U.S. patent number 3,922,015 [Application Number 05/425,345] was granted by the patent office on 1975-11-25 for method of mining with a programmed profile guide for a mining machine.
This patent grant is currently assigned to Consolidation Coal Company. Invention is credited to William N. Poundstone.
United States Patent |
3,922,015 |
Poundstone |
November 25, 1975 |
Method of mining with a programmed profile guide for a mining
machine
Abstract
A method for mining a mineral deposit underground in a vein
having an underburden and an overburden which comprises boring a
pilot hole into the vein between the underburden and the
overburden. The thickness of the material is then measured at
predetermined distances along the pilot hole, between the pilot
hole and the overburden, and between the pilot hole and the
underburden. The information measured is stored in a storage
mechanism which relates the measurements to the distance in the
borehole. A mining machine is then controlled in accordance with
the distance between the borehole and the overburden, and the
borehole and the underburden. The invention further contemplates a
method of mining where the tunnel being mined is sealed off and
filled with an inert atmosphere. This method will provide an
explosion-free environment during the mining operation.
Inventors: |
Poundstone; William N.
(Pittsburgh, PA) |
Assignee: |
Consolidation Coal Company
(Pittsburgh, PA)
|
Family
ID: |
23686150 |
Appl.
No.: |
05/425,345 |
Filed: |
December 17, 1973 |
Current U.S.
Class: |
299/1.1; 175/62;
299/12; 299/30; 702/9; 175/50; 175/94; 299/18; 701/400;
701/538 |
Current CPC
Class: |
E21C
41/18 (20130101); E21C 35/24 (20130101); E21C
39/00 (20130101) |
Current International
Class: |
E21C
35/00 (20060101); E21C 35/24 (20060101); E21C
39/00 (20060101); E21C 41/00 (20060101); E21C
041/00 () |
Field of
Search: |
;299/1,10,12
;235/151.11,151.1 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Abbott; Frank L.
Assistant Examiner: Pate, III; William F.
Attorney, Agent or Firm: Miller, William J.
Claims
What I claim is:
1. A method for mining a mineral deposited underground in a vein
having an underburden and an overburden comprising:
a. boring a pilot hole into said vein between said underburden and
said overburden;
b. measuring a first mineral thickness between said pilot hole and
said overburden at periodic distances along said pilot hole;
c. measuring a second mineral thickness between said pilot hole and
said underburden at periodic distances along said pilot hole;
d. storing said first and second measured mineral thickness each
with respect to its respective distance along the axis of said
borehole from a common point of origin;
e. controlling a mining machine in accordance with said stored
information whereby the total mineral removed and the direction of
the progress of the mining machine is controlled by said pilot hole
and said memory.
2. A method as described in claim 2 wherein said first and second
mineral thickness is measured as said pilot hole is formed.
3. A method as described in claim 1 wherein said first and second
mineral thickness is measured as said pilot hole is formed and
additionally including the step of controlling the direction of
said pilot drill to maintain said pilot hole equi-distant between
said overburden and said underburden.
4. A method as described in claim 1 wherein said step of
controlling said machine by said pilot hole and said memory
comprises;
a. probing said pilot hole from said mining machine;
b. determining the orientation of said mining machine from said
probed pilot hole;
c. communicating said determined orientation to a mining machine
control unit along with said stored measured mineral thickness;
and
d. operating a mineral removal apparatus with the output from said
mining machine control unit whereby said meterial can be removed by
said mining machine in accordance with said measured mineral
thickness.
5. A method as described in claim 1 including the step of:
a. sealing said mined portion between said overburden and said
underburden at least at said point of origin; and
b. filling said mined portion and said pilot hole with a
noncombustible gas.
6. A method as described in claim 5 wherein said non- combustible
gas is nitrogen.
