GB2063976A

GB2063976A - Mine Roof Support Unit for Longwall Recesses

Info

Publication number: GB2063976A
Application number: GB8033874A
Authority: GB
Original assignee: CT KT MASZYN GORNICZYCH KOMAG
Current assignee: CT KT MASZYN GORNICZYCH KOMAG
Priority date: 1979-11-23
Filing date: 1980-10-21
Publication date: 1981-06-10
Also published as: DE3041929A1; PL219868A1; PL123664B1

Abstract

A mine roof support unit for longwall recesses has a roof-bar (2) a flat element (1) slidably mounted and extending parallel to the roof, and as an extension of the roof-bar (2). An auxiliary roof-bar (3) is slidably mounted on the element (1) and is supported by a hydraulic prop 4. The flat element (1) may in some embodiments be in a form of a forked plate having two parallel arms extending forwardly of the first said roof-bar (2). Further flat elements and auxiliary roof bars may extend from the said auxiliary roof bar vide Fig 3. A ram (5) acts between the first said roof-bar (2) and the auxiliary roof-bar (3) for effecting movement thereof relative to the first said roof-bar (2). <IMAGE>

Description

SPECIFICATION Mining Lining for Longwall Recesses The invention relates to a mining lining for longwall recesses comprising an extended roofbar supported by at least one individual prop.

U.S.S.R. Inventors Certificate No. 206,487 disclosed a longwall lining which is provided with an extended roof-bar. The lining comprises a sill piece and a protective shield on the side where the roof fall occurs, together with a roof-bar connected to the upper part of the shield. The roof-bar extends far beyond the sill piece in the direction of the longwall face. Owing to this the roof-bar supports the roof over a substantial depth. The roof-bar consists of two elements connected to each other by means of an articulated joint. With the element of the roof-bar which projects towards the longwall face being supported by a hydraulic ram propped against the element of the roof-bar situated on the side of the roof fall and connected with the protective shield.

That element of the roofbar is supported with hydraulic props. On the account of the length of the two-element roof-bar, it is supported with two hydraulic props. Both props rest against the sill piece and support the element of the roof-bar connected with the protective shield. Owing to this the pressure of the roof-bar upon the roof is in principle uniform, while this uniformity in relation to a self-aligning frontal part of the roof-bar is additionally obtained by means of a hydraulic ram spragged between the two elements of the roofbar.

The mining longwall lining disclosed in U.S.

Patent Specification No. 3,925,995 comprises a sill piece and a two element roof-bar. Particular elements of the roof-bar are connected to each other by means of an articulated joint about an axis parallel to the roof and at the same time parallel to the longwall face. The elements of the roof-bar are additionally connected to each other by means of a hydraulic ram serving for mutual tilting of the elements about the articulated joint.

The element of the roof-bar which is situated nearest to roof fall side of the lining is located in principle above the sill piece and said articulated joint is in the region above the end of the sill piece from the side of the longwall face. Therefore the other element of the roof-bar projects beyond the sill piece towards the longwall face. The element of the roof-bar situated above the sill piece is supported by four props resting against the sill piece. Also the element of the roof-bar extending beyond the sill piece is supported with a hydraulic prop which rests directly against the floor, whereby after its retraction it hangs from the roofbar and can be displaced along it. A characteristic feature of this lining is that the sum of the lengths of both elements of the roof-bars is always constant because they are connected to each other by means of the articulated joint.Another characteristic feature is that although the prop supporting the front element of the roof-bar can be displaced along the roof-bar in its retracted state, at the moment of spragging it always takes up the same position in relation to the roof-bar and the other props.

A disadvantage of the lining disclosed U.S.S.R.

Inventors Certificate No. 206,487 is that the props of the lining always lean against the sill piece at the same point, and therefore the lining despite the extended roof-bar, cannot be used for the lining of deep longwall recesses because the element of the roof-bar which extends towards the longwall face is, nevertheless, too short to protect effectively the roof in a deep longwall recess. On the other hand, the location of the conveyor above the sill piece and between the props is not taken into account because the row of props from the side of the longwall face would hinder the movement of the combine along the conveyor situated between props.

An advantage of the lining disclosed in U.S.

Patent No. 3,925,995 is that the conveyor can be situated either from the side of the longwall face, in front of the first row of props resting against the floor, or between the first and second rows of props. In the latter case, when the combine advances on the conveyor, the props resting against the floor are retracted and moved along the roof-bar towards the roof fall, which allows the combine to advance. Although this lining makes it possible to support longwalls, nevertheless its application is limited to longwalls which are not very deep and in principle to longwalls of the same depth.

According to the invention there is provided a lining for longwall recesses, comprising an extendable roof-bar assembly supported by at least one individual prop, said assembly comprising a fundamental roof-bar supported by at least one prop resting on a sill piece, wherein there is provided a flat element mounted slidably on the fundamental roof-bar and located to extend, in use, parallel to the roof of a recess as an extension of the fundamental roof-bar, and an auxiliary roof-bar mounted slidabiy on said element and supported by an extendable prop which, in use, rests on the floor of a recess.

An advantage of the invention is that it makes it possible to provide a lining for recesses in longwalls, said recesses being a considerable depth and at the same time having varying depths. The depth of a recess means the distance between the face of the recess and the longwall face.

