Abstract
An active temporary roof support apparatus for attachment to a mining machine includes at least one set of support members, each set including at least a first support member and a second support member for supporting the roof of an underground tunnel. A drive assembly is arranged to drive the set of support members, such that the first and second support members are sequentially moved for engaging the roof so that the roof is supported by at least one support member during an excavation operation of the mining machine. A mining machine and a corresponding method is also provided.
Claims
1. An active temporary roof support apparatus for attachment to a mining machine, comprising: first and second sets of support members arranged adjacent to each other facing an advance direction of the machine such that the first set of support members is arranged on a lateral side of the second set of support members, each set of the first and second sets of support members including at least a first support member and a second support member arranged to support a roof of an underground tunnel; and a drive assembly arranged to drive the at least one set of support members such that the first and second support members are sequentially moved for alternatingly engaging the roof such that the roof is supported by at least one support member during an excavation operation of the mining machine, the first and second support members of the first set of support members being configured to be driven to move independently from the first and second support members of the second set of support members.
2. The active temporary roof support apparatus according to claim 1, wherein the drive assembly is arranged to move the first and second support members of the first set of support members oppositely relative to the first and second support members of the second set of support members.
3. The active temporary roof support apparatus according to claim 1, wherein the first and second support members are connected to each other.
4. The active temporary roof support apparatus according to claim 3, wherein the first support member includes a first engaging portion and the second support member includes a second engaging portion corresponding to and engaging the first engaging portion.
5. The active temporary roof support apparatus according to claim 4, wherein the first and second engaging portions are arranged to provide movement of the first and second support members in the machine direction.
6. The active temporary roof support apparatus according to claim 3, wherein the first and second engaging portions are arranged to pivot the first and second support members to each other in a predetermined angular range.
7. The active temporary roof support apparatus according to claim 1, wherein the drive assembly includes first and second upright drives arranged to move the first and second support members with respect to the roof.
8. The active temporary roof support apparatus according to claim 1, wherein the drive assembly includes first and second forward drives arranged to move the first and second support members in the machine direction.
9. A mining machine comprising: a main frame; a cutting unit; and an active temporary roof support apparatus according to claim 1 attached to the main frame and arranged in the machine direction immediately behind the cutting unit.
10. The mining machine according to claim 9, further comprising a machine stabilization having a support member arranged behind the active temporary roof support apparatus, the support member being arranged to stabilize the mining machine during an excavation operation.
11. A method for temporary supporting a roof of an underground tunnel during cutting the tunnel, comprising the steps in the following order: providing an apparatus according to claim 1; engaging a first area of the roof with the first support member; engaging a second area of the roof with the second support member disengaging the first support member from the first area; engaging a third area of the roof with the first support member; and disengaging the second support member from the second area.
12. The method according to claim 11, wherein the first, second, and third areas are arranged adjacent to each other and offset in the machine direction.
13. The method according to claim 11, wherein the first, second, and third areas are arranged immediately behind a cutting unit of a mining machine.
14. The method according to claim 11, comprising after disengaging the first support member the step of pushing the first support member forward in machine direction by a first range which is less than a distance twice as long as a length of the second support member seen in the machine direction.
15. The method according to claim 11, comprising after disengaging the first support member the step of pushing the first support member forward in machine direction by a first range which is less than a length of the second support member seen in the machine direction.
16. The method according to claim 11, wherein at least one support member is controlled to advance substantially simultaneously with the cutting unit.
17. The method according to claim 11, wherein the steps are carried out simultaneously as cutting the tunnel.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIG. 1 shows a side view of a mining machine comprising an active temporary roof support apparatus;
(2) FIG. 2 shows an elevated perspective view of the mining machine of FIG. 1;
(3) FIG. 3 shows an elevated perspective view of a portion of the mining machine of FIGS. 1 and 2;
(4) FIG. 4 shows a side view of an active temporary roof support apparatus mounted against a mining machine;
(5) FIG. 5 shows a full cut through an active temporary roof support apparatus;
(6) FIG. 6 shows a schematic illustration of a method according to the invention;
(7) FIG. 7 shows a second schematic illustration of a method according to the invention; and
(8) FIG. 8 shows a third schematic view of a representation of the method according to the invention.
