AU2006342399B2

AU2006342399B2 - Prop installation

Info

Publication number: AU2006342399B2
Application number: AU2006342399A
Authority: AU
Inventors: Dion Booyens
Original assignee: MINE SUPPORT PRODUCTS Pty Ltd
Current assignee: MINE SUPPORT PRODUCTS Pty Ltd
Priority date: 2006-04-25
Filing date: 2006-07-06
Publication date: 2012-02-16
Anticipated expiration: 2026-07-06
Also published as: ZA200703351B; AU2006342399A1; WO2007124516A1

Abstract

A method of installing a first prop in an underground location which includes the steps of supporting the first prop in a retracted mode on a previously installed second prop, moving the first prop, while so supported, relatively to the second prop to an installation position, actuating the first prop to an extended operative mode, and disengiging the first prop from the second prop. A corresponding apparatus is also disclosed.

Description

WO 2007/124516 PCT/ZA2006/000087 PROP INSTALLATION BACKGROUND OF THE INVENTION [0001] This invention relates primarily to the installation of a prop such as an elongate support in an underground excavation, particularly in an area which is not 5 adequately protected. [0002] As mining takes place, for example in a coal mine, a working face is continually advanced. It is necessary at all times to provide roof support to ensure safe working conditions. Typically an area is excavated or opened up adequately to enable personnel to enter the area and place appropriate props. To some extent this 10 does meet the aforementioned requirement but it carries with it the danger that, during the installation process and before suitable supports are installed, the hanging wall may collapse. [0003] The invention is concerned with a prop installation method which at least partly addresses the aforementioned factor. 15 SUMMARY OF INVENTION [0004] The invention provides, in the first instance, a method of installing a first prop in an underground location which includes the steps of supporting the first prop in a retracted mode on a previously installed second prop, moving the first prop, while so supported, relatively to the second prop to an installation position, actuating the first 20 prop to an extended -operative mode, and disengaging the first prop from the second prop.

WO 2007/124516 PCT/ZA2006/000087 2 [0005] Each prop may be of any appropriate kind but preferably is actuable by hydraulic means. [0006] The first prop, when in the retracted mode, may be telescopically retracted. Thus the first prop, when actuated, may be extended telescopically. 5 [0007] The first prop, when supported on the second prop, may be supported above a footwall in the location. Preferably use is made of a cantilevered type support which is movable along an arc relatively to the second prop when the first prop is moved to the installation position. [0008] The method may include the step, prior to actuation of the first prop, of 10 allowing the first prop to move downwardly into engagement with a footwall. This downwards movement may be guided by means on the aforementioned support. [0009] The invention also extends to apparatus for installing a prop which includes an attachment mechanism which is engageable with a suitable support, a structure which is mounted to and which extends from the attachment mechanism, the 15 structure being movable relatively to the attachment mechanism, at least one support member on the structure which is engageable with the prop so that the prop is then supported by the structure and is movable together with the structure, a release device which is actuable at a location which is remote from the support member for causing the support member to disengage from the prop, and at least one guide 20 member which then guides movement of the prop. [0010] The attachment mechanism may be adapted to be engageable with a prop or formations on a prop which is similar to the prop which is being installed. The WO 2007/124516 PCT/ZA2006/000087 3 structure may extend in cantilever fashion from the attachment mechanism and may be pivotally movable relatively thereto through an arc. [0011] The support member may include opposed formations, for example opposed limbs of a fork, which are respectably engageable with appropriate formations on 5 opposed sides of the prop. [0012] The release device may be of any appropriate kind and may be adapted to cause movement of the support member relatively to the prop thereby to cause the support member to be disengaged from the prop. The release device is preferably positioned at or close to the attachment mechanism. 10 [0013] The guide member may be orientated so that movement of the prop is guided in a vertical downwards direction. To achieve this the guide member may, itself, be tubular or include one or more formations e.g. rings which encompass respective portions of the prop. [0014] The invention also provides a prop which includes a cylinder, a piston which 15 is telescopically movable inside the cylinder, an inlet to a portion of the cylinder to provide a means whereby an interior of the cylinder can be pressurised thereby to cause telescopic movement of the piston outwardly relatively to the cylinder, and at least two spaced formations on an outer side of the cylinder for engagement with a structure which is used to support a similar prop. 20 WO 2007/124516 PCT/ZA2006/000087 4 BRIEF DESCRIPTION OF THE DRAWINGS [0015] The invention is further described by way of example with reference to the accompanying drawings in which: Figure 1 is a side view illustrating the installation of a prop in an underground 5 excavation in accordance with the method of the invention; Figure 2 is a cross sectional view of part of the arrangement shown in Figure 1 taken on a line 2-2; Figure 3 is a cross sectional view of part of the arrangement shown in Figure 1 taken on a line 3 - 3; 10 Figures 4A and 4B are simplified plan views of the arrangement shown in Figure 1 illustrating different stages during the installation of a prop according to the invention; and Figure 5 illustrates the prop, correctly located and in the process of being actuated. DESCRIPTION OF PREFERRED EMBODIMENT 15 (0016] Figure 1 of the accompanying drawings illustrates from one side, a first prop 10 which is in the process of being installed in an underground excavation 12 between a hanging wall 14 and a footwall 16. [0017] The prop 10 has a cylinder 18, a piston 20 which is telescopically mounted in the cylinder and a valve inlet 22 which is connected to a hydraulic hose 24 extending 20 from a hydraulic source, not shown, which is used to pressurise an internal volume of the cylinder, when required. This type of operation is known in the art and thus is not further described herein.

