Note: Descriptions are shown in the official language in which they were submitted.
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ON-SITE LAND MINE REMOVAL SYSTEM
BACKGROUND OF THE INVENTION
This invention relates generally to neutralization of explosive devices, such
as land
mines, unexploded ordnance (UXO), bombs, and the like. More particularly, the
present
invention relates to a system for neutralizing an explosive device on-site
with controlled
collateral damage, the system including both neutralizing components,
conveying
components, sensing components, motivating components, and an integrated
system.
Various explosive devices have been and may continue to be deployed around the
world. These explosive devices are present in various forms and provide
various threats to
people, vehicles, livestock, and other property that may be near such
explosive devices. For
example, explosive devices may include anti-personnel or anti-vehicle land
mines. In
addition, unexploded ordinance (UXO) may be located near, and present a threat
to, people
and property. Examples of UXO include various ammunition such as aerial bombs,
or shells,
which may be armed but have not yet exploded. Unknown or unforeseen conditions
may
cause the LJXO to explode inadvertently with potentially disastrous results.
In addition, various types of explosive devices, sometimes termed bombs, can
be
assembled and deployed in areas where an explosion could threaten people or
property. For
example, such a bomb may be formed and positioned by an individual in a public
area of a
city. Often the triggering parameters of such a bomb are either unknown and/or
out of the
control of authorities who would otherwise desire to disable the bomb. For
each of the above-
described explosive devices, it is desirable to disable the system to avoid
inadvertent damage
to nearby people and property.
One traditional method ofdisabling explosive devices is to disarm them.
Disarming
can entail the disconnecting of the detonator or triggering mechanism from the
explosive
charge. Unfortunately, the appropriate manner of such disconnection may be
diilicult to
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determine or difficult to implement, or both, resulting in a highly dangerous
situation for the
person disarming the explosive. Further, even a$er being successfully
disarmed, the
explosive charge may still pose a danger of explosion due to other known or
unknown
mechanisms. Therefore, the explosive charge must still be neutralized or
otherwise disposed
of.
Another traditional method of disabling an explosive device is removing and
transporting the system to a location that poses less danger to people and
property, and
detonating the explosive device there. Unfortunately, the removal ofthe
explosive device
without detonation may prove to be impossible, impractical, or difficult. For
example, during
a removal attempt there may be an inadvertent explosion and damage to people
and/or
property. Further, even if the explosive device was successfully removed, an
inadvertent
explosion and/or damage may occur during transit of the explosive device to a
desired
detonation location. Finally, even if the explosive system is successfully
removed and
transported to a desired detonation location, the detonation may involve
collateral damage at
I S the detonation site or require the provision of an explosion-resistant
container.
The explosive device can also be conventionally disabled by in-place
detonation
where the explosive charge is triggered to explode. This method is often
practiced in the case
of land mines. While the land mine is covered with soil, such mines can also
be covered with
foliage or other camouflage, or can be uncovered. Mines ofthis type can be
mechanically or
non-mechanically (e.g., influence-type) activated. An influence-type mine
contains an
explosive bulk charge that is triggered by non-mechanical external conditions.
For example,
such a mine can be triggered by the detection of a sufficiently large and
sufficiently close
metal object. In contrast, a mechanically activated land mine is triggered in
response to
mechanical application of a force to one or more parts of the land mine. The
triggering device
may include, for example, one or more plates supported by one or more springs.
When a
sufficient amount of pressure is imparted to the plates of the triggering
device, for example
due to a person or vehicle moving onto the portion of the ground surface
directly above the
triggering device, the plates can press down. Under certain predetermined
conditions of
pressure or time, a fuse within the triggering device can be initiated, which
in turn detonates
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the bulk charge. The bulk charge can be formed of various materials such as
trinitrotoluene
(TNT), Composition-B, C-4, mercury fulminate, binary compositions, or some
other
explosive material.
An explosive charge is desirably disposed of at or near the ground surface.
