GB2148977A

GB2148977A - Mine roof support structure tie bars

Info

Publication number: GB2148977A
Application number: GB08424927A
Authority: GB
Inventors: Leslie Arthur Neale
Original assignee: Wincobak Foundry & Engineering
Current assignee: Wincobak Foundry & Engineering
Priority date: 1983-10-21
Filing date: 1984-10-03
Publication date: 1985-06-05
Also published as: GB8328205D0; GB8424927D0; GB2148977B

Abstract

A tie bar for use as part of mine roof support structure, the opposite ends of the tie bar having plate elements 24 (26 Fig. 3) by means of which the bar is to be bolted to a spaced pair of roof supports. In order that the support structure can be set in position with a minimum of time and trouble even if the tunnel or mine roadway is curved, the tie bar is made in two elongate parts 14 (16 Fig. 3) adjustably connected together and the opposite ends of the tie bar are connected to the respective plate elements 24, 26 by articulable connections 28, 30. <IMAGE>

Description

SPECIFICATION Mine roof support structure The invention relates to the support structure of mine roofs, that is to say along the tunnels or roadways.

It is usual in present day coal mining technique to support the roofs of the tunnels or roadways by means of roof supports set in position at regular intervals, each roof support generally being formed of I-section material in the form of an arch. Each roof support is connected to the adjacent roof supports on its opposite sides by means of tie bars, the opposite ends of each tie bar being bolted to the webs of the respective I-section supports, the bolts extending through respective plate elements to which the opposite ends of the tie bar are welded. This conventional support structure works quite well and can usually be set in position by the mine workers with a minimum of time and trouble.However, if the tunnel or roadway is curved it can become difficult to set the tie bars in position as described because those on the outside of the curve need to be somewhat longer than those on the inside of the curve. In addition, depending upon the degree of curvature of the tunnel or roadway, the plate elements welded to the opposite ends of the tie bar need to be welded thereto at a particular angle rather than in a plane perpendicular to the length of the bar. If the tunnel or roadway is to merge with a tunnel or roadway of larger size, and in particular if this occurs at a curve or at a junction, the working out of the required lengths of the tie bars, and the required angles at which the plate elements are to be welded thereto at their opposite ends, can be very complex indeed.

The object of the invention is to provide a form of tie bar, for use as part of the mine roof support structure referred to, which will at least alleviate the problems described above.

According to the invention, there is provided a tie bar for use as part of mine roof support structure including a plurality of roof supports set in position at intervals along a tunnel or roadway, the tie bar being made in two elongate parts capable of being connected together in such a way that the effective overall length of the tie bar is adjustable, the opposite ends of the tie bar being connected to respective plate elements, by means of which the bar is to be bolted to a spaced pair of roof supports, by articulable connections. The articulable connections will preferably be constituted by respective pairs of interconnected chain link elements welded respectively to the ends of the bar and to the plate elements. The two elongate parts of the tie bar may be made of angle iron so that one can be located within the other.In this case, means whereby the two elongate parts of the tie bar can be connected together in such a way that the effective overall length of the bar is adjustable will preferably be constituted by a series of spaced apart holes in one of the two parts and at least one hole in the other so that the parts can be bolted together. On the other hand the two elongate parts of the tie bar may be made of tubular material telescopically connected together with some form of clamp securing them at a required overall length.

In order that the invention may be fully understood and readily carried into effect, the same will now be described, by way of example only, with reference to the accompanying drawings, of which: Figure 1 is a diagrammatic view of a mine roof support structure embodying the invention, Figures 2 and 3 are side views, drawn to a much larger scale than Figure 1, of the two parts of a form of tie bar used in the support structure, Figure 4 is a sectional view on the line 4-4 in Figure 2, Figure 5 is a perspective view of one end of the tie bar, Figure 6 is a view similar to Figure 5 which illustrates a possible modification which will be referred to, and Figure 7 is a view similar to Figure 5 of a different construction of tie bar embodying the invention.

