Mineral mining installations

A mineral mining installation serves to win mineral by explosive blasting. The installation employs a shuttle conveyor arranged alongside a mineral face. Roof supports stand side-by-side at the side of the conveyor remote from the conveyor. The roof supports are connected to the conveyor through shifting rams and have roof-engageable caps or the like supported on hydraulic props. The pans of the conveyor have upstanding walls at the rear side nearest the roof supports which carry rails at their upper ends. The roof caps have wall components pivoted thereto and hydraulic piston and cylinder units serve to swing the wall components up and down. When explosive blasting takes place the wall components are swung down to engage on the walls of the conveyor pans to form a screen between the winning region and the access region of the working.

BACKGROUND TO THE INVENTION 
The present invention relates to a mineral mining installation which serves 
to win mineral by explosive blasting. 
In underground mine workings where mineral ore is won by blasting it is 
known to arrange a continuous protective screen wall on a conveyor. The 
screen wall can be composed of individual wall sections formed by 
resiliently supported lower and upper wall parts which can be selectively 
raised and lowered by means of hydraulic units. Such a construction is 
described in German Patent Specification No. 2 509 801. The screen wall 
can be erected to close off the conveying and winning region, where the 
blasting takes place, from the rear access region. During blasting, the 
wall acts to protect the access region from the effects of the blasting 
and ensures no high grade mineral ore becomes lost. After blasting, the 
wall can be collapsed to permit the loose material to be transported away 
by the conveyor. Another type of screen wall, described in German Patent 
Specification No. 2 558 884, employs wall parts hinged to the pans of the 
conveyor. These wall parts can be set up against the roof and supported by 
hydraulic units. 
In general, the known screen walls hinder the access to the winning and 
conveying region and are relatively expensive and prone to damage. A 
general object of the present invention is to provide an improved form of 
mineral mining installation of the type described hereinbefore. 
SUMMARY OF THE INVENTION 
In its broadest aspect the present invention provides a mineral winning 
installation for winning mineral by explosive blasting, said installation 
comprising a shuttle conveyor alongside a mineral face, a roof support 
system arranged at the side of the conveyor remote from the conveyor and 
wall components pivotably carried by roof-engageable structures of the 
roof support system and capable of being swung down to depend from the 
roof-engageable structures to form a screen between the winning and 
conveyor region and the access region of the working. 
An installation constructed in accordance with the invention comprises a 
conveyor extending alongside a mineral face, roof supports disposed 
alongside the conveyor remote from the mineral face, said roof supports 
having roof-engageable structures supported by hydraulic props, hydraulic 
shifting rams operably connected between the conveyor and the supports and 
means for selectively screening off the winning and conveying region of 
the working from the access region, wherein the screening means includes 
wall components pivotably connected to the roof-engageable structures of 
the supports and capable of adopting an operating position depending from 
the roof-engageable structures or an inoperative stowed position. Piston 
and cylinder units can serve to swing the wall components up and down. An 
abutment is preferably provided on the conveyor against which the wall 
components engage when they are swung down into the operative position. 
The abutment can be formed as further wall components with rails at their 
upper ends. The rails can serve to support drilling equipment used to set 
the explosive charges into the mineral face. 
With the wall components set in their stowed inoperative position they can 
perform a supportive function assisting to support the roof. It is 
preferable to provide the roof-engageable structures of the roof supports 
with advance linings which project towards the mineral face. The wall 
components can then engage on the underside of the advance linings when 
set in their stowed inoperative position. The advance linings can be 
plug-in leaf springs which support the roof over the conveyor during the 
blasting operation. With the wall components in their stowed inoperative 
position the winning and conveying region of the working is freely open to 
the access region where the roof supports are located. 
To reliably secure the access area behind the conveyor, where personnel are 
sited, it is desirable to have the roof supports set close together so 
that their roor-engageable structures combine to form a more-or-less 
continuous canopy pressed against the roof. 
To enable the installation to cope with seams of different heights it is 
desirable to make the wall components and/or the abutment-forming means 
adjustable in height, for example as described hereinafter. 