The
explosive charge can be a conventional explosive that can be remotely
detonated through
known methods. Such conventional explosives can include TNT, Composition-B, or
others
such as dilute explosive tile (DET) available from SRI International of Menlo
Park,
California. As the explosive charge explodes, material and energy travel away
from the
explosive charge. As the material and energy from the explosive charge travel
in the direction
of and to the land mine, the land mine, and more particularly the bulk charge,
may experience
a particular peak pressure for a particular duration, both of which are
suffcient to trigger and
therefore explode the bulk charge.
Unfortunately, the effectiveness of an explosive charge formed of conventional
explosives is strongly effected by how much material is between the explosive
charge and the
land mine. When underground, this amount can be characterized by the medium
depth MD of
the medium (here the ground or soil) between the explosive charge and the land
mine through
which the explosive material and energy travels. The effectiveness is also
strongly affected
by the type of the ground or other intervening medium between the explosive
charge and the
land mine. Also, the effectiveness is affected by the overall distance from
the land mine to the
explosive charge. For example, this distance is greater when there is more
lateral offset
between the explosive charge and the land mine, and increases when the
explosive charge is
exploded at larger heights above the ground surface.
Due to each of the foregoing factors, conventional explosive charges can be
unreliable
for neutralizing underground land mines with a medium depth (MD) of greater
than thirty
(30) centimeters. Also, because the land mine may be detonated by the reaction
of the bulk
charge itself, and not the triggering device, the effectiveness of the
conventional explosive
charge is affected by the particular type of bulk charge used in the land
mine. More
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specifically, the effectiveness is influenced by the required peak pressure
and or duration
required for detonating the type of material that forms the bulk charge.
Instead of a conventional explosive, a shaped explosive charge can be used for
in-
place detonation of the land mine. The conventional explosive charge
essentially explodes
with material and energy directed substantially equally in all directions. In
contrast, the
shaped explosive charge can be configured such that when exploded, the
material and energy
(sometimes referred to as the "jet" and including hot molten material such as
copper) are
projected outward in one or more predetermined directions, with reduced or
substantially no
projection in other directions. Thus, the shaped explosive charge can be
placed near or on the
land mine, for example near or on the ground surface, and remotely detonated.
Upon such
explosion, the jet can project into the land mine with sufficient pressure
and/or duration to
detonate the bulk charge.
Another prior art method of in-place detonation involves explosively formed
penetrators (EFP), or self forging fragments. A detonating device can be
disposed some
distance away from the targeted land mine, for example, above the ground
surface, and
exploded. Upon such explosion, fragments and penetrators are formed and
projected toward
the explosive device. When the fragments and penetrators penetrate into the
device bulk
charge, they can produce the required peak pressure for the required duration
to produce
detonation of the bulk charge. Unfortunately, the effectiveness of the EFPs
are strongly
effected by the overall distance between the EFP device and the land mine, the
amount and
type of intervening material, and the type of explosive used for the bulk
charge.
Therefore, it is desired to have an apparatus and method for neutralizing
explosive
devices that are more effective, are less sensitive to the medium depth MD,
less sensitive to
intervening obstacles, and less sensitive to the type of explosive material
used for the bulk
charge. Further, it is desired that such an apparatus and method disable the
explosive device
without necessarily exploding the bulk charge, thereby substantially avoiding
collateral
damage.
