GB2044331A

GB2044331A - Mine-roof Supports

Info

Publication number: GB2044331A
Application number: GB7908418A
Authority: GB
Original assignee: Dobson Park Industries Ltd
Current assignee: Joy Global Industries Ltd
Priority date: 1979-03-09
Filing date: 1979-03-09
Publication date: 1980-10-15
Also published as: ZA801330B; IN152972B; AU5622180A; GB2044331B; MX150136A

Abstract

A self advancing mine-roof support (10) comprises two spaced floor beams (12) interconnected at least at one end by a bridge 16 and advanceable by a ram 66, front and rear props (22, 24) mounted on each floor beam supporting a canopy (26), and linkages (42) disposed between the front and rear props (22, 24) which constrain the canopy against movement relative to the longitudinal direction of the floor beams. The linkages (42) shown have an upper link (48) pivoted to the canopy and to two unequal length lower links (56, 58) pivoted to the floor beams. The linkages are disposed close to one of the props (24) so as to minimise obstruction of the passage through the support. <IMAGE>

Description

SPECIFICATION Mine-roof Supports The invention relates to mine-roof supports and has particular, but not exclusive, reference to packhole and/or face-end supports.

In mining, the working of mine faces using a row of self-advancing mine roof supports has become a commonplace proposal. At face-ends, however, it is the case that special purpose support units tend to be used, for example to give a greater rearward extent of roof support or a greater capability for varying the attitude of the roof-engaging structure, or better access through the support away from the face. Such features contribute variously in facilitating goaf-packing in a safe and orderly manner, inspection and countering the problems raised by modification at the face-ends of the normal straight-line caving line requirement.

Thus, the present invention is predicated upon the obviously desirable objective of providing a support structure that is not over-complicated nor so different from other supports in the row as to require either radically revised manufacture or to inhibit access through the support. An advantage of embodiments of this invention is found to be improved general access at right angles to the face.

According to the invention there is provided a self-advancing mine-roof support of strikingly simple construction wherein a pair of spaced parallel skids are end-interconnected for bodily advancement together and, via skid-based front and rear pressure-fluid-operated prop or jack means, adjustably support a canopy, preferably with both front and rear overhangs, such canopy being attitude adjustable on said prop or jack means and constrained against substantial relative movement fore and aft of the skids via linkages themselves located between the front and rear prop or jack means and within the widths of the skids, preferably close to one or the other of the front and rear prop or jack means. Such a support is advanceable by pressure-fluid-operated means acting relative to an anchorage or abutment.

Suitable linkages are of lemniscate type with an upper link pivotted at one end to the canopy and, at both its other end and a medial position, to ends of two lower links pivotted at their other ends to spaced positions on or otherwise fixed relative to the skid. In that way it is possible to retain desired registration of a central part of the canopy relative to the skids regardless of the attitude of the canopy. Preferred lemniscate linkages have unequal-length lower links with the shorter link extending between the end of the upper link and, a lower one of the pivots to the base skids. Such a construction results in a minimum extent of the extended linkages in a direction between the front and rear prop or jack means of each skid.

Embodiments of the invention can thus provide a maximum width of fully-protected walk-way between the prop or jack means parallel with the face and a minimum obstruction at right angles thereto through the supports between the skidmounted prop or jack means. Thus, mere bridges, preferably cast, can be used to interconnect the skids front and rear, without further groundcontact, but permitting passage thereunder of advancing rams serving the supports and located between their side-skids.

If desired, the supports can by virtue of double overhangs, i.e. to front and rear, and provision in each overhang for extension poles or bars, be wholly reversible as to which is their front and which is their rear.

Specific embodiments of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a side view of one preferred support; Figure 2 is a rear view of the support of Figure 1; Figure 3 is a plan view of part of a mine-face installation of the supports of Figures 1 and 2; and Figure 4 is a partial isometric view of one installed support.