DETAILED DESCRIPTION
(9) An active temporary roof support apparatus 1 (FIGS. 1 to 4) is attached to a mining machine 100 for cutting an underground tunnel. The mining machine 100 comprises a machine main frame 50 and a cutting unit 60. The cutting unit 60 is only shown in a schematic manner and is provided with a cutting unit advancing drive 61, which itself is supported by the main frame 50. The mining machine 100 moreover comprises crawler tracks 102 (only one shown in FIG. 1) for driving on an underground road way. The mining machine 100 also comprises a conveyer 104 for conveying excavated material from the cutting unit 60 to a discharge end 106 of the mining machine.
(10) When performing a cutting operation, the mining machine 100 is braced between a roof of the tunnel and a floor of the tunnel. For this, the mining machine 100 comprises a bottom support structure 108 for engaging a floor of the underground tunnel and a machine stabilization 110 for engaging the roof of the tunnel. The machine stabilization 110 and the bottom support 108 together provide a force on the tunnel roof and floor, such that the mining machine 100 is braced when the cutting unit 60 is advanced into the rock material. At the same time also the machine stabilization 110 provides a temporary roof support. Additionally, the mining machine 100 comprises a bolting unit 112 for implementing a permanent roof support to the tunnel roof, by installing bolts or anchors into the tunnel roof.
(11) As can be inferred from FIG. 1, the active temporary roof support apparatus 1 is arranged immediately behind the cutting unit 60 in the machine direction MD. In particular, the active temporary roof support apparatus 1 is provided between the cutting unit 60 and the machine stabilization 110 and also in front of the bolting unit 112 for implementing the permanent roof support.
(12) The active temporary roof support apparatus 1 comprises according to this embodiment a first set 2 of support members 6, 8 and a second set 4 of support members 10, 12. It shall of course be understood, that any other number of sets and support members might be provided. It is not necessary, that each active temporary roof support apparatus 1 comprises two sets, also three, four, five and so forth sets are preferred. Moreover, it is not essential that each set 2, 4 comprises only two support members 6, 8, 10, 12. Much more the sets may also comprise three, four, five and so forth separate support members.
(13) According to this embodiment, the support members 6, 8, 10, 12 are substantially plate shaped (see also FIG. 4) and have a substantially rectangular form. Again, this is also not essential. The form of the support members 6, 8, 10, 12 can vary depending on the application, as e.g. an inverted conic, or also mesh shape. The first and second support members 6, 8, 10, 12 are in sliding engagement with each other.
(14) As can be inferred from FIG. 1, the range R between a front edge 64 of the cutting unit 60 and a front edge 3 of the active temporary roof support apparatus is in the range of 500 to 2000 mm, and thus, the active temporary roof support apparatus 1 is immediately behind the cutting unit. The specified range R is one example. The range can be scaled up, when e.g. using a larger cutting unit.
(15) Beneath the first and second sets 2, 4 of support members 6, 8, 10, 12 is schematically shown a rolled mesh 114 which is used to permanently support the roof. The machine stabilization 110 comprises a bar shaped body 116 and four recesses 118 (only one indicated with reference sign in FIG. 2) which provide space for the drill carriages 120 of the bolting unit 112 (again only one drill carriage 120 indicated with reference sign in FIG. 2). As can be seen from FIG. 2, the machine stabilization 110 almost contacts the first and second sets 2, 4 of the active temporary roof support apparatus 1 and is thus arranged directly behind the sets 2, 4 (see also FIG. 4). Again, this allows a well-supported roof of the tunnel. The machine stabilization 110 is independent of the operation of the active temporary roof support apparatus 1. The support members 6, 8, 10, 12 can be repositioned even when the machine stabilization 110 is engaged with the roof for stabilizing the mining machine 100. At least one of the support members 6, 8, 10, 12 is adapted to provide an active support force to the roof in substantially vertical direction
(16) The active temporary roof support apparatus 1 comprises a drive assembly 20 (FIGS. 3 and 4) for moving the sets 2, 4 of support members 6, 8, 10, 12 such that the first and second support members 6, 8, 10, 12 are sequentially moved for engaging the roof such that the roof is supported by at least one of the support members 6, 8, 10, 12 during an excavation operation of the mining machine 100. The drive unit 20 comprises according to this embodiment first and second upright drives 22, 24 for each first and second support members 6, 8, 10, 12. Thus, each support member 6, 8, 10, 12 is provided with a separate upright drive 20, 22 (in FIG. 3 only 2 shown) such that the support members 6, 8, 10, 12 can be pushed upwardly independent from each other. For a floor support, each upright drive 22, 24 is provided with a bottom plate 26, 28, which are slidably attached to each other by a slide connection 30.