Description
BRIEF DESCRIPTION OF THE PRIOR ART
Controlled mining machines are well known in the art. The patents
to Risse et al., No. 3,485,531; Moon, No. 3,232,688; Hartley et
al., No. 3,294,449; and Carnegie, No. 3,362,750, are exemplary of
those type patents relating to controlled mining machines. For
example, in the patent to Moon, the mining machine is constructed
to include a control system for operating the mining machine from a
position that is remotely located with respect to the mine face.
The patent to Hartley et al includes means for measuring the coal
thickness on the mining machine as the mining machine progresses
into the coal face and includes means for adjusting the operation
of the mining machine in accordance with the thickness thus
measured.
The patent to Carnegie discloses a coal digging machine which
includes a preset programmer in which is stored information
regarding the height of the cutting machine according to its
position along the working face. The programmer compares the actual
height of the cutting machine with the programmed height according
to the distance of the cutting machine from the predetermined
location, such as a roadway. Any error is transmitted to a
comparator which corrects the height to the predetermined distance
of travel of the cutting machine. The patent also contemplates an
information storage device which takes the information from an
initial run and utilizes this information on subsequent runs.
The patent to Risse et al also discloses a tape-controlled
preprogrammed mining machine; however, the tape in this machine is
more for modifying the particular type bore cutting than it is the
operation of the mining machine along a predetermined
direction.
BRIEF DESCRIPTION OF THE INVENTION
This invention contemplates a method for mining a material such as
coal which is deposited underground in a vein having an overburden
and an underburden. The method essentially consists of boring a
pilot hole into the vein between the underburden and the
overburden. At predetermined distances along the bored hole, the
thickness of the vein is determined by use of a radioactive source
and a radioactive detector inserted into the hole. The radiation
received from the radioactive source which is back scattered from
the interface between the coal for example and the overburden will
be an indication of the thickness of the coal. It is also known
that the shale between the coal and the overburden is
self-radioactive; therefore, a radioactive detector alone can be
inserted into the hole and the thickness of the coal measured by
comparing the radiation level in the hole with the known radiation
level at the interface. The thickness being determined in the above
manner, the information is recorded on a permanent record, such as
for example a magnetic tape. The tape will contain the thickness of
the coal with its corresponding distance in the pilot hole. The
stored information will then be used to control a mining machine.
The invention further contemplates sealing off the area being mined
and filling the sealed area with an inert atmosphere. Since the
mining machine can be controlled completely by the predetermined
information relating to the particular vein being mined, no
personnel need be in the mine area controlling the continuous
mining machine. With the area completely sealed and filled with an
inert atmosphere, no possibility of explosion exists during the
mining operation .
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a side view of an area being mined illustrating the
formation of the pilot hole;
FIG. 2 is the top view of the formation of the pilot hole
illustrated in FIG. 1;
FIG. 3 is a view of the mining method utilizing the pilot hole as a
guide for the mining machine;
FIG. 4 is a second method for boring a pilot hole using a
horizontal drilling apparatus. FIG. 4 also illustrates the
radioactive source and the radioactive detector, along with block
diagrams of the apparatus required to control the continuous mining
machine;
FIG. 5 is a chart illustrating the measurements taken by the
apparatus shown in FIGS. 2 and 4; and
FIG. 6 is a cross-sectional view of a tunnel being mined by a
continuous mining machine where the tunnel is filled with an inert
atmosphere.
DETAILED DESCRIPTION OF THE INVENTION
Referring to all of the FIGS. but in particular to FIGS. 1 and 2, a
vein 10 which is to be mined lies between an overburden generally
referred to by the number 11 which lies above the vein, and an
underburden 12 which lies below the vein. Overburden 11 may be
composed of shale, rock, and other usual materials. Underburden 12
may likewise be composed of clays, shale, and other well- known
rocks. Material to be mined may for example be coal. In order to
perform the method of mining using a fully automated process, a
pilot hole 12 is drilled into vein 10 by a pilot hole drilling
machine generally referred to by the number 14. Pilot hole drilling
machine 14 comprises a motor 15 which has attached thereto a head
16 which rotates a drilling pipe 17 which has attached at its
terminus a rotary drill 18. Drill pipe 17 may also carry
stabilizers 20 along the drill pipe in order to stabilize the
drilling operation. Pilot hole drilling machine 14 may have for
example a driving mechanism comprising a track 21. A distance
measuring tachometer 22 is connected to track 21 and will measure
forward movement of the track only. A circuit means 23 connects
tachometer 22 to recording equipment 24. An instrument housing 25
contains a radioactive source 26 and a radioactive detector 27.
