tunnel; 5 an upper portion capable of abutting said roof of said tunnel; and connecting means between said lower portion and said upper portion adapted to position and retain said upper portion abutting said roof of said tunnel. |
| 2. | A device as defined in Claim 1 wherein said connecting means is a l o movable arm or similar,. |
| 3. | A device as defined in Claim 2 wherein said movable arm or similar is operated manually, electrically or hydraulically. |
| 4. | A device as defined in Claim 3 wherein said movable arm or similar is at least one hydraulic ram. |
| 5. | 5. A device as defined in Claim 4 wherein said movable arm or similar is a set of hydraulic rams,. |
| 6. | A device as defined in Claim 5 wherein said set of hydraulic rams is selected from two, three or four hydraulic rams. |
| 7. | A device as defined in Claim 1 which includes positioning means to assist said device to be placed and maintained at a required position within said tunnel. |
| 8. | A device as defined in Claim 7 wherein said positioning means is 5 affixed to at least one side of each said device, each said positioning means being independently adjustable to abut a side of said tunnel or the like,. |
| 9. | A device as defined in Claim 10 wherein said clearing means is a gradertype blade. |
| 10. | i 5. |
| 11. | A device as defined in Claim 1 wherein any trailing said device includes a shield to substantially prevent ingress into said device of any material that may fall from said roof. |
| 12. | A device as defined in Claim 9 wherein said coupling means couples a ft'rεt said device and a said second device together laterally. |
| 13. | : ' (). |
| 14. | A device as defined in Claim 13 wherein said coupling means includes a pivoting connector, said connector being adapted to allow staggered movement of said first device and said second device at least in a substantially longitudinal direction, . |
| 15. | A device as defined in Claim 1 which includes a rail means, said rail means adapted to enable a carting means to travel reversibly along 5 said rail means from the leading end to the trailing end of said device. |
| 16. | A device as defined in Claim 15 wherein said rail means ts positioned along one side of said device. |
| 17. | A device as defined in Claim 14 which includes a rail means, said rail means adapted to enable a carting means to travel reversibly along o said rail means from the leading end to the trailing end of said device. |
| 18. | A device as defined in Claim 17 wherein said rail means is positioned substantially between said first device and said second device coupled together laterally, said rail means being further adapted to be removably affixable to one end of said pivoting connector. |
| 19. | i .s. |
| 20. | A method of supporting the roof of an underground tunnel or the like, said method including the use of at least one of said device as defined in any one of Claims 1 to 18. |
| 21. | A method as defined in Claim 19 wherein two or more of said devices are connected only in tandem. |
| 22. | 021. A method as defined in Claim 19 which further includes a first line of at least one said device, and a second line of at least one said device, said second Ji ne being positioned substantially parallel to said first line. and wherein laterally adjacent said devices are connected together by a pivoting connector. |
| 23. | 22, A method a defined in Claim. |
| 24. | wherein each said first line and said second line Includes at least two of said devices connected in tandem, 5 23. |
| 25. | A method as defined in Claim 21 wherein said first line and said second line are advanced independently,. |
| 26. | A method as defined in Claim 22 wherein said first line and said. second line are advanced independently. |
| 27. | A method as defined in Claim 24 wherein said first line and said second l o line are alternatively advanced independently to positions whereby the respective spacings between adjacent devices connected in tandem in each of said first line and said second line are staggered. |
| 28. | A method as defined in any one of Claims 19 to 25 wherein said method is used in ^n underground mine. |
| 29. | S. |
| 30. | A method as defined in Claim 26 wherein each of said device is powered from a source common with other machinery used at a working face of said mine. |
| 31. | A method as defined in Claim 26 wherein each of said device is powered independently from other machinery used at a working face of 0 said mine. |
| 32. | A method of supporting the roof of an underground tunnel or the like, said method including a first line of at least one support device, and a second line of at least one support device, said second line being positioned substantially parallel to said first line, and wherein laterally adjacent said support devices are connected together by a connection means. |
| 33. | A method as defined in Claim 29 wherein each said first line and said second line includes at least two said support devices connected in tandem,. |
| 34. | A method as defined in Claim 29 wherein said connection means is adapted to allow staggered movement of each said device of said first line and said second line at least in a substantially longitudinal direction,. |
| 35. | A method as defined in Claim 30 wherein said first line and said second line are advanced independently. |
| 36. | A method as defined in Claim 32 wherein said first line and said second line are alternatively advanced independently to positions whereby the respective spacings between adjacent devices connected in tandem in each of said first line and said second line are staggered. |
THIS INVENTION relates to the mining industry. In particular, the present invention Is directed to an apparatus and methods for its use in underground mining operations and finds especial, but not limiting, use in the longwall s mining of coal.