The conveyor is preferably a shuttle conveyor able to withstand the forces 
occurring in the explosive blasting operation. The conveyor is then 
composed of individual pans arranged end-to-end and entrainment devices 
which are oscillated to and fro along the pans. The pans are preferably of 
rigid stout construction interconnected by connection means allowing 
relative angular displacements. One form of connection means comprises 
toggle members seating in open pockets at the ends of the pans. 
The invention may be understood more readily, and various other aspects and 
features of the invention, may become apparent from consideration of the 
following description.

DESCRIPTION OF PREFERRED EMBODIMENT 
As shown in FIGS. 1 to 3, a mineral mining or winning installation serves 
to win mineral, especially valuable ores such as gold, from a mineral face 
10. The mineral is detached from the face 10 by explosive blasting and the 
detached loose material 11 is transported away by a conveyor 12. The 
conveyor 12 can be of any suitable type and is constructed from a series 
of individual pans 25 arranged end-to-end and along which the material is 
transferred. The conveyor 12 is preferably a so-called shuttle conveyor 
with entrainment devices or scrapers oscillated to-and-fro above a bed 
formed by the pans 25. Examples of suitable shuttle conveyors are 
described in German Patent Specification No. 
2 558 884 which has a counterpart in the U.S. Pat. No. 4,241,824. 
In the access region 13 of the working at the side of the conveyor 12 
remote from the mineral face 10 there is a hydraulic walking roof support 
system. This system is composed of individual supports 14 in side-by-side 
relationship. Each support 14, has four hydraulic props 15 in rectangular 
configuration supported on a slidable floor-engageable structure, such as 
a single or multi-part sill, or girder 16. A roof-engageable structure 17, 
such as a single or multi-part cap or girder is carried by the props 15. 
Extension of the props 15 causes the structure 17 to be urged against the 
roof 18. The individual supports 14 are positioned to stand closely 
adjacent one another so that when braced their roof caps 17 form a 
more-or-less continuous canopy in contact with the roof 18. Each support 
14 has a hydraulic shifting ram 19 linked to the conveyor 12. More 
particularly, the rams 19 have piston rods 20 attached with pivot joints 
22 to rear extension components 21 of the floor sills 16. The cylinders of 
the rams 19 are similarly connected with pivot joints 23 to coupling 
members 24 which are articulatedly connected to the individual pans 25 of 
the conveyor 12. The coupling members 24 may take the form of 
substantially flat trough-like components known per se. By extending the 
rams 19, the conveyor 12 can be shifted in the direction of arrow S in 
FIG. 2 towards the mineral face 10. Normally the conveyor 12 would be 
advanced towards the face 10 in sections. FIG. 1 depicts the situation 
where a region of the conveyor 12 at the right-hand side of the FIG. has 
been advanced while a region of the conveyor 12 at the left-hand side of 
the Figure has not yet been advanced. Once the conveyor 12 has been 
advanced overall in this manner the individual supports 14 can be drawn up 
to follow the winning progress. This would involve relief of the props 15 
of the unit 14 which is to be shifted and retraction of the associated ram 
19. The supports 14 would be drawn up one-by-one in sequence and as the 
winning progresses the advancement of the conveyor 12 and shifting up of 
the supports 14 would be repeated as known per se. 