Radioactive source 26 comprises two sources which radiate in the
directon of 30 and 31. Radioactive detectors 27 detect along a path
32 or 33, measuring the radiation returned from the overburden 11
and underburden 12, respectively. At predetermined distances,
d.sub.1, d.sub.2, d.sub.3, and d.sub.4, radiation strengths are
measured which will determine the thickness, p.sub.1 and p.sub.1 '
with respect to d.sub.1, p.sub.2 and p.sub.2 ' with respect to
d.sub.2, p.sub.3 and p.sub.3 ' with respect to d.sub.3, and p.sub.4
and p.sub.4 ' with respect to d.sub.4. These distances are plotted
in an illustrative graph shown in FIG. 5 to be later described.
FIG. 2 is a top view of the area being mined which is illustrated
in FIG. 1 and illustrates a first room 40 and second room 41 with
previously bored pilot holes 42 and 43 communicating therewith. A
pilot hole 13 is being formed parallel to holes 42 and 43 which
will likewise communicate with rooms 40 and 41.
FIG. 3 illustrates the method of mining utilizing a continuous
mining machine which has a pilot attachment added to the frame of
the mining machine. The mining machine essentially consists of a
frame 45 which has a hydraulically controlled or operated arm 46
attached thereto. A cyclindrical coal dislodging device 47 is
rotatably attached to arm or boom 46 and has a plurality of picks
48 attached thereto. A means not shown rotates cylinder 47 in a
direction to dislodge the coal 10. A drive means 49 is attached
under frame 45 and provides a means of propelling the coal digging
machine. A tachometer 22 is attached to drive means 47 and
communicates to a wire 23 to recorder 24. Recorder 24 is
electrically connected to a wire 50 to a continuous mining machine
control unit illustrated by a box 51. The coal once dislodged by
picks 48 drops and is conveyed by conveyor 52 to a shuttle car 53
which has its own conveyor for handling and storing the material
therein. A plurality of wheels 54 propels shuttle car 53 to a point
where it may be unloaded. Attached to the continuous mining machine
frame 45 is a pilot hole probe apparatus generally referred to by
the number 56 and consists of a mount 57, and arm 58 which is
pivotally attached to mount 57, and a probe assembly 59 which is
pivotally attached to arm 58. A position sensing apparatus 60 is
attached between frame 45 and probe 59 and primarily relates the
position of the probe to the frame and relays this information back
to the control unit 51. A second position control 61 determines the
position of hydraulically controlled arm 46 with respect to frame
45. This information is likewise continually transmitted to control
unit 51. Referring to FIG. 4, an alternate method for drilling a
pilot hole is illustrated and essentially comprises a horizontal
drilling apparatus which includes a motor 65 which is coupled
through a shaft 66 to drill 18. Instrument package 25 as previously
described contains radiation sources 26, radiation detectors 27. An
amplifying apparatus 69 is coupled through a wire 67 to memory 24
and a mechanical recorder 68. Power to drive the drill motor 65 is
provided by a hydraulic propulsion unit for example generally
referred to by the number 70 and essentially comprises a shaft 71
which is connected directly to instrument package 25 and to a reset
hydraulic cylinder 72. Main propulsion unit 73 which contains a
hydraulic piston (not shown) which is attached to shaft 71 which is
in turn connected to instrument package 25. A plurality of pressure
feet 74 is attached to both the main propulsion unit 73 and the
reset cylinder or unit 72. The unit operates by the propulsion unit
73 being nearly adjacent to instrument package 25. Hydraulic fluid
is then applied to the left side of the main propulsion unit 73
which drives shaft 71 toward the right of the drawing. Once reset
unit 72 nearly reaches main propulsion unit 73, hydraulic pressure
is dropped on both the pressure feet 74 and the left side of
propulsion unit 73. The pressure feet associated with reset
cylinder 72 are then pressurized and hydraulic fluid is applied to
the right side of main propulsion unit 73 driving it once again
toward instrument package 25. The reverse procedure is then
followed, and the instrument is ready for again propelling drill 18
into the formation. Such a device is manufactured by Drillco
Corporation of Midland, Tex., and is well known in the art.
