GB1582305A

GB1582305A - Apparatus for supporting mine roofs

Info

Publication number: GB1582305A
Application number: GB1754177A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-04-27
Filing date: 1977-04-27
Publication date: 1981-01-07

Description

(54) APPARATUS FOR SUPPPORTING MINE ROOFS (71) We, OROSZLÁNYI SZENBÁNYÁK of Felso telep, Oroslany, Hungary, a body corporate organized under the laws of Hungary, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention concerns apparatus for supporting mine roofs, which may in particular be used with advantage in mining along the face of the shaft, e.g. in longwall miming systems.

The apparatus according to the invention belongs to a family of mine roof support apparatus in which hydraulic props are interposed between a floor plate and the roof cap lying against the overburden. Such roof support apparatus is generally equipped with a hydraulically operated advancing mechanism to provide for step-wise advance and is also connected to material conveying or transporting mechanisms. In the patent literature such apparatus is generally described as a single unit but in practice several adjacently placed roof support units such as described in this patent application are used together to provide full safety.

There are numerous known types of eqipment for the propping of mine roofs.

Such equipment is classified according to its usability under varying geological conditions. It is a known fact that geological conditions may vary in most mines even within the same extraction area. Under the generally prevailing conditions it can be predicted where and how the geological conditions may change. In cases where favorable geological conditions unexpectedly change to detrimental ones and the safety equipment is selected to suit the favourable conditions, the equipment may be subjected to specially high loads and may even be destroyed, thus rendering the continuation of mineral winning impossible. In such cases the safety equipment cannot take up the load and if this goes beyond the yield-point of the equipment it will be destroyed.

There is already known roof support equipment that can be used with satisfactory safety results for floors of low rigidity and easily friable caprocks. Such roof support equipment cannot, however, be used for propping caprocks of high rigidity, due to the inadequate length of propping and because the fault-line of the cap-rock is too close to the longwall face.

This circumstance sooner or later leads to a fall of the face and to the destruction of the roof support equipment.

In the case of non-friable cap-rocks of high rigidity containing so-called thick bench seams, roof support equipment with long roof girders must be used.

The distance of the fault-line of the caprock from the longwall face thus becomes greater.

If the hitherto known roof support equipment is subjected to adverse geological conditions, e.g. if the rigidity of the cap-rock is changing and/or becomes easily friable or there are faults in the seam, then stress-forces of such magnitude act on the equipment that they cannot be absorbed by the structural elements of the roof support equipment. In the case of such abnormal forces, the hydraulic props are the first structural elements to become inoperative.

To absorb these abnormally strong forces.

already known roof support equipment employs various pivot systems between the floor and the cap. Such known pivotsystems generally yield in the direction of the longitudinal axis of the props whilst absorbing the effect of the forces acting in a direction perpendicular to the mentioned direction. These known constructions do not however, provide sufficient safety.

Such equipment is disadvantageous because in the case of different working levels the caps associated with these levels are spaced too far from the working face, thus leaving wide areas of the roof unsupported.

A further drawback of these known types of equipment is that since such constructions are based on the application of lever-arms (moments) and the effect of the propping forces supporting the roof is reduced in proportion to the leverage ratio.

Another known attempted solution to this problem is the application of a linear pantograph-like four-bar linkage system.

But roof support apparatus constructed on the basis of this system, while ensuring that the distance between the roof cap and the face will not increase when the working heights vary, have other drawbacks. A serious disadvantage is such that equipment is complicated to manufacture and to use; therefore both from the point of view of economy and of technicel solution they are undesirable. A further drawback is that due to the inevitable large fitting clearance of the pivots the resulting back- lash reduces the lateral stability of the roof support equipment. This reduction of stability can be of a magnitude sufficient to cause damage to the props and consequently to the roof support equipment itself.It has to be borne in mind that the fitting tolerances of the pivot elements of mining machinery are substantially wider and the back lash is consequently bigger than in general engineering.

The aim of the apparatus according to the invention is the elimination or at least a substantial reduction of the drawbacks of the known equipment. To try to achieve this aim the apparatus according to the invention provides apparatus for supporting mine roofs comprising a floor plate and a roof cap interconnected by hydraulic props and a connecting element which extends in non-vertical direction and which has one end thereof articulated to a member projecting from the roof cap towards the floor plate while its other end is pivotally connected to a support member secured to and extending from the floor plate towards the roof cap, and wherein the said connecting element is capable of being inclined at a positive or negative angle with the horizontal, in dependence on the spacing between the roof cap and the floor plate.

