CA2297494A1 - Conveyor apparatus for open-cut mining - Google Patents

Abstract

An inclined elevator for excavating an open cut mine in scopes has a traveling platform and counterweight coupled by cables whose upper and lower passes extend over upper and lower cable pulleys to the drum of a conveyor or drive machine. The cables can pass around a rerouting pulley which can be shifted on the foundation for the inclined elevator to compensate for increased depth of the excavation. The traveling platform which carries the car or truck for the mined material can have pins engaging in a bottom which is removable from the platform and can be locked in upper and lower positions relative to the foundation by pawls engaging in notches or recesses of the bottom.

Description

cowvs~ox ~npa~azvs go~a op~-cur ~~
SP$CIFICATrON
FIBI~ OF T~ INVBNTIOII
Our pxeseat invention relates to a conveyor apparatus for open-cut mining and especially far removal of the overburden and mine deposits ixi the formation of scopes is a step-Zike manner with progressively increasing widening of the excavation.
with i~screasing e$cavation depth.
OF T~ ~3TION
~a open-cut m~r~ag the overburden a~ad mute deposits are removed iaz a step-like forruation, i.e. with the formation of scopes. The depth of the excavation continuously increases arid with increasing depth. thexe is as increased w~.de~niug of the funnel-shaped opening of the excavation. The excavator is usually moved along a bottom of the excavation to form a scope and, depeadiztg upon the stability of the ground, the equipment used and economic conditions, the scope height can average arawad 15 m and for the removal of the loose material, the inclined planes betweext the scopes serve as roads along which the excavated material is xemoved. The deeper the deposit being mined, the wider must be the opening of the cut by a factor of 400 to 600, thereby defining the funnel shape of the excavation.

Material loosened by drilling or explosives (hard rock and solid aces) as well as the overburden are transported awray as a rule in trucks formed as trough tippers, mine cars and the like. These trucks txavei from the stopes to the grade surface or ground level along the road. The serpentine path increases with m3.ning depth and the travel can be at a speed of about 10 Km/h upwardly and about 35 Rm/h dowawardly. this requires high concentration of the part of the vehicle drivers and always creates the possibility of accidents.
08~7~G'~8 aF T8S I~1V'8"~TIO~
zt is the prixicipal object of the present invesztion. to provide a conveyor apparatus which can carry out mined material including the mined deposit and the overburden fro~a locations z,n an open-cut mining operation to the surface in a more ecoao~cal and reliable manger without significant cast.
Another object of the invention is to provide an apparatus for this purpose which allows ad~ust~aeat to increasing miu.iag depths .
It is also as object of thus invenrfon to provide a conveyor apparatus.for open-cut mining in a funnel-shaped excavation with removal of overburdened Wined deposits, formations of stopes and ~.rr~tereased v~idth at as opening of the funnel-shaped excavation at grade level w~.th increased excavation depth, whereby the drarabacks of earlier excavation techniques are avoided long transport distances are eliminated and the dagger of aGCldeatS Z8 mln3miZed.
Still another object of this invention is to provide an improved apparatus which obviates the drawbacks of earlier excavation systems.
SPRY OF T~ IfIV~TIQ~
The objects are attained, in accordance with the invention in a conveyor apparatus far the purposes described and which cart be advanced dov~iwardly for increasing depth of excavation. The conveyor apparatus of the invention eoznprises:
axe inclined elevator extending fremt ~ edge of the open.iag at grade level to the floor level;
a traveling platfczai riding oa the i.ucliaed eleirator and adapted to receive a truck to be filled with overburdex~ or 1~ mined deposits;
at least one cable passing over separate upper and lower cable pulleys alld having au upper pass of the cable egtexlding to the upper cable pulley from the traveling platforul and a lower pass of the cable extending fram the lower cable pulley along the elevator;
a counterweight riding oa the elevator and connected to the lower pass of the cable; and a conveyor mechanism operating at grade level at an upper end of the elevator gad having a cable drum looped by a 35 portion of the cable between the upper and lower sable pulleys.

