Note: Descriptions are shown in the official language in which they were submitted.
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ORE PASS INSPECTION SYSTEM
FIELD OF THE INVENTION
This invention relates to an ore pass inspection system that allows
imaging of the ore pass in an underground mine. This ore pass inspection
system is especially useful in cases of hang-ups or blockages within the ore
pass. This inspection system can also be used to help clear such hang-ups
or blockages.
BACKGROUND OF THE INVENTION
An ore pass is a generally vertical or near-vertical passage excavated
1o between at least two levels in an underground mine. The levels occur at
different vertical displacements in the mine. The vertical distances between
such levels. and thus the vertical extent of the ore pass, may range up to
hundreds of feet or even more. Such ore passes provide a passageway for
delivering mine products (i.e.. ore. coal, and the like) from a higher level
to a
lower level within the mine. Generally, the lower level contains ore carts.
carriages. trams. or other transport devices which allow the mine products to
be removed directly or indirectly out of the mine. In some cases, the lower
level can serve several higher levels through the same or different ore
passes.
2G The interior walls of an ore pass may contain surface structures
ranging from smooth to very rough. The surface features may depend. for
example; on the geological structures traversed by the ore pass, the nature of
the mining tool or apparatus used in boring out the ore pass, and similar
factors. Additionally, the cross-sectional dimensions of such ore passes may
vary. Likewise, the sizes, shapes, and structures of the mining products
being transported via the ore pass may vary greatly. Thus, from time to time
in a given ore pass, the mining products may "hang up" within the ore pass.
The just mentioned factors contribute to the likelihood of such hang-ups and
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blockages within ore passes. The likelihood of such blockages will be
significantly higher in some cases (e.g., rough ore pass surfaces,
"bottlenecks" within the ore pass, non-vertical passageways within the ore
pass. large and irregularly shaped mine products). Once a hang-up or
blockage occurs, the piling up of additional mine product on top of the hang-
up often packs the blockage more tightly and makes removal of the blockage
more difficult.
Clearing an ore pass hang-up or blockage presents significant safety
concerns. For example, a miner at the lower end of the ore pass attempting
to remove the blockage could be exposed to any material dislodged from the
hang-up. If the miner is standing at the bottom end of the ore pass, and
directing a disrupting force upwards into the ore pass toward the hang-up. any
sudden rush of ore attending a successful clearing operation may trap the
miner and cause serious injury or death. As of the time of this invention.
there have been at least five ore pass-related fatalities in the preceding
five
years in the United States. and a far larger number of ore pass hang-up-
related injuries.
The United States has about 100 to 200 mines containing working ore
passes Any given mine may have one or more ore passes; some mines
2~ have upwards of 10 or even more ore passes. Depending on the factors
identified above. the frequency and likelihood of an ore pass hang-up may
vary considerably. In some case, an ore pass may become hung-up only
rarely in other cases. it may be an almost daily occurrence. Likewise. and for
similar reasons, the degree of difficulty in clearing such a hang-up varies
2~ widely. Numerous techniques to remove the blockage have been developed.
These include, for example. delivering blows to structures adjoining or
related
to the ore pass; placing a small blasting charge either just inside the ore
pass
or as close to the blockage as possible using. for example, a long pole; or
propelling the explosive charge as a ballistic slug toward the location of the
3o hang-up. Alternatively, a separate long hole may be drilled from below
(mobilizing a drill rig in the passageway beneath the blockage) in order to
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deliver a blasting agent through the drilled hole into the hang-up. Clearly,
the
latter tactic is both time consuming and expensive. In some cases, the mine
operator may choose to abandon the blocked ore pass and bore a new one.
U.S. Patent 4,930,595 discloses a method of remotely determining the
profile of a subterranean passage within a mine using an instrument pod that
can be moved along the passage. The pod includes a rangefinder for
determining the distances from a defined longitudinal axis of the pod to
multiple points on the internal wall of the passage and providing an output
signal representing the profile of the passage. A clinometer is used to
indicate the orientation of the pod in the passage. The signals are
transmitted to a remote location and provide a visual representation of the
profile of the passage at a given location. As the pod is moved, successive
representations at different locations are obtained. The pod is preferably
also
provided with a television camera and lighting so that the wall of the passage
~5 can also be visually inspected. Since the pod moves by gravity. it is
generally
intended for use by being lowered down the passage; in some cases. the pod
can be pulled up the passage.
