GB2233379A - Support for underground mining - Google Patents

Abstract

A roof support for underground mining having a base frame 6, a roof cap 1, and a prop 8 connected to the base frame and roof cap, is characterised by the roof cap including two members 1, 2 pivotally interconnected by a hinge 3. <IMAGE>

Description

- i,s / C.B t Support for underground mining operations The invention

relates to a support for underground mining operations. The recommended supporting equipment belongs to the group of equipments serving for this purpoEe,.,vhich have a solepart bearing up againct the f ootwall roofing propping means connected thereto via a back-part,as well as one or more props having been inserted between the roofing. propping 'and/or the back-part.

Producing underground working pleceeg--. mining, are changing their position by diEcontinuous advance. Supporting equipments must be in compliance with said motions. These,.requi-rementzo directed to motion are met by means of the so-called mechanized propping means in mining to full extent.These safety propping equipments must meet other requirements toog which serve finaly for safety and productivity.

MoEt general requirements-for supports are claimed by the eircumstance,Li so far as mining is to be performed under rock conditions becoming increaEingly viorse, under,.aid circumstances all preventive measures are to be made to avoid compresEion of the equipment due to rock pressure and to Drevent narrowing of min.ing area. Process of nerz.oiving of the mining area used to be called convergence. Within certain limits convergence may be useful, however, when exceeding said li-mits,it becomes- he-ri-lfuL. Harmful circumstance can be illustrated by mear-E of the fol-lowing process. Within a producing cycle of mining operations - meaning the interval between two shiftings related to one unit of the supporting equipment - the supporting means are compressed to a certain extent as a consequence of the excited rock loadjEimultaneously height will be les..O 1 0 1 1 c In course of the next cycle Ea-id.-..reduced height will represent initial height which decresces further,as approaching the end of the cycle. At the same time this process cannot be:maintaned for an unlimited time,as workability of the whole mining operation could be endangered. In this case heightening of the mining area yields the only -olution,i,jhich may be achieved by recovering the rock lying above the equipment.

Over a certain limit -Yjhile this limit can be determined empirically only - convergence results in drawbecks, to a 'lesser extent in respect to Safety,to a larger e fent in rc-s-pect to productivity. Productivity used to be influenced di-eadvantaceously by two Circumstances. One of the circumstances appears in the fact that _._',multenecuEly -,.jith reducLT1g the height of mining, at a given velocity of advance productivity xelating to one unit of time jjill decrease. The other dil- advantageous circumstance lies in that heightening - becomLig periodically -necessary is time-con..u=Lig and co-n-sidering the e-. sence,it is c re-ther improductive activity.

With known solutions decrease of convergence used to be achieved by increasLig resistance of propping. To achieve the aim Ect,j-ncreasingly stronger steel structures and larger hydraulic props have been installed. This way of decregELlig convergence makes production of the safety equipment more and more expensive. It seems to be expedient -to promote intelligibility of specifications to b.. detailed later-to clear some fundamental matters. First of all peculiarities in connection between equipment and rock should be aurveyed briefly.For this purpose let us tbke the most

G generally used support for mining operationsgthe shields as a basis. Sith its lo,,.jer partsthe so-called soleparty and -vvith its upper parttcalled top-...upport,the shield is staying in a direct connection -,, .iith the secondary rocks. The task of the top support lies in to prevent cavL-lge of the rock lying above onto the working place.' On the side facing the breaking, on the side being opposite to direction of advance top support and solepart are connected by structural elements facing the breaking,out of which the back-part -as a structural element - is connected to the top support generally by means of a pin.It may happen, that the back-part Is loaded directly by the rocke.when the rock behind. the top Support gets in a caved state. In ca.ce,if Etructural elements behind the too support -that means, arranged opposite to direction of advance - are lying below the upper plane of the top Eupport,cavings of the rock ray occur# in the scheme of known Constructions -as outlined hereconvergence appears sosthat top support a-rid the solepart i- -,hich are - in cour.,sL- of proper use,but not necessarily - paralelly positioned - approaching one a no ther. As for the denomination of the single structural elements of the chield"s the matter is not unambigously cleared by professional..=.-. In consideration of this fact,the structural elementInamely the top support,has to be defined,viewed from the point of view of the invention. AcCordinxly.the to-P support represent-e the uT)rer element of the Ehield,which is arranged parallel ivith the sole-part in an ideal case and allows motion of the rock onlygvjhe-rl the props -bearing the load- are shifted C.