(17) Moreover, the drive assembly 20 comprises upper forward drives 32, 34 (again in FIG. 3 only two drives shown) for each support member 6, 8, 10, 12. Thus, again each support member 6, 8, 10, 12 is provided with its own upper forward drives 32, 34 for advancing the support members 6, 8, 10, 12 in the machine direction MD (see FIG. 1). At the same time for positioning the bottom plates 26, 28, bottom forward drives 36, 38 are provided for the bottom plates 26, 28, such that the bottom plates 26, 28 can be positioned in accordance with the support member 6, 8, 10, 12. This allows to position the upright drives 22, 24 in a substantially vertical position, such that the support members 6, 8, 10, 12 can be pressed against the roof in a substantially vertical manner. All drives 22, 24, 32, 34, 36, 38 are driven pneumatically or hydraulically and the forward drives 32, 34, 36, 38 are supported by the main frame 50 of the mining machine 100. The upright drives 22, 24 are not supported additionally, they are only supported by the bottom plates 26, 28 and push against the support members 6, 8, 10, 12. Even though the upright, upper and bottom forward drives are not shown for the second set 4 of support members 10, 12 in FIG. 3, it shall be understood that they comprise a similar arrangement as the first set 2 of support members 6, 8.
(18) As shown in FIG. 5, the first support member 6 and the second support member 8 of the first set 2 of support members are connected to each other by a positive locking connection 40. This connection 40 comprises first engagement means 42 provided at the first support member 6 and second engagement means 44 which are provided at the second support member 8. The first engagement means 42 are formed as a protrusion which is substantially T-shaped and the second engagement means 44 are formed as a partially closed groove having an undercut or indentation, such that the T-shaped first engagement means 42 can be received in the second engagement means 44. The engagement means 42, 44 allow a relative movement of the support members 6, 8 to each other. A first movement is perpendicular to the drawing plane of FIG. 5, such that the support members 6, 8 can slide relative to each other in the machine direction MD (which is perpendicular to the plane of FIG. 5). Moreover, the tolerances of the first and second engagement means 42, 44 are selected such that the first and second support members 6, 8 can be pivoted to each other. In FIG. 5 it is shown that the first support member 6 can be pivoted with respect to the second support member 8 within an angle . This angle is preferably in the range of 10 to 45, in particular 10 to 30. This allows that for example the first support member 6 is pivoted downwards by retracting the upward drive 22, than advanced forward into the direction of the plane of FIG. 5 and when engaged with the roof, again pivoted upwardly. The upward pivotal movement of the support members 6, 8 also allows for balancing deviations in the roof surface of the tunnel.
(19) FIGS. 6 to 8 now illustrate the walking movement of the active temporary roof support apparatus 1 according to the invention. First of all FIG. 6 shows the preferred schedule of movement. FIGS. 7 and 8 show alternative movements which are particularly suitable when advancing fast (FIG. 7) or having bad and uneven roof conditions (FIG. 8). In FIGS. 6 to 8 the machine direction MD is indicated to the left. Also the scale is indicated with steps of 100 mm. This is a suggested scale, which can be smaller or larger, such as e.g. 50 mm or 200 mm.