Embodiments of the invention will be described by way of example and with reference to the accompanying drawings in which: Figure 1 is a side view of a mine lining embodying the invention; Figure 2 is a side view of the lining of Figure 1 showing it in its extended position; Figure 3 is a side view of a second embodiment and, Figure 4 is a plan view of two lining assemblies arranged side by side.

Referring to Figure 1 there is shown a protective lemniscate lining illustrated with the auxiliary roofbars thereof in its completely retracted position against the fundamental roofbar, the roof-bars being connected to each other by means of a hydraulic ram serving for advancing the auxiliary roof-bar. Figure 2 shows of the lining with one auxiliary roof-bar in its position moved away from the fundamental roof-bar. Figure 3 shows a lining provided with two auxiliary roofbars which one is supported by one propand the other is supported by two props.Figure 4 stows two lining assemblies which each have a forked flat element, and in one assembly the flat unit is in a retracted position in the fundamental roof-bar with one of the auxiliary roof-bars in its advanced position, whereas in the other assembly the flat unit is in its advanced position projecting from the fundamental roof-bar.

The lining according to the invention, in which by way of example use is made of a protective lemniscate lining, comprises a sill piece 6 and a fundamental roof-bar 2 situated above it. On the side of a possible break-down or fall of roof, a caving shield 7 is attached to the fundamental roof-bar 2 by means of an articulated joint 9. The shield 7 is provided with sliding integral screens 11, and similarly the fundamental roof-bar 2 is provided with sliding lateral screens 10 which contact the corresponding lateral screens of a neighbouring lining assembly. The shield 7 is connected to the sill piece 6 by means of arms 8 which are pivotally mounted on pins 12 provided in the shield 7 and the sill piece 6 respectively.

The fundamental roof-bar 2 is pressed against the roof by means of a hydraulic prop 15 the other end of which rests against the sill piece 6. The prop 15 can be extended or shortened by forcing a hydraulic medium into it, which makes the roofbar 2 either rise or lower. The motions of the roofbar 2 produced by the prop 15 are controlled by the articulated joint 9 on the shield 7, and by the articulated joints 12 on arms 8. Arms 8 cause that the roof-bar2 to move along a curve called a lemniscate. The fundamental roof-bar 2 is provided with a flat plate 1 which is mounted parallel to the roof and extends toward the longwall face. The plate 1 is mounted so that it can be advanced with respect to and longitudinally of the roof-bar 2 and together the plate 1 and the roof-bar 2 can be moved by movements of the prop 15 and a ram 13 which extends between the roof-bar 2 and the shield 7.

An auxiliary roof-bar 3 is mounted on the plate 1.

The roof-bar3 is mounted on the plate 1 in a slidable manner and is supported by a hydraulic prop 4 resting on the floor. The auxiliary roof-bar 3 is shifted along plate 1 by means of a ram 5 which one end is fixed to the fundamental roofbar 2 and the other end is fixed to the auxiliary roof-bar 3, the most preferable disposition of the ram 5 being parallel to the plate 1. For deep recesses the plate 1 will be considerable longer than the roof-bar 2. Besides the auxiliary roof-bar 3, the plate 1 may be provided with a further frontal auxiliary roof-bar 3a mounted by means of the prop 4a, so that it can slide on the plate 1 and supported by at least one prop 4a the other end of which rests on the floor (see embodiments in Figures 3 and 4).

Where the fundamental roof-bar 2 is relatively wide the lining may be provided with a forked plate 1 of which a part la is mounted slidably in the roof-bar 2. The plate 1 is provided with two parallel strips 1b connected to and extending forwardly of the part la. The auxiliary roof-bar 3 are mounted on the strips 1 6 and in case of deep recesses further frontal auxiliary roof-bars 3a are also mounted thereon.

Claims

1. A lining for longwall recesses, comprising an extendable roof-bar assembly supported by at least one individual prop, said assembly comprising a fundamental roof-bar supported by at least one prop resting on a sill piece, wherein there is provided a flat element mounted slidably on the fundamental roof-bar and located to extend, in use, parallel to the roof of a recess as an extension of the fundamental roof-bar, and an auxiliary roof-bar mounted slidably on said element and supported by an extendable prop which, in use, rests on the floor of a recess.

2. A lining according to claim 1, further comprising a further auxiliary roof-bar mounted slidably on the element on the side of the firstmentioned auxiliary roof-bar remote from the fundamental roof-bar, said further auxiliary roofbar being supported by at least one prop for resting on said floor.

3. A lining according to claim 2, wherein said flat element is in a form of a forked plate having a base part slidably mounted in the fundamental roof-bar, and a pair of mutually parallel arms extending from the base part in a direction towards the longwall face away from the fundamental roof-bar, an auxiliary roof-bar and a further auxiliary roof-bar being mounted slidably on each of said arms and each being supported by a respective prop.

4. A lining according to claim 1, wherein a hydraulic ram is provided to act between the fundamental roof-bar and the first-mentioned auxiliary roof-bar effecting movement of that auxiliary roof bar.

5. A lining for longwall recesses, substantially as hereinbefore described with reference to and as illustrated in Figures 1 and 2, or Figure 3 or Figure 4 of the accompanying drawings.