Information from the radiation detectors 27 as previously mentioned
is conveyed through wire 67 to a recorder 68 and a memory system
24. Distance measuring tachometer 22 from the drill is also
communicated through wires 23 to the recorder 68 and memory 24. In
the case of recorder 68, the distance tachometer may be used to
determine the rate of feed of the recorder paper 75 and the method
in which the information is stored on memory 24. Paper recording 75
provides a visual information for the operator of the system during
the pilot hole drilling process. If the operator is satisfied with
the recording information received from the horizontal drill, then
the information stored in memory 24 is applied through circuit 76
to a continuous mining control unit 51. Position sensor 60
communicates the position of probe 59 as previously mentioned to
continuous mining control unit 51 through a wire 80. Sensor 61
communicates its information through a wire 81 to continuous mining
control unit 51. Information from control unit 51 is applied to a
wire 55 to various hydraulic control circuits contained on the
frame 45 of the ocntinuous mining machine.
Operation
The method of mining described herein comprises two distinct
operations. The first operation is the drilling of a pilot hole
illustrated in FIGS. 1, 2, and 4. The pilot hole is formed by a
drilling apparatus, such as 14 illustrated in FIGS. 1 and 2, which
has the drill rod 17 mounted on a chuck 16 with drill 18 connected
at the end of drilling apparatus 14. As motor 15 rotates drill pipe
17, drill 18 will penetrate the seam or vein 10. As the drilling
apparatus 14 proceeds forward, track 27 will turn tachometer 22
which will measure the forward advance of drilling apparatus 14. If
for any reason, for example the insertion of the new drill pipe,
the drilling apparatus will reverse its direction of travel,
tachometer 22 will not measure the reverse direction. In fact, it
would be preferable to interconnect motor 15 with tachometer 22 so
that the tachometer is recording forward movement only while the
drill is rotating. This will account for any incidental forward or
backward movements necessitated by the drilling apparatus to
positon additional drill pipe to remove a defective drill or other
reasons well known in the drilling art. As the drilling apparatus
penetrates pilot hole 13 at for example distance d.sub.1, sensitive
detectors combined with a radioactive source will measure the
distance, for example p.sub.1 and p.sub.1 ' , which is indicative
of the thickness of the coal seam between the pilot hole being
drilled and the overburden in the case of p.sub.1, and the pilot
hole and the underburden in the case of p.sub.1 '. This distance is
directly relatable to the amount of back scatter received by the
detector. It is also well known that shale which generally lies
between the coal seam 10 and the overburden 11 is naturally
radioactive. If the above exists, then a detector need only be used
to measure the natural radioactivity of the shale which will be an
indication of the thickness of the coal between the overburden and
the underburden with respect to the pilot hole 13. As the drill
progresses to for example a point d.sub.2, d.sub.3, and d.sub.4 ,
the respective thicknesses p.sub.2, p.sub.2 ', p.sub.3, p.sub.3 ',
and p.sub.4, p.sub.4 ' will be measured and recorded on recording
apparatus 24. It should be noted that recording apparatus 24 is
recording both the distances and the measured radiation levels for
each of the corresponding distances. The recorder will generally
comprise (see FIG. 4) a mechanical recorder which will provide a
visual output 75 for an operator so that the progress of the
drilling apparatus and its operability can be continually
ascertained. In addition to the recording apparatus, a memory 24
may also be incorporated which will normally magnetically record
the data being recorded in recorder 68. The magnetic memory, if
satisfactory, which can be determined by the record 75, then memory
24 will be used in a subsequent mining process in combination with
the continuous mining machine. Referring to FIGS. 3 and 4, a
continuous mining machine is shown removing the material 10 between
the overburden 11 and the underburden 12. A probe 59 is inserted
into the borehole. Position sensing device 60 and 61 will
continuously relay through wires 80 and 81 to the continuous mining
control unit the exact positon of the probe 58 with respect to the
frame 45 and the position of boom 46 with respect to frame 45.
