GB2115048A

GB2115048A - Mine roof supports

Info

Publication number: GB2115048A
Application number: GB08302271A
Authority: GB
Inventors: John Cooke
Original assignee: Dobson Park Industries Ltd
Current assignee: Joy Global Industries Ltd
Priority date: 1982-02-02
Filing date: 1983-01-27
Publication date: 1983-09-01
Also published as: GB2115048B; GB8302271D0

Abstract

A face end mine roof support 10 has a base 12, a canopy 14 and props 16 acting between them for extension and retraction of the canopy into and out of roof engagement. The canopy has a rearward support element 60 which is pivoted by an extensible and retractable piston rod 82, between an extended position wherein the element extends upwardly above the canopy and a retracted position wherein the elements extends downwardly below the level of the canopy. <IMAGE>

Description

SPECIFICATION Mine roof supports The invention relates to mine-roof supports.

We have recently been developing mine roof supports for use at ends of face workings of socalled longwall mining systems, see our copending patent applications numbers 8131969 and 8131970. Such supports are, of course, located at ends of roadways or gates extending from ends of the face working itself. In many, if not most, instances the face-height is less than that required of the roadway or gate and the proposed face-end or roadway supports, of an advanceable type, then serve for strata support over the roadway extension prior to it being excavated to its full height. The present invention has originated in seeking to provide for improved strata support and safety shielding behind the roof-engaging canopy of the face-end or roadway support proper, i.e. in the region of the so-called ripping lip at the step between normal face-height and roadway height.

According to the present invention there is provided a mine roof-engaging structure having a rearward support element that is extendable and retractable between an extended position wherein the element extends upwardly above the roof engaging structure and a retracted position wherein the element extends downwardly below the level of the roof engaging structure.

The invention also provides a mine roof support including a roof engaging structure hereof.

Mine-roof supports hereof are thus capable of supporting and protecting against debris from the face of the heading or step up from the ripping lip itself, especially where, as is preferred, the rearward support element is extendable to be substantially perpendicular upwards relative to the canopy of the mine-roof support, thus supporting the ripping lip in two directions.

It will further be appreciated that a retracted position with the rearward support element substantially level with the roof-engaging canopy of the support also affords support and protection to the underside of the ripping lip as the support is advanced with the mine face, i.e. before ripping out to full roadway height immediately behind the support, also giving access to the face of the heading for drilling, etc.

It is also preferred herein that, at such ripping out behind the support, i.e. of the ripping lip, the rearward support element is further retractable to a downward disposition wherein it protects against ingress into the support of the material ripped out. We shall refer to such a preferred rearward support element as a three-position type, and three positions being upwards, level and downward.

Pressure-fluid-operated, usually hydraulic, means is preferred for powering extension and retraction of the rearward support element.

An advantageous three-position rearward support element is hinged to the support canopy clear of the rear of the canopy with a system of pivotted links across and cross-linked to a position behind the hinge position. A preferred link system allows the use of a rearwardly and shallowly downwardly acting ram. Considered in intermediate or level position of the rearward support element, it has a first link pivotted at one end to a downwardly extending lug of the element and at its other end to a lower pivot of a crosssection having another spaced lower pivot position for a ram coupling and a higher pivot position to the support canopy inboard of the element hinge. Permitted movement of the support element is through about 1 8or or more.

Conveniently the hydraulic circuit of the ram for operating the element may be operated from a remote location and may be provided with a relief valve to compensate for overloading in its level and upward supporting positions.

The system may be used at either the main or tail/supplies roadway.

In its downward position the support element will form a shield of suitable dimensions. In the main roadway or gate those dimensions will be such as to avoid fouling the conveyor in the main roadway. However, in the tail or supply roadway, where it is more important to avoid the ingress of debris and general obstruction, the support element can be dimensioned so that, in its downward position, it approaches floor level.

The support element may also be used as a temporary platform for men setting permanent roadway arches but in this case a mechanical interlock would be provided to avoid accidental lowering or raising when in use by operatives.

Specific implementation of the invention will now be described by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of a face-end support hereof; Figure 2 is an end view on the arrow II of Figure 1.

In the drawings, a face end support 10 has a floor-engaging base 12, a roof-engaging canopy 14, and props 1 6 acting between them for extension and retraction of the canopy into and out of roof engagement. The canopy 14 is shown with a downward extension 1 4A at one side actually the side remove from the end-most one of a row of roof supports extending along the face itself. Effectively, then, the face end support 10 "opens" into that row of supports at an end thereof whereat a roadway or gate is to be extended as the mine face advances.