In another aspect, the apparatus according to the invention includes a connecting rod which is joined by a pivot at one end to a projection extending between the roof cap and the floor plate and at its other end is linked by a pivot to a support member protruding from the floor plate towards the roof cap. This connecting rod is nearly parallel to the longitudinal direction of the equipment and is capable of ensuring the alignment or guiding of the mechanism, even in the presence of undesirable large forces when they arise, without reduction of the reactive force of the props. The connecting rod absorbs the forces which are not directed along the longitudinal axes of the props, or at least a substantial portion of such forces.

It is very important that the axes of the two pivots at the respective ends of the connecting rod should not be in the same vertical plane.

The proposed construction makes it possible to provide a shield which seals the goaf side of the apparatus in such a way that no debris on the goaf side can intrude into the inner part of the apparatus.

In a preferred embodiment of the invention the support member is rigidly fastened to the floor plate is on the goaf side of the floor. In another embodiment a universal joint is fitted between the connecting rod and the member projecting extending towards the floor. The same pivotal effect can be achieved by using two mutually perpendicularly acting pivots.

To move the apparatus to and from the place of extraction it is advantageous to provide the apparatus with a hydraulic advancing ram one end of which is connected via a pivot to the floor plate, while the other end is similarly linked to the trough of a conveyor mechanism placed at the front of the apparatus.

As mentioned before, the apparatus according to the invention comprises a pivoting shield facing the goaf thus isolating it from the apparatus.

A preferred embodiment of the apparatus according to the invention is described, purely by way of example, with reference to the accompanying drawing, wherein: Figure 1 is a diagrammatic layout of the preferred embodiment of the apparatus in side view, Figure 2 is a side view of the apparatus on an enlarged scale, and Figure 3 is an enlarged scale end elevation of the apparatus as seen from the left-hand side of Figure 2, without the trough of the conveyor mechanism.

Referring to the drawing, the apparatus according to a preferred embodiment of the invention has a floor plate or beam 1 at its lower part. Four hydraulic props 2 are articulated by pivots 3, expediently ball-and-socket-joints 3 to the floor plate 1 to allow movement of the props in any direction.

The upper erids of the hydraulic props 2 are connected by respective pivots 4, expediently also ball-and-socket joints, to a roof cap 5. A lug 6 extends from. the roof cap 5 towards the floor plate 1. The free end of the lug 6 is connected to one end of a connecting rod 11 by a pivot 9. The other end of the connecting rod 11 is linked by a pivot 10 to the end of a support member 7 rigidly fixed to the floor plate 1.

The vertical dimensions of the support member 7 and the lug 6 are selected so that they should not cause any obstacle to the free movement of the roof cap to be adjusted to varying heights of operations.

That is to say, the rod 11 can be inclined either upwardly with respect to a horizontal plane passing through the pivot 10, as in the drawing, or downwardly i.e. with the pivot 9 lower than the pivot 10, dependent upon the spacing between the roof cap 5 and the floor plate 1. This is referred to herein by the expression "the conneting member (rod 11) is capable of being inclined at a positive or negative angle with the horizontal".

The apparatus is protected against the intrusion of debris from the goaf by a shield 13 mounted for pivotal movement about a pivot 12. The bottom part of the shield 13 is supported by the back of the support member 7. The dimensions of the shield 13 are selected in such a way that the fitting and engagement with the support member 7 is maintained even at the highest position of the roof cap 5 and it does not abut against the floor when the roof cap 5 is in its lowest position.

The drive mechanism for the apparatus includes a hydraulic advancing ram 8. One of the hydraulic advancing ram 8 is linked to a pivot 14 associated with the floor plate 1 while its other end is similarly connected by a pivot to the trough of a transport mehanism (conveyor) 15, illustrated purely diagrammatically. As already indicated, the whole mine roof support system is composed of a plurality of units of apparatus each as described above. During extraction (winning), the advancing of the apparatus is performed so that the troughs 15 of the conveyors are always pushed into the face of the seam worked on by the winning machine. Thereafter, one must release the load on the hydraulic prop 2 of that unit from among the plurality of such units which it is desired to advance behind the trough 15.

During this operation all other adjacent roof support units must be maintained under load. This means that the advancing rams 8 are connected when under load with the troughs 15 adjacent them. The stressrelieved hydraulic props 2 may then be advanced behind the trough 15 by the desired extent and thereafter fixed in the new position, and by putting the hydraulic props 2 under load the roof cap 5 is pressed against the mine roof.

Subsequently all adjacent roof support units are advanced similarly, thus moving the full roof support system to a new position.