In longwall mining, a cutting head moves back and forth across a panel of coal, the cut coal falling onto a flexible conveyor for removal. This form of mining is done under hydraulic roof supports that are advanced as the seam is cut. The roof in the area immediately above the cut coal is allowed to
10 collapse behind the line of supports as they advance forming the goaf, One side of the face of the coal wall Is provided with an intake tunnel and the other side is provided with an exhaust tunnel. Alternatively, the two tunnels can be positioned on the same side of thø coal face, The exhaust tunnel represents a second, emergency access for the workers underground and it is a
] 5 government legislative requirement that such a second egress be accessible at all times the mine is in active operation.
Under some mining conditions, the roof of the mine may fall and sides of the wali face which abut the intake and exhaust tunnels collapse hindering the intake and exhaust of air to and from the longwall face thus necessitating 20 ceasing of the mining operation until the problem is rectified. This downtime lowers coal mining efficiency. Of course, the partial blocking of the exhaust tunnel is of particular concern as it denies the workers underground access to an emergency exit.
In an attempt to overcome this problem, prior art methods include supporting ;>5 the roof of the exhaust tunnel with various frames of timber and/or steel.
However, such supports are passive, being fixed in any given position, and their construction limits ready access to and from the coal wall face. As the mines cut deeper underground, the collapsing of the tunnel walls becomes more frequent with greater debris to be removed thus necessitating even larger and more intrusive support frames. Access to the coal wall face is thus further restricted and the downtime for the mine as the debris is cleared from the collapsed tunnel roof increases.
Jt is a general object of the present invention to overcome, or at least ameliorate, one or more of the above disadvantages.
According to a first aspect of the present invention, there is provided a movable support device for use in supporting the roof of an underground tunnel or the like, said support device including:
a lower portion adapted to rest on the floor of said tunnel;
an upper portion capable of abutting said roof of said tunnel; and
connecting means between said lower portion and said upper portion adapted to position and retain said upper portion abutting said roof of said tunnel.
Preferably, said connecting means is a movable arm or similar.
Preferably, said movable arm or similar can be operated manually, electrically or hydraulically.
Preferably, said movable arm or similar is at least one hydraulic ram.
More preferably, said movable arm or similar is a set of hydraulic rams.
Preferably, said set of hydraulic rams is selected from two, three or four hydraulic rams.
Preferably, said support device includes positioning means which assist said device to be placed and maintained at a required position within said tunnel.
Preferably, said positioning means is affixed to at least one side of each said support device, each said positioning means being independently adjustable to abut a side of said tunnel or the like.
Preferably, said support device includes a coupling means adapted to be reversibly attachable to a second of said support device.
Preferably, any leading said support device further Includes a clearing means to clear any debris from said floor of said tunnel as said leading support device is moved along said tunnel.
Preferably, said clearing means is a grader-type blade.
Preferably, any trailing said support device further includes a shield to substantially prevent ingress into said support device of any material that may fall from said roof,
When there are two of said support device coupled together laterally, said coupling means includes a pivoting connector, said connector being adapted to allow staggered movement of each said support device at least in a substantially longitudinal direction.
Said support device may include a rail means, said rail means adapted to enable a carting means to travel reversibly along said rail means from the leading end to the trailing end of said support device.
In those embodiments wherein two of more of said support device are 5 connected only in tandem, said rail means is preferably positioned along one side of each said support device.
In those embodiments wherein two or more of said support devices are connected laterally, said rail means is preferably positioned substantially between laterally adjacent said support devices, said rail means being further io adapted to be removably affixable to one end of said pivoting connector.
