US2155415A - Coal mining system - Google Patents

Description

porting pillars.

Patented Apr. 25, 1939 UNITED STATES PATENT OFFICE 4 Claims.

My invention relates to coal mining and. covers particularly an improved system for development of a mine and the mining and removal of the rcoal therefrom.

In underground mining of coal from a seam, the room and pillar plan of development has been used, the procedure having been to mine out a main entryway, passage or tunnel through the selected panel of operation and along the median line thereof, and then to proceed laterally in a direction substantially at right angles to such main passageway to mine out room territories to leave rooms with intervening roof sup- In mining these room territories, the cutting has been crosswise of the rooms and progressed lengthwise through the rooms from the main passageway to the sides of the coal panel under operation, and after completion of a cutting operation in one room the mining machinery and operation were transferred for a cutting operation in another room.

For transporting the mined coal to the exterior of the mine, railway cars have generally been employed requiring the laying of tracks throughout the mine as the work progressed. This trackage comprised the main track through the main passageway or tunnel and branch tracks into the rooms to follow up as the mining proceeded outwardly in the rooms to the sides of the coal panel under operation. The cost of the tracks, the necessary switches and other special track parts together with the labor for shifting and relaying tracks constituted a considerable item of eX- pense in the development of a mine. The same is true where conveyors are used for carrying the cut coal away from the working places as the cutting progresses through the rooms.

With the short, cross cutting of the coal in the room territories, the cutting machine after a cross cut in one room would have to be transferred to another room While the coal which has been cut and broken down is being loaded by loading machines into the cars for hauling away, and owing to the comparative small tonnage resulting from the short cross cuts, the loading machines required only a very short time to load the coal on the cars after which it became necessary to move the loading machines to other rooms for loading of cut coal therein onto the cars, this causing serious interruption in the daily output of the loading machines and further increasing the cost of production. Furthermore, with this procedure of mining, where several rooms may be under operation at the same time, it requires more or less complicated Ventilating arrangement in order to provide adequate air supply to the workers as the workings reach the outer ends of the rooms.

The object of my invention is to provide a system whereby the coal can be removed from a mining panel in less time, more economically, and more efficiently. In the first place, in accordance with my invention, I dispense entirely with tracks and track vehicles and utilize automotive vehicles running directly on the ground for hauling the mined material, the vehicles being in the form of trucks or tractor-trailer units properly dimensioned and designed for mobility and for use in underground mines, the haulage being from the room territories to receiving or concentration points within the main passageway or tunnel from which points the coal is carried to the exterior of the mine by suitable conveyor mechanism or, in some cases, by cars running on a track through the main passageway or tunnel to the exterior.

In order to get the most eicient and economical service out of the truck or tractor-trailer haulage, my system provides for mining the coal at approximately to existing methods, the procedure being to cut the room territories lengthwise instead of crosswise in order to provide larger tonnage of broken down coal available ior loading so as to keep the loading machines in full time service. In accordance with my system, the cutting of the main passageway or tunnel and the room territories extending laterally therefrom proceeds simultaneously from a frontal line of attack, the cutting in the room sections being lengthwise thereof and progressively rearwardly until the rooms are formed, the trucks receiving the broken down coal from the loading machines for hauling to a transfer point within the main entry or tunnel for reception by the conveyor mechanism and conveyance t0 the exterior of the mine, the transfer points being adjacent to the inner ends of the rooms of the opposite room territories which are being worked, the transfer points being shifted rearwardly in the tunnel as the room and tunnel formation progresses rearwardly. Coal pillars are left between the rooms for roof supports and these pillars are designed and located for the most eicient functioning of the trucks in cooperation with the loading machines. A simple A apparatus would, like the haulage vehicles, be designed for direct ground traction to thus entirely eliminate the use of rails in the rooms.

On the accompanying drawing, the one figure is a horizontal sectional View of a mine panel to be mined and showing more or less diagrammatically the procedure for cutting, loading, and hauling,

Referring to the drawing, the panel layout comprises a main passageway or tunnel T to be cut along the median line of the panel, and rooms l extending laterally from the tunnel to the panel sides. In the cutting of the tunnel longitudinal rows oi comparative heavy pillars 2 are to be left to protect the passageway aisles 3, and between the rooms lighter pillars l are to be left during the cutting operation. Flanking the passageway aisles are the passageways 5 which form breaker lines between the room territories and the tunnel in case a squeeze, creep or weakening of the roof occurs in the minedover room territories.