U.S. Patent 4,023.862 provides a coal mining method wherein the coal
seam is disintegrated by utilizing a jet of hot oil under pressure. Since an
2~ operation can be remotely controlled in a deep mine shaft. exposure of mine
workers can be minimized. The method further reduces the amount of coal
dust produced and, thus. reduces the risk of dust explosions. A TV camera
can be mounted on the mining machine for transmitting a picture of the
operation to the surface so that appropriate guiding signals can be
25 transmitted to the machine.
U.S. Patent 4,708,395 discloses a method and apparatus for
hydraulically mining a coal seam using a monitor and a hydraulic jet powered
by high pressure water. The monitor includes means for remotely positioning
the jet vertically and horizontally so that the jet can be aimed at any
location
3o within the zone of a mine face being mined. This system is especially
useful
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in hazardous locations within a mine (e.g., unstable areas where the risk of
roof falls is significant).
U.S. Patent 5.069,108 discloses a blasting device for unblocking ore
passes, backfill raises, mine draw points, or other near vertical raises where
rocks or other materials normally fall freely but may get blocked during use.
The device includes a propulsion unit including an air chamber mounted at
the end of a hollow tube with an inlet for receiving pressurized air and at
least
one outlet for allowing compressed air jets to exit downwardly from the air
chamber to propel the propulsion unit upwardly. A reservoir is mounted on
the propulsion unit and adapted ro hold an explosive charge and an igniter
which can be remotely activated.
As those skilled in the art realize, it is generally more effective to attack
a blockage from below. But efforts from below place the workers at maximum
risk since. once the blockage is clear. the hung-up materials will. of course.
~5 continue their fall through the ore pass. Even if the blockage is not
completely cleared, material dislodged from the blockage place workers
located below at significant risk.
Thus. there still remains a need for an apparatus and method that
integrally permits placing the apparatus in a location immediately under a
2o hana-up in an ore pass in order to clear the hang-up while minimizing the
risks to the operator. There additionally remains a need for an apparatus and
method that substantially eliminates guesswork in placing a device to clear an
ore pass hang-up. and that employs an image based guiding mechanism to
direct the apparatus to a preferred position for clearing a hang-up. There
25 further remains needs for method for clearing blockages and for an
apparatus
and that is reusable. The present invention addresses these unresolved
needs.
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SUMMARY OF THE INVENTION
The present invention discloses an apparatus for clearing a material
hang-up in an essentially vertical shaft having walls which is used for moving
material from a higher level to a lower level, said apparatus comprising:
(1 ) a platform having an upper surface and a lower surface and at least
two ends, wherein the platform is movable along a longitudinal direction
within
the shaft:
(2) a remotely controllable propulsion unit affixed to the lower surface
of the platform capable of propelling the platform along the longitudinal
direction within the shaft and up to the hang-up:
(3) an imaging unit affixed to the upper surface of the platform capable
of generating an image of an upward view within the shaft, wherein the image
is transmittable to a remote viewer, and wherein the image can be viewed by
an operator to assist in controlling and operating the apparatus;
~5 (4) one or more extensible immobilizing units affixed to the ends of the
platform, wherein the immobilizing units are remotely controllable. and
wherein the immobilizing units. when activated by the operator. immobilize the
platform within the shaft:
(5) a remotely controllable clearing unit affixed to the platform and
2~ adapted for clearing the hang-up within the shaft: and
(6) a remote controller for controlling the propulsion unit, the
immobilizing units, and the clearing unit:
wherein the apparatus can be controlled and operated by the operator
using the remote controller at a safe distance from the shaft. This apparatus
25 is especially adapted for use in ore passes in underground mines.
Preferably.
the immobilizing unit allows the operator to immobilize the apparatus at a
fixed longitudinal position within the ore pass by providing members that can
contact the walls of the ore pass in a manner to immobilize the platform in
the
desired position (i.e., generally a position from which the hang-up can be
3o cleared). Preferably the apparatus has a light source to provide light for
the
imaging unit; preferably, both the light source and the imaging unit can be
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remotely controlled. If desired, the imaging unit may incorporate a zoom-type
lens.