WO 2007/124516 PCT/ZA2006/000087 5 [0018] Mounted to an outer surface of the cylinder 18, at spaced intervals, are an upper ring 26, a middle rirng 28 and a lower ring 30. These rings have respective pivot support members 32, 34 and 36 secured on the respective upper surfaces of the rings and positioned so that, viewed from one side, the members are located on 5 a vertical line. [0019] A second prop 1OA which for all practical purposes is the same as the first prop 10, is shown in an installed configuration. The piston 20A is telescopically extended from the cylinder 18A to a maximum extent, as is known in the art, so that the prop provides support between opposed surfaces of the hanging wall 14 and the 10 footwall 16. Support structure 40 is m unted to the second prop I0A. This structure includes an attachment mechanism 42 and a cantilever support in the form of a boom 44 which extends from the attachment mechanism. The attachment mechanism has two pins or rings 46 and 48 respectively, according to requirement, which are engageable with the respective pivot support members 34A and 36A on 15 the second prop in a manner which is permits pivotal movement of the boom relatively to the second prop 1 OA. [0020] The boom 44, at an end which is remote from the attachment mechanism 42, has a vertically extending rod 50. The position of the rod relatively to the boom can be adjusted in a vertical sense using any appropriate device, not shown. Two fork 20 shaped members 52 and 54 respectively, which are vertically spaced from each other, are mounted to the rod 50 and project outwardly from the rod, in line with the boom, when viewed in plan. Locking pins 56 and 58 are engageable with the fork shaped members 52 and 54 respectively, as is more clearly illustrated in Figure 3.