Referring first to Figures 1 and 2, a mine-roof support 10 has two spaced floor-engaging skids 12, interconnected by a front cast bridge 1 6 that may be rigid with the skids or hinged thereto. The skids have compliant mounts or seats 20, for front 22 and rear 24 props supporting a canopy 26 also via compliant mounts or seats 28. The canopy is shown with front 30 and rear 32 overhangs, a cam-packer box 34 being shown housed below the latter.

Compliance of the props or jacks to the base need not, of course be provided unless sideways misregistration of the canopy and base skids is permitted.

The compliance of the canopy is controlled by lemniscate linkages 40, 42 each disposed close to one of the rear props and within the width of the corresponding skid 12. Each of the linkages 40, 42 is shown as a double linkage between pairs of pivot lugs 44 to the canopy and pairs of pivot lugs 46 to the base skids. Upper links 48 are shown end-pivoted at 50 to the upper lugs 44 and also end-pivotted at 52 and lower medially pivoted at 54 to unequal lower links 56 and 58, respectively, both end-pivotted to the skid lugs 46 at 60 and 62, respectively. The shorter lower link 56 is pivotted (60) to the skid lugs 46 lower than the longer link 58.At least on extension of the roof-support, these linkages occupy a minimum space between the props or jacks 22, 24. This could allow the support to be reversible without much hindering access to the front of the support, e.g. to a face-conveyor (64 in Figure 3).

Excellent access through such a support both along and at right-angles to the face is manifest.

Most conveniently, an advancing ram 66 can be pivotted near the rear of the support and extend forwardly below the front bridge.

Figure 3 shows a face-end layout with supports 10 and their campackers 66, other, generally similar, supports 70 being disposed across the gate or roadway 72 with a mine face controller's position 74 at the end-most support.

Figure 4 shows a modified support with its rearward canopy extension truncated and an alternative lower mounting position for the campacker 34 between the rearward props or jacks 24. More detail is shown of preferred compliant skid mounts for the latter by way of lower locating skid parts 78 and upper parts 80 having compliance, usually by way of rubber mounting bushings. It will be noted that two forward (82) and only one rearward (84) extension poles or bars are shown so as to be intercalated on retraction within the canopy.

Preferably, similar support strengths are provided by having the single rearward pole or plate of a double web construction.

Claims

1. A mine-roof support comprising a pair of spaced, parallel ground engaging skids interconnected at least at or near one end for bodily advancement together, pressure-fluidoperated prop or jack means based at both front and rear parts of each skid and supporting a roofengaging canopy so that the attitude of the latter is adjustable, and skid-to-canopy linkages disposed between front and rear prop or jack means within the widths of the skids and serving to constrain the canopy against substantial movement relative to the skids in the direction of the skids, and pressure-fluid-operated means whereby the support can be advanced relative to an anchorage or abutment.

2. A mine-roof support according to claim 1, wherein two said linkages are each disposed close to one or other of the front or rear prop or jack means of each skid.

3. A mine-roof support according to claim 2, wherein each said linkage is close to the rear prop or jack means.

4. A mine-roof support according to claims 1, 2 or 3, wherein each linkage comprises an upper link pivoted at one end to the canopy and both are at its other end and a medial position to ends of two lower links pivoted at their other ends to spaced positions on or otherwise fixed relative to the skid.

5. A mine-roof support according to claim 4, wherein for each linkage, the two lower links are of unequal lengths with the shorter thereof extending between the end of the upper link and a lower one of said spaced positions.

6. A mine-roof support according to any preceding claims, comprising a non-ground engaging bridging interconnection of at least forward ends of the support.

7. A mine-roof support according to claim 6, comprising an advancing ram arranged to pass below said bridging interconnection.

8. A mine-roof support according to any preceding claims, wherein the canopy extends beyond the skids at least forwardly of the support.

9. A mine-roof support according to claim 8, wherein the canopy also extends beyond the skids rearwardly of the support above powered goafpacking means.

10. A mine-roof support according to any preceding claim, comprising extensible and retractable roof bars at front and rear of the canopy.

11. A mine-roof support substantially as herein described with reference to and as shown in Figures 1 and 2, or Figure 4 of the accompanying drawings.