According to the invention, therefore, au elevator along which trucks for receiving the mined material can be guided is provided to extend from an edge of the opening of the funnel-shaped excavation at grade level to a floor level at arhich S excavation is carried out and preferably to the bottom of the cut. At least one cable i.s provided which has upper and lower passes extending over respective cable pulleys with the upper pass of the cable being affixed to a glatform oa which the car.
usually a trough tripper or dumpable car can be carried while~the L0 lower pass of the cable is affixed to a counterweight. Both the platform and the upper weight are being guided along the inclined conveyor.
At grade level the cable passes around a conveyor mechanism ox machine. The mined material carried by the car or 15 truck is thus transported along the elevator in an uparard direction to the edge of the cut.
Because of the inclinatiaa of the conveyor which can correspond to the inclination of the funnel-shaped excavation, e.g. even with increasing mining depth, and by elimination of the 20 serpentine path which the cars or truck had to travel previously from the bottoia of the excavation to the top thereof, the distance which the trucks travel is min~mi.zed thereby simplifying the operations and xni.nimizing the burden placed on the trucks or cars.
25 A loaded trunk or car at the bottom of the excavation l need only be placed on the platform in its lo~rered position, secured in plane with appropriate arresting means and then transported driverlessly to the surface at which point another driver can take over control and transport of the ear or truck.
The result is a highly flexible. economical usage of personnel since different individuals can be provided at the surface and at the floor of the excavation for transport purposes.
Since the counterweight moves in a direction opposite the platform and balances the comparatively high oveight of the platform and the loaded car, which may amount to about 500 metric tons, the net mass which must be displaced by the input of energy can be only a fraction of the sum of the load carried by the truck or car. the weight of the truck or car itself, the oveight of the platform and the weight of the cable paths courr.ected thereto. The conveyor mechanism thus need only supply a fraction of the energy wh~.ch v~ould otherwise be necessary to move this latter total mass. It is possible to operate in a single track system with the workload operating iu its track and the counteraveight iu its track.
According to a feature of the invention, the conveyor mechanism driving the cable has a rerouting dram looped by the or each cable and beta~reea the upper and lorover passes of the or each cable or has individual pulleys or wheels far each cable the cable returning after being looped around this dru:a or the rerouting pulleys. The conveyor mechanism or drive may be of the Koepe type.