In a significant embodiment of the apparatus, the propulsion unit
comprises a gas receiving chamber, a source of a gas under high pressure in
communication with the chamber , and at least one gas nozzle affixed to the
chamber and projecting downward therefrom. Preferably, the gas source is
located at a remote, and protected, position relative to the platform (e.g.,
at a
safe location near the bottom of the ore pass). In a further significant
embodiment. the imaging unit includes a light source directing tight generally
upward along the ore pass above the platform and an imaging device capable
of generating the image. When the apparatus is positioned just below the ore
pass hang-up. the image allows the operator to view the blockage and place
the platform in position to remove or breakup the blockage.
In an important embodiment of the apparatus. the extensible
immobilizing unit includes at least one balloon or bladder inflatable by gas
under pressure, and a first remotely controllable valve capable of
controllably
admitting the pressurized gas into the balioon(s) or bladder(s). Furthermore.
in an alternative important embodiment, the extensible immobilizing unit
includes at least one prong or leg extendabiy engaged to a remotely
2c controllable driving unit capable of controllably extending the prong. In
operation. the balloon(s) and/or prongs) are activated so as to extend out
from the platform and contact the walls of the ore pass. The activated
balloons) and/or prong(sl effectively lock the platform in place by applying
pressure through the balloons) and/or prongs) or leg(s). in another
2~ important embodiment of the apparatus, the extensible immobilizing unit or
units can also be remotely retractable to allow the apparatus to be removed
entirely or repositioned as desired. For example, the extensible immobilizing
unit or units include one or more balloons, the retractable mobilizing unit or
units would include a second remotely controllable valve for controllably
3o releasing gas from the one or more balloons. Where the extensible
immobilizing unit includes one or more prongs or legs, the retractable
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mobilizing unit would allow retraction of the prongs or legs. Of course, the
extensible immobilizing unit can be modified to allow both activation (i.e.,
extension) and deactivation (i.e., retraction).
In an advantageous embodiment of the apparatus, the unit for clearing
ore pass hang-ups includes a device to deliver high-impact blows to the
blockage in general or to a particular location in the hang-up (e.g., to "key"
pieces of material in the hang-up that appear to be responsible for the hang-
up). In an alternative advantageous embodiment, the unit for clearing the ore
pass hang-up includes a stream of a fluid under high pressure to breakup the
1U hang-up.
Where these methods of breaking up the hang-up fail, the platform can
be equipped with a remotely controlled explosive material or charge. In such
cases, the apparatus preferably allows the explosive charge to be affixed or
attached to blockage so that the apparatus itself can be removed from the ore
~5 pass before the charge is remotely activated. Of course. if desired,
explosive
charges could be used without first attempting to use other methods. Thus, in
another significant embodiment of this invention, the unit for clearing the
ore
pass hang-up includes an emplacement unit and an explosive charge.
wherein the emplacement unit includes: (1 ) a remotely controllable drive
unit:
2c and (2) a holder having a proximal end and a distal end. wherein the
proximal
end is pivotally and swivelably affixed to the drive unit; wherein the distal
end
is releasably holding the explosive charge: wherein the drive unit is capable
of
causing the holder to be moved in order to move the explosive charge to the
desired location; and wherein the explosive charge further includes (a) a
25 detonation device and (b) an attachment element whereby the explosive
charge can be attached to the desired location on the hang-up. Preferably
the detonation device allows the explosive charge to be triggered remotely.
Suitable attachment elements include, for example. adhesives, grappling
hooks or devices, and the like. Additionally, the explosive charge can be of
3o the plastic type which can simply be "packed" within voids or crevices
within
the hang-up. Preferably, the platform is removed before the explosive charge
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is triggered. In some especially difficult hang-ups, a second platform (but
without the imaging equipment) can be locked into place just below the
explosive charge and the hang-up so as to direct the force of the charge up
into the hang-up.
The invention furthermore provides a method for imaging and clearing
a shaft or ore pass containing a hang-up using the above-discussed systems
and apparatuses. More specifically, this method comprises:
(1 ) introducing an apparatus for clearing the hang-up into the lower end
of the shaft blocked by the hang-up, wherein the apparatus is capable of:
(a) being remotely propelled within the shaft so that the
apparatus can be positioned adjacent to and below the hang-up by an
operator located at a safe distance from the lower end of the shaft.