(20) With reference to FIG. 6, on the left hand side four support members A, B, C, D are indicated in which the support members A, B belong to a first set of support members and the support members C, D to a second set of support members. With respect to the beforehand described embodiments, A equals 6, B equals 8, C equals 10, and D equals 12. The numbers in FIGS. 6 and 7 indicate the steps in which the support members A to D are advanced forward into the machine direction MD.
(21) When the active temporary roof support apparatus 1 according to this embodiment (FIG. 6) is set into action in a first step (marked with number 1) the inner support members B, C are advanced forward and placed and engaged with the roof at a first area. When the support members B, C are engaged with the roof, the outer support members A and D are pushed forward and also placed and engaged with the roof. They are placed and engaged adjacent to the support members B, C, such that the roof is supported substantially over the whole width. When advancing forward, due to advancement of the mining machine 100 during an excavation operation, the support members B, C are disengaged and in a third step pushed forward and again engaged with the roof (shown with number 3 in FIG. 6). Subsequently, the outer support members A, D can follow and may be relocated and engaged as shown in step 4 of FIG. 6.
(22) The dashed rectangular on the right hand side of FIG. 6 indicates that this operation as in the steps 1 to 4 of FIG. 6 is continued during the whole excavation operation.
(23) FIG. 7 shows in a first section (steps 1 to 4) a second preferred walking scheme and in steps 5 to 7 a third preferred walking scheme. According to this embodiment of FIGS. 7 and 8, the first and second support members are arranged in the same manner, and therefore, in the first step (number 1 in FIG. 7), the second support member of the first set of support members (support member B) is advanced forward to a first area while at the same time the first support member of the second set of support members (support member C) is advanced to a second area. Thus, the inner support members are advanced and engaged with the roof portion. When the excavation operation continuous, the mining machine can move forward. While the support members B, C stay engaged (step 1), the support members A, D are not engaged with the roof and are free to advance forward. They advance forward about 200 mm, which is substantially equal to a length of the support members in the machine direction, overtaking the other support member. Due to the overtaking action, the active temporary roof support apparatus 1 may advance quickly in this embodiment (FIGS. 7 and 8).
(24) Where indicated with number 2 FIG. 7, the support members A and D are engaged with third and fourth areas of the roof portion. Now support members B, C can be disengaged since support members A and D are engaged with the roof, and advanced forward as indicated by step 3. Thus, at about 300 mm from the initial position measured from the initial position, support members B, C are again engaged with the roof portion and support members A and D can be disengaged. They are subsequently advanced forward to step 4 and again engaged with the roof portion.
(25) After the vertical dashed line in FIG. 7 in steps 5 to 7 a different walking scheme is shown. In this walking scheme the first and second support members of the first and second set of support members walk in accordance to each other. Thus, in step 5, support members A and C are engaged with the roof portion while support members B, D can advance forward. This is done in step 6. In step 6 support members B, D are engaged with the roof portion and members A and C are disengaged and advanced forward to step 8. Both walking schemes are preferred and can be carried out in average roof conditions.
(26) When roof conditions are bad, it might be necessary to implement a different walking scheme. This is shown in FIG. 8. In FIG. 8 only support member B is engaged in the first step. In the second step support member A is being engaged. Now support member B can be disengaged. In the third step only support member C is engaged with the roof portion and also support member A can be disengaged. Subsequently in a fourth step, support member D is engaged. Now support member C is disengaged. Since support member 2 is still engaged with the roof portion, this is possible. Thus, support member D can be repositioned and engaged with the roof in step 5. Thus, in step 5 the support members A and D are engaged with the roof portion. In step 6 support member B is disengaged and support member A is positioned and engaged with the roof portion. Subsequently in step 7 also support member A is engaged with the roof portion. As can be understood from FIG. 8 also an asymmetrical walking scheme can be implemented, however, at all times at least one support member A, B, C, D is engaged with the roof portion and provides roof support. In general, the active temporary roof support apparatus 1 of the present invention allows a walking action of the support members 6, 8, 10, 12 along the roof of the tunnel for continuously supporting the roof.