Preferably the rerouting drama is connected with the conveyor mechanism with a variable spacing therebetweeu, the system i-acludiag a cable magazine containing a supply of cable for lengthening of the travel of the cable. With increasing depth of excavation and thus v~ith increasing travel distance, the cable must be effectively lengthened so that there is a progressive increase ix: the cable weight as well.
For deeper excavations and thus the need to displace the platform to ix~.creasingly greater depths, it is merely necessary to release the rerouting dremz anchored to the foundation and move it to a new position closer to the dru~on of the drive mechanism. The movable drum is then fi-ged at this =lent position. The reroutixtg drum can have a diameter of, for example, 9 m cad can have jourBal blocks v~thlGh are shiftsble linearly on respective tracks. The force required for the shifting can be developed hydraulically and when a number of cables are provided for the elevator, a corresponding cumber of rerouting pulleys can be used instead of a single rerouting drum.
For increased output of the mine, a multiplicity of such inclined elevators caF1 be provided is the funnel-shaped excavation is spaced apart relatiox~ship therein.
According to a preferred emba.t of the invention, the rerouting drum or assembly of pulleys or rerouting roller can be inclined to the horizontal and each cable can pass around the cable dxupn of the drive mechanism 'with double looping so that each cable has at least two turns ou the cable drum in a pair of grooves. This permits the drive to be a conventional Koepe conveyor machine because, With the double looping, sufficient friction against the cable drum is achieved to enable the cable system to move extremely large loads which could not be handled S by a Koepe drive machine with a single L80° Ioop.iag of the cables. The double looping provides cables in two grooves to prevent slippage under the high weights which must be transported. Alternatively a dr~tt drive machine would have to be very large and hea~ce very expensive to handle lengths of cab7.e 1b wrhich can exceed 700 m, multiple cables of such length, and the loads coupled to them. The inclined orientation of the rerouting roller or the individual pulleys enables the double looping of the or each cable Without danger that cross over regions will bring about contact of upper and lower cable passes.
25 In that connection, the upper pass and lower pass cable pulleys are offset vertically relative to the cable drum of the drive machine. The upper. cable stretch a~od the lower cable stretch pass tangentially onto the rerouting roller and from the latter without interference of the oppositely travelling passes 20 with one axtother.
According to a further feature of the invention anal in another embod~m~~t thereof, to provide a greater degree of loosing of the cable around the drum or pulley of the drive mechanism and thus affording increased friction force between the 25 cable and cable carrier to allow large load ratios between the traveling platforia cable and the counterweight cable, the upper axed lower cable pulleys are laterally offset with respect to the drive machine and preferably offset from one another oppositely.
This arrangemex~.t can permit a looping of about 240° around the cable drum or pulley of the drive. ThE cable coming ~rom the platform passes over the upper cable pulley and cart meet the groove of the cable on the drive machine at a slight angle, e.g.
of 0.7 grad.
This deflection is obtained in spite of the fact that the cable pulleys have their axis paral7.el to the axis of the drive machine and perpendicular to the axis of displacement by laterally offsetting the upper and lower cable pulleys o~ith respect to the cez~.ter of the cable guide on the dz~m. After a 240° looping in the groove of the cable carrier on. the drive machine, the cable is deflected again at an angle of 0.7 grad ~.n xS the opposite direction to the lower cable pulley anal to the latter toward the counterweight. Since the center of the cable of the lower pulley is thus slightly offset from the center of the cable on the drive machine, at the crossing point bet~reen the oncoming and outgoing cable a substantial separation can be 2Q provided so that the passes do not interfere arith one another.
The angle or degree of offset thus contributes to the requirement for nox:interfering cable travel even. in the case of jumping of the cable. All of the cables in all of the regions which are equivalent can be parallel to one another.
25 The slight oncoming and outgoing angle which would otherwrise be required at the cable pulleys can be eliminated is _ g that the cable pulley axes can be inclined to the foundation.
The lateral shifting of the cable cexlters on the one haxid between the upper cable disk and the drive and on the other hand between the drive and the lower cable disk can be compensated by connecting the cables to the counterweight asymmetrically with respect to the center of gravity of the latter.
According to a further feature of the invention the cable neagazine to compensate for increasing depth by effectively lengthening can. be provided ozt the platform or the couate~eight in the form of a windlass drum v~hich is looped by two or more turns of the or each cable. Sufficient friction is thus obtafned by the plural looping in that the plural looping has been found to provide a sufficient Level. of friction. The multiple turns for cable allow sufficient cable to be stored for usual mina.ng operations. With a diameter of the windlass drsmi of 3 m, cable useful lives of two years o~ri.tI~ increases is depth of say 15 m per year may require three additional turns per cable. The arrange~~n,t of a windlass dz-um as the cable supply has the advantage that the weight of the windlass drat cad the cable supply can be part of the counterweight which would otherwise have to be weighted additionally.
According to a feature of this aspect of the ~..nventioa, the windlass dry is mounted rotatably on a support frame or has a shaft common to a number of w~dlass drums mounted don the support frame. If required the requisite cable supply can ba provided in readiness and mounted with the support frame or _ g _ the support frame. The windlass drums can be drive. by a anotar via a chain drive althoug~t the pay out of as additional cable supply is naturally done in load-free state of the cable.
In a multiple cable arrangemezst, each windlass druzu can be provided with a hydrau3.ic cylinder and Locking device which can serve to take up the Load and thus relieve the motor and chain transmission from the Load when the load is reapplied.
This mechanism can operate follo~ri.ng rotation of the drum to pay out (or take up) excess cable or to engage the drum 1Q for retensioning of the cable. The hydraulic cylinder and locking device can be mounted oa the support frame. T'ha cable, the hydraulic cylinder cad the locking mechanism can extend is the force application directly and can relieve the drive of the windlass dn~ from cable tension forces as has been mentioned.
~.5 According to still another feature of the invention, the traveling platform is formed is two parts from a frame std a removable bottom arhich is seated oa this frame. This feature increases the transport reliability since the bipartite configuration enables the bottom with the considerable weight of 20 the loaded truck to be held both ix~.upper cad in lower positions for loading and unloading relative to the elevator without le~zgtheniag the cables by loading or shortening the cables by unloading. In other words the bottom can be locked to the foundation, accordix~g to the iav~ztion, independently of the 25 traveling frame in upper cad lower positions of bottom and with precision.