(bj providing an image of an upward view of the shaft as the
apparatus is propelled within the shaft and is positioned adjacent to and
~5 below the hang-up. where the image is transmitted to the operator,
(c) being remotely immobilized in a position adjacent to and
below the hang-up by the operator. and
(d) remotely clearing the hang-up after being immobilized in a
position adjacent to and below the hang-up:
2c (2i remotely propelling the apparatus upward within the shaft until the
apparatus is positioned adjacent to and below the hang-up. wherein the
image is used by the operator to guide the apparatus within the shaft:
(3) remotely immobilizing the apparatus adjacent to and below the
hang-up; and
25 (4j remotely clearing the hang-up
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1A provides a schematic diagram (side view) of the apparatus
for imaging and clearing an ore pass hang-up. Figure 1 B provides a
schematic diagram (viewed from above) of the apparatus from Figure 1A
3o having a rectangular platform. Figure 1C provides a schematic diagram
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(viewed from above) of the apparatus having a triangular platform. Figure 1 D
provides a schematic diagram (viewed from above) of the apparatus having a
circular platform.
Figure 2. A diagram of a guidable or controllable propulsion unit of the
present invention based on expulsion of a gas under high pressure through
gas nozzles.
Figure 3. A diagram of an imaging system used in the present
invention.
Figure 4. A diagram of an embodiment of an immobilizing and
remobilizing unit of the invention based on a balloon inflatable and
deflatable
using a set of controllable valves.
Figure 5. A diagram of an embodiment of an immobilizing and
remobilizing unit of the invention based on an extensible and retractable
prong.
Figure 6. A diagram of clearing mechanism using an explosive charge
which is attached to the materials forming the hang-up.
Figure 7. A diagram of clearing mechanism of the present invention
using a ram to strike or impact the materials forming the hang-up.
DETAILED DESCRIPTION OF THE INVENTION
2o This invention relates to a shaft inspection system (including apparatus
and methods) for inspection and clearing of hang-ups. More particularly, this
invention relates to an ore pass inspection system (including apparatus and
methods) that allows imaging of the ore pass in an underground mine. This
ore pass inspection system is especially useful in cases of hang-ups or
blockages within the ore pass. This inspection system can also be used to
help clear such hang-ups or blockages. As used herein, an "ore pass" relates
generally to an essentially vertical (i.e., vertical or near-vertical) shaft.
chute.
raise, winze, or similar passage bored between at least two levels in an
underground mine wherein the ore or other mined material can be moved
3o from an upper level to a lower level using gravity. As used herein, a
"shaft"
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relates generally to an essentially vertical (i.e., vertical or near-vertical)
ore
pass, chute, raise, winze. or similar passage spanning at least two levels
wherein a solid material can be moved from an upper level to a lower level
using gravity. As used herein, "ore" relates generally to any mine product
developed during the course of mining operations. For example, ore may be
rock or other mined material which has sufficient mineral or other value to
justify extraction and recovery. Ore may also be the intended material for
which a mine is established and which the mine produces for market.
Additionally, as used herein, ore may be by-product tailings or similar waste
1o produced in a mining operation that results, for example. when it is
necessary
to pass from one mineral-bearing vein to another, or it may be otherwise
produced as required in a mining operation. Ore furthermore encompasses
materials bearing elemental mine products with value, such as rocks bearing
diamonds or rocks bearing elemental gold. Still further ore, as used herein,
15 encompasses coal and similar non-mineral mining products. As used herein.
"material" includes any solid. particulate material, including ore, that is
moved
from a higher level to a lower level using the force of gravity. As used
herein.
the "longitudinal direction" of an ore pass or shaft is considered to be the
long
axis of the ore pass or shaft.
2~ The apparatus and the methods of the present invention provide for
imaging and clearing an ore pass hang-up. As shown schematically in Figure
1A (side elevation view), the apparatus 10 includes a platform or framework
20 having an upper surface 22 (i.e.. on the surface adjacent to the hang-up)
and a lower surface 24 (i.e.. on the surface opposite to the hang-up), and at
25 least two ends or sides 51 for mounting the extensible immobilizing units
50.
The platform may having various shapes (i.e., triangular, square, rectangular.
oval, circular, and the like). A rectangular platform 20 is shown in Figure 1
B.