Intercoupling of the base 12 and canopy 14 is by way of double parallel so-called lemniscate linkages 20, 22 that serve to maintain desired registration of the canopy above the base throughout relevant operative movement for roof engagement and disengagement for support and movement when released, respectively, end pivotted at 24, 26 to the canopy and at 28, 30 to an upstanding frame/shield 32 itself secured at 34, 36 to the base through upstand 38.

The base 12 has, below an edge plate 42, a housing location 40 for a conveyor feeding in the direction of the support 10 and roadway or gate in order to take away material removed from the face via a face conveyor delivering onto the transfer conveyor 44 (see Figure 2).

The face-end support 10 has, in accordance herewith, a rearward support element 60 of platelike form with depending lugs 62 pivotted at 64 to extension ears 66 from the underside of the canopy 14. The axis of pivoting 64 is rearward of the end of the canopy 14 and allows the element 60 to be extended to an upward position substantially perpendicular to the top surface of the canopy and retracted to a downward position as shown by dotted lines on Figure 1. Clearly, the pivot axis will permit of such preferred threeposition pivotting via a suitable mechanism.

The mechanism shown comprises one or more further lugs or tongues 68 extending from the element 60 to pivotting 70 below and beyond the pivotting 64 in the retracted position of Figure 1.

Pivotting 70 carries one end of a first link or links 72 shown with other end or ends pivotted at 74 to cross-linking 76 pivotted at 78, to bracket 83 fitted to the underside of canopy 14 and, at 80, to the extensible piston rod 82 of a hydraulic ram 84 itself pivotted 86 at its other end to a canopy anchorage the form of another depending lug or lugs 88.

The mechanism 68 to 88 is particularly compact with a relatively small occupation of space allowing the ram 84 to act rearwardly at only a shallow downward inclination. The triangular disposition of pivotting 76, 78 and 80 on the cross-link contributes substantially to the freedom of achievement of the desired three limit positions of the element, i.e. upward to protect a ripping lip, horizontal to form an extension of the canopy top, and downward to shield the interior of the support itself during ripping to extend the roadway or gate.

Also shown in the drawings is a hydraulic valve block 90 conveniently disposed via a bracket 92 on shelf or flange 94 under the downward extension 1 4A of the canopy 14. The props 1 6 are secured to the base via retainer blocks 96 and bolts and are connected to the canopy via caps 98 and pins or bolts for affording desired freedom of accommodating movement.

Also a spill plate system is shown on the props side of the conveyor 44, and retainers 102 for the pivot bolts 24, 26.

Claims

1. A mine roof-engaging structure having a rearward support element that is extendable and retractable between an extended position wherein the element extends upwardly above the roof engaging structure and a retracted position wherein the element extends downwardly below the level of the roof engaging structure.

2. A mine roof-engaging structure as claimed in claim 1 wherein the rearward support element is extendable to be substantially perpendicularly upwards relative to the roof engaging structure.

3. A mine roof-engaging structure as claimed in claim 1 or 2 wherein the rearward support element is retractable to be perpendicularly downwards relative to the roof engaging structure.

4. A mine roof-engaging structure as claimed in claim 1,2 or 3 wherein extension and retraction of the rearward support element is by pressure-fluid-operated means.

5. A mine roof-engaging structure as claimed in claim 4 wherein extension and retraction of the rearward support element is by means of a hydraulically operated ram.

6. A mine roof-engaging structure as claimed in any one of claims 1 to 5 wherein the rearward support element is hingedly connected thereto.

7. A mine roof-engaging structure as claimed in claim 6 wherein positioning of the rearward support element is by a system of pivotted links.

8. A mine roof-engaging structure as claimed in claim 7 wherein the ram is attached to the roofengaging structure and to the link system.

9. A mine roof-engaging structure as claimed in claim 8 wherein the ram operates on a first pivotted link.

10. A mine roof-engaging structure as claimed in claim 9 wherein the link system has an intermediate link between the first link and the element.

11. A mine roof-engaging structure as claimed in claim 7 wherein said link system comprises a first link pivotted at one end to a downwardly extending lug of the support element and at its other end to a lower pivot of an intermediate link having another spaced lower pivot position for a ram coupling and a higher pivot position to the support canopy inboard of the element hinge.

1 2. A mine roof-engaging structure as claimed in any one of claims 5 to 11 wherein the hydraulic circuit of the ram is operable from a remote location.

13. A mine roof-engaging structure as claimed in claim 12 wherein the hydraulic circuit is provided with a relief valve.

14. A mine roof-engaging structure as claimed in any one of claims 1 to 13 including mechanical locking means for the element.

1 5. A mine roof-engaging structure substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

1 6. A mine roof support comprising a roof engaging structure as claimed in any one of claims 1 to 14, a floor engaging structure and means for urging said structures apart.

17. A mine roof support substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.