Mobile connecting belt bridge for open pit mining

The connecting belt bridge provided with the feed end side and the discharge side end each supported on their respective travelling means, the discharge side travelling means including a travelling unit which is not railbound, the connecting belt bridge being pivotally supported on the discharge side travelling means about a vertical as well as a horizontal axis and on the feed side travelling means by a longitudinally displaceable single point support including a support beam which can be horizontally aligned and has at its feed side end a feed jib hinged on by way of a horizontal transverse axis.

This is a national phase application of PCT/EP 93/00318 filed 10 February 
1993 and based, in turn, on a German application P 42 05557.1 filed 24 
February 1992 under the International Convention. 
FIELD OF THE INVENTION 
The invention relates to a mobile connecting belt bridge for open pit 
mining comprising one end on the feed side for being fed by a mining or 
winning apparatus and a discharge end for transferring conveyed material 
onto a pit level belt. 
BACKGROUND OF THE INVENTION 
Known connecting belt bridges are--optionally by way of an intermediate 
belt bridge-fed with a material to be conveyed either by a 
substantially-stationary winning apparatus (e.g. a bucket wheel excavator) 
or a crusher plant. Such connecting belt bridges either convey on the same 
level or in the form of elevator conveyors onto a higher level (of e.g. 
DE-OS 36 23 813). The known connecting belt bridges are substantially 
stationary and are only moved onwards once the feeding apparatus or the 
feeding plant undergoes a change in locality. 
Linearly moving a winning or mining apparatus comprising an excavating 
means excavating in the direction of travel (of e.g. U.S. Pat. No. 
3,897,109) is known from DE-OS 39 11 119 and this machine deposits the 
material which is excavated on the pit level belt by a belt arrangement 
comprising a plurality of mobile belt units. However the operation of such 
a belt arrangement requires considerable monitoring effort. 
From DE-OS 39 20 011 a band bridge is furthermore known cardanically linked 
to a linearily moving winning apparatus and which at its discharge end is 
likewise cardanically linked to a funnel wagon travelling on the 
travelling rails of the pit level belt and movable jointly with the 
winning apparatus and the funnel wagon. However, this known belt bridge is 
permanently coupled to the winning apparatus and the pit level belt and 
therefore severely restricted in respect of its dimensions, in particular, 
in relation to level differences between the winning or excavation plane 
and the plane of the pit level belt. 
OBJECT OF THE INVENTION 
Accordingly a need exists to so improve a connecting belt bridge of the 
type referred to in the introduction, that it is suitable to be fed by the 
discharge belt of an excavating or winning apparatus and is linearly 
movable. 
It is therefore an object of the invention to provide a connecting belt 
bridge overcoming drawbacks of the known connecting belt bridges. Yet 
another object of the invention is to provide the connecting belt bridge 
fed by the excavating or winning apparatus linearly movable both in a high 
level cut mode (excavation above the level of the pit level belt) as well 
as in a low level cut mode (excavation below the plane of thee pit level 
belt). 
SUMMARY OF THE INVENTION 
The present invention provides an apparatus wherein both the feed end as 
well as the discharge end of the bridge are each supported on a separate 
travelling means, the discharge end travelling means is of portal-like 
design comprising at each of both sides of the pit level belt at least one 
non-railborne travelling unit (e.g. a chain drive), the bridge on the 
travelling means at the discharge end is pivotal both about a vertical 
axis as well as a horizontal axis and on the feed side the travelling 
means is supported by way of a longitudinally displaceable single point 
support with a support beam which is horizontally alignable and the bridge 
at its feed end comprises a feed jib linked about a horizontal transverse 
axis. 
The two travelling means permit unimpeded manoeuvring of the connecting 
belt bridge during a locality change. This is substantially contributed to 
by the fact that the travelling means on the discharge side comprise 
travelling units which are not railborne. By virtue of the three-point 
support the connecting belt bridge is suitable both for the high level cut 
as well as the low level cut of the winning apparatus. The linkage 
connection of the feed jib permits, moreover, to always provide the 
winning apparatus which feeds the material with a favorable feeding level 
both under high level cut as well as low level cut conditions. 