/Generallylthe back-part is connected to the sole-part of the shield, in general the roof is connected thereto by means of a hinge. The roof is in compliance with the top support. Howevexqif the surface of the roof being in contact with the rock is not -coplanarly arranged, the top -support forms only one pert thereof, interpreted in accordance with the definition. In the same way, according to eense,th-1 top support can be separated even for the caselif roof and back-part are forming one single structural element/.

Prior to specifying the invention in detail,,.ve have to consider the following. Convergence is caused by the rock load,exerting the influence from the top. Normally rock load affects the top support. It has been observed in ceneral that under given circumstances -..ith the simultaneous increase of the surface 'of the top support, absolute value - and as a &consequence., convercence too are also it seems to be exD.-=dient to reduce the surface of the top support to the mi.11lir-lLum fo-- the sake of reducing convergence. At the same titne, reduction of the surface of the top support Ects the limit for technologies directed to safety.

These considerations led to the recognition$serving as a base of the invention,in so far as -the EtpuCtural elemeu6 has to fulfil a double function by applying proper structural solutions without the necessity of reducing the surface of the top support. These functions are reduction of convergence and reduction of" rol-k load. For the sake of order it should be mentioned that some of the known equipments are well suitable for the cavings methodIfor the recovery of coal f-rom the top.

5_ In. minings having been supported by means of shields three methods are known for the Cavings method for the viecovery of coal. One of the processes is based on the fact that coal is introduced onto the conveyor having built,.f.or this special purpose through an opening of the equipmentlfacing the cave. This is the system with two scraper.-., having numerous disadvantages in respect to safety,technicE and economicalness.

The equipment,as described in the Hungarian Patent specification HU-H 179 85-0 vies destined for elimineting certain deficiencies of the aforementioned system with the two -ccr@1D,-.rsy this solution represents another of th'. caving.. metho'd fo.2;;o-31 recovery. the equipment of the type Hemscheidt 320-20/30 is simil2r to the equiDr-entla.c described in the cited publication. Common characteristic of 'the aforementioned shields lie..in that for the sake of cavingfor recovery coal from the top, behind the top support,belo,,,; the plane thereof,an opening iE formed Li the back-p3rt. Reaular performance of the cavings method for the recovery from the top will be achieved by the movable closing means. The drawback of said solution lie., in that the top sup-ort will be a load bearing element even during caving for the recovery of coal from the top, accordingly,

U the average. Essentially, the third version of caving coal from the top used to be performed so,that cavings of the coal from the top ie takirgplace on the butt end, used to be called..its means as eublevel caving shields..

Coal having been recovered from the top is allowed to fall down onto the conveyor arranged on the butt end by letting down the top support and automatic tilting. The drawback of said solution lies in that while performing cavings for the recovery of coal from the top,the butt end is not supported anymore,accordingly, crush of the butt end occurs frequently,leading to severe problems in respect to safety.

As the second version of cavings method for gaining coal from the top,as deEcrLbed in the Patent Specification HU-PS 179 855, and the constructions represented by the shield of the type Heimscheidt 320-20/10 are based on the classiebl principle of rock-mechanice,in so far as, the rock complex above the top support is keeping its orizinal v,,holen.-ss, it is not cracked. Cracked zone,-i-thi-^h can be caved easily,is starting backwards,from the rear edge of the top -cU;D0rt / OPPOSitC to the direction of advance/. However, this classical ar-rangement is not confirmed generally in practice, as according to observation rocks are disintearated already above the top c support. This circumstance enables the use of the type of zublevel caving shields._ Provocation of top represents a part of all technologies directed to the cavingE method for gainin.a coal frosm the c top,thiE method become-z nece2sary,if coal in the top cannot -be caved in due time. The only of this circum stance lies in that formation of the cracked zone suit able for caving doc--i nue Vel-ic metriod Enouli be prefe=ed to the other,as a deEint.egrated zone can be formed.

