GB2043740A - Positioning roof arches - Google Patents

Abstract

A mine heading machine has a roof-engaging structure or shield 42 and is advanceable on ground-engaging means 50,52 with the roof-engaging structure urged upwardly by rams 56 to give continuous roof support. The machine has at its rear, and coupled to the roof-engaging structure a linkage mechanism 80 for placing permanent roadway arches in place. The mechanism includes arms 82, 84 which can be retracted under the roof engaging structure and are also extendable rearwardly to engage under arches 76 which are to be lifted into position. A parallelogram linkage system 86, 88 operated by a ram (not shown) connected to a crossbar 96 is used. The arches are lifted into place by upward movement of the arms 82, 84 by jacks 98 thereon. The arches 76 are lagged with corrugated sheeting 78A, 78B. <IMAGE>

Description

SPECIFICATION Setting underground roof arches The invention relates to underground workings and, in particular, mechanisms for setting roof supporting arches, such as can be incorporated into machines for driving tunnels or roadways, typically at ends of mine face workings.

We have previously proposed a so-called heading machine for this purpose that has a generally arched shield structure supported via props or jacks on spaced ground-engaging tracked units at each side thereof, and having roof-engaging tracked units to permit permanent pressing of the shield structure upwards for roof supports purposes, even while the machine as a whole is moved, usually by driving its ground-engaging tracked units. The preferred material cutting means is then a percussive rock breaker or ripper mounted overhead by an extensible and rotatable boom from a carriage on rails within the shield structure. The carriage, the boom, and a rock breaker mount cradle adjustable on the end of the boom permitting manipulation of the rock breaker in cu-tting out material ahead of the machine proper.

Other types of tools, e.g. grinders, and mounts, e.g.

medially articulated, could be used.

For that machine we had in mind the desirability of providing some mechanism that assists in the installation of more permanent roof supporting arches rearwardly of the machine as it progresses in driving a heading, roadway or tunnel. The present invention concerns a particularly advantageous design of such a mechanism by reason especially of its location and operation at and from an elevated position within and at the rear of a heading machine, which could of course be different from that mentioned above, or below some other roof-engaging structure or mining machine.

According to the invention there is provided a heading machine having a roof-engaging structure to give protected access and work space therebelow, the machine being advanceable as an underground heading, tunnel, roadway, or gate is excavated thereby and with the roof-engaging structure urged upward to give continuous roof support, wherein there is provided at or towards the rear of the machine a roof arch lifting mechanism located at and operable from an elevated position below and relative to the roof-engaging structure, but in respect of raising arches rearwardly beyond the roofengaging structure.

Practising this invention is greatly facilitated by the nature of certain support arches and cladding that we are at present developing. The arches will, of course, match the tunnel or heading to be supported and will usually, but not essentially, have curved crowns. Such arches are characterised by having extension devices so that complete arches can be assembled into desired position with a substantial clearance from the roof to be supported and also the walls of the tunnel or roadway except at the feet of the arches. Due to the extension devices, such arches can then be raised into roof-supporting position simply by lifting the upper parts or crowns of the arches. This is readily done by mechanisms of this invention having an arch crown engager positionable immediately below an arch crown by a linkage that is preferably power driven.The same or another related linkage may then be driven to raise that arch crown up to the roof. Hydraulic rams or motors are suitable power means, say acting on pivotted parallelogram or other linkages.

Two spaced arch crown engagers moved in concert by the same linkage or similar simultaneously operated linkages permit of engagement of curved such crowns at spaced positions well below their highest points thus facilitating operations.

The above-mentioned clearance of the assembled arch before raising into its roof supporting configuration is utilised in our proposed cladding arrangements where crown sheets placeci over an arch or arches, and preferably interlocating therewith by channelling, has side sheets hung therefrom before the arch and its cladding is raised to the roof.

It will be appreciated that the arch raising mechanisms hereof offer substantial advantages in being elevated and thus presenting only a minimal interference or obstruction relative to tree passage of men, materials and equipment, especially if a linkage is used that can be retracted from an arch engaging position both upwardly and away into a rest position below and wholly within its supporting roofengaging structure.