For this purpose, at the four corner regions of the bottom, recesses or notches are provided into which upper and lower retaining pawls, controlled by appropriate signals, can be swung. As soon as the platform has been slowed down and shortly before it is brought to standstill, the end position which ca=t be signalled by limit switches or other electrical monitoring mesas can cause the retaining pawls to be swung into the travel path and swung either above or below the bottom to engage the latter.
Further lifting or lowering is then not possible even when, for exau~ple. the support frame continues to travel.
According to a further feature of the invention, at the four corners of the bottom there are holes in which pins of the traveling frame engage. the holes and the pins being inclined in the travel direction. At each o~ the four corners two 1S mechanically independent retaining pawls can be provided which engage over or under the removal bottom and which are free to move only when the friction force of the bottom against the respective pawl is relieved. When the pawls are all swung inwardly and the botto~t is pressed against the upper pawls, a signal instructing the pawls to swing outwardly will only be effective on the pawls lower whereas the reverse is true when the weight of the bottom is on the lower pawls. Wben of course the frictional contact is relieved, the pawls which have been fractionally retained are permitted to swing.

axlsF n$sc~z~rlo~ of T~ n The above and other objects, features, and advantages will become more readily apparent from the fol.lowiag description, reference being made to the accompanying drawing in which:
FIG. 1 is a side elevational view, partly in section showing the basic elements of an iz~clined conveyor is accordance with the invention;
FIG. 2 is a detail of structure at the grade level showing the cabling pattern for the conveyor of FIG. 2 cad with different diameters of the pulleys and the drum;
FIG. 3 ~s a section along the line III-III through a corresponding structure with eacaggerated inclination and differences in diameters of the cable drum of the conveyor mechanism and the rerouting rollers;
FIG. 4 is a detail of the region IV of FIG. 3 drawn to a larger scale;
FIG. 5 is a deta~.l of the cabling system with an exaggerated inclination of the rerouting drum;
FIG. 6 is a section through the region VI of the apparatus of FIG. 5;
FIG. 7 is a side view drawn to a larger ~3cale is FIG. 1 of the cabling system at the mouth of the excavation illustrating another feature of the invention;
FIG. 8 is a side view of a detail of the iaciiaed elevator showing features of the traveling platform:
- is -FIG. 9 is a front view of the platform of FIG. 8 ixt which a windlass type of cable magazine is provided;
FAG. 10 is a detail of FIG. 8 showing a load takeup device for the cable magazine of FIG. 8;
S FIG. lX is a side view of a holding pole at the upper end of the inclixted elevator;
FIG. I2 shoars the pole of FIG. 11 is its engaged position in front view;
FIG. 13 is a detail, partly ix1 section, of axt arresting 1.0 pin as provided at each of the four corner regions of the removable bottom;
FIG_ 14 is a view similar to FIG. 11 but of an alternative reta~.niag pale arrangement as provided at each of the four corners;
15 FIG. 15 is a detail of an alternative cable to that of FIG. 2 without a rerouting drum as provided in the system of FZG.
2;
FIG. 16 shoxs a detail of the cable travel of FIG. 15;
and 20 FIG. 1? is a plan view of a metlticable system with cable travel in accordance with the principles of FIGS. 1S and 16.
SPgCIFIC D$SCRI~IdN
~'IG. 1 shows one of a number of inclined elevators 2 25 which can be provided iz~ a funnel-like excavation and which serve to advance the excavation downwardly by remrwing the mined material, forming stopes and a wide mouth for the open-cut mine.
The open-cut or funnel-shaped excavation as a whole has beez~