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U.S. Patent No. 6,298,763 describes a system for neutralizing a bulk charge of
an
explosive device including a reaction stake having a first end and a second
end, and including
a reaction initiation material that can facilitate non-explosive
neutralization of the bulk charge
of the explosive device. Also included is a deployment mechanism disposed near
the first end
of the reaction stake, and a penetrating tip disposed near said second end of
said reaction
stake. In some embodiments, the reaction initiation material can facilitate
neutralization of
the bulk charge when the reaction initiation material is burned. In
particular, the reaction
initiation material can include magnesium-Teflon, thermites, solid rocket
propellant, and/or
liquid rocket propellant. Another system for neutralizing a bulk charge of an
explosive
device includes an array device, and a plurality of individual neutralization
systems supported
by the array device. Further, each individual neutralization system includes a
reaction stake
having a first end and a second end, and including a reaction initiation
material that can
facilitate non-explosive neutralization of said bulk charge of said explosive
device. The
individual neutralization system also includes a deployment mechanism disposed
near the
first end of the reaction stake and a penetrating tip disposed near the second
end of the
reaction stake. In some embodiments, the reaction stake further includes a
stake housing in
which the reaction initiation material is disposed, and the stake housing has
an egress hole
proximate the reaction initiation material. In addition, the reaction stake
can include an
ignition system proximate the reaction initiation material. More specifically,
the ignition
system can include an ignition fuse and a primer cap. A method is disclosed
for neutralizing
a bulk charge of an explosive device including positioning a neutralization
system relative to
an explosive device that includes a bulk charge. The method also includes
piercing the bulk
charge with the neutralization system and bringing a reaction initiation
material in contact
with the bulk charge. This contact causes at least a portion of said bulk
charge to be non-
explosive. In some embodiments, piercing the bulk charge includes positioning
at least a
portion ofthe reaction initiation material within the explosive device and
creating an initial
gap between the reaction initiation material and the bulk charge. This initial
gap reduces the
probability of pressure build up that can cause the bulk charge to detonate
before it is
rendered non-explosive by the reaction initiation material.
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One class ofmethods requires that the ordnance be taken to a central location
for
processing. For example, U.S. Patent No. 5,434,335 discloses destruction
ofexplosives and
other 'energetic' materials by feeding a stream of the material with diluent
into a high
temperature bath of molten alkali metal or alkaline earth metal salt. Organic
material is
destroyed, and inorganic material is separately recovered from the salt. Other
destruction
methods are known for particular types of material. For example, U.S. Patents
No. 3,916,805
and U.S. Patent No. 5,516,971 are directed to destruction of nitrogenous
explosives, the
former by controlled oxidation and the latter by digestion in aqueous caustic
solution. U.S.
Patent No. 5,523,517 is directed to destruction of nitramine explosive by
heating a mixture of
such explosive with an aqueous dispersion of powdered metal that does not
react with water.
Examples of suitable metals include aluminum, zinc, manganese, and magnesium.
Controlled
combustion ofselected combinations ofmaterials is disclosed in U.S. Patent No.
5,463,169.
Treatment of explosive waste is carried out in a bed of granular material,
such as sand. The
' energetic' material is ignited in the bed, and the granular material absorbs
the force of any
explosion, dampens the destructive power of propelled debris, and conveniently
collects the
unexploded debris.
As disclosed in U.S. Pat. No. 5,035,756, devices containing thermite (or
Thermit~)
mixtures have been used to burn vent holes into the propellant/motor portion
of ordnance
carried on, e.g., aircraft for the purpose of venting the propellant during a
fire. Thus venting
the propellant is meant to preclude excessive pressure and explosion of the
propellant during
such a fire. This patent is directed to a thermite composition comprising
particular
components intended to yield selected density, tensile strength, and
elasticity characteristics.
Another class comprises methods that can be applied to either material in
ordnance or
only to the explosive material removed from the ordnance. One such method is
disclosed in
U.S. Pat. No. 5,434,336. Sulfur and the explosive material are heated in an
oxygen-free
atmosphere to a temperature above 110°C for a time sufficient to
degrade the material to non-
explosive reaction products. When liquid sulfur is used and introduced to the
reactor in a
stream of solvent, particularly carbon disulfide, the UXO need not be
dismantled before
treatment. Use of a liquid sulfur stream is preferred with waxy or cast
explosives, as the
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warm sulfur will soften the explosive and improve mixture thereof with the
sulfur. However,
in accordance with this method, an oxygen-free atmosphere must be maintained
during the
initial step. Then, thus-decomposed material is subjected to high temperature
sulfur vapor to
complete the destructive reaction.