FIG. 4 and 5 depict in greater detail the construction of the conveyor pans 
25. Each pan 25 has an angular profile with a floor surface 26 forming 
part of the bed along which the material is transferred by the scrapers 
27. As is known, the scrapers 27 are pivotably connected to a common 
traction means (not shown). The traction means is preferably a jointed 
beam composed of guide blocks guided within a guide channel 45 located 
behind a face wall 28, of each of the pans 25. Guide strips 29, which are 
easily replaceable, are provided in the channel 45 to contact the traction 
means. The traction means is preferably driven at both ends of the 
conveyor 12 to reciprocate back and forth parallel to the longitudinal 
direction of the conveyor 12. As is known during movement of the traction 
means in one direction, the scrapers 27 adopt a working position more or 
less perpendicular to the direction of motion of the traction means 
thereby entraining the material collected on the floors 26 of the pans 25 
and forcing the material in the conveying direction. When the traction 
means reverses its direction of movement the scrapers 27 automatically 
pivot inwards towards the face walls 28 and do not cause any significant 
movement of material. The material thus progresses along the conveyor in a 
series of intermittent steps. The pans 25 are connected together with 
connections which permit angular mobility therebetween. The pans 25 have 
open pockets 30 at the ends open towards the supports 14 and receiving 
shaped toggle members 31 each composed of a central shank between enlarged 
heads 32. The combination of the toggle members 31 within the pockets 30 
form connections between the pans 25 which resist traction forces while 
permitting canting. To retain the toggle members 31 in the sockets 30 
detachable locking elements such as pins 33, are introduced through 
aligned bores in the pans 25 to overlap the pockets 30. 
Screening means 35 serves to seal off the main winning region 34 of the 
working selectively from the access region 13 when blasting takes place. 
This screening means 35 is composed of individual wall components 36 which 
are pivotably connected with pivot joints 37 to the forward end regions of 
the roof-engageable structures 17 of the supports 14. Hydraulic piston and 
cylinder units 38 are pivotally connected between the wall components 36 
and the roof-engageable structures 17. The cylinders of the units 38 are 
connected with pivot joints 39 on the undersides of the roof-engageable 
structures 17 while the piston rods of the units 38 are connected with 
pivot joints 40 to the rear sides of the wall components 26. These units 
38 thus serve to adjust the position of the wall components 36 between an 
inoperative position stowed near the roof 18 as shown in FIG. 3, and an 
upstanding operative position as shown in FIG. 2. The roof engageable 
structures 17 are provided with advance lining or girders 17' in the form 
of plug-in leaf springs. The girders 17' project forwardly towards the 
mineral face 10 to support the region of the roof 18 above the conveyor 12 
and the wall components 36 engage on the girders 17' when they are pivoted 
upwards into their inoperative position, (FIG. 3) to assist in the roof 
supporting function. 
The individual pans 25 of the conveyor 12 are provided with upwardly 
extending wall components 41 having support rails 42 of tubular form at 
their upper ends. The wall components 41 and the support rails 42 form 
abutments against which the pivotable wall components 36 engage when they 
are pivoted downwardly into their operative position (FIG. 2). When the 
wall components 36 are pivoted downwards into their operative position 
they combine with the wall components 41, and their support rails 42, to 
form the screening means 35 to screen off the winning region 34 from the 
access region 13 over the centre height and length of the working. When 
the screening means 35 is inoperative and the wall components 36 are 
stowed away, the support rails 42 can be used to support drilling 
equipment. 
It is desirable to make the screening means 35 adjustable in height to cope 
with different seam thickness and this can be accomplished by making the 
wall components 36 and/or the wall components 41 variable in the effective 
height dimension. For example, the wall components 41 can be extended 
upwardly by fixing detachable extension pieces or by making the components 
41 from slidable or pivotable parts. 
During use, the wall components 36 are swung downwardly into the operative 
position to complete the screening means 35 as shown in FIG. 2. In this 
position the roof is supported above the conveyor 12 solely by the advance 
lining girders 17'. The mineral face 10 is then subjected to explosive 
blasting and the detached material is confined in the winning region 34 by 
the presence of the screening means 35. After blasting has been completed, 
the wall components 36 are pivoted upwardly into the stowed position as 
shown in FIG. 3 and the loose material is transported away by means of the 
conveyor 12. The conveyor 12 is progressively shifted up towards the face 
10 by the rams 19 as the material is removed as described previously. Once 
sufficient loose material has been removed, the conveyor 12 is drawn back 
away from the face 10 temporarily to permit drilling of the holes for in 
the face 10 the next batch of explosive charges. The supports 14 are drawn 
up to the face 10 either before or after the drilling operation. The wall 
components 36 are then lowered again for blasting to take place and the 
sequence is repeated.