Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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Description
FINISHED-PART TRACK FOR AN INCLINED CONVEYOR SYSTEM FOR
MINING TRUCKS
BACKGROUND OF THE INVENTION
[0001] The invention relates to a finished-part track and the production
thereof.
Specifically, the invention relates to a finished-part track for an inclined
conveyor
system for mining trucks in opencast mining.
[0002] Application for the invention is found in opencast mining, particularly
for
removing the mineral deposit and the waste piles accumulating during
horizontally progressing mining taking place in stair-like sections, wherein
with
increasing mining depth, a mining funnel is formed that is widening
correspondingly greatly towards the top.
[0003] Mining excavation on the earth's surface requires that the waste
located
on top of the deposit, and subsequently, deposit and waste be removed, for
which purpose deposit and waste are mined in so-called stopes, that is, in
step-
like sections. The height of the stopes determined by the firmness of the
ground,
the equipment used, and economic considerations is on average about 15 m.
For removing the loosened material, inclined planes between the stopes are
made into transport routes. The deeper the deposit is mined, the larger is the
opening of the mining funnel thus being formed, widening by about 40 to 60
towards the top. As a general rule, the material to be mined loosened by
drilling
or blasting (hard stone, compact ores) as well as the waste are transported
from
the mining sites to the earth's surface by mining trucks, which are heavy
goods
vehicles built as dump trucks, via the transport routes established between
the
stopes. The serpentines getting longer and longer with increasing extraction
are
thereby travelled upwards at about 10 km/h and downwards at about 35 km/h,
which requires extraordinarily high concentration from the drivers, and always
bears the risk of serious accidents.
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[0004] In order to circumvent this problem, inclined conveyor systems are
proposed, with the aid of which the mining trucks are conveyed in an empty
state
to the mining site, and are then conveyed out of the mining funnel in a loaded
state. Essentially, the inclined conveyor system is a mobile plafform, which
can
be moved up and down on an inclined track by way of corresponding tackles.
[0005] The travel track extending down below with the incline of the mining
funnel thereby makes serpentine navigation dispensable, which on the one hand
makes working conditions substantially easier, and on the other hand relieves
the mining trucks at the same time. For a mining truck loaded on the floor of
the
funnel only needs to be placed onto the lowered mobile plafform equipped with
locking means for the car wheels, and is then conveyed automatically to the
top,
where a driver enters the truck for further transport. In this way, a very
flexible,
economical interplay can be achieved, for which different personnel is on hand
at
the funnel floor than is on the earth's surface.
[0006] However, the problem with these inclined conveyor systems is that as a
general rule, the inclined tracks have to be installed using site-mixed
concrete,
which is costly on the one hand, and on the other hand makes it almost
impossible to extend or alter the inclined track as the mining progresses.
SUMMARY OF THE INVENTION
[0007] It is the object of the invention to provide a class-specific conveyor
system, which can be constructed and installed directly at the site of
operation in
a simple and cost-effective manner.
[0008] This objective is met according to the invention by the method and the
finished-part track as defined in the claims.
[0009] Accordingly, an inclined conveyor system is installed extending from
the
edge of the mining funnel, that is, the opencast mine, on the earth's surface
to
the floor of the mining funnel, starting at an upper edge of the opencast
mine.
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According to the invention, the travel track of the inclined conveyor system
is
made of prefabricated components. The inclined conveyor system further
comprises a conveyor platform that can be accessed by mining trucks, and a
counterweight, which runs underneath said conveyor platform in the travel
track.
In this way, conveyor plafform and counterweight travel within the travel
track on
different tracks arranged in a superimposed fashion, said tracks being
provided
with rails.
[0010] In the method for producing a track system from prefabricated parts, a
foundation is provided initially. The track system can thereby be assembled
starting from the floor of the open pit, or else from the upper edge of the
open pit
to the floor. Preferably, this foundation is built from the excavation
material at
disposal in opencast mines, that is, directly into the walls of the open pit.