U.S. Patent No. 5,988,037 describes an apparatus for clearing land mines from
below
the surface of soil overgrown with vegetation and for rendering land cleared
of mines suitable
for agriculture or other use, said apparatus being mountable on a blast
resistant vehicle that
moves over the land along a line of movement, said apparatus comprising: at
least one
cylindrically shaped cutter member positionable ahead of the vehicle so as to
precede the
vehicle as the vehicle moves along the line of movement, said cutter member
being rotatable
about an axis normal to the line of movement of the vehicle; drive means for
driving the
cutter member to rotate about the axis of the member independently of any
movement of the
vehicle, said cutter member being driven at a peripheral speed of from 8 to 20
meters per
second; means for mounting said cutter member on the front of the vehicle to
lower the
exterior of said rotating cutter member into the soil ahead of the vehicle to
destroy the land
mines and comminute vegetation into the soil as the vehicle moves along the
line of
movement; said cutter member being formed of a plurality of disks lying normal
to the axis
of said cutter member and spaced along the axis of the cutter member, the
peripheries of said
disks forming the exterior of said member, each of said disks of said cutter
member having a
plurality of cutting teeth circumferentially spaced along the periphery of the
disk, certain of
said teeth of each of said disks extending laterally from the disk toward an
adjacent disk and
into contiguity with similarly extending teeth of the adjacent disk so that
the cutter member
engages substantially the entirety of the swath of soil traversed by the
cutter member during
movement of the vehicle; and a shield interposable between said cutter member
and the front
of the vehicle for protecting the latter from debris discharged from said
cutter member.
Another class of methods is directed to reformulation of the 'energetic'
material. For
example, U.S. Patent No. 5,445,690 discloses a method for reformulating
polymer and wax-
bound explosives to improve brisance. Added materials can include oxidizer,
plasticizer, and
stabilizer.
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None of the above-described methods is suitable for destruction or
neutralization of
UXO and mines in situ. Known methods of in situ destruction, primarily
providing for
physical impact on the mines are unsatisfactory.
In one class of such methods, mines and UXO's are destroyed after detection by
S detonating a small explosive charge placed in or projected to the vicinity
of the object to, be
destroyed. Detonation of this small charge causes a sympathetic detonation of
the object and
thus neutralizes the mine or UXO. Alternatively, a plurality of objects to be
destroyed are
removed from the site and relocated into one area, then detonated. This method
requires use
of an explosive charge and personnel skilled in the use of explosives. It also
requires accurate
detection and safe removal of individual mines.
Another class of methods of neutralizing UXO's and mines include use of plows,
rollers, or flails attached to an armored vehicle. For example, U.S. Patent
No. 3,771,413
discloses use of wheels mounted on a vehicle, such as a tank, to detonate
pressure-activated
land mines buried in the ground in the path of the wheels. 'This method is
slow, as the area to
1 S be cleared typically must be traversed a plurality oftimes, typically with
the top layer of
ground scraped away (itself a costly and dangerous undertaking) between
traverses;
cumbersome, as the necessary equipment must be sturdy, yet transportable from
site to site;
expensive, as it requires equipment and trained personnel; tedious, as a grid
or other manner
of ensuring thorough coverage must be established and adhered to assiduously,
and
dangerous, as the object is to cause the mines and UXO's to detonate.
Another class of methods is directed to temporarily disabling mines and UXO's,
typically by cooling them to a temperature at which it becomes inoperative. In
U.S. Patent
No. 4,046,055, the case of the mine or UXO is penetrated so that liquid
nitrogen can be
injected therein. This method is unsatisfactory, as merely piercing the
outside of the device
may cause it to detonate. U.S. Patent No. 3,800,715 discloses drawing a mine
or UXO into a
tubular shell, closing the ends, and introducing liquid nitrogen into the
interior. This method
is less than satisfactory because it requires that the explosive device be
moved before it is
made less dangerous. Whereas each of these methods requires that each object
be treated
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individually, U.S. Patent No. 5,140,891 discloses a method and apparatus for
neutralizing
mines and UXO's by spraying cryogenic material over the area to be cleared to
render the
materials at least temporarily inoperable. Ordnance removed by this method
should be placed
in liquid nitrogen as quickly as possible. This is a difficult method, with
many potential side-
effects (e.g., creating an oxygen deficient environment) and inefficiencies.