One of the advantageous further embodiments has a connecting belt bridge in 
the linkage region of the feed jib which comprises a special carrier 
structure including three frame members including separate roller 
positions for the upper limb and the lower limb of the connecting belt 
which in the case of angular deflection of the feed jib provides a 
polygonal configuration for the belt path. This structure eliminates 
abrupt deflection and thereby disadvantageous stresses on the material of 
the connecting belt are avoided. 
In order to always permit a smooth transfer of the material onto the pit 
level belt even at maximum travelling speed of the connecting belt bridge, 
provision is made for a feed carriage supported underneath the travelling 
means on the discharge side on the travelling mils of the pit level belt, 
providing the travelling means with mechanical means for moving along the 
feed carriage in the direction of travel and associating the travelling 
means with a regulating means for the steering thereof. The control of the 
travelling means on the discharge side is provided automatically as a 
function of the lateral distance between the travelling means (and 
accordingly the pit level belt) and the feed carriage within 
predeterminable permissible tolerances. 
The mechanical means suitable for moving along preferably take the form of 
bumpers and appropriate counter-formations. 
For steering the travelling means at the discharge end the control means 
comprises a directional signal generator which is preferably connected to 
a steering rod mechanism. The steering rod mechanism offers the advantage 
that the signal generator is linked to a short lever arm by which the 
large change in distance is converted into a smaller travelling signal. 
Both the means for the (automatic) moving along of the feed carriage as 
well as the (automatic) steering of the travelling means on the discharge 
side as a function of the feed carriage allow operating personnel during 
the normal excavating operation, to be dispensed with at the discharge end 
of the connecting belt bridge. 
In order to permit movement of the discharge end travelling means or a 
locality change of the connecting belt bridge independently of the pit 
level belt, the former comprises means for lifting the feed carriage off 
the travelling rail, thereby to cancel its railbound condition, after 
first having dismantled the feed mechanisms of the feed carriage. For 
additional freedom of movement provision is made to deflect the supporting 
legs of the feed carriage and fix them in the deflected position. 
In order to enable the operating personnel to readily co-ordinate 
travelling of the connecting belt bridge with the winning apparatus, a 
horizontally alignable driver cab is provided close to the feed end of the 
connecting belt bridge. Normally the winning apparatus is driven by a 
combustion engine. If the winning apparatus is to be driven electrically 
an adjustable cable jib for a connecting cable to the winning apparatus is 
provided at the feed side end of the connecting belt bridge.

SPECIFIC DESCRIPTION 
An excavating or winning apparatus illustrated in FIGS. 2 and 3 only in 
respect of its discharge jib 1 and its cable conduit 2 moves parallel to a 
pit level belt 3 and in doing so, picks up the material present in its own 
track (overburden, coal seam, mineral bed, etc.) and delivers this 
material by way of its discharge jib 1 onto the feed end 4-of a connecting 
belt bridge 5, which in mm conveys it to the pit level belt 3. The 
linearily moving excavator apparatus operates in relation to the plane of 
the pit level belt 7 which is lower than the original ground level 6, on 
the one hand in high cutting mode (FIG. 1), wherein it excavates the 
material down to the level 7 of the pit level belt 3 and on the other 
hand, on the opposite side of the pit level belt--under low cutting 
conditions (FIG. 2), wherein it excavates the material below the level 7 
of the pit level belt 3. 
The connecting belt bridge 5 moves jointly with the excavating apparatus, 
i.e. at the same velocity--independently of its particular 
direction--generally parallel to the pit level belt 3. For that purpose 
the connecting belt bridge is provided at both ends with respectively 
travelling means 8 and 9 . The travelling means 8 provided underneath the 
discharge end has a portal-like design and straddles the pit level belt 3. 
