GB2087963A - Shield support suitable for use in mines - Google Patents

Abstract

A shield support 11 comprises a floor-engaging structure 12, prop means 14, a roof-engageable member 13 and shield means 23 which is supported from the structure 12 by a guide means 17 and is pivotally connected to the member 13. The support 11 is so adapted that at least one extension link 30 can readily be fitted between the shield means 23 and the member 13 so as to increase the roof-supporting height attainable by that member. <IMAGE>

Description

SPECIFICATION Shield supports suitable for use in mines This invention relates to shield supports suitable for use in mines for supporting the mine roof during mineral-mining operations.

Such shield supports can be of self-advancing type and comprise a floor-engaging structure provided with an advancing means, extendable and retractable prop means, a roof-engageable member supported by the prop means, and shield means which is supported from the floor-engaging structure by guide means and which is pivotally connected to the roof-engageable member.

Hitherto difficulty has been experienced when, during advancing of the support, a position in the mine is reached in which changes in the mine roof contour result in the roof height being such that even with the prop means in their fully extended condition the roof-engageable member fails to engage the roof.

The invention as claimed is intended to provide a remedy. It solves the problem of how to design an improved shield support which is adapted to receive means which overcome this problem.

According to the invention a shield support suitable for use in mines comprises a floorengaging structure, extendable and retractable prop means carried by the floor-engaging structure, a roof-engageable member supported by the prop means, and shield means which is supported from the floor-engaging structure by a guide means and which is pivotally connected to the roof-engageable member, said shield support being so adapted that at least one extension link can readily be fitted between said shield means and said roof-engageable member so as to increase the roof-supporting height attainable by the roof-engageable member.

Preferably the shield support may also be so adapted that a further link or links can readily be fitted between said prop means and said roofengageable member to assist in so increasing said height.

The advantages afforded by the invention are mainly that the shield support can be better utilized and in consequence hindrance to mining operations, otherwise due to the need for alternative roof-supporting provision in areas where increases in roof height locally occur, is avoided.

One way of carrying out the invention is described in detail below with reference to the drawings which illustrate one specific embodiment, of which, Figure 1 is a side elevation of a shield support in accordance with the invention, Figure 2 is an enlarged view of a part of the construction shown in Figure 1, and, Figure 3 is a partial cross-section taken along the line Ill-Ill on Figure 2.

In the drawings a shield support 11 for use in a mine for supporting the mine roof during mineralmining operations comprises a floor-engaging structure in the form of a floor beam 12, a roofengageable member in the form of a canopy 13, and prop means in the form of a plurality of extendable and retractable hydraulically operable props 14 which act between the floor beam and the canopy for adjustably urging the canopy into engagement with the mine roof.

At the rearward end portion of the floor beam 12, that is to the right in Figure 1, a pair 15 of upstanding brackets is provided centrally of the floor beam. Further, two pairs, as at 16 of upstanding brackets are provided to the rear of the rearmost props 14. The brackets 1 5, 1 6 together support guide means in the form of a pivotal guide linkage 17 which comprises a single link 18 and a pair of links 1 9. The singie link is pivotally connected at 20 to the pair of brackets 1 5 and the links 19 are respectively pivotally connected at 21 to the pairs of brackets 16. The link 1 8 is pivotally connected at 22 to a goaf shield 23 which forms a main shield means for the support. The links 1 9 are pivotally connected, as at 24, at laterallyspaced positions, to the goaf shield 23.The goaf shield includes side plate portions, as at 25, which extend in the direction forwardly of the support, and frame members one of which is shown in the drawings at 26. Each member 26 has an aperture 27 by which a pivotal connection 28 can be made either directly to a pair of lugs 29 on the rearward end portion of the canopy 13, or, alternatively, indirectly thereto each through the intermediary of a respective extension link 30.

Each of the two links 30 has an upstanding projection 31 and a flat forward surface 32 each respectively engageable with the surfaces 33 and 34 of a compartment 35 formed within the rearward end portion of the canopy 13. In this way when the extension links are fitted to the rearward end portion of,the canopy they are restrained from any substantial tilting movement with respect thereto.

Each extension link 30 is provided with a vertical flange 36, the two flanges together supporting a small shield plate 37 disposed transversely of the shield support. This plate suppiements the goaf shield and resists the ingress of mineral debris into the structure when the links are so fitted.