Another area-wide treatment is disclosed in U.S. Patent No. 4,493,239. The
area to be
treated is infused with an electrolyte and subjected to a direct current
voltage to enhance
natural corrosion. The temperature of the area also may be increased, for
example, by
covering the area with black material, such as a plastic sheet, to further
accelerate corrosion.
This method is unsatisfactory because it takes on the order of five to ten
years and requires
continuing attention.
U.S. Patent No. 6,232,519 describes a method of reacting on or near the
surface of the
mine or UXO a charge of a compound that reacts with an extremely high heat-
release rate.
The intense exothermic reaction generates high temperature combustion products
that will
1 S melt, burn, or otherwise disrupt, a metal, plastic, composite, or wooden
casing, thus leading
to combustion or decomposition of the explosive. In an alternative embodiment,
the high
temperature in the casing decomposes the content thereof, causing the pressure
in the casing
to rise, fracturing the casing before the explosive detonates. In either case,
the disrupted
casing enables ignition ofa large area ofthe explosive charge and provides
easy access for
atmospheric air to support active burnout of the explosive.
6,109,112 describes a prodding implement for determining acoustic
characteristics of
objects comprising: an acoustically transmitting probe having a detecting end
and a coupling
end; an acoustic transducer having a first end, for generating an acoustic
emission, and for
receiving an acoustic wave and generating an electrical signal in dependence
thereon; an
electrically insulating acoustic coupler for operatively connecting the probe
and the acoustic
transducer including; a frst receiving end for receiving the coupling end of
the probe and
having an internal probe contact surface for contacting the coupling end of
the probe when
received and lateral support means for surrounding a portion of the coupling
end of the probe,
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a second receiving end for receiving the first end of the transducer and
having lateral support
means for surrounding portion of the transducer and an internal transducer
contact surface
opposite and acoustically contacting the internal probe contact surface;
sealing means for
contact between the coupling end of the probe and the internal probe contact
surface and
5 between the first end of the transducer and the internal transducer contact
surface for
acoustically transparent coupling of the coupling end of the probe to the
internal probe
contact surface and of the first end of the transducer to the internal
transducer contact surface;
and processor means for comparing known acoustic wave patterns to a received
wave pattern,
wherein acoustic coupling is provided over the internal probe and transducer
contact surfaces,
10 substantially without distorting acoustic wave transmission.
U.S. Patent No. 5,892,360 describes a probe carrying vehicle is described
which has
at least one probe carrier which preferably carries at least one eddy current
probe and at least
one magnetic field probe for ground and foreign matter detection in a search
area. Spacing
means that may be in the form of a bogie assembly with wheels or chains or the
like are
provided to maintain spacing between the ground and the probes. The probe
carrier is
movable over the search area by means of a craft, to which the probe carrier
is flexibly
coupled by means of coupling means. The coupling means are disposed on one end
of a
preferably long pole, the other end of the pole being fixed rigidly to the
probe can ier. The
pole ensures a proper orientation of the probe relative to the ground
particularly on uneven
ground.
U.S. Patent No. 5,884,160 describes a forwardly-rotatable, driven-drum, land
mine
clearing tool has a plurality of robust, easily-repairable tool spokes
extending radially from
the outer surface of the drum. The land mine clearing tool is connected to the
front end of a
tracked vehicle and is operatively raised and lowered from the tracked
vehicle. The drum and
tool spokes engage the earth of a land mine field in a milling action, which
grinds and
destroys some land mines while triggering detonation of other land mines.
U.S. Patent No. 5786,542 describes a system for clearing anti-personnel mines
includes a vehicle, a blast shed on the front of the vehicle, and arms pivoted
to the blast
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shield. A roller wheel subassembly is connected to the arms by cables or
chains. Cross
members fastened diagonally between the arms minimize side-to-side swing of
the arms on
the blast shield while allowing the anus to swing up and down relative to each
other. The
vehicle has a boom for lifting the arms and roller wheel subassembly. The arms
connect to
S the boom by another chain or cable that slides through an eye on the boom so
that the chain
or cable accommodates relative vertical swing of the arms. The roller wheel
subassembly has
an axle and roller wheels on the axlo, the inner diameter of the roller wheels
being greater
than the axle's diameter. Annular spacers on the axle alternate with the
wheels, the spacer
diameters being larger than the wheels' inner diameters but smaller than the
wheels' outer
diameters. The wheels and spacers move independently of one another
rotationally and
radially relative to the axle.