represented at 1 and the inclined elevators 2 can be identical to one another, The elevators are themselves mounted upon concrete foundations 3 and extend frvan the ground surface or grade 4 to the base 5 of the funnel which may be of a depth of say 180 ~n from the grade surface 4. The elevators 2 can be inclined at an angle a at about 50° axed can be spaced around the excavation to aLin;,~,;ze travel of the oars onto the platforms of these elevators at the excavation levels.
each of the elevators has a traveling platform 6 azld a couuterareight 7 which move oppositely up and do~ra the elevator via cables 8, 81. . . . $a, the cable ends being fixed on tote one baud to the traveling platform 6 and on the other hand to the counterweight ?.
The Gables 8 - $n run over cable pulleys 9 or ZO and are looped aro~d a cable dram 11 of a conveyor meehan.ism or drive machine Z2 fixed at grade level. Fach cable has upper and lo~,rer cable passes I9 or 14 running in opposite senses to the cable dry 11.
The traveling platform 6 can carry cars or trucks 16 which can be loaded with the mined material and can be secured on the platform to transport the mined mater~.al upwardly as shotva iu.
F'1G. 1 from the base of the funnel-shaped excavation t4 the surface while the counterovei.ght ? travelled into its lowermost position. The traveling platform 6 arid the counterweight 7 move on wheels 17 riding on rails 1$ (FIG. ?) on the inclined base.
A rerouting drum is provided opposite the cable drum 1i as2d receives the cables 8 - 8a. This rerouting drums can also be formed as a series of individual pulleys for the respective cables 8 - $a. The rerouting drum or set of pulleys 15 serves oa the orte hand to increase the frictional engagement of the cables against the cable drum 11 wh~.ch are looped at least twfce by each cable and to spread the load applied to the foundation. Far this IO purpose, the rerouting drum LS is inclined tp the horizontal plane S on the foundation 3 (FIGS. 3 and S?. The cable pulley 9 Which s.s vertically upwardly offset from the cable drum i1 (FIGS.
Z and 2), receives the upper pass of the respective cable 8 - 8s extending tangentially from the cable drum 21, zn DIGS, 3 and 5, for simplicity of illustration, only a single sable groove 19 is shown for the rerouting meager 15 although it will be understood that the plurality of cables 8 - 8n will pass around the rerouting drum or assembly of pulleys as well following a f~.rst loopir~g of the cable~ drum 11. In other words each cable caxt be first looped around the cable drum 11 and they pass around the rerouting drum 15 back to the cable drum 11.
FIG. 4 showB that each loop around the cable drs~ 11 lies in a respective groove 19a, 19b for such cable. In FIG. 3 for simplicity as well, only a single groove l9~and the pair of grooves 19a cad 19b for one cable 8 have been shown.

Corresponding grooves being provided for each of the other cables. Each cable 8 - 8a loops the drum 11 at least twice.
As can be seen from grG. 2, the cable 8 passes over the cable pulley 9 {from the platform 6) is a pass al tangentially onto the cable drum 11, then loops the latter through about 180°
to farm the cable pass bl running tangentially to the rerouting drum 15 passes tangentially from the rerouting drum is a pass b2 back to the cable drum 11 and after traveling 180° around the cable drum 11, extends at a2 tangentially onto the cable pulley ZO to the counterweight 2.
In FIG. 3 the points at which cable 8 arrives~fro~tt the cable pulley 9 and from the rerouting drum 15 have been idezltified at 20 and Zl and the points at which the cable 8 leaves the rearouting drum for the cable pulley and the rerouting IS drum 15 are designated at 22 and 23 while the point at which the pass bl meets the rerouting drum, is shown at 24 while the point at which'the pass b2 leaves the routing drum 1S is represented at 25.
The rerouti.ag drum 15 can be used as a cable magazine 2p and in this case its distance from the drum 11 of the drive xnechaaism 12 caa be varied as has been shown in FIG. 7. For au increase in the effective cable length with depending of the mixing excavation, the rerouting drum 15 can be moved from position II into position I, at a very short distance from the 25 cable drum, so that the length of the cable can effectively double the stroke of the platform.