On each side the portal-like travel means 8 comprises an independent 
travelling unit 10 in the form of a chain (crawler) drive. 
The excavating track most remote from the pit level belt 3 is determined by 
the length of the connecting belt bridge 5. If the excavating apparatus 
operates in an excavating track closer to the pit level belt 3, the 
connecting belt bridge 5 occupies in relation to the pit level belt 3 a 
position which--viewed in plan view--is appropriately oblique to the pit 
level belt 3. 
The discharge end of the girder structure 11 of the connecting belt bridge 
5 is supported on a support member 13--in a manner pivotal about a 
horizontal axis 12--and which is supported on a support member 13 which in 
turn is mounted by way of a pivoting connection 14 having a vertical 
pivoting or swivel axis 15, on the travelling means 8. The support member 
13 also comprises a baffle plate 16 for deflecting the material being 
conveyed towards the pit level belt 3. 
The feed end is supported in a linkage 17 (FIG. 3) comprising a horizontal 
axis 17a on a support beam 18. The support beam 18 at that end thereof 
which is directed towards the discharge end of the connecting belt bridge 
5 is connected by way of hydraulic cylinders 19 to the girder structure 11 
of the connecting belt bridge 5 so as to always permit horizontal 
positional alignment of beam 18. At its underside the support beam 18 
comprises travelling rails 20 by means of which it rests on running 
rollers 21 of a transverse support 22. The transverse support 22 in turn 
is supported by way of a ball joint connection 23 along the chain track 
vehicle 9. Accordingly the support of the connecting belt bridge 5 at the 
discharge side end is effected at two points (on the axis 12) and at the 
feed side end in a single point (the ball joint connection 23), so that 
altogether a stable three-point support for the torsionally rigid girder 
structure 11 of the connecting belt bridge results. This furthermore 
ensures that the feed side travelling means 9 is enabled to travel by way 
of inclined ramps from the low level cutting plane onto the level of the 
pit level belt 7 respectively from there onto the high level cutting plane 
6 and vice versa. 
Close to the linkage 17 a feed jib 25 supported elsewhere by the support 
beams 18 is linked to hydraulic cylinders 26 and hinged about a further 
horizontal axis 24 to the girder structure 11. The hydraulic cylinders 26 
are normally retracted. If the connecting belt bridge travels with its 
feed end above the plane 7 of the pit level belt, the feed jib 25 can be 
lifted by means of these cylinders if this becomes necessary due to edges 
of cuttings in the high cutting region. At the linkage point 24 the feed 
jib 25 embraces the girder structure 11 of the connecting belt bridge 5 in 
a bifurcated manner (cf FIG. 8). 
A support construction in three parts as can be seen in FIG. 8 is provided 
about the linkage point 24 and constructed as is provided about the 
linkage point 24 constructed as follows:-- 
A central H-shaped frame member 28 is linked on one side at 29 to the 
girder structure 11 and on the other side at 30 to the feed jib 25. 
Between the central cross beam 31 of the H-shaped frame member 28 and the 
girder structure 11 on the one hand and the feed jib 25 on the other hand 
a rectangular frame member 32 respectively 33 is hinged on. The foremost 
and the rearmost frame member 32 respectively 33 each comprise three 
roller positions 34a to 34c and 35a to 35c respectively, the H-shaped 
central frame member comprises two roller positions 36a, 36b for the upper 
limb 37 of the conveyor belt 38 mounted on the connecting belt bridge 5. 
For the lower limb 39 of the conveyor belt the frame members 32, 33 each 
comprise a further roller position 40 respectively 41. In the event of the 
feed jib 25 being deflected in relation to the girder structure 11, there 
is no prominent deflection of the conveyor belt 38, but rather a gradual 
change and therefore a favorable transition. 