U.S. Patent No. 5,373,774 describes a lightweight mine extracting plow is
provided
that can be mounted on any type of armored vehicle to enable the vehicle to
cross minefields
in an attack formation or to assist the armored vehicle in escaping from
scattered minefields,
1 S either laid by air or by artillery, by removing obstacles, such as mines,
from all areas of land.
The plow has tines which penetrate the land to extricate the mines. Blades are
shaped to
dispose the mines sideways out of the path of the tracks of the vehicle. A
folding skid device
controls articulation of the plow over ground undulations and extends forward
to assist in
bridging ditches. The skid has a device which automatically positions it in
front of the plow
and overturns it into a pre-operation mode. A mechanical lifting device is
operable by
reversing the vehicle to lift the plow out of the ground. Thereafter, the
device automatically
reverts to its pre-operation mode. A locking device holds the plow in its pre-
operation mode
and allows it to drop to the ground when desired. A sliding bracket
arrangement is provided
such that the plow can be discarded by reversing the carrying vehicle.
2S U.S. Patent No. 5,223,661 describes a system and process for neutralizing
unexploded
ordnances and clearing explosive infested areas such that maneuvers can be
both readily and
confidently continued without significant delay is disclosed. The system
clears such
unexploded ordnances infested areas by initially spraying the explosive
infested area with a
cryogenic liquid to neutralize the unexploded ordnances and reduce an output
voltage of a
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detonator of the unexploded ordnances thereby rendering the unexploded
ordnances inert,
gathering the now unexploded ordnances and submerging the inert unexploded
ordnances in a
tank containing the same or similar cryogenic liquid so that the unexploded
ordnances are
maintained in a neutralized and inert state to allow for disposal.
Alternatively, the
neutralization of unexploded ordnance and clearing of explosive infested areas
may be
carried out by spraying the explosive infested area with liquefied methane to
neutralize the
unexploded ordnance and reduce an output voltage of a detonator of the
unexploded
ordnances to render such ordnance inert, igniting the liquefied methane,
deflagrating the
unexploded ordnances at a temperature less than that required for detonation
and
subsequently removing the neutralized ordnances from the explosive infested
area.
U.S. Patent No. 6,064,209 describes a two-step process for clearing unexploded
ordnance ("UXO") from the ground. First a high power electromagnetic
transmitter sweeps
the ground area to be decommissioned. Secondly a lower-power time-domain
electromagnetic transmitter or metal detector sweeps the same area to locate
UXO. The high
power transmitter employs a waveform of having the same frequency and pulse
duration as
that of the metal detector but does so with at least twice the power, Firstly,
when the higher
power waveform is applied to the ground, UXO which does not trigger and
detonate or
"function" is proved as non-functioning at lower detection power.
Subsequently, the ground
area can then be safely scanned by human personnel with impunity, applying the
more
accurate, lower power metal detector. The detected locations of unexploded
ordnance are
recorded for subsequent manual removal.
U.S. Patent No. 5,307,272 describes a multi-sensor system for detecting the
presence
of objects on the surface of the ground or buried just under the surface, such
as anti-personnel
or anti-tank mines or the like. A remote sensor platform has a plurality of
metal detector
sensors and a plurality of short pulse radar sensors. The remote sensor
platform is remotely
controlled from a processing and control unit and signals from the remote
sensor platform are
sent to the processing and control unit where they are individually evaluated
in separate data
analysis sub-process steps to obtain a probability "score" for each of the
pluralities of sensors.
These probability scores are combined in a fusion sub-process step by
comparing score sets
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to a probability table which is derived based upon the historical incidence of
object present
conditions given that score set. A decision making rule is applied to provide
an output which
is optionally provided to a marker sub-process for controlling a marker device
to mark the
location of found objects.