The aim of the invention was to develop EUDU0Zting Eafety means for underground mining operations, which is c suitable for reducing convergence hoiv.ever, the aim set should not be achieved by increasing the mass of steel structures or the forces exerted by the hydraulic props.

In sense of the invention the aim set is achieved by means of a propping eguipment which is meeting the requirements being contradictory to each other so.that the top support is incorporated in a divided construction, wherein the members of the top support are actuated always in compliance with technology and local facilities. From the point of view of the equipment according to the invention it is of utmost importance, that nature of the top support shouldbe interpreted in accordance with the given d---firiition.

As a consequence, the essence of the equipment acno-rdinR, to the invention 1LCE in that the top su'onort is composed of two mem.bers out of,vhich one of the members of the top support is practically stationary, while the other member Y is L-i-talled cogac being rotatable around e.g. a hir.ge Lrl reEpect to the first rieraber. It seems to be expedient to form the equiplment a.^,^- oding to the invention Eo,as the movable member of the top support should be enclosed at least partly by the stationary member in a frame-like manner.

With the equipment according to the invention it is conEidered as adventageouelivith which there is a hydraulic cylinder inserted bf?tween the movable member of the top support and the back-part. It ie. considered as an advantageous solution,if the equip- a closing element being displaceable in respect to the stationary member of the top support and a h-.draulic c.-..-linde.r is provided for for actuating said closing element.

R# 1 1 Advantageously the equipment may be formed sol that the stationary mejbe-- r--of the top support should be co.nMected to a support for the"butt end.

In several cases it may be advantageous.if the closing element is staying in a rigid connection with a guide plate.

Said version can be further developed,In so far as the. guide plate can be put into motion in respect to the closing element.

The invention will be described in detail by means of some preferred embodimentE, by the aid of the draw:LngSenclos-ed. The dra-wings are schematic illu..tration-c,whil,h enable several versions of structural forL-atio-- For the sake o'L order it ShoulJ be mentioned that fron the 1 point of view ofL the Jarivention it is absolutely indif.AI7--re-'ltg which t e m ozo Mo t ion is f o 1 -1ot!.-e J by the Shie ld 9 ns -.-e ly t mhether -me EDeak el-lout a circular are or a lemniscate.

Accordingly, Fi!zuXe 1 iE the side view of one of the embodimentz of the equipment according to the irnvention -erving as an excample, FiRure 2 shows the equipment ac-n-o--J:LnR to fi-aure 1 in its operative positions Figure 3 is the side view of another er,,bod-.!ne.vlt of the equipment aCCording to the invention, Figure 4 the equipment according to figure 3 in its operative position, Figure the sije view of a further iDo!E ible embodiment of the equipment according to the invention, Figure 05 the equipment acco.rding to figure 5 in its operative Dositiong c Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 FiRure 13 Figure 106 Ficure 17 c Figure 18 Figure 19 the side view of a further embodiment, the equipment acCording to figure in its operative position, shovis the side view of another possible embodiment of the equipment according to the invention. is the equipment according to ficure 9 in its operative position.

chow., - the side view of an equipmentbeing essentially in compliance with the embodiments shown in figs. 9 and 10,ho.,rever fo-- application in steeply pitching coal seame, the equipment ak-.-ording to figure 11 in its operative position the side view of another possible embodiment of th.2 thee.quipm-ent according to figure 13 in its operative position, Ehoufs the side view of another equipment Eerving as an example, shows the equipment a-.cording to figure 1-2 L.1 its operative position, -illustrates the side view of a further possible embodiment and the operative position thereof, is a side view of anither embodiment, is the side view of aanother possible em- Figure 2o shove the operative position of the equipment acco2ding to figure 19.