At the feed end of the girder structure 11 a driver cab 43 is hinged on at 
42 which by one or more hydraulic cylinders 44 is maintained in a 
horizontal position. The associated access step-ladder 45 is fitted with 
automatic means for keeping the step horizontal. Because the ascent and 
the descent of the belt curve in the region of flexing about the linkage 
point 24 affects the axial spacing of the conveyor belt 38 the belt 
tension is constantly monitored by way of (not illustrated) pressure 
measuring boxes and the conveyor belt 38 is automatically retensioned or 
relieved by hydraulic cylinders 38a (FIG. 3). 
Behind the driver cab 43 on a pillar 46 a cable jib 47 is provided so as to 
pivot in an up and downward direction. From there a cable 48 proceeds for 
electricity supply to the excavator apparatus and enters there into a 
receiving structure or cable conduit 2 at the tip of the jib 1. The free 
length of the cable loop should be so dimensioned that the winning 
apparatus and the connecting belt bridge 5 are afforded freedom to perform 
all turning and evasion manoeuvres. During operational travelling, when 
both machines are in closest proximity to one another, the low hanging 
cable loop is kept out of the transfer region by lifting and pivoting away 
of the cable jib 47. 
Underneath the portal-like travelling means 8 a smaller likewise 
portal-like feed carriage 50 (FIG. 6) is provided which travels on the 
transport rails 51 of the pit level belt 3. The feed carriage 50 comprises 
a rectangular chassis 52, laterally provided with inclined chute 
respectively guide baffles 53. The legs 54 of the feed carriage are hinged 
at 55 (FIG. 5) to lateral projections of the chassis 52 where they can be 
locked for the travelling position. 
The movement respectively advancement of the feed carriage 50 is brought 
about by the travelling means 8 on the discharge side for which purpose 
transverse beams 56 provided on the travelling means 8 coact with bumpers 
57 (FIG. 6) fitted to the chassis 52 of the feed carriage 50. Accordingly 
the travelling means 8 and the feed carriage 50 are mechanically 
releasably interconnected. In relation to the course of the pit level belt 
3 they move synchronously and always occupy the same neutral position. 
The travelling means 8 is provided with a winch 58 (FIG. 4) operating a 
rope 59 suspended at its opposite end at 60 from the travelling means 8 
and by means of which the feed carriage 50 can be lifted, so as to be 
suspended securely by shackles 61 from the travelling means 8 before the 
connecting belt bridge 5 performs a change in locality. On one side a 
linkage connection composed of two levers 62, 63 (FIG. 4) is provided 
between the feed carriage 50 and the travelling means 8. The movable part 
of a steering signal generator 64, the remainder of which is connected to 
the travelling means 8, is linked to a relatively short lever arm of the 
lever 62. If the distance between the discharge carriage 50 and the 
travelling means 8 determined on the side of the travelling sensor 64 
becomes larger than the predetermined normal value, the travelling units 
10 are steered to follow a curved or oblique direction such that the 
distance is decreased correspondingly.. If the said distance drops below a 
predetermined normal distance a corresponding steering in the reverse 
sense is brought about. While coacting with the winning apparatus the 
travelling means 8 of the connection belt bridge 5 accordingly travels 
automatically, essentially guided by the track, along the pit level belt 
3. Only in the event of a locality change a second driver must steer the 
vehicle 8 (FIG. 5). In that case the connecting belt bridge 5 is 
disconnected from the normal electricity supply and the travel means are 
operated by way of an emergency power aggregate (not illustrated). 
The travelling means 9 is steered from the driver cab 43. The driver 
retains contact to the winning apparatus and he steers the discharge jib 1 
of the winning apparatus. The feed jib 25 is always kept in its lowest 
position in which the hydraulic cylinders 26 are not under load. They are 
only pressurised in the event of a risk of collision with a cutting. The 
evasion and turning manoeuvres of the connecting belt bridge 5 in the 
event of changes in cutting line and level and the movement required for 
changing the operating field (from high level to low level cutting) and 
travelling on the ramp are also conducted from the driver cab 43.