The foundation 3 is, of course, previously provided with fixing points, for example, the positions I and II, at which the journals 27 for the rerouting dru~2 or pulleys can be anchored. It is thus only necessary to release the anchorage o~
the rerouting drum 15 and to move it to the new position to lock it in place again, usually with bolt-type fasteners.
To displace the rerouting dx~ 25 after release of the anchorage to the cozzcxete foundation 3, hydraulic lines 26 can be provided as has been shawxt in FIGS. 5 , and 6, the sot~.xce of the hydraulic fluid under pressure having not been shown. The journal 27 can be shifted along rails from one position,.to the other and, where farce is required for this purpose, hydraulic cylinders can be utilized.
A variant of the cab~.e magazine has been shown in FIG.
x5 8.
zn this figure, oa a common shaft 29, a multiplicity of windlass dress 30 are rotatable in a support frame 28, the number of windlass drums 30 being equal to the number of cables 8 - $n coupling the platfoma with the counterweight. Reference may be had to FIG. 9 which shows a plurality of such windlass drums.
The support frame 28 with its windlass dress 30 is disposed in the traveling frame 31 of the traveling platform 6 which has tyro major parts, namely, the traveling frame 3i and a removable bottom 32 which is mounted thereon. Alternatively, the cable magazine can be provided on the counterareight.