As a second aspect of the present invention, there is provided a method of supporting the roof of an underground tunnel or the like, wherein said method includes the use of at least one of said supporting device as hereinbefore described.
i s In one embodiment of said method, two or more of said support devices are connected only in tandem.
In a second embodiment of said method, said method includes a first line of at least one said support device, and a second line of at least one said support device, said second line being positioned substantially parallel to said 0 first line, and wherein laterally adjacent said support devices are connected together by a said pivoting connector.
Preferably, in said second embodiment of said method, each said first line and said second line includes at least two of said support devices connected in tandem.
In those embodiments of said second embodiment of said method which include a first line and a second line each of at least two support devices, said first line and said second line are advanced independently.
In those embodiments of said second embodiment of said method which include a first line and a second line each of at least two support devices, said first line and said second line are alternatively advanced independently to positions whereby the respective spacings between adjacent support devices connected in tandem in each of said first line and said second line are staggered.
When said methods are used in an underground mine, preferably, each of said support device is powered from a source common with other machinery used at the working face of said mine, but is preferably adapted to move independently of that said other machinery,
Although the afore-mentioned methods which include a first line and second line of support devices have utilised the preferred support devices as hereinbefore described, it will be appreciated that the successful operation of this particular embodiment of the present invention is not limited to the use of such preferred supports.
Accordingly, as a third aspect of the present invention, there is provided a method of supporting the roof of an underground tunnel or the like, said method including a first line of at least one support device, and a second line
of at least one support device, said second line being positioned substantially parallel to said first line, and wherein laterally adjacent said support devices are connected together by a connection means,
In those embodiments of the third aspect of the present invention, preferably, each said first line and said second line includes at least two said support devices connected in tandem.
In those embodiments of the third aspect of the present invention, preferably, said connection means is adapted to allow staggered movement of each said device of said first line and said second line at least in a substantially longitudinal direction.
In those embodiments of the third aspect of the present invention, preferably, said first line and said second line are advanced independently.
In those embodiments of the third aspect of the present invention, preferably, said first line and said second line are alternatively advanced independently to positions whereby the respective spacings between adjacent devices connected in tandem in each of said first line and said second line are staggered.
Preferred embodiments of the present invention will now be described with reference to the following drawings wherein;
FIG, 1 is a schematic illustration of a longwall mine with a first set of devices of the present invention in use;
F ( G. 2a is a schematic illustration of a first device of the present invention depicted in FIG. 1 ;
FIG, 2b is a schematic illustration of one component of the first device Of FIG. 2a;
FIG, 2c is a schematic illustration of another component of the first device of FIG. 2a;
FIG. 3 is a schematic illustration of a second device of the present invention;
FIG. 4 is a schematic illustration of a longwall mine with a second set of devices of the present invention in use; and
FIG. 5 is a schematic top plan view of two spaced lines of a series of second device of FIG, 3.
Referrjng first to FIGS. 1 and 4, a typical longwall mine for coal includes the underground cutting face (1); a conveyor C to remove the cut coal from the face; a series of hydraulic roof supports (2) that are advanced as the coal (5) is cut at the face (1), the roof immediately above this cut coal collapsing behind the series of roof supports (2) forming the goaf (β); an intake tunnel (3); and an exhaust tunnel (4). Into the exhaust tunnel (4) of this typical longwall mine is a series of support devices S or S', each support device S and S f constructed in accordance with the present invention.
Referring now to FIGS. 2a-c, each support device S includes a substantially rectangular-shaped base (7) and a substantially rectangular-shaped upper
portion (8) connected, and of corresponding dimensions, to the base (7) by four hydraulic rams (9), On each opposite side of the base (7) is a bar (10a,b) of a length similar to the length of the base (7) and operated by a corresponding set of hydraulic rams (11a,b). Each bar (10a,b) can abut the respective side of the exhaust tunnel (4) independently thus enabling positioning of each support device S essentially centrally within the exhaust tunnel (4). The trailing end of a trailing support device S in a series of sυch support devices includes a shield (12) which is removably attached to the upper portion (8) by any convenient hook (13a,c) and eye (13b,d) connection (FIG. 2b). The trailing end of the base (7) includes a coupling means (14) to releasably secure a second of the support device thereto. The leading end of the base (7) includes a coupling (15) (FIG. 2c) to releasably secure the support device S to another leading such support device S. The leading end of the leading support device S in a series of such support devices includes a grader blade (16) (FIG. 2a) attached by any convenient means. Each undersurface of each upper portion (8) includes a longitudinal recess (17) which is adapted to secure a monorail system of the type known in the art to enable goods to easily pass by a series of support devices S when in use. The undersurface of the base (7) includes a hydraulically propulsion mechanism (not illustrated) of the type known in the art to enable each support device to be powered in any required direction.