Such a rectangular platform 20 would have at least two ends 51 and at least
two extensible immobilizing units 50; other shaped platforms 20 would have a
3o plurality of ends 51 adapted for their specific shapes. Thus, the
triangular
platform 20 shown in Figure 1C has three ends 51 (i.e., one on each side of
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the triangle) and, preferably, a corresponding number of extensible
immobilizing units 50; the imaging unit 40 consists of a light source 142 and
an imaging device 144. A circular platform 20 (see Figure 1 D) could have a
plurality of ends 51 (preferably at least three) located around its
circumference; thus. for a circular platform 20, the ends 51 are considered to
be arbitrary locations or positions around the circumference such that. when
activated, the immobilizing un;ts 50 can lock the platform in place within the
ore pass. The circular platform 20 shown in Figure 1 D has four immobilizing
units 50. The apparatus, especially its footprint, is small enough that it can
1o move freely along generally a longitudinal direction of an ore pass, but it
is
large enough that it may be readily immobilized as described below. Thus.
the size of the platform 20 will generally be determined by the smallest cross-
sectional dimension of the ore pass. Generally. a rectangular platform 20, for
example will often have dimensions in the range of about 12 to about 48
15 inches wide and about 18 to about 48 inches long. Generally, for a circular
platform 20, the diameter will generally be about 12 to about 48 inches. As
those skilled in the art will realize. platforms smaller or larger than the
general
dimensions just given and platforms of different shapes may be used and
may. depending on the three-dimensional geometry of the particular ore pass
2~ be preferred.
The apparatus includes a guidable or controllable propulsion unit
shown schematically at 30 affixed to the lower surface 24 of the platform 20.
The propulsion unit 30 should he capable of propelling the platform 20 along
th<~ generally longitudinal direction of the ore pass (i.e., up into the ore
pass)
25 in order to reach the hang-up. In a preferred embodiment, the propulsion
unit
30 achieves levitation using a high pressure gas. Thus, the high pressure gas
is supplied to the propulsion unit 30 and allowed to escape through at least
one thrusting nozzle directed downwards. This generates a lifting force such
that the apparatus is generally propellable upwards along the longitudinal
3o direction of, and into, the ore pass and in the direction of the ore pass
hang-
up. In such a preferred embodiment, shown schematically in Figure 2, a
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source of high pressure gas (not shown) is supplied using a high pressure
gas line 132. The source of gas can be any conventional gas supply such as,
for example, a compressor. compressed gas tanks, and the like. The high
pressure gas line 132 is in communication with a receiving chamber 130 that
receives the pressurized gas from the source. The gas is controllably
released to atmospheric pressure through at least one gas nozzle 134 affixed
to the receiving chamber and projecting downward therefrom. The preferred
gas is air.
Two nozzles134 are shown in Figure 2; as those skilled in the art will
1o realize. only one or more than two such nozzles can be used. Preferably. at
least three nozzles, arranged in a symmetrical pattern around the platform.
are used to achieve more stable flight within the ore pass. More preferably,
three nozzles are used. The expanding gas provides the thrust to propel the
apparatus upwards along the ore pass. Preferably the nozzles incorporate
15 supersonic or converging-diverging type designs in order to maximize
thrust.
In alternative embodiments. the propulsion unit 30 may include solid or liquid
chemical propellants such as may be used in rockets. It may further be a
motor driven propeller or similar equivalent systems of propelling the
apparatus in a controllable fashion along the longitudinal direction of the
ore
2c pass The propulsion unit 30 can provide the levitating effect required to
controllably position. reposition. and/or remove (i.e., back out) the
assembly.
Normally, the high pressure gas line 132 will extend from the platform.
down the shaft or ore pass. and then to a remote gas source. If desired
other lines could be bundled with the high pressure gas line. These other
25 lines could include electrical cables, hydraulic lines, optical fibers,
liquid
supply lines (i.e., to provide high pressure liquids for clearing the hang-
up),
and the like. Preferably, such lines are bundled (with or without the high
pressure gas line) and protected with a protective cover.