C' As it becomes obvious from the embodiment,as illustrated in fig....1 and 2,the sole-part 06 is connected to the top support via the back-part 12. The top support in itself comprises the relatively stationary member of the top support and the movable member 2 of the top support. Resulting from the basic conception of the invention, one membe.r of the divided top support,In our case the movable member 2 of the top support can be rotated around the hinge 3 in respect to the relatively stationary member 1 of top support.

In connection with the stationary member of the top support the expression ".relatively" may be motivated by the fact that in Course, of proper use of the equipment we cannot speak about"/GO.olute stationary statel at the same time motion of the member 1 of the top support, called here as stationary,iE unintentional.

JAs it is to be seen in figure 2.the movable member of the top support iE turning around the hinge 3 and occuzies a pozition,Sloping in the direction being opposite to the direction of advance. Figure 2 illustrates the case too,iv-hen Lri courSe of motion of the member 2 of the top support the pieces of rock lying above are failing Lito the break 10.

For the embodiment as illustrated heretwe illustrated Echematically the element for supporting the butt end 11.

Relative displacement of the movable member 2 of the top support will be determined commonly by the rock load acting from above and the props 8.

The relatively stationary member 2 of the top support encloses in a framelike way the movable member 2 of the top support, This may mean an enclosure in form of a fiame,that means that in this case the member 1 of G the top support encloses the member 2 of the top support from four side... It is possible to form the equipment according to the invention Eo,that the member 1 of the top support encloses the member 2 of the top support but from three sides,in the latter case the open side must be formed on the part lying opposite to the direction of advance.

Stationary state of the stationary member 1 of the top support is achieved by mewlf of the props 7 and by the eircumEtance,in so far as a part of rock load is carried nearly by the member 2 of the top support itself and evades the load by the relative displacement.

The embodiment according to figure 3 and 4 corresponds essentially to th.. . equipmentas illustrated in fig.. 1 and 2 the only difference lies in that props 7 and 8 have been built-in in a different ivay,furtheron,in course of displacement the member 2 of the top support may arrive at', a poEition,that it may sink spatially below the hinge 4 establishing the con.nection between the stationary member 2 of top support and the backpart 12. Furthe.ron,'L.rom the embodiment eh-.cording to figs.3 and 4 it becomes obviousthat the difference lies in that the back-part 12 is connected to the stationary member 2 of the top support by means of the hinge 4, Otherwise, with this embodiment too, between the sole 05 and the top support the back-part 12 is inserted,we also illustrate the organ for supporting the butt end 11. For the sake of order it should be mentioned that the pin forming the hinge 4 (see f ials. 3 and 4 c,1Rnnnt be a throughgoing pin,but lt must consist of two separate parts with the purpose,that the member 2 of the top support could also occupy the position below the hinge 4.

C In respect to the fundamental conception, the embodiment shown in figs. 5 and 6 corresponds to the earlier illustrated equipraente,however,i.7ith this embodiment the hinge 5 was built-in to the movable member 2 of the top support, in such a manner it becomes possible that in course of the displacement of the member 2 of the top support, W while being in operationicould occupy a parallel position with the stationary member 1 of the top Euprort. Othex- ir wise, the layout ie. in compliance with that of the figures 1 and 4.

Tn case of the embod-iraentce.,= illuEtrated in figs. 1 to it seems to be expedient to insert gap c16sing means between the members of the top support, moving in relation to each other, to be able to prevent inrush of the rock.Mhen forming the gap closing means it Ehould be considered that periodically it miSht b.e necessary to remove the rock fror, the space bet,,vecn the two members of the top EUPPOrt. Application Of gaD Closing meens become'. s uperf luoul,', if the d is ple C. e ment be t.,-, ,e en the tivo me nberS of the top support does not exceed structural thickness of the members.