Specific implementation of the invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings, in which: Figures 1 and 2 are plan and rear views of one mine face tail-gate installation utilising a tracked heading machine; and Figure 3 is a perspective view of an arch setting mechanism at the rear end of a machine such as shown in Figures 1 and 2.

In explanation of one application of the invention in mining, reference is made to Figure 1 showing a face end system at the corner between a tail-gate 10 and a mine face 12 protected by a row of roof supports 14 that will usually be of a self-advancing type operative by hydraulic rams acting between each support 14 and a face conveyor 16 that is located under forward cantilevered canopy parts 18 of the roof supports 14 and is driven buy a power unit 20. A least end-most ones of the roof supports 14 are shown fitted at their rears with pivotting cam-type packers 22 for consolidating waste into the goaf pack 24.

The roof supports 14 are of a type we have designed to maximise access through them by the use of one forward prop 26 and one rearward prop 28 into seatings for which both floor-engaging and roof-engaging parts 30,32 curvingly taper. In this eay, the customary protected access walk-way (arrow 34) through the support along the face is provided between the props 26 and 28, and at the same time access transversely of that walk-way is also good between the props of adjacent supports.

In the tail-gate 10 is a heading machine 40 having a curvingly arched roof and wall support structure and shield 42 equipped with side and central tracked units 44,46 and 48, respectively, to bear on the exposed strata for support purposes whi Ist facilitat- ing advance of the machine as a whole by driving of ground engaging tracked units 50, 52 with props or jacks 54, 56 acting to urge the structure 42 upwardly.

Normaily the upper tracked units 44,46 and 48 are free-running, but could be driven if desired. 1 his type of machine maximises both temporary roof support and freedom of access, see for example the load haulage dump truck schematically indicated at 57.

Parallel rails 58, 60 are shown secured to the underside of the shield 42 and serve in affording translation of a ripper carriage 62 located and braced by trailing arms 64, 66 having grippers for arched supports of the shield 42. A rocker breaker or ripper of an hydraulically powered impacting type is shown at 68 adjustably mounted on a cradle 70 itself pivotal on the end of a boom 72 extensibly and rotatably articulated to the carriage 62.

It will be noted that, at least at that side adjacent to the row of roof supports 14, the heading machine has spaced forward and rearward ground-engaging units 50A and 50B in front of and behind the access walkway 34 of the supports 14. The side walling of the shield 42 will also be apertures to permit easy access between the tailgate and that walkway 34.

Clearly, the heading machine enables the tail-gate to be advanced with the mine face itself on a highly convenient and efficient manner. On such advance, permanent supporting arches 74 are erected in the tailgate behind the heading machine.

Referring nowparticularlyto Figure 3, the nature of our preferred permanent support system is indicated as comprising arches 74 of I-section reinforcing steel joisting usually assembled from side parts 74A and a crown part74B fisliplated together. The arches 74 have adjustable extension devices or legs 76 at each side so that as their crowns are lifted the ends of those devices 76 remain stationary, but with a non-return system, for example using a loadbearing dry fluent material and one-way flow control thereof.

In order to raise the arched permanent supports 74, preferably after cladding with corrugated sheet 78, the rear of the heading machine has a setting mechanism 80. The latter comprises a pair of arms 82,84 resembling the arms of a fork-lift device and capable of being retracted and raised within the shield 42 of the heading machine, and of being extended into the position shown, by virtue of the pivotted parallelogram linkages 86,88 and 86', 88' to flanges 90,90' depending from the roof of the shield 42 and a pressure-fluid-operated, preferably hydraulic, ram (inducted by dashed arrow 94) pivotted at opposite ends to the shield flange 90 and to a crosspiece 96 between the linkages.

If the upper surfaces of the arms 82,84 are equipped with sliders or rollers it may be practical to raise the arch 74 vertically by continued extension of the arms rearwardly of the heading machine. However, and as shown the ram locks in the position of arrow 94 with the linkages 86, 88 just rearwardly of vertical.