The props 14 are suitably tiltably mounted at their bases to the floor beam 12, and, at their upper end portions in Figure 1, can either be directly pivotally connected at 38 to the respective pairs of lugs 39 carried on the underside of the canopy 13, or, alternatively, indirectly thereto through the intermediary of respective extension links 40.

The drawings show the extension links 30, 40 fitted respectively between the goaf shield 23 and the canopy 1 3 and between the props 14 and the canopy.

However in normal use of the shield support these links 30, 40 are omitted so that pivotal connection is made directly at 41 between the goaf shield 23 and the lugs 29, and the upper end portion of the piston rod 42 of each prop 14 is directly pivotally connected to the respective pair of lugs 39 on the under side of the canopy.

In operation of the shield support 11 upon raising and lowering of the canopy 13 by extension and retraction of the props 14 the pivotal guide linkage 1 7 ensures that the axis of the pivotal connection 41 moves in a substantially vertical plane. Thus the forward tip 44 of the canopy 13 likewise moves in a substantially vertical plane. Also the goaf shield 23 resists the entry of debris from the mine roof into the interior of the shield support structure.

Should the shield support be advanced by its self-advancing means (not shown) during mineral mining operations to a position where the mine roof contour is such that the height of the roof increases locally sufficiently far that even when the props 14 are fully extended the canopy 13 fails to reach the roof and thus is then unable to provide little or no roof support, the props are partially retracted and by the use of suitable equipment the pivotal connections between the props 14 and the canopy 13 and betweenthe goaf shield 23 and the canopy are disconnected. The extension links 40 can now be inserted in place between the props 14 and the canopy 13 and the links 30 can be inserted in place between the goaf shield and the canopy.

As shown in Figure 1 in order to provide such connections between the props 14 and the lugs 39 of the canopy 13 pivot pins 45 and 46 are provided. Also as shown in Figures 1 to 3 in order to provide the connections between the goaf shield 23 and the lugs 29 on the rearward end portion of the canopy 13, pivot pins 47 and 48 are provided. In order to retain the pivot pins in place, Tetention blocks 49 are welded to the lugs and links at positions adjacent each pin and a retention element 50 which is introduced to each retention block engages an annular recess 51 formed in each pin.

On re-extension of the props 14 the canopy is raised to a greater height than before and into engagement with the higher roof surface for adequate support of the roof in this area.

If so desired at a later stage the extension links 30, 40 can be readily removed from the shield support to return it to its original condition.

In this embodiment further transversely disposed shield plates as at 52 and 53 are provided in association with the links 18 and 19, being attached thereto by suitable retention means.

Although in the embodiment above described with reference to the drawings extension links are provided between said prop means and said canopy and between said goaf shield and said canopy, in other embodiments of the invention an extension link or links may only be provided between the goaf shield and the canopy. In this case when it is required to raise the roofsupporting height attainable by the canopy it is necessary, upon fitting the or each extension link, to remove the prop means completely from the support and to replace them by prop means which are extendable to a suitably greater overall length.

Claims (6)

1. A shield support suitable for use in mines comprising a floor-engaging structure, extendable and retractable prop means carried by the floorengaging structure, a roof-engageable member supported by the prop means, and shield means which is supported from the floor-engaging structure by a guide means and which is pivotally connected to the roof-engageable member, said shield support being so adapted that at least one extension link can readily be fitted between said shield means and said roof-engageable member so as to increase the roof-supporting height attainable by the roof-engageable member.

2. A shield support as claimed in claim 1, wherein said support is so adapted that a further link or links can readily be fitted between said prop means and said roof-engageable member to assist in so increasing said height.

3. A shield support as claimed in either claim 1 or claim 2, wherein said prop means are hydraulically operable.

4. A shield support as claimed in any one of the preceding claims, wherein two of said extension links are provided for fitment between said shield means and said roof-engageable member, each of those links having an upstanding projection and a flat forward surface which are respectively engageable with complementary surfaces of a compartment formed within the rearward end portion of said roof-engageable member.

5. A shield support as claimed in claim 4, wherein said extension links are each provided with a flange, the two flanges together supporting a shield plate disposed transversely of the shield support and so positioned as to supplement said shield means.

6. A shield support substantially as hereinbefore described with reference to the accompanying drawings.