At least
one base element is placed onto the constructed foundation. This base element
is formed of at least two base plates, wherein said base plates are spaced
apart
by at least one cross member, and the base plates are connected to the cross
member. This connection of the base plate to the cross member can be done by
way of a form-fit and/or force-fit connection. Beneficial are form elements in
the
connection, which are complemented by screws. For this purpose, both in the
base plate and in the cross member, preferably metal structures are provided
at
appropriate locations, which, particularly preferably, are integrally cast.
Furthermore, the space provided in the supports for the screw connection
(pockets, recesses etc.) can be filled by a grouting with concrete or another
suitable material.
[0011] In order to improve the stability, it is conceivable to construct an
adhesion-promoting, that is, adhesion increasing intermediate layer from
suitable
materials between the base element and the foundation.
[0012] The base element is fixed in place on the foundation by way of
anchorages, which can also extend through the foundation into the natural
subsurface. At least some of the anchorages can thereby be installed in an
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overlap area of two adjacent base elements so that the anchors used there
anchor both base elements.
[0013] When anchoring, the anchors can be mounted on previously prepared
structures in the respective base elements, or else these structures are only
prepared when installed at the installation site. Preferably, these structures
are
bores, through which the anchors are driving into the subsurface. However,
other structures, to which the anchors can be connected, are also feasible.
The
number of anchors primarily depends on the weight of the assembly to be
anchored and the condition of the subsurface.
[0014] After anchoring, at least one track element, preferably at least two
track
elements, are placed onto and connected to the base element. Alternatively,
the
base element can be mounted together with the track elements, wherein in this
case, the structures for the anchors can already be present, or they can be
prepared at the place of installation, wherein the structures can extend both
through the respective track element and through the base element. It is
beneficial that the track elements for the two tracks are identical parts so
there is
no need to manufacture, store, and install different parts.
[0015] With the aid of spacer elements, which are interposed between the base
element and the track element, the individual track elements are aligned with
one another. Furthermore, the individual faces of work, or possible gaps that
developed, both between the adjacent base parts and the adjacent track parts,
and the adjacent rails positioned on the track parts, can be filled, and the
parts
can be coupled in this way. This is particularly beneficial with regard to the
rails
since vibrations of the conveyor plafform, that is, the counterweight can be
reduced.
[0016] Furthermore, the respective bordering base elements and track elements
can be connected by way of connection structures like tension anchors, thread
connections, or any other imaginable form-fit, force-locked, or adhesively
joined
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type of connection. The connections, with which cross member and base plate
are connected, are also conceivable here.
[0017] An element of the prefabricated track comprises at least one base
carrier,
at least one track element, and a plurality of spacer elements, which are
arranged between the base carrier and the track elements for the alignment
thereof with one another. Furthermore, at least one shear cleat is provided,
which is likewise arranged between the base carrier and the track element, and
which transfers the static and dynamic stresses impacting the track element to
the base carrier/the base element, and thus to the foundation by way of the
anchorages. Preferably, the shear cleats are centered and in conformity with
one another, both in the track element and in the base carrier. The surfaces
of
the shear cleats touching one another can be made without cladding of the
material of the base carrier/track element, or, for example, metal plates can
be
interposed. Furthermore, shear force consoles for the occurring shear forces
(not in the direction of the travel direction of the plafform/the
counterweight) are
provided on the base carrier. These absorb potentially occurring shear forces
and transfer them to the foundation by way of the anchorages.
[0018] The base carrier can also be provided with at least one structure on
the
two ends pointing to the next base carrier during installation, which allows
adjacent base carriers to be connected to one another, preferably by form fit,
such that while being anchored to the foundation, the base carrier no longer
has
to be held by additional structures. The underside of the base elements facing
the foundation can be calculably roughened by way of inlaid, that is, attached
strips or similar structures molded on the base element, and can be connected
to
the foundation, that is, the subsurface, by local grouting. Furthermore,
shelves
can be placed into the developing interspaces between the cross members and
the base plates for reinforcement. Preferably, these are geometrically
designed
such that they are held between the base carriers and cross members by form-
fit.