Relative displacement of the two members of the top support can be characterized in that first of all the member 2 of the top support arranged inside i S moving in relation to the relatively stationery member of the top support enclesing the former one, and dovin wards. In special cases it should be possible that the member 2 of the top support could move in the opro..ite d-i-rect4.-in too _In. c-1y7 '.',h,;2truct;..uei. i-iick ness of the top Eupport,such a displacement should be permitted. Otheinvizeg the construction does not hinder c the displacement. One of the common characteriEticSof the embodiment illuEtrated on figures 1 to 06 lies in that with the embodimentE according to figures 1 and 2, as well aE to figures 3 and 49Eo with the embodiment according to figure... 5 and 06 in course of the displacement of the member 2 of the. top support,f-rom direction of the top suprort the equipment remains in a closed state.

Another common characteristic lies in that with all the equipments --serving as an example - having been de.

Ecribed up to now - the common planar hinge of the two members of the top support is arranged in the vicinity of the edge lying L71 direction of advance. That m.-ans,+hat in a concrete case ' the hinxes 3 reEP. thlhinges 5 are to be found on thZ part of the equipment facing the butt end 11.

In the follovjing we intend to describe sone embodiments, with which the hinge eztabliEhing the con"-ection bet,.,v,een thj-,2 member 1 and the member 2 of the top support is not on the part facing the butt end,but it is arranged zo,thet it iú facing 'the break 10..A-.co-rdj-ngly, follo-F.-.ing the displacement of the member 2 of the 'Lop support the position sloping to the. butt end will be ocCupied.

Vith the embodiment cho,,,jn in figures 7 and 8 - in accordance,iith the fundamental conception of the invention - the movable member 2 of the top support can be diSplaced in relation to the relatively stationary Member 1. L.LI Lhit cad e lio-,;,jevee iat;Laiu.L; d oi the top Eupport is able to turn around the hinge having be-en arranged at the end facing the back -part 12, -14 acCordingly,in the displaced position it slopes towardsc the butt end 11. At the movable end of the member 2 of the top support we indicated the gap closing means 139 by the aid of which i=uúh of the rock into the inside of the equipment can be prevented.It is quite obvious, that the Eize of gap closing means 13 and possible displacement of the member 2 of the tOD support will determine the depth, as far as the rock havixbeen accumulated on the member 2 of the top Euppport can fall into the equipment. Up to this limit displacement of the member 2 of the top support will be determined by the restricted loadability of the prop/E/ 8. After having reached said lirait,by Uosening the prop/s/ 8 the rock is allowed to pass into the caving space, to be able to push back the member 2 of the top support to the relatively stationary member 1 of the top support. By allowing periodically inrush of the rock into the equipment convergence can be reduced.

The embodim-Int,@E described in f icures 7 and 8 has r_ some common characteristics with the embodiments according to ficures, 1 to -0, in so far as during r_ relative displacement of the members of the top support in case of proper use - rock lying above the top support must n6t fall into the equipment. Prom this point of view the only difference between the embodiment according figs. 7 and 8 and the solutions according to figures 1 to 06 lies in, that periodical.removal of the rock from the space between the two members of the top support can be performed more easily with the embodiment acco--ding to figures 7 and 8 in comparison to earlier specified solutions.

c The embodiment acco-rding to figures 9 and 10 illustrates an equipment, with which it may occupy an open position -in case of proper use - from the direction of the members of the top support Under the open arrangement we mean the positionin so far as the rock lying above the top EUDPO2t may get into the caving Epace,accordingly,for this case we assume regulation a-rid expediency of thd process& Under regulation of the process it is meant,that open position of the equipment from the side of the top support should depend on the operatorlit must not be accidental.

Under expediency of the process it is meant that it Eeez:s to be useful to apply said equipments e v er ywher e where t-here is some exDloitable raw material above the equipment, - hich,,,vhen inrushing into the equipment, does nou cause qualitatively,,0'iiuted 9 rocks,the mcre it -.!i=1d.. useful results. Said t:-nch.,-iology of devl-lopment hes. been spread widely in coal min:Lng,knov,,n as cavLngs method for the recovery of coal, as already nentioned before-. In aCcordance.7ith the fundamental Conception olo the invention,,,jith the embodiment sho...-jn in figs. 0 and 10, top support is divided. In this case too there is a relatively stationary member 1 connected to the movable member 2 of the top Eilpport. Between the two members of the top support the connection is established by means of the hinge 15. This hinge 15 is arranged in the vicinity of the back-part and forms a plener hinge.