The widths of the sable drums 30 correspond to that required for the requisite cable supply and, as a rule, each cable drum 30 will permit the respective cable 8 to be looped therearound in a number of turns as has been shows especia~.ly for S the two outeranost windlass drvxas 34.
For paying out the requisite amount of cable, thereby permitting the greater travel of the platform, the windlass dxum,s 3a are provided with a motor 33 and a chain drive coupling the mortar arith the windlass drums 30.
In addition, a load take up device 35 is provided to engage the windlass dxums and far retightening of the cable. As can be seen from FIG. 10, the latter can include a repositioning device 37 and a hydraulic cylinder 36. The cables 8 - 8n in their new lengths are fixed and the drive 33, 34 relieved by this mechanism.
As can be seen from FIG. 10, the hydraulic cylinder 3G
and the locking mechanism 37 are connected by links 38 and 39 with the w~.ndlass drum 39 and for each of the lengths 38 and 39, a respective roar of bores 40, 4I are provided along a part of a circle so that by changing the points at which the links 38 and 39 are pivotally connected to the drum 30, the effective links of the cable 8 - 8~ can be changed, effectively fareshorteaed.
The pins which connect the ends of the links 38 and 39 to the selected bores 40 and 41 have not been shovPn. Iu operation, the pin connecting the links 38 with a hole 40 is withdrawn, the drum 30 is rotated to extend or reduce the effective length of the travel of the cable and hence of the platform, the hydraulic cylinder 36 permitting that adjustment, and the pin is then reinserted. When a major ratatiaa or fraction of a rotation is required, the pan, coax~ecting the lip3c 39 is ~rithdrawn from the hole 41 and replaced in the hole s~rhea the rotation of the windlass drt~ 30 is completed. The holes 40 and 41 being selected to set the effective length of the cable desired.
To fix the replaceable bottom 32 on the frame 31 of the platform 6 (FIG. 8), at each corner o~ the platform 31 an arresting pin 42 is provided. The pins 42 are angled ixi the travel direction of the inclined elevator and engage is complementary bores 43 of the replaceable bottom 32 and bald the latter previously in position on the traveling frame 31.
Z5 The two part platform 6 has the advantage that the replaceable bottama 32 with the loaded truck or ear 16 thereon can be held in place with precise positioning even in au emergency.
For this purpose. at the four corners of the bottom 32, detest recesses or notches 44 are provided (see also FIa. 8? 5.n.arhich detest pawls 45 (FIG. 11} can engage. The pawls 45, which are shiftable between their end poai.tioas by cylinder 45 are responsive to locking arid unlocking signals, can engage in the notches 45 and retain the bottom 32 against a loa~rer pawl or rest 44. The pos3.tioas of the pawls can be monitored by the control system. FzG. X2 shows the engagement of an upper pawl sa its notch 44. when the paGrls axe xetxacted, of course, the bottom 32 can, be retmoved .
FzG. 14 shoars a modification of the pawl and detent system of FIG. Il for the exact poaitioniag from both top and bottom of the replaceable bottom 32. Here at each of the four corners, two detent pawls 45a and 45b are provided. The decent pawls 45a and 45b are operated by respective cylinder 46 independently of one another. Although all eight upper and all eight Zower pawls can be simultaneously activated and swung 1o together for fixing the bottom 32 for loading or unloading using a signal system which has not been illustrated. The pawls thus engage in correspond3.ng recesses (see FIG. 12) in the bottom 32.
The pawls 4Sa azid 45b defining the upper and lower end.
positions for the bottom 32 can operate ag follows:
Upper end position.
The bottom 32 carrying a loaded truck or car is stopped with the aid of the signalling system at a defined position. Ail eight pawls are simultaneously actuated and swung inwardly. In this position the bottom 32 can be moved upwardly or downovardly through several cars (compare FIG. 14) until it comes to rest against either the upper or lower retaining pawls 4Sa ox' 45b.
After the loaded truck has Left the replaceable bottem~
32, since the cable tension has been reduced, the bottom 32 comes to rest against the upper pawls 45b.
The bottom 32 is again loaded. The cables are more strongly stressed. With the increase in stress, contact of the bottom 32 against the pawls 45b is terminated and thus all eight pawls 45a anal 45b are free.
The renewed loading can, however, be so snxall that a contact with the bottom 32 and the upper pawls 45b holds the latter in. All eight pawls 45a and 45b. however, si.multa~seousLy receive the signal. to swxag outwardly. The pawls 45a which are intended to engage 25 bottoat 32 from below then. xtwing out immediately. The pawls 45b which are intended to engage the bottom frcoa0. above, cannot however swing outwardly because of the frictional eilgagtm~t with the bottom. A requiremteat for this operating state is that the hydraulic force be suffi.ciex~.tly small that it does not overcome the friction force.
The travelling platform, frame and bottoms are moved downwardly and this movement causes the frictional contact to be 1S removed so that the pawls 45b swing outwardly and a signal produced as a result to signal the disengagement of the body 32.
Dower end position:
The bottom 32 with the aid of the aignalliag system is stopped at a defined position. All eight pawls 45a and 45b are simultaneously actuated anal swung ia. in this position the bottom 32 can still move upwardly and dawawardly until engaged by the upper or lower pawls. ~,'he platform is moved dowaxardly somewhat further where upon contact between, the bottoiu 32 and the travelxag frame 3s released. The bottom 32 rests on the Lower pawls 45a. In this position the bottom 32 is unloaded and reloaded. It remains resting on the lower pawls 45a. A aigaal is then obtained to swing all eight pawls outwardly. The upper pawls, out of frictional contact with the bottom 32, s9,ra..ag outwardly ia~ediately. The latter pawls ~Sa remain s~rvng in since the hydraulic force of cylinder 46 is less than the friction. force between the bottom and these pawls.
The traveling frame 31 is moved upwaz'dly so that the bottom 32 is lifted and via pins 42 is again fixed on the traveling frame 31. Pith increasing displacement the lower pawls 32 are freed from frictional engagement cad fall out. The result is a reliable engagement of the bottom 32 at grade level from transfer of trucks to and from the bottom and nevertheless simple transfer to axtd froa~a the traveling frame 3Z. The pawls can he triggered simultaneously both for the upper and lower end portions and in spite of that, the cad portions are defined.
Iu FIGS. 15 - 17, the cables are looped on the dram, 11 of the mechanism through about 240° so that with reduced cable tension, a comparatively high friction force can be generated between the cable dry and the cable or a cable carrier oa this drum, namely, a cable carrier such as the groove member 19 shoava is FIG. 16 cad the respective sable 8a through 8n. Ths cable pulleys 9 and 10 are here somewhat offcenter arith respect to the conveyor mechanism 12 with its cable drum 11 as can be seen from SIG. 17. The cables 8...8a eomi.ng frown the platform 6 or the trucks in the multicable arrangement of FIG. 17, gals firstly over the upper cable pulleys 9 cad then at a small angle 4$ over th4a grooved carriers 29 of the dram. 11 cad f rom the lower i,ri the opgosite sense over a small aagle 49 to the lowEr cable pulleys (see FIG. 16) to the cable ends connected to the counterweight at the cross over pouts 5Q betw~eea the oacoming aad outgoing cable, a relatively large cable spacing 51 (FIa. 16) is provided 5 that prevents contact betmeea the tvro passes of the cable.
- a3 -