Referring now to Figure 1 of the drawings, the mine roof support structure there illustrated includes a plurality of roof supports 10 set in position at regular intervals to support the roof of a tunnel or roadway. Each roof support 10 is formed of I-section material in the form of an arch.

Each roof support is connected to the adjacent roof supports on its opposite sides by means of tie bars 12, the opposite ends of each tie bar being bolted to the webs of the respective I-section supports.

However, it will be seen that at that particular region, the tunnel or roadway is curved.

Consequently, the tie bars required on the inside of the curve are shorter than the tie bars required on the outside of the curve, the actual lengths of the tie bars required being dependent on the radius of the curve in the tunnel or roadway. It will also be seen that the tie bars do not extend exactly perpendicularly from the planes in which the webs of the I-sections of the mine roof supports are disposed.

Referring now to Figures 2 to 5 of the drawings, it will be seen that the tie bar there illustrated is made in two elongate parts, that is to say two lengths of angle iron 14 and 1 6 bolted together in such a way that the effective overall length of the tie bar is adjustable.

The length of angle iron 14 is provided with a series of spaced apart holes 1 8 and the length of angle iron 16 is provided with a pair of holes 20 at a somewhat greater spacing than the spacing of the holes 1 8. The arrangement is such that one of the lengths of angle iron can be located within the other, as shown, and the two lengths bolted together by means of a single bolt 22. By the suitable selection of one or the other of the pair of holes 20 and the appropriate one of the series of holes 18, the overall length of the tie bar can be adjusted in a series of very small steps, each step being half the spacing of an adjacent pair of holes 18.

The opposite ends of the tie bar are connected to respective plate elements 24 and 26 having bolt holes 25 by means of which the bar is to be bolted to a spaced pair of mine roof supports. The ends of the tie bar are connected to the plate elements by articulable connections, these being constituted by respective pairs of interconnected chain link elements 28 and 30 welded respectively to the ends of the lengths of angle iron and to the plate elements. The ends of the link elements 30 extend through holes in the plate elements and are welded on the reverse sides of said plate elements. The latter are shown to have been slightly cranked to compensate for the portions of link elements which are to project from the plate elements.The link elements 28 are shown to project slightly from the ends of the lengths of angle iron to which they are welded so that the plate elements are allowed a certain amount of articulation without contacting the ends of said lengths of angle.

Thus there is provided a form of tie bar for use as part of mine roof support structure of the kind described, the tie bar having been found to be a complete solution to the problem encountered when a tunnel or roadway is to curve as in Figure 1. The tie bar is equally effective in solving the similar problem which arises where an underground tunnel or roadway is to merge with a tunnel or roadway of larger size, and especially where this occurs at a junction.

In Figure 6 there is illustrated a possible modification of the tie bar described above. In this modification, instead of the link element of each articulable connection being welded to the respective plate element in the manner illustrated in Figure 5, it is formed from a complete link welded to the face of the respective plate element.

Referring now to Figure 7, this illustrates a different construction of tie bar, the two elongate parts of the tie bar in this case being constituted by two lengths of tubular material 32 and 34 telescopically connected together.

A clamp generally indicated 36 is shown to be provided for securing the two elongate parts at a required overall length, the length of tubular material 32 being shown to be slit at 38 to enable it to be tightly clamped on the tubular length within it.

As in the earlier described embodiments, the opposite ends of the tie bar are connected to respective plate elements, only one of which, 24, is shown. Also as in the earlier described embodiments, the ends of the tie bar are connected to said plate elements by articulable connections, the latter in this instance being constituted by respective pairs of interconnected chain link elements 28 and 30 welded respectively to the ends of the lengths of tubular material and to the plate elements (but it will be understood that the link elements welded to the respective plates could equally well be complete links welded to the faces of said plates as illustrated in Figure 6).

The Figure 7 construction of tie bar is particularly advantageous because in addition to having articulable end connections, it is adjustable in length in a stepless manner.