In use, a series of support devices S can be coupled together and positioned within the exhaust tunnel (4) of a longwall coal mine (FIG. 1 ). As the coal face (1 ) advances, the support devices are moved further into the tunnel (4) maintaining support for the roof of the exhaust tunnel (4). The grader blade (16) of the leading support device clears a path for the series of support devices as they move forward. The side bars (10a,b) are hydraulically operated to maintain a position essentially abutting the side walls of the
exhaust tunnel (4). The shield (12) of the trailing support device assists in the prevention of debris falling into the support devices S and hindering their operation as the goaf forms, As the side bars (10a,b) maintain an essential constant distance between the support device S and the side wall of the exhaust tunnel (4), the operation of a monorail is maintained allowing easy access past the series of support devices should it be necessary for personnel to vacate the mine through the exhaust tunnel (4),
Referring now to FIGS, 3 to 5, the support device S 1 of FIG. 3A is essentially identical to that of the support device S of FIGS. 2a- c with the exception that (a) the bar (10a) and recess (17) are omitted; and (b) a connector (18) is pivotally connected at one end to the upper portion (8) and at the other end to a stabilisation rail (19). The pivot connections at the respective ends of the connector (18) can be any suitable connections known in th© art but are preferably of the type that may be easily and relatively rapidly disconnected and reconnected at their respective attachment points. The rail (19) is adapted to incorporate a monorail system (20) of the type known in the art to enable goods to easily pass by a series of support devices S 1 when in use.
In use (FIG, 4), a first line (21) of support devices S' are coupled together in tandem and affixed to one side of the rail (19) by their respective connector (18) (FIG. 4). Each bar (10b) is adjusted to abut the respective one side of the exhaust tunnel (4). A second line (22) of support devices S 1 are coupled together in tandem and affixed to the other side of the rail (19) by their respective connector (18) (FIG. 4). Each bar (10b) is adjusted to abut the respective other side of the exhaust tunnel (4). As the coal face (1 ) advances (FjG. 4), the assembled devices are moved, either simultaneously or, more usually, line by line, further into the tunnel (4) maintaining support for the roof of the exhaust tunnel (4). The grader blade (16) of the leading support device
clears a path for the series of support devices as they move forward. The side bars (10b) are hydrauϋcally operated to maintain a position essentially abutting the respective side walls of the exhaust tunnel (4). The shield (12) of the trailing support device assists in the prevention of debris falling into the support devices S' and hindering their operation as the goaf forms. The individual lines (21) and (22) of support devices are moved independently such that the longitudinal spacing between two adjacent devices in tandem in one line can be covered by the positioning of a device in the adjacent line (FIG.5). This staggering of laterally adjacent devices maximises the support available for the roof.
Although the embodiments described with particular reference to FIGS. 3 to 5 illustrate supports with four (4) hydraulic rams, it will be recognised by those skilled in the art that the individual supports In such a split system bear less weight, could function safely with a lessor number of rams (preferably two (2)) and can be fabricated from lighter materials leading to reduced manufacturing costs. Other advantages offered by various embodiments of the present invention include:
prevents collapse of mine roof as mining proceeds along a working face;
can maintain a more even constant support of the roof at ail times;
maintains a constant clear access within the exhaust tunnel of an underground mine; and
U can be moved independently of other machinery operating in a mine and thus maintain a safe exit through the exhaust tunnel in the event of malfunction of other equipment operating in the mine.
It will be appreciated that the above described embodiments are only exemplifications of the various aspects of the present invention and that modifications and alterations can be made thereto without departing from the inventive concept as defined in the following claims,
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