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[0019] The track elements form two levels of different heights on each base
carrier, and together with another base carrier in a base element, form two
tracks, which, as a result of the differing height levels, are arranged
superimposed upon one another, and are formed of two rails each. These rails
can be connected to the track element either directly, or by way of interposed
structures. Preferably, the rails are of a two-part design so that an upper
part of
the rail is connected to a lower part of the rail by a ¨ preferably detachable
-
connection. Said lower part is detachably or fixedly connected to the track
element. For example, the lower part of the rail ¨ or with a one-piece design,
the
one rail ¨ can be directly cast with the track element. This has the advantage
that a worn upper part of a rail can be replaced, and no elaborate welding of
material on site, for example, is needed. Preferably, all rails for the two
tracks
are of the same type and size so that there is no need for different types of
rail to
be held available at the building site. The spacer elements are arranged
between the base element and the track elements such that a space between
the two elements can be varied. Furthermore, the spacer elements can be
placed such that they are able to transfer the dynamic and static stresses
impacting the track part to the base element. Thus, shear cleat can be
dispensed with. In a preferred embodiment, a spacer element is a trapezoidal
thread spindle with fitting nut, that is, threaded sleeve. A spacer element
such
as this is then inserted into a base carrier, that is, a track element such
that it
can be adjusted, and the respective screw part can engage with the nut part in
the state of assembly of both elements. Generally, any kind of spacer element
can be used (wedges, hydraulic presses etc.). The spacer elements allow a
precise alignment of the travel tracks for the platform and the counterweight,
even with lower installation precision of the base elements. Furthermore, once
the interspace has been adjusted, it can be advantageous to relieve the spacer
elements, at least partially, by using supports between the track element and
the
base carrier.
[0020] Furthermore, the track element can be provided with shear force
holders,
which, in turn, can carry rope guide pulleys. Preferably, each track has a
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dedicated shear force holder and with rope guide pulleys. However, a central
shear force holder is also feasible. Separate rope guides not configured for
transferring the shear forces are feasible as well. The shear force holders,
together with the shear force consoles, reinforce the prefabricated component
in
a beneficial way.
[0021] Possible materials for the prefabricated components are concrete and
steel, however, fabrication from composite materials is also feasible, which
can
also have recycled portions, where appropriate.
[0022] On the outer sides of the base plates, devices for fastening handrails
and
stair segments can be provided so that a walkway next to the track can be
provided.
[0023] The aforementioned features of the invention can be used in any desired
combination without deviating from the essence of the invention. Likewise, it
is
not necessary for all features to be present in one embodiment.
Additional features, characteristics and advantages are shown in the following
description of a preferred embodiment of the present invention, with reference
made to the attached figures, which are to be viewed exclusively as
illustrative,
and in no way as limitative.
BRIEF DESCRIPTION OF THE FIGURES
[0024] Fig. 1 is an overview of an inclined conveyor system for mining trucks
built of prefabricated components according to the invention.
[0025] Fig. 2 is a perspective sectional view of a prefabricated component of
an
embodiment of the invention according to Fig. 1.
[0026] Fig. 3 is a side view from the outside of a prefabricated component of
an
embodiment of the invention according to Fig. 1.
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[0027] Fig. 4 is a cross-sectional view of a prefabricated component of an
embodiment of the invention according to Fig. 1.
DETAILED DESCRIPTION OF THE EMBODIMENT
[0028] Fig. 1 shows an inclined conveyor system for mining trucks 1, the
travel
track of which is built from the prefabricated components 5 according to the
invention. On said travel track 2, both a conveyor platform 4, which can
accommodate a mining truck 3, and a counterweight 6 travel. The conveyor
plafform 4 and the counterweight 6 travel on tracks A and/or B, which are
arranged superimposed upon each other. The incline of travel track 2 is
identified by angle a, which is typically between 40 and 60 .