It follows from the description of this embodiment of the invention that the roof support safety apparatus according to the invention is very simple both from the point of view of operation and production and ensures satisfatory movement of the roof cap even in the case of undesirably high forces. Since the side of the apparatus facing the goaf can be closed off by the shield 13, the apparatus is protected against the intrusion of debris from the goaf.

WHAT WE CLAIM IS:- 1. Apparatus for supportng mine roofs comprising a floor plate and a roof cap interconnected by hydraulic props and a connecting element which extends in a nonvertial direction and which has one end thereof articulated to a member projecting from the roof cap towards the floor plate while its other end is pivotally connected to a support member secured to and extending from the floor plate towards the roof cap, and wherein the said connecting element is capable of being inclined at a positive or negative angle with the horizontal in dependence on the spacing between the roof cap and the floor plate.

2. Apparatus acording to claim 1 wherein the support member is connected to the floor plate and is disposed at the goaf end of the floor plate.

3. Apparatus according to claim 1 or claim 2, wherein between the connecting element and the said projecting member there is or are interposed pivot means capable of pivoting about two mutually perpendicular directions.

4. Apparatus according to any preceding claim wherein a hydraulic advancing ram is disposed directly on the floor plate and has one end pivotally linked to the floor plate or to said support member while its other end is pivotally linked to a trough of a conveyor.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. end of the lug 6 is connected to one end of a connecting rod 11 by a pivot 9. The other end of the connecting rod 11 is linked by a pivot 10 to the end of a support member 7 rigidly fixed to the floor plate 1. The vertical dimensions of the support member 7 and the lug 6 are selected so that they should not cause any obstacle to the free movement of the roof cap to be adjusted to varying heights of operations. That is to say, the rod 11 can be inclined either upwardly with respect to a horizontal plane passing through the pivot 10, as in the drawing, or downwardly i.e. with the pivot 9 lower than the pivot 10, dependent upon the spacing between the roof cap 5 and the floor plate 1. This is referred to herein by the expression "the conneting member (rod 11) is capable of being inclined at a positive or negative angle with the horizontal". The apparatus is protected against the intrusion of debris from the goaf by a shield 13 mounted for pivotal movement about a pivot 12. The bottom part of the shield 13 is supported by the back of the support member 7. The dimensions of the shield 13 are selected in such a way that the fitting and engagement with the support member 7 is maintained even at the highest position of the roof cap 5 and it does not abut against the floor when the roof cap 5 is in its lowest position. The drive mechanism for the apparatus includes a hydraulic advancing ram 8. One of the hydraulic advancing ram 8 is linked to a pivot 14 associated with the floor plate 1 while its other end is similarly connected by a pivot to the trough of a transport mehanism (conveyor) 15, illustrated purely diagrammatically. As already indicated, the whole mine roof support system is composed of a plurality of units of apparatus each as described above. During extraction (winning), the advancing of the apparatus is performed so that the troughs 15 of the conveyors are always pushed into the face of the seam worked on by the winning machine. Thereafter, one must release the load on the hydraulic prop 2 of that unit from among the plurality of such units which it is desired to advance behind the trough 15. During this operation all other adjacent roof support units must be maintained under load. This means that the advancing rams 8 are connected when under load with the troughs 15 adjacent them. The stressrelieved hydraulic props 2 may then be advanced behind the trough 15 by the desired extent and thereafter fixed in the new position, and by putting the hydraulic props 2 under load the roof cap 5 is pressed against the mine roof. Subsequently all adjacent roof support units are advanced similarly, thus moving the full roof support system to a new position. It follows from the description of this embodiment of the invention that the roof support safety apparatus according to the invention is very simple both from the point of view of operation and production and ensures satisfatory movement of the roof cap even in the case of undesirably high forces. Since the side of the apparatus facing the goaf can be closed off by the shield 13, the apparatus is protected against the intrusion of debris from the goaf. WHAT WE CLAIM IS:-

1. Apparatus for supportng mine roofs comprising a floor plate and a roof cap interconnected by hydraulic props and a connecting element which extends in a nonvertial direction and which has one end thereof articulated to a member projecting from the roof cap towards the floor plate while its other end is pivotally connected to a support member secured to and extending from the floor plate towards the roof cap, and wherein the said connecting element is capable of being inclined at a positive or negative angle with the horizontal in dependence on the spacing between the roof cap and the floor plate.

5. Apparatus accordng to any preceding

claim wherein there is provided a shield for covering the goaf side of the apparatus, the shield being mounted for pivotal movement about a pivot secured to the cap.

6. Apparatus for supporting mine roofs substantially as herein described with reference to and as shown in the accompanying drawing.