Various other modifications may be made.

For example, it is not essential for the two elongate parts of the tie bar to be made of angle iron or of tubular material. They could conceivably be made of lengths of I-section material or of T-section material for example, although of course in that case not being able to be so conveniently nested together. It will also be understood that it may be found preferable to secure the two elongate parts of the tie bar together by more than one bolt.

For example, the two holes in part 16 could be at the same spacing as the holes in the part 14 (or some multiple of that spacing) or, alternatively, the pair of holes 20 in the part 16 could be duplicated so that at each setting one hole of each pair of holes is used.

Claims

1. A tie bar for use as part of mine roof support structure including a plurality of roof supports set in position at intervals along a tunnel or roadway, the tie bar being made in two elongate parts capable of being connected together in such a way that the effective overall length of the tie bar is adjustable, the opposite ends of the tie bar being connected to respective plate elements, by means of which the bar is to be bolted to a spaced pair of roof supports, by articulable connections.

2. A tie bar according to claim 1, in which the articulable connections are constituted by respective pairs of interconnected chain link elements welded respectively to the ends of the bar and to the plate elements.

3. A tie bar according to either one of the preceding claims, in which the two elongate parts of the tie bar are made of angle iron so that one can be located within the other.

4. A tie bar according to claim 3, in which means whereby the two elongate parts of the tie bar can be connected together in such a way that the effective overall length of the bar is adjustable are constituted by a series of spaced apart holes in one of the two parts and at least one hole in the other so that the parts can be bolted together by at least one bolt.

5. A tie bar according to claim 4, in which said other of two parts has at least one pair of holes at a greater spacing than the spacing of the series of spaced apart holes in said one of the two parts whereby the overall length of the tie bar can be adjusted in a series of relatively small steps.

6. A tie bar for use as part of mine roof support structure including a plurality of roof supports sets in position at intervals along a tunnel or roadway, the tie bar being constructed and arranged, and adapted to operate, substantially as hereinbefore described with reference to Figures 1 to 5 or Figure 6 or Figure 7 of the accompanying drawings.

6. A tie bar according to either one of claims 1 and 2, in which the two elongate parts of the tie bar are made of tubular material telescopically connected together with some form of clamp securing them at a required overall length.

7. A tie bar for use as part of mine roof support structure including a plurality of roof supports set in position at intervals along a tunnel or roadway, the tie bar being constructed and arranged, and adapted to operatc, substantially as hereinbefore described with reference to Figures 1 to 5 or Figure 6 or Figure 7 of the accompanying drawings.

CLAIMS New claims or amendments to claims filed on 8.1.85 Superseded claims 1-7 New or amended claims 1-6 1. A tie bar for use as part of mine roof support structure including a plurality of roof supports set in position at intervals along a tunnel or roadway, the tie bar being made in two elongate parts capable of being connected together in such a way that the effective overall length of the tie bar is adjustable, the opposite ends of the tie bar being connected to respective plate elements, by means of which the bar is to be bolted to a spaced pair of roof supports, by articulable connections, the latter being constituted by respective pairs of interconnected chain link elements welded respectively to the ends of the bar and to the plate elements.

2. A tie bar according to claim 1, in which the two elongate parts of the tie bar are made of angle iron so that one can be located within the other.

3. A tie bar according to claim 2, in which means whereby the two elongate parts of the tie bar can be connected together in such a way that the effective overall length of the bar is adjustable are constituted by a series of spaced apart holes in one of the two parts and at least one hole in the other so that the parts can be bolted together by at least one bolt.

4. A tie bar according to claim 3, in which said other of two parts has at least one pair of holes at a greater spacing than the spacing of the series of spaced apart holes in said one of the two parts whereby the overall length of the tie bar can be adjusted in a series of relatively small steps.

5. A tie bar according to claim 1, in which the two elongate parts of the tie bar are made of tubular material telescopically connected together with some form of clamp securing them at a required overall length.