Imaging units or systems, shown schematically at 40, are affixed to the
3o upper surface 22 of the platform. The imaging unit is capable of generating
an image of an upward view along the ore pass. In a preferred embodiment
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shown in Figure 3, the imaging unit includes a light source light 142 directed
upwards along the ore pass such that it illuminates generally the walls and
lumen of the ore pass and the hang-up (including component pieces of ore
comprising a hang-up) when the apparatus reaches the vicinity of such a
hang-up. The light source may have fixed or variable intensity. The imaging
unit 40 further includes an imaging device 144 such as, for example, an
electronic video or TV camera (analog or digital) to provide an upwards field
of view within the ore pass If desired, the imaging device could have
zooming capabilities. The image generated by the video camera is
1o transmittable to a remote viewer such that an operator can view the image
and use the information contained therein to guide the progress and
operation of the apparatus. If desired. the light source and/or the imaging
device can incorporate fiber optic technology. In cases where an open flame
could be hazardous, the use of fiber optic technology for the light source may
be preferred.
The apparatus also includes extensible immobilizing units shown
schematically at 50 in Figures 1A and 1 B affixed to the ends of the platform
which are used to effectively ''lock" the platform in place within the ore
pass at the appropriate location (generally just below the hang-up). If the
2o platform is rectangular (as shown in Figure 1 B), the ends of each side arm
will
generally have its own immobilizing unit 50. For oval or circular platforms, a
plurality (preferably about two to ten and more preferably about 2 to 5) of
immobilizing units 50 are disposed in a regular or Pquidistant manner around
the circumference. Alternatively, a circular platform 20 (or other shaped
platforms) could have a single immobilizing unit attached around the entire
outside surface of the platform. Thus, if desired, the circular platform 20
could be used with an inflatable bladder having an inner-tube or donut shape
to engage the ore-pass walls. When extended or engaged, the immobilizing
units are intended to engage the walls of the ore pass with sufficient force
that
3o the apparatus is immobilized at a fixed longitudinal position within the
ore
pass. Depending on the geometry of the cross section of the ore pass in
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which the apparatus is to be fixed. some or all of the immobilizing units 50
may be used. Extending the immobilizing units 50 furthermore is remotely
controllable by an operator in response to the image transmitted by the
imaging unit 40. The apparatus is intended to be so immobilized just below
the lower extent or lower limit of the ore pass hang-up.
In a preferred embodiment shown in Figure 4, the extensible
immobilizing units comprise balloons or bladders 150 which can be inflated
using gas under pressure. For example, the pressurized gas may be
delivered from the gas receptacle 130 (Figure 2) using a gas feed line 151:
alternatively. a separate gas supply line (which could run along side of line
132) could be used if desired The balloon or bladder 150 may be
constructed of any gas impermeable, flexible material strong enough not to be
torn or ruptured as the material engages the potentially rough surface of the
ore pass. The flow of gas that inflates the balloon and causes it to engage
~5 the ore pass wall 100 is regulated by a first controllable valve 152
admitting
the gas to the balloon.
In an alternative preferred embodiment shown in Figure 5. the
extensible immobilizing units comprise at each end of the platform 20 a prong
157 which can be extended using a controllable driving unit 155 to contact the
2c wal! 100. Preferably, the platform will have a plurality of such prongs
spaced
around its circumference: more preferably. the platform will have about three
to about five prongs. The driving unit 155 could, for example, comprise an
electric motor. solenoid valves. gas driven valves. and the like. Once
determined to be in the proper position, the operator activates the driving
unit
25 or units to extend prong 157 (and other prongs, not shown. which may be
used) to contact and engage the wall 100 of the ore pass with sufficient force
to immobilize the apparatus. Prongs 157 can, if desired, be formed of nested
tubes or rods (similar to a retractable antenna) that can be extended and
retracted as needed using. for example, air pressure, vacuum, and/or multi-
3o stage pneumatic actuators.
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The embodiments shown in Figures 1 A, 1 B, 1 C, 1 D, 4, and 5 have the
extensible immobilizing units 50, 150, or 157 mounted externally on the
platform 20; alternatively, such extensible immobilizing units could be
mounted within the structure forming the platform. Indeed, in some cases,
internal mounting of the extensible immobilizing units may be preferred since
such a location would provide protection to the extensible immobilizing units
as the assembly is raised or lowered within the ore pass.
The platform also has affixed to it a controllable unit or mechanism 60
to allow clearing of the ore pass hang-up. Once immobilized in the desired
1o position within the ore pass (i.e., normally just below the hang-up), the
operator activates the clearing mechanism to try to break up the hang-up and
reestablish the flow of ore. In some cases. reestablishment of the flow of ore
can damage or even destroy the apparatus. When damage to the apparatus
is expected to be extensive. the apparatus will preferably be constructed of
inexpensive materials and components. Alternatively, especially in cases
where complete destruction is not expected, components susceptible to
damage (e.g.. imaging and light source units) may be retracted or otherwise
covered and protected during the attempts to clear or break up the hang-up.