LI.L the top,bytoostr'Cnl the props 8 the member 2 of the top c 1 0csupport can be tilted to the desired position. when the rock lying above the top support -as it becomes obvious from figure 10 - is allowed to fall into the inside of the equipment,namely onto the conveyor next to the butt end 11. With this way of production the member 2 of the top support is forming simultaneously the guiding profile reEp.the guide element. In connection with this solution let us detail the technology of caving of the roof for the recovery of coal.

As already mentioned in conrectionwith figures 9 and 10, in the period of caving the roof for the recovery of coal the equipment will be opened from the direction of the top EuiDport.as by loosening the props 8 the member 2 of the top support begins to move doivnviards.

L"'cani,7hile 'the h-light of the equipment may remain un - anRed.az the props assure the stationary state of ch t.he member 1 of the top SUDport. In this case too the 1 of the top sup-port c.,,icloEcE the P-em'L-cr 2 of the top E up---. ort in a f rame-like way _rom &three or four member 2 is iEtalled rotetabl-.,. It becomes obvious from the embodiment heving been discussed nojj,, that by Inea,7s of the Eupport/14/ of the butt end, the butt end is secured even. in course of caving the coal of the top.In-Such a.manner,in course of caving by the use of sublevel caveing shields the ferquent and unavoidable break of the butt can be avoided.

Closine back of the member 2 of the top support is carried out by meanE of the props 8. Minimal level of iizu.-h of barren.,jill be en3bled by the fac-!'- due to relatively low r.ltci!stance required by protping, liquid claimed for displacing the props 8 is inconsiderableg accordingly displacement can be carried c out quickly / ObviouElysliquid quantity claimed relates to the hydxaulil- liquidlin considerationAhat both the props 7 and props 8 are hydraulic props,as it Is usual with these types of equipmente/.

As a matter of factgon figures 11 and 12 an equipment has been illustrated,iqhich was described already In connection with figures 9 and 109ho,,vever,in this ease the equipment accoInding to the invention is well suitable for steeply pitching seams. It can be well seen that the movably Installed member 2 of the top support is. connected by means of the hinge 15 to the relatively stationary member of the top Eupport.The rock may pass said member 2 and get into the inside of the equipment, that means, the roCk whiCh falls onto the conveyor next to the butt end in course of caving th e top fox coal recovery.

With the embodiment according to figures 13 and 14 c-on, 1 a nnetion, between tiie xelativel- stationary member 1 of the top support and the movable member 2 of the top suiport iE e-.'kabliEhed by means of the hinge 1-0. Said hinge occupies a position in relation to the of the top zupport,L-1 whiCh the member 2 of the top support extends far on both sijes In r,--lat-ion to the hinge 10',frora this fact it r=-zultú,that the equipment I.. unEuitabllt-- for general use,it can be used expediently under special rock co-,,ditio...-E only. DiEedvant-cgd.nou.. feature of said solution results from the a-rangement that a part of the member 2 of the top SUD,2Ort SCtS above the plane of the stationary member 1 of the top support. Disregarding the fact, the embodiment discussed iioil La eecencially idencical with shown in f iguzes.0. to 12.

r18- All the embodiments having be-In discussed up to now are suppoxted-by four props.Howevertapplication of the four props does not represent an exclusive requirement of the invention, in certain cases use of three props may be expedient toolthis solution suffices for the case, when under the movable member of the top support one single hydraulic prop i. axranged,namely preferably in the symmetry plane of the equipment running parallel with the plane- in the drawing. However,in accordance with the invention any e-quipment could be operative ivith two load bearing props, in this case the movable member of the top supr-ort does Pot transfer the rock load onto the hydraulic prop connected to the sole-Dart of the equipment or onto the cylinder.