Claims (16)

1. A conveyor apparatus for open-cut mining in a funnel-shaped excavation with removal of overburden and mined deposits, formation of scopes and increased width at an opening of the funnel-shaped excavation at grade level with increased excavation depth, said apparatus comprising:
an inclined elevator extending from an edge of said opening at grade level to said floor level;
a traveling platform riding on said inclined elevator and adapted to receive a truck to be filled with overburden or mined deposits;
at least one cable passing over separate upper and lower cable pulleys and having an upper pass of the cable extending to said upper cable pulley from said traveling platform and a lower pass of the cable extending from said lower cable pulley along said elevator;
a counterweight riding on said elevator and connected to said lower pass of said cable; and a conveyor mechanism operating at grade level at an upper end of said elevator and having a cable drum looped by a portion of said cable between said upper and lower cable pulleys.

2. The conveyor apparatus defined in claim 1 wherein said conveyor mechanism comprises rerouting means receiving said portion of said cable from said cable drum and returning said portion of said cable to said cable drum, said rerouting means comprising a rerouting drum looped by said portion of a plurality of cables or respective pulleys individual to a respective cable of a plurality of cables.

3. The conveyor apparatus defined in claim 2 wherein said rerouting means is said rerouting drum sad said rerouting drum is inclined to a horizontal and said cable drum has a pair of grooves for receiving two turns of each cable.

4. The conveyor apparatus defined in claim 1 wherein said upper sad lower cable pulleys are vertically offset relative to said cable drum.

5. The coaveyor apparatus defined in claim 1 wherein said sable drum is operatively connected to said conveyor mechanism with a variable distance between said cable drum and said conveyor mechanism.

6. The conveyor apparatus defined in claim 1 wherein said upper sad lower cable pulleys are laterally offset from said coaveyor mechanism.

7. The conveyor apparatus defined in claim 1 wherein said upper and lower cable pulleys are offset from one another in opposite directions.

8. The conveyor apparatus defined in claim 1 wherein at least one of said platform and said counterweight has a traveling frame guided oa said elevator and provided with a windless drum around which said cable is windable is a plurality of turns.

9. The conveyor apparatus defined in claim 8 wherein a plurality of said cables are provided and said traveling frame is provided with a support frame carrying a common shaft on which a plurality of said windlass drums are mounted, each of said windlass drums receiving a respective one of said cables.

10. The conveyor apparatus defined in claim 8, further comprising a hydraulic cylinder and a pin mechanism acting upon said windlass drum for controlling an effective length of said cable.

11. The conveyox apparatus defined is claim 8, further comprising a motor and a chain coupling said motor with said windlass drum for driving said windlass drum.

12. The conveyor apparatus defined in claim 1 wherein said platform comprises a traveling frame and a removable bottom loosely resting on said traveling frame.

13. The conveyor apparatus defined is claim 12 wherein said traveling frame has at four corners thereof arresting pins engaging in said removable bottom and extending is a travel direction of said platform along said elevator.

14.. The conveyor apparatus defined is claim 12 wherein at corner regions of said removable bottom, detent receptacles are provided into which signal-controlled retaining defeats can be swung in a travel direction of said platform at upper and lower end positions of said platform.

15. The conveyor apparatus defined in claim 14 wherein at each of four corners of said removable bottom two retaining detents are provided including one detent engaging said bottom from above and a second detent engaging said bottom from below.

16. The conveyor apparatus defined in claim 15 wherein a total of eight upper detents and eight lower detents are provided sad all of said detents are swung away from said removable bottom by a control signal.
ge-