WO 2007/124516 PCT/ZA2006/000087 6 [0021] A rod 60 which is engaged at one end with the uppermost pivot support member 32A on the second prol:r extends above the boom towards the first prop. A fork-shaped member 62, see Figure 2, is secured to an end 64 of the rod which is remote from the second prop. It is to be noted that the fork-shaped member 62, 5 although generally of the same shape as the members 52 and 54, has a smaller transverse dimension and does not have a locking pin engaged with it. [0022] A guide 66 extends upwardly from the boom 44. The guide is vertically adjustable, in any appropriate way, so that it cradles a portion of the rod 60. As noted Figure 2 illustrates in plan the uppermost fork-shaped member 62. Figure 3 is 10 a similar view of the fork-shaped member 52. Figure 3 has an inset drawing which is a cross sectional view in a direction which is transverse to the plan view and which shows in slightly enlarged detail a portion of the vertical rod 50, a portion of the fork shaped member 52 and part of the intermediate ring 28. The fork-shaped member has an inner surface which opposes the cylinder 18 and which tapers inwardly from 15 an upper end of the fork-shaped member towards a lower end. [0023] The second prop 1 OA once installed, and acting together with other props, not shown, provides adequate support for the hanging wall and thereby creates an acceptable environment in which personnel can with a fair degree of safety continue mining activity. In the process a working face 70 is advanced. Once the face 70 is at 20 a distance from the second prop 1 OA at which additional roof support is required then the first prop 10, and where required additional similar props, is installed. This is done as follows. [0024] The support structure 40 is attached to the second prop 10A in the manner described. The boom 44 is however swung in a direction 72, see Figure 4A, at which WO 2007/124516 PCT/ZA2006/000087 7 the boom is remote from the working face 70 and, in effect, is within an area which is protected by props which have already been installed. At this point the first prop 10 is engaged with the structure 40 in the manner shown in Figure 1. The prop 10 is retracted so that the piston 20 is telescopically withdrawn into the cylinder 18. The 5 fork-shaped support member 62 is engaged with an undersurface of the upper ring 26 and the rod 60 is positioned on the guide 66. The mass of the first prop then keeps the prop resting firmly on the fork-shaped member 62. The locking pins 56 and 58 are respectively engaged with the fork-shaped members 52 and 54 and thus prevent the first prop from becoming inadvertently disengaged from the support 10 structure. [0025] Thereafter, as is shown in Figure 4, the boom is pivoted in a direction 74 so that the prop 10 is moved towards the face 70. When the first prop is at a desired position the rod 60 is retracted in a direction 76, towards the second prop 10A, as is shown in Figure 5, and the fork-shaped member 62 is thereby disengaged from the 15 upper ring 26. During this movement the rod 60 slides through the upper pivot support member 32A. [0026] When the fork-shaped member 62 is disengaged from the ring 26 the prop 10 is free to fall under gravity action towards the footwall 16. This movement is however guided by the constraining effect of the middle and lower rings 52 and 54 20 and the locking pins 56 and 58. The prop therefore falls downwardly, at the chosen position, until a lower end of the cylinder 18 comes to rest on the footwall 16. [0027] At this stage the cylinder is internally pressurised by introducing hydraulic fluid into the cylinder through the hose 24. The piston 20 is thereby extended until it is firmly braced between the hanging wall 14 and the footwall 16. The prop, installed WO 2007/124516 PCT/ZA2006/000087 8 in this manner, functions to provide overhead support and personnel can approach the prop 10 and disengage the locking pins from the rings 52 and 54. The structure 40 can then be detached from the second prop so that it is available for use, when required, on the first prop or, for that matter on any other similar prop. 5 [0028] The vertical position of the rod 50 is preferably adjustable relatively to the boom so that the height at which the first prop is supported on the uppermost fork shaped member 62 is variable in order to accommodate a footwall of irregular height. By correctly setting the vertical rod or the boom the first prop can be pivoted to and fro above the footwall without impactir g on a part thereof. 10 [0029] When the prop falls downwardly any of the rings 26 to 30 could impact on, and come to rest on, one of the fork-shaped members 52 and 54. To obviate this the rings are preferably bevelled or formed in the manner shown in Figure 3, i.e. with an upwardly facing sloping surface so that even if a ring does impact one of the members there is a natural tendency for the ring to slide off the member and so not 15 impede the downwards movement of the prop.

Claims

1. A method of installing a first prop in an underground location which includes the steps of supporting the first prop in a retracted mode on a previously installed second prop, moving the first prop, while so supported, relatively to the second prop to an installation position, actuating the first prop to an extended operative mode, and disengaging the first prop from the second prop,

2. A method according to claim 1 wherein each prop is actuable by hydraulic means.

3. A method according to claim 1 wherein first prop, when supported on the second prop, is supported above a football and is movable along an arc relatively to the second prop to the installation position.

4. A method according to claim 1 which includes the step, prior to actuation of the first prop, of allowing the first prop to move downwardly into engagement with a footwall.

5. A method according to claim 4 which includes the step of guiding downwards movement of the first prop towards the footwall.

6. Apparatus for installing a prop which includes an attachment mechanism which is engageable with a suitable support, a structure which is mounted to and which extends from the attachment mechanism, the structure being movable relatively to the attachment mechanism, at least one support member on the structure which is engageable with the prop so that the prop is then supported by the structure and is movable together with the structure, a release device which is actuable at a location which is remote from the support member for causing the support member to disengage from the prop, and at least one guide member which then guides movement of the prop.

7. Apparatus according to claim 6 wherein the structure extends in cantilever fashion from the attachment mechanism and is pivotally movable relatively thereto through an arc. 10

8. Apparatus according to claim 6 wherein the support member includes opposed formations which are respectably engageable with formations on opposed sides of the prop.

9. Apparatus according to claim 6 wherein the guide member includes one or more formations which encompass respective portions of the prop and is orientated so that movement of the prop is guided in a vertical downwards direction.

10. A support system for an underground excavation which includes at least a first prop, a second prop which is installed between a footwall and a hanging wall in the excavation, a cantilever support which is secured to the second prop and which is usable to support the first prop in a telescopically retracted mode above the footwall, the cantilever support being movable in an arc relatively to the second prop thereby to move the first prop to an installation position, a release device which is operable from the second prop thereby to release the first prop from the cantilever support, a guide member which guides the first prop as it moves downwardly to the footwall, and an actuator for causing a telescopic extension of the first prop at the installation position.