[0029] Fig. 2 shows the prefabricated component 5, the primary elements of
which are a base element 51 comprising two base carriers 510 (only one is
shown) and three cross members 520 (only one is shown), as well as four track
elements 52 (only two are shown). The base element 51 is connected to the
track elements 52 by way of shear cleats 53 and a plurality of spacer elements
54, and supports 60. The spacer elements 54 are anchored both in the base
carrier 510 and in track element 52, thus connecting elements 510 and 52 in an
adjustable manner. The spacer elements 54 are configured as trapezoidal
spindle lifting units. After adjustment of the spacer elements 54, the
supports 60
relieve the spacer elements 54, at least partially.
[0030] The prefabricated component 5 is provided with two tracks A and B, as
can further be seen in Fig. 2. Said tracks A and B are arranged superimposed
upon one another so that the counterweight 6 can travel through underneath the
conveyor platform 4 when the two meet. The different levels of the tracks come
about as a result of the shape of the base carriers 510, where the fittings
(shear
cleats, spacer elements, support elements etc.) for the track elements 52 are
located on different levels. The track width of the inner and lower track for
the
counterweight 6 is smaller than that of the track for the conveyor platform 4.
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Tracks A and B each are comprised of a pair of rails 55 (shown schematically).
In this embodiment, crane rails of type DIN 536 A 150 are used.
[0031] As can be seen in Fig. 3, the prefabricated component 5 has a shear
cleat, however, only the shear cleat 53 formed between the base carrier 510
and
the track element 52 is shown. Each of the shear cleats 53 of prefabricated
component 5 is provided with an upper part 53a and a lower part 53b. The
upper part 53a is arranged with respect to the lower part 53b such that it is
in
uphill position and overlaps with the lower part 53b. In this way, a static
and
dynamic stress can be transferred to the respective base carrier 510 of the
base
element 51 by way of frictional engagement of the two parts 53a and 53b. The
shear cleats are each centered in the base carrier 510. The overlap of the two
parts 53a and 53b of the shear cleat has to be large enough so that even at
maximal distance between the base carrier 510 and the track element 52 a
sufficiently large overlap surface is available in order to transfer the
occurring
static and dynamic stresses.
[0032] The track element 52 is further provided with a plurality of holes 59,
into
which the anchors are inserted, which then connect the base element to the
foundation. The number
of holes 59, and thus the anchors used per
prefabricated component 5, primarily depends on the load to be transferred,
the
type of anchors, and the subsurface. The holes 59 can already be provided
during the manufacture of the prefabricated component, or they can be made at
the installation site at the open pit, depending on the number of anchors
needed
in the particular section.
[0033] Fig. 3 further shows overlap areas, that is, engagement areas C and D,
respectively, by way of which adjacent prefabricated components are in
engagement with one another. Furthermore, shear force consoles 511 of the
base carrier 510 are shown, which laterally support the track element 52, and,
together with the shear force holders 56, reinforce the prefabricated
component
5. A handrail 512 is mounted to the shear force consoles 511. Together with a
flight of stairs 513, the handrail 512 forms a staircase next to the travel
track of
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the plafform. Sectional view E shows the use of interposed plates in the shear
cleat.
[0034] Fig. 4 is a cross-sectional view of the essentially symmetrical
construction of the prefabricated component 5. The prefabricated component 5
is further provided with two shear force holders 56 and 57, which support the
respective track A and B. These shear force holders 56 and 57 prevent a
deforming of the prefabricated component 5. In this embodiment, shear force
holders 56 and 57 also carry a plurality of rope guide pulleys 58, with which
the
ropes needed for operating the inclined conveyor system 1 are guided.
Sideways on the base carrier 510, shear force consoles 511 are shown. Shear
force holders 56, 57, and shear force consoles 511 reinforce the track
elements
52. By way of the holes 59, both the base carriers 510 and the cross members
520 can be anchored. A joining area of the base carrier 510 with the cross
member 520 is not shown. Details E and F show, obscured, the shear cleats 53
between the respective track elements 52 and the base carriers 510.