The embodiment'shown in figures 13 and 106 is in complien..,-= with the aforementioned theoretical concept. The embodiment -hown here i. similar to that according to figures 13 and 14, hoivever,-vjith the difference,that the movable member 2 of the top support is not Eupported by the hydraulic props connected to the sole-part 08 o'L the equipment,but hydraulic cylinders 17 serve for this purpoSe, whiCh are coInnected partly to the back-part 12 of the equipment,partly to the member 2 of the top support.

Vith thir solution the hydraulic prop 9 is inserted between the back-part 12 of the equizzent snJ the sole part -0.

In figures 17 and 18 9n embodiment of the equipment a,--cor.dina to the invention is sho-,7n,vjith,,;h-ich the c sense of the displacement of the movable member of the tor, can be c2ia-zLged.In case oLo the as illustrated in figure 17, the member 2 of the top support may turn around the hinge 181which is c arranged on a part of the relatively stationery member 1 of the top supportglying opposite to the butt end 11.In this case the member 2 will be supported by the prop 89 while the prop 7 supports the member 1 of the top support. With this embodiment -ass shown in figure 17 -the coal having been recovered in course of top caving can be led onto the conveyor next to the butt end and at last into the inside of the e:luipment.

With the embodiment according to figure 18 the member 2 c of the top support can be displaced arouncL the.hinge 19 in relation to the member 1 of the top support.In this case the member 2 of the top support slopes to the backpart 12 resp.to the break 10.

/For the sake of order it shoullu be mentioned that with the simultaneous use of the hinges 18 and 19 both clembers of the top support stay Lrl 9 rigid connection,,-ihich each othergit seems,as if the two members were united. This structural solution does not belong to the subject of the invention/. Com16n. peculiarity of thle equipment.. having been di-cuEsed up to now lies j-n,that the members 1 of the top support are able to, take up the rock load in itselvez,while their differentiated -. ubmisEivene..s towards the rock load will be guaranteed by a restricted forced corii-Intion, from this two important advantages result,.,jhich callnot be found with known apparatuses.

The first advantage lice in that under the effect of rock load not the complete top support approaches,to At the same time the relatively stationary member of the top support assures mining height.

The other advantages lie in that when using more then ti,vo hydraulic prope,aE a result of the aformentioned advantages,in comparison to known solutions an equipment tnith a more efficient load bearing can be obtained. In Pigs. 19 and 20 an embodiment of the equipment aCcording to the invention may be seen, with which,in relation to the stationary member 1 of the top support the other member of the top support - being movable according to the fundamental principle of the invention - IE not turning around the hinge but it. is gliding parallel with its o.,vn plane.

Said closing means 21 - be-ing able to perform a sliding motion - is arranged belo-ij the member 1 of the top support. motion k.vill be performed by mcanS of the hydraulic cylindecr 20. Otherviiseg with this solution the prop 22 assure-- support between the sole-paxt -0 and the member 1 of the top -cu,rort.

z iVith the equipment acln-o-:.Jiny to figures 19 and 20 it is not nee-.ssary to use a zauide plate for C.uiding the coal into the inside of the equipment, having been recovered in course of caving the topeas the windov; -erving for the guidance of the coal into the equipment may be arranged above the conveyor, resp.such an arrangement becomes poE,-ible. Inspite of that,another version becomes possible too,,,,.jith which a stationary guide plate 24 is uSed or another guije plate 23 maY be u-.ed,,,rhich can be actuated and moved independently, in it..elf.

The beL-.jjeU-n the figures 19 and 20,and the previously described ecamples lies in,thet Ehe construction of the top support does not show a differenCiated submissiveness on the effect of rock load.

C, From the specification of the embodiments serving as examples it becomes obvious that with the equipment according to the invention by the divided state of the top support convergence and rock load can be decreased without in creasing the mass of the equipment.