Along the front of the panel are two development entries or passageways 6 and 1, the passageways t being comparatively narrow to provide air courses for the Ventilating system. The passages 'i are wider and from these passages the mining oi the room territories is started. Between the passages 6 and l, comparatively heavy pillars t are left to protect the air passages 6 from squeezes or subsidence that may occur in the: room territories. At the sides of the panel and the outer ends ci the room territories, air passages 2 outer ends of the front passages 8, and `between the passages 9 and the room territories substantially heavy pillars l are left to protect the air passageways. The air is charged in from any suitable point, as for example, into one of the passageways 6 at the front end oi the panel.

The air passagesand the territories i are rst cut and the coal removed and thereafter the cutting proceeds to the wider room territories. The work is started all along the line from the te^ritories i and proceeds simultaneously rearwardly the full width of the panel to mine out the room territories I, and at the same time out of the tunnel proceeds, the cutting of the tunnel being thus substantially only at the same rate as the cutting and mining of the room territories. After mining out of the territories l, curtains or walls Il are applied between the pillars 8 so that the air ilow from the passages 6 will iiow to the side air passages s and from there longitudinally through the territories E into the tunnel to be expelled to the exterior oi the mine, curtains or walls i2 being also applied'between the pillars i3 in the tunnel, so that one of the tunnel aisles, as for example the aisle 3' wili serve for the air outlet. An overhead or overcast air passage I4 maybe provided at the aisle 3 for connecting the left and right front air passages 5 together and to separate these passages from the air outlet passage. As the work progresses through the room territories and tunnel territories, curtains i5 arel provided between the panel side pillars I0 and curtains It are provided between the pillars of the outer pillar rows in the tunnel territory so that the incoming air is conducted by the passages 5 and to o-w lengthwise through the rooms and territories in which work is being carried on, the air then leaving by way of the tunnel aisles and the air outlet aisle 3. On the drawing, the laterally opposite rooms A and A' and the next room territories B and B are cut which communicate with the are shown connected in the Ventilating air streams, the rooms A and A' having been mined out and cutting of the coal having been started in the territories B and B', all the room territories in advance of the rooms A and A having been mined out, these room territories being indicated by the broken section lines. While these territories were being worked out, the working out of the tunnel proceeded at the same rate.

In prior systems of mine development, the main passageway or tunnel was first completed throughout the length of the panel and then the rooms mined progressively from the tunnel out to the panel sides. In this plan of development, main track was first layed throughout the eX- tent of the tunnel and with switches at the inner end of each room territory for extension of the track into the rooms as the coal was progressively and periodically removed therefrom. The cutting in the rooms by the cutting machine was transverse or crosswise of the room and after each of such cross cuts in a room, it was necessary or the cutting machine to be withdrawn and transferred to another room while the cut and broken down coal was being hauled away, so that with this method of mining a great part of a days run of a cutting machine was taken up by the transferring of the cutting machine, during which time they were non-productive.

In accordance with my improved system, the cuts by the cutting machine are lengthwise of the rooms so that in a days run the entire time of a cutting machine will be taken up in cutting operations, and after breaking down of the cut coal the loading machines and the haulage system will be kept continuously busy.

The cost of the tracks, switches and other special track parts and the labor for laying, shifting and transferring tracks constituted a considerable item of expense in prior systems of mine development, and furthermore in such systems the transportation was iniiexible and limited to the tracks. In place of such antiquated track and car haulage, I provide a more econom- Y ical, more mobile, and more eicient haulage system by utilizing truck or ltractor-trailer automotive units s0 designed that they may travel safely directly on the mine oor without the use of rails, and I also equip the cutting machines, loading machines, or any other mine traveling machines with tractor wheels for direct traction on the mine floor.

Referring to the drawing, l1 represents a mechanical cutter machine, I8 represents a loading machine, and iii represents atractor-trailer unit being loaded by a loading machine, 2B representing a tractor-trailer unit on its way to the loading machine to replace the unit I9 being loaded. The lines 2l extending longitudinally through the laterally opposite room territories B and B and the corresponding intervening tunnel territory T indicate the swathsV out by the cutting machine lengthwise of the rooms and in the tunnel territory. With such long cutting lines, a cutting machine will be kept busy doing nothing but cutting throughout a full days run, so that, after the. cut coal has been blasted and broken down, there will be sufficient mined coal for continuous operation of the loading machine and the haulage units.

The cutting machine il is shown advancing toward the left while the loading machine I8 is loading the broken down coal onto the haulage unit i9. The loaded unit travels along the roomV to the tunnel to deposit its load into the receiving apparatus 22 located at the most convenient position within the tunnel, and the empty haulage unit (20) then travels back to the room space for another load from the loading machine, and any number of such haulage units may travel through the haulage orbit depending upon the capacity of the loading machine, the loading machine and the haulage unit being kept continually busy without any loss of time.

As the room and tunnel mining line proceeds rearwardly of the panel, the coal receiving apparatus 22 is moved rearwardly. The receiving apparatus discharges the received coal onto suitable conveying mechanism which may be a conveyor belt or other conveyor structure installed in the outlet aisle 3', or as shown, a track 23 may be laid in the aisle for a train of Vcars 2,62 ior receiving the coal from the collecting apparatus and transporting it to the exterior of the mine.

It will be noted that the pillars between rooms have rear conical faces. This results from the lengthwise cutting of the room territories by the cutting machine. After completion of cutting in one room, the cutting machine cuts the spaces between the pillar locations, the direction of this cutting being parallel to the length of the room and progressively rearwardly, the cutter bar from the cutting machine being swung laterally to an angle to out the rear sides of the pillars diagonally so that, after the spaces between pillar locations have been cut and the broken down coal removed, the cutting machine will have provided a path for continuous travel thereof lengthwise of the roo-m to begin cutting out of the room territory beyond the pillars just formed. The diagonal facing of the pillars also permits greater mobility and ease of travel of the haulage units around the pillars.

As has already been pointed out, the worked out territories are disconnected from the air passages 9 by means of curtains between the side pillars I so that no air is wasted and the air is forced lengthwise through the rooms and room territories in which work is in progress, the air flowing along the working iield from the outer ends thereof and into the tunnel from where it is discharged to the exterior, it being understood of course that the spaces between the pillars of the outer pillarrows in the tunnel are blocked off by curtains I6 up to the operating iield as the work progresses.

The haulage units, the cutting and loading units, and other traction equipment may be mounted on pneumatic tired wheels of ample tread and traction area so as to sustain heavy loads without danger of sinking into the floor of the mine. The design of these traction devices is also such that they may eciently operate within the narrow limits of seam thickness and Width of rooms and passageways.

My improved mining system, involving the rearward progress through a coal panel from the front thereof and the full width thereof and the lengthwise cutting in the room areas in which each continuous cut will produce more than sufficient tonnage to maintain loading at full capacity during a shift operation and the employment of mobile ground traction hauling vehicles, will remove the coal from a mine at a cost per ton much less than is possible with prevailing systems of mining. With my improved system a mine can also be more safely operated as the mining operation is more concentrated and affords opportunity for better localization oi ventilation in the field of operation and closer supervision of the workmen, and accident possibilities are materially reduced.

I do not desire to be limited to the exact structure and procedure shown and described as changes and modifications may be made without departing from the scope of the invention.

I claim as my invention:

l. In the method of mining coal in a panel in which a series of entries and a series of rooms are formed, with elongated rooms extending laterally from a main tunnel to the side of the panel, the steps of mining the coal in each room which comprise driving a series of spaced entries through the front wall of the room territory and then continuing the cutting of the coal lengthwise of the room territory in a series of cuts along the length of the room territory to remove elongated strips oi coal and provide communi cation between the room and the tunnel, and removing a plurality of elongated strips oi coal to provide the desired width of the room.

2. In the method of mining coal in a panel in which a series of entries and a series of rooms are formed, with elongated rooms extending laterally from a main tunnel to the side of the panel, the steps of mining the coal in each room which comprise driving a series of spaced entries through the iront wall of the room territory, then continuing the cutting of the coal lengthwise of the room territory in a series of cuts along the length of the room territory to remove elongated strips of coal and provide communication between the room and the main tunnel, removing a plurality of elongated strips of coal to increase the width of the room, and increasing the length of the main tunnel by cutting as the room width is increased.

3. In the method oi mining coal in a panel in which a series of entries and a series of rooms are formed, with elongated rooms extending laterally from a main tunnel to the side of the panel, the steps of mining coal in each room which comprise driving a series of spaced entries with forwardly diverging sides through the front wall of the room territory to provide laterally spaced pillars of coal having forwardly directed converging side walls and to form an elongated and laterally extending passageway, then continuing the cutting of the coal lengthwise of the room territory to remove elongated strips of coal and pro-vide communication between the room and the tunnel.

4. In the method of mining coal in a panel in which a series of entries and a series of rooms are formed, with elongated rooms extending laterally from a main tunnel to the side of the panel, the steps of mining the coal in each roomwhich comprise providing a passageway extending along the front wall of the room territory and in communication with the tunnel, driving a series of spaced entries from the passageway through the front wall of the room territory, continuing the cutting of the coal lengthwise of the room territory in a series of cuts along the length of the room territory to remove elongated strips of coal and provide communication between the room and the tunnel, and hauling the mined coal through the haulage ways in parallel provided by the entries into the passageway and the room.

J AMJilS H. FLETCHER..

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