Examples of clearing mechanisms that may be employed to break up the
2~~~ hana-up include high-impact blows directed towards the hang-up and high
pressure fluid streams directed towards the hang-up.
Alternatively, clearing mechanisms can be used which allow the
apparatus to be removed from the ore pass prior to activating the clearing
operation. For example, the clearing mechanism (e.g., an explosive charge)
may be attached directly to the hang-up and the apparatus simply removed
before activation of the clearing mechanism. In such cases, the apparatus
would be removed from the ore pass using essentially the same technique,
except in the reverse direction. used to initially guide the apparatus to the
hang-up.
3o Alternatively, the immobilizing unit and the clearing mechanism could
be adapted to controllably separate from the remainder of the apparatus. The
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remainder of the assembly (including the more expensive lighting, imaging,
and propulsion units) could.be removed while the immobilizing unit and
clearing mechanism remain in place. Only after the remainder of the
assembly is out of harm's way would the clearing operation begin. If desired.
relatively inexpensive lighting and imaging units could be used which could
remain within the ore pass to provide visual information regarding the
clearing
operation.
These additional operational features (i.e., removal of the assembly
prior to the clearing operation) are accomplished in general by including
1o retractable mobilizing units in addition to the extensible immobilizing
units
affixed to the ends of the platform. Retraction of the immobilizing units is
also
remotely controllable, and is carried out after placing clearing units on or
near
the hang-up. Retracting the immobilizing units serves to mobilize the
apparatus for propulsion back down along the longitudinal direction of the ore
1~ pass
Using inflatable balloons as the immobilizing unit, as shown in Figure
4, a second controllable valve 153 can be used to depressurize or deflate the
balloons so that the assembly can be removed. In such a case, balloon 150
is inflated by controlling the first valve 152 to open and admit gas to the
2~ balloon to lock the assembly in place. After the clearing unit is properly
positioned. the second controllable valve 153 is activated to deflate the
balloon. The first and second valves may be separate units or may be
combined in a single valve system (e.g.. a "Tee" valve). Such a valve could
have. for example, a first operating position wherein the balloon inflates, a
25 second operating position wherein gas cannot pass into or out of the
balloon,
and a third operating position wherein the balloon gas can exit to atmosphere
and allow the balloon to deflate. Similar systems could, of course, be used to
operate the prongs157 shown in Figure 5 (i.e., engage and disengaged the
prongs as appropriate). Equivalent configurations of the first and second
3o valves 152 and 153 can be used as long as they accomplish the same
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operational objectives (i.e., allow the immobilizing units to be controllably
engaged and disengaged as desired) .
The preferred embodiment of the present apparatus includes
mechanisms for clearing the ore pass hang-up. In a particularly preferred
embodiment. the mechanisms for clearing the hang-up comprises an
emplacement unit that allows the placement and attachment of an explosive
charge directly on the hang-up (i.e., on a portion or a particular boulder.
stone. or similar fragment of the actual hang-up). The emplacement unit of
Figure 6 includes a drive unit 160 and a remotely controllable holder 162 with
1o a proximal end and a distal end The proximal end is pivotally and
swivelably
affixed to the drive unit 160. such that the drive unit is capable of causing
the
holder 162 to be pivotally raised or lowered, and to swivel. The distal end
releasably holds the explosive charge 164. For example, as shown in Figure
6. the explosive charge 164 rests by gravity on a curved holding container
163 at the distal end of holder 162. The explosive charge 164 further
includes a detonation unit 166 such as. for example, a fuse wire ignitable
from
a remote location. or an electrical detonation wire closable by a remote
switch. and an adhesive 165 capable of affixing the charge to the ore
fragment in the hang-up. Of course, other methods of attaching the explosive
2o charge to the hang-up can be used if desired. Such methods could include
for example. grappling hooks or claws. plastic explosives which could be
inserted into cracks or voids within the hang-up, and the use of the platform
with its immobilizing units to simply lock the platform and explosive charge
in place below the hang-up. If the platform is used to mount and hold the
explosive charge in places, an assembly wherein at least a portion of the
assembly (especially the more expensive components) can be removed from
the ore pass before detonation is preferred. Moreover, the use of such a
platform to hold the explosive charge in place may. in some cases, be
preferred since the platform can act as a reflector or barrier to direct the
force
of the explosion into the actual hang-up.