Then, raising of the arch 74 is by retraction of rams within the arms 82,84 and a scissors or lazy-tongs linkage to lifting members 98 topside of the arms.

As indicated, particularly in Figure 3, provision is also made for protecting personnel employed in assembling the permanent support arches and cladding them. This is done by extendable and retractable shield plates 100, 102, 104 and 106, perhaps especially the two between the upper tracked units.

This provision may also be of particular value if extended after setting to the roof in the event that only the rearward-most one of the arches 74 is provided and reliance placed on overlapping of adjacent spaces of cladding to achieve one arch per cladding span. Then, after setting of the arch at least the plates 102 and 104 can be extended under the clad- ding, and are advantageously of such length as to exceed the width of cladding sheets so as still to offer protection until the next arch and its cladding are ready to be positioned.

Figure 3 also shows more details of how the ground-engaging tracked units are housed in inverted channel or open-box base-units 103,110 offering seating for the rams to act against plates, e.g. 112, on the shield structure.

It will be appreciated that the linkage 86,88 may be modified or replaced in providing for vertical raising of the arms 82,84 and avoiding use of lifting members on the arms and jacking means. For example, both of the links might be made telescopically retractable, say as pressure fluid operated rams.

Alternatively, the links may be medially hinged with a pivoted ram acting between the hinges and extending parallel to the arms.

In alternative arrangements, the arms 82,84 may simply be swung further in order to lift the arches and either slide on the latter, or carry them outwards and then bring them back due to the arc described by the arms on their linkages, their pivots to the beam 90 being at an appropriate height relative to the lengths of the linkages to secure accurate placement of the arches against the roof to be supported. In these cases, of course, no lifting mechanisms 98 are required and ends of the arms 82,84 must clear the beams 90. It may, then, be most convenient for ram means such as 74 to serve onlyforstowing of the arch raising mechanism underthe shield when not in use and for separate ram means to be used for continuing the movement of the arms 82,84 and their linkages 86,88 to lift the arches.

Clearly, an alternative way of viewing this invention is as a method of fitting roof-supports from the upper rear cf a heading machine, perhaps especially using lift arms that remain substantially horizontal throughout.

We have specifically mentioned arch placement at ends of cladding sheeting, but clearly these may be disposed centrally thereof.

Claims (12)

1. A heading machine having a roof-engaging structure to give protected access and work space therebelow, the machine being advanceable as an underground heading, tunnel, roadway or gate is excavated thereby and with the roof-engaging structure urged upward to give continuous roof support, wherein there is provided at or towards the rear of the machine a roof arch lifting mechanism located at an operable from an elevated position below and relative to the roof-engaging structure, but in respect of raising arches rearwardly beyond the roofengaging structure.

2. A heading machine according to claim 1, wherein the arch lifting mechanism comprises an arch crown engaging member or members and a linkage by which they are movable into and out of position for arch crown engagement.

3. A heading machine according to claim 2, wherein said linkage is power driven.

4. A heading machine according to claim 3, comprising pressure-fluid-operated ram means for driving said linkage.

5. A heading machine according to claim 4, wherein the ram means is connected to act between a part of the linkage and an anchorage on the roofengaging structure.

6. A heading machine according to any one of claims 2 to 5, wherein said linkage serves to swing said engager between rearwardly outward and inwardly upward positions relative to the rear end of the roof-engaging structure.

7. A heading machine according to any one of claims 2 to 6, wherein other powered means of the same linkages serves to raise the arch crown engaging member or members.

8. A heading machine according to claim 7, wherein said other powered means serves to vary the height to length or area ratio of the linkage.

9. A heading machine according to any preceding claim, wherein two spaced arch crown engaging members are provided to be moved in concert by the same linkage or similar simultaneously operated linkages.

10. A heading machine according to any preceding claim, further comprising selectively extensible bars or plates at the rear of the heading machine.

11. A heading machine according to claim 10, wherein said extensible bars or plates are extensible at least by the desired spacings between arches to be raised.

12. A heading machine substantially as herein described with reference to, and as shown in, the accompanying drawings.