U.S. Patent No. 5,189,243 describes a minefield clearing apparatus for
attachment to a
vehicle and having: an interface assembly for raising and shunting aside mines
and other
objects buried below the ground surface including: an articulated rake having
a plurality of
plow teeth which, in operation, extend below the ground surface; and a
conveyor apparatus
extending along the side of the vehicle and adapted to transport the contents
of the earth
raised by the articulated rake to the rear of the vehicle.
U.S. Patent No. 4,467,694 (Azulai et al.) discloses a mine clearing apparatus
having
two widely spaced plow blades oriented so as to form a "V" and a frame
mountable to a
vehicle for selectable positioning in a raised or lowered orientation.
U.S. Patent No. 4,491,053 (Bar-Nefy et al.) describes a minefield clearing
apparatus
1 S mountable upon a vehicle having two widely spaced plow blades oriented so
as to form a "V"
and apparatus for automatically raising the plow from its lowered orientation
to its raised
orientation in response to backwards motion of the vehicle.
U.S. Patent No. 4,552,053 (Bar-Nefy et al.) shows a minefield clearing
apparatus
mountable upon a vehicle having two widely spaced plow blades oriented so as
to form a
"V", such blades have two plow sections. An upper section moves soil, sliced
by the teeth of
the lower section, laterally.
U.S. Patent No. 4,590,844 (Bar-Nefy et al.) discloses a minefield clearing
apparatus
for attachment to a vehicle having two widely spaced plow blades so as to form
a "V" which
may be raised or lowered automatically from inside the vehicle.
U.S. Patent No. 4,667,567 (Schreckenberg) describes an apparatus for clearing
light
land mines provided with clearing elements which can freely move up and down
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independently of one another and which are disposed in a V-shaped movable
carrier
attachable to a vehicle.
U.S. Patent No. 4,690,030 (Bar-Nefy et al.) provides a minefield clearing
apparatus
for attachment to a vehicle having two widely spaced plow blades oriented so
as to form a
"V" and being a continuation-in-part of U.S. Pat. No. 4,590,844.
U.S. Patent No. 4,727,940 (Bar-Nefy et al.) discloses a tank mounted minefield
clearing apparatus having a single plow section mounted parallel to the front
of a vehicle and
having a conveyor apparatus extending along the length of the plow section
adapted to
convey the contents of the earth raised by the plow section to one side of the
vehicle.
U.S. Patent No. 4,909,330 (Kasher et al.) describes an automotive earth moving
vehicle for civil and military applications having a blade which is comprised
of two
horizontally linked segments adapted to alternate between a single plane dozer
mode and a V-
shape plow mode.
U.S. Patent No. 4,919,034 (Firth) discloses a mine clearing apparatus having
at least
one plow blade and mounted in such a way that such a blade is pivotable about
two axes. The
preferred embodiment of the invention discloses an apparatus with two separate
blades
orientated in V-shaped fashion.
U.S. Patent No. 4,938,114 (Matthews et al.) shows a mine clearing apparatus
having
float shoes that slide along the ground and adjust to maintain a chosen
plowing depth. The
float shoes are caused to move by powered adjusting means mounted upon a
crossbeam and
controlled by sensing means. The preferred embodiment of the inventive
apparatus is
provided with two blades oriented in V-shaped fashion.
Mine Clearance is one of the five core components of mine action. In its broad
sense,
it includes surveys, mapping and minefield marking, mine detection, mine
education &
awareness, medical assistance, relocation, etc. as well as the actual
clearance of mines from
the ground. This range of activities is also referred to as "demining".
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Mine clearance is essential if communities are to regain full use of their
land. In many
situations mine clearance is a precondition for the safe return of refugees
and people
displaced by war from their homes, for the delivery of humanitarian
assistance, as well as for
reconstruction and sustainable development. Although mine clearance operations
carried out
to international standards are expensive, recent studies have shown that they
not only allow
for the social recovery of affected communities, but can also be justified on
the basis of
purely economic cost-benefit analysis.