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As shown in Figure 7. the clearing mechanism 60 can also be
designed to deliver mechanical blow or impact to the hang-up. For example.
an hydraulically controlled ram 180 can be used to directly pound or strike
the
hang-up material: the general direction of the ram is illustrated by arrow
184.
The ram could operate in fixed position (i.e., essentially in a single
vertical
direction) or could be pivotally mounted on the platform to allow more than
one portion of the hang-up to be impacted. The ram 180 could also be fitted
with a battering plate 182 (preferably of steel or similar material). If
desired.
the battering plate 182 could also have protrusions on its upper surfaces
(i.e..
cones. picks. or other shapes: not shown) which could allow the battering
plate 182 to ''grip" the materials within the hang-up during impact (i.e.. to
reduce the loss of force that would be expected if the battering plate were
allowed to more easily slide off to the side during impact).
In general. the apparatus of the present invention is relatively easy to
~5 use. In operation. the apparatus is introduced into the lower end of an ore
pass that is blocked by an ore pass hang-up. The apparatus is propelled
upward along the ore pass while using images of the upward view of the ore
pass for guidance. The operator. preferably at a remote location (i.e . out of
danger in the event the hang-up is cleared). continually monitors the image
2~ transmitted by the imaging unit while controllably guiding the apparatus as
it
moves upward along the ore pass Once the lower portion of the hang-up is
located and the apparatus is moved into the desired position. the operator
immobilizes the apparatus using controllable immobilizing units to engage the
walls of the ore pass with sufficient force that the platform is held in
place. In
25 some cases, sufficient dust may be stirred up as the platform is moved into
position to create visibility problems. In such cases, the platform may also
be
equipped with one or more upward directed water nozzles that can be
remotely controlled by the operator wet down the ore pass for improved
visibility.
3o Once in place, the clearing mechanism can be activated. In cases
where the apparatus is to remain in place during the clearing operation, the
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clearing mechanism can be activated immediately. Where the apparatus, or
portions of the apparatus, are to be removed prior to initiating the actual
clearing operation. the clearing mechanism is, of course, only activated after
the apparatus is removed from the ore pass. Removal of the apparatus,
especially in cases where it is to be removed prior to the clearing operation,
is
essentially carried out using the same techniques and systems as used
during the initial placement of the apparatus. In other words, once the
apparatus is ready to be removed. the immobilizing units are disengaged from
the walls and levitating units are activated to allow the apparatus to
essentially "back out' of the ore pass. Of course, where the apparatus
remains in place during the clearing operation, the weight of the freed hang-
up material may essentially "flush" the apparatus out of the ore pass. In such
cases. the apparatus may be damaged or destroyed. Of course, where such
damage or destruction is expected, systems using relatively inexpensive
~5 components are preferred. Additionally, it may be preferred to use a
separable apparatus (as discussed above) whereby the immobilizing units
and the clearing mechanisms can be separated from the remainder of the
apparatus: the remainder of the apparatus (preferably containing the most
expensive components) can be removed prior to initiating the actual clearing
2~ operation. Generally. when using an explosive charge as the clearing
mechanism, it is preferred that the charge is physically attached to the hang=
up and that the apparatus is removed from the ore pass prior to activating the
explosion.
As those skilled in the art will realize, the present system can be used
25 in a number of systems to remotely and safely remove hang-ups from vertical
or near-vertical shafts. Thus, although this invention was developed for use
in underground mines, in can be used in a number of industries where solid
materials must be moved from a higher to a lower level using vertical or near-
vertical shafts or passageways and where the solid materials are prone to
3o hanging up within the passageway. Such an apparatus would be especially
useful in cases where the passageway is extensive along its longitudinal
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direction and/or the passageway is difficulty to access. In such cases, the
clearing mechanisms to be used will preferably be non-damaging (i.e., not
explosive charges). In cases where dust explosions are possible, a clearing
mechanism employing an inert fluid under high pressure may be preferred in
order to reduce the risk of such explosions. Likewise, in underground mines
where dust explosions are possible, such a clearing mechanism may also be
p refe rred .
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