In connection with the embodiment Epecified,additionally it can be stated that the equipment according to the invention is well suitabLe for the caving E method for the recovery of coal from the top and every possible technological version can be realized therewith. The equipment accozding to the invention differs in so far as from equipments being suitable for-the use of the known sublevel caving shields that in contrast known other equipments not the complete top support is, to be loosened in course of caving the coal in the top, but only the iovable member is to be loosened. A further considerable difference lies in that even during the period of cavings the butt end will be supported.

Out of the known equicments, in comparison the so-called sjEtems with two..cr-.pers,it is not even necessary to delimit the equipments accor-ing- to the invention,as the arrangement and system of the opening for draiving-off the coal from the top,is absolutely different.It becomes possible to establish a system with two Ecrapers,az shown -aE a matter of fact - in figures 9 to 20,vihich differ.. from the equipmentS shown as examples in so far ae,thet through the the roof caved coal does not arrive at the conveyor next to butt end,but it arrives to a secoid conveyor arranged at the rear part of the equipment.

c Naw,,the hinge -forming the fulcrum of the top Eupport reEp.the roof-in contrast to the embodiments illustrated in figures 7 to 20, is not arranged on th-e side lying oprosite to the butt end,but similarly to the embodiments according to figures 1 to '09 is arranged on the side facLrig the butt end.

The circumstance should be repeatedly emphasized,that with the equipment according to the invention the -opening for the coal caving method is not arranged in the parts of the equipment ljing below the plane of the top support,in,,hich cases the rock aboV@ the shield is not supported anymore, With the equipment according to the invention the opening for supporting the top is formed in the plane of the top support, being far most advantageous from the point of view of loading,than with the known Eoluti on_.,aS the relatively stationary member of the top Euppoxt,due to its decreased Eurface,tran-.fers a smaller load to the load bearing elements of the equipment.

At all events the equipment according to the invention is cheaper, conditions of production are more advantageous, safety can be increased,. accodingly considerable advantages can be achieved in mining opearation...

C

Claims (8)

What we claim:

1. Equipment for the support for underground mining operationE,having a Eole-part bearing up against the footwall, a top support connected thexeto,furtheron between the Eole-paxt and the top support and/or the back part one or more hydraulic props are. inserted, c h a r a c t c x i z c d in that it hat a top support coaDoEed of two membezE,lvhile out of these one member of the top support is practically -.tationerygvjhftreas the other member of the top..up,-ort is instaIled Eo,a...

to be able to turn around a hinge in re latLon to the member.

2. Equipment as claimed in claim 1, c h a r a c t e r i z c d iri that the Etg.fl-ionary of the top support encloEcE partly the member of the top support in a frame-like irlanner.

3. Equipment as claimed in claim 1 or 29 c h a r a c t c r i z c d in that a hydraulic cylinder is inserted between the member of the top zup,-ort and the back-part

4. Equipment as claimed in claim 1 or 29 c h a r a c t e r i z e d in that a clol-inz element is provided for, which can be displaced Lrl r-:.lation to the member of the top support a-rid vjhich is ectuated by a hydraulic cylinder.

5. Equipment as claimed in any of the claims 1t04, chara c t erized in that ithas a scuDr-ort for the butt end whi.-h is Co.r_nected to the stationary member of the top Eup,l-.oxt.

6. Equipment as claimed in claim 4,c h a r a c - t c r i z c d in that it is provided with a guide plate staying in a rigid connection with the closing element 0

7. Equipment as claimed in claim 4, c h a r a c t e r i z c d in that the guide plate can be displaced in respect to the closing element.

8. A device for use underground mining operations substantially as hereinbefore described with reference to any one of: Figures 1 and 2; Figures 3 and 4; Figures 5 and 6; Figures 7 and 8; Figures 9 and 10; Figures 11 and 12; Figures 13 and 14; Figures 15 and 16; -Figure 17; Figure 18; or Figures 19 and 20 of the accompanying drawings.

Published 1991 at The patent office. state House, 66171 High Holborn. London WC1R47P. Further copies maybe obtained from The Patent Office Sales Branch, St MarY Cray. Orpington. Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray. Kent. Con. 1187