Surveying, or the formal gathering ofmine-related information, is required
before
actual clearance can begin. Impact surveys are intended to assess the level of
socio-economic
10 impact of the mine contamination and to help assign priorities for the
clearance of particular
areas. Impact surveys make use of all available sources of information,
including minefield
records (where they exist), data about mine victims, and interviews with
former combatants
and local police, informants, and the community in general. Technical surveys
then define the
minefields and provide detailed maps for the clearance operations.
15 Maps resulting from the impact surveys and technical surveys are stored in
the Information
Management System for Mine Action (IMSMA), and provide baseline data for
clearance
organizations and operational planning.
Minefield marking is carried out when a mined area is identified, but
clearance operations
cannot take place immediately. Minefield marking, which is intended to deter
people from
entering mined areas, has to be carried out in combination with mine
awareness, so that the
local population understands the meaning and importance of the signs.
Clearance operations make use of three main methods:
~ Manual clearance relies on trained deminers using metal detectors and long
thin
prodders to locate the mines, which are then destroyed by controlled
explosion;
. Mine detection dogs, which detect the presence of explosives in the ground
by smell.
Dogs may be used in combination with manual deminers;
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Mechanical clearance using machinery, including flails, rollers, vegetation
cutters and
excavators, often attached to armored bulldozers, to destroy the mines in the
ground.
These machines can only be used when the terrain is suitable, and are
expensive to
operate. In most situations they are also not 100% reliable, and the work
needs to be
checked by other techniques.
Advances in technology have been made in recent years, both in mine detection
systems and
in mechanical means for destroying mines in place. However, in many situations
manual
clearance remains the preferred method, for reasons both of cost and
reliability.
The UN bodies involved in mine action do not carry out mine clearance
directly. In
most countries they advise and assist the national authorities, or a UN
peacekeeping mission,
to establish a Mine Action Authority or Coordination Centre to oversee
clearance activities.
The actual clearance operations may then be carried out by national civilian
agencies,
military units, national or international NGOs or commercial organizations.
Existing technologies for tactical breaching include the M58A4 Mine-Clearing
Line Charge (MICLIC), a rocket-propelled explosive line charge which basically
blasts a
vehicle width lane through a minefield. Another example of the line charge is
the
Antipersonnel Obstacle Breaching System (APOBS), The APOBS is a man-portable
line-
charge capable of blasting a footpath through a minefield. Other methods of
breaching or
clearing, essentially expanding footpaths created by a line charge, are
through the use of
plows, blades, rollers disks, and flails attached to a tank. Each of the
methods described
above was employed in Desert Storm, as was probing.
U.N. CLEARANCE STANDARDS
The United Nations provides a number of regulations and standards regarding
the clearing
and deactivation of mines
5.9 An area is cleared when all mines and munitions have been removed and/or
destroyed.
All debris, from mines and munitions, such as fusing systems, percussion caps
and other
items that constitute an explosive hazard, is to be removed.
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5.10 The area should be cleared ofmines and UXOs to a standard and depth which
is agreed
to be appropriate to the residual/planned use of the land, and which is
achievable in terms of
the resources and time available. The contractor must achieve at least 99.6 %
of the agreed
standard of clearance. The target for all UN sponsored clearance programs is
the removal of
all mines and UXO to a depth of 200mm.
MANUAL CLEARANCE TOOLS
5.16 The following tools are used in demining operations with the objective of
locating or
assisting in the location of mines or munitions. Should any item be located,
an immediate
action (IA) drill must be known to all deminers.
a) Probing. The most commonly used method to check sub-surface for buried
mines
or munitions. Details of the angle and spacing for the use of the probe must
be stipulated in
the SOPS. See also Section One- Safety.
b) Excavation. An area where the detector or other methods have indicated the
presence of metal will be excavated. Details of the depth, methods and tools
to be used must
be outlined in the SOPS.
c) Cutting tools. A variety of tools are available for the task of cutting
small bushes,
scrub and grass. All cutting tools must be used in the horizontal plane.
Details of types and
methods of use are to be outlined in the SOPS.
d) Metal Detectors. All detectors must be able to detect the landmines used in
theatre
to the depth of clearance specified. Consideration must be given to the depth
of laying during