Since the coal thickness between the pilot hole and the underburden
is known, the distance between probe 59 and conveyor 52 should
correspond to the predetermined distance. Boom 46 will be operated
against the coal face to maintain the distance between the pilot
hole and the underburden in accordance with the predetermined
distance. Boom 46 will also be operated so that the distance
between the pilot hole 13 and the overburden 11 is removed in
accordance with the predetermined thickness of the coal. The
tachometer 22' through wire 23 will continually provide distance
information to the continuous mining control unit. Once the
distance of the unit is known, which is continually compared from
memory circuit 24, the position of the mining machine with respect
to its cutting apparatus is known and continually conveyed to the
continuous mining control unit 51 through wires 80 and 81, will
remove the material 10 in accordance with the predetermined
thicknesses above and below the pilot hole 13.
Referring to FIG. 5, an illustration of the data shown on the graph
75 is depicted. The horizontal axis represents the distance
penetrated by the drill and illustrative distances are for example
100, 200, 300, and 400 feet, respectively, for d.sub.1 through
d.sub.4. The seam thickness measurements are represented by the
vertical axis and correspond to 10 to 40 feet, respectively. The
plot of p.sub.1 through p.sub.4 is illustrated as increasing from
15 to approximately 35 feet, while p.sub.1 ' decreases from 25 to
approximately 15 feet. The information illustrated in FIG. 5 as
previously discussed is applied to recorder 68 and memory 24.
Memory circuit 24, of course, may be a tape unit which is easily
transferrable to the continuous mining machine. Any form of
continuous mining machine can be used. A drum mining machine is
illustrated; however, other well-known types can be obviously
adapted using the principles discussed above. A probe 59 is
illustrated as one means of following the pilot hole 13. Other
well-known systems can be incorporated, for example, a light beam
can be utilized to follow the pilot hole. Lasers can also be used.
The invention is not restricted to the particular pilot hole probe
illustrated in the drawings.
Referring to FIG. 6, an important feature of the method is
illustrated. One of the greatest hazards in continuous mining is
the possibility of roof falls and explosions due to the release of
methane gases in the environment where the mining operation is
taking place. The invention disclosed can be continuously operated
without the presence of a human mining operator. Under these
conditions, a mine room 40 can be sealed off with a partition 90. A
nitrogen generator 91 located in the mine can convey nitrogen
through a pipe 91 into tunnel 93 being mined. a conveyor generally
referred to by the number 94 can be attached to a beam 95 to the
frame 45 of the continuous mining machine. As the machine moves
forward, conveyor 94 will move with it. The coal material 96
conveyed from the continuous mining machine will fall onto a belt
97 and be conveyed through an opening 98 outside partition 90. A
plurality of hanging members 99 can substantially close the opening
which provides a passage for the conveyor and the material. If
nitrogen should pass from room 93 into room 40, no hazard to mining
personnel will be present since breathable air contains 80 percent
nitrogen. The usual mine ventilating system will remove any excess
nitrogen that will normally accumulate.
It is obvious that other changes and modifications may be made in
the method as described and claimed in this application. It is also
obvious that other types of apparatus can be utilized to carry out
the method described herein and still be within the spirit and
scope of the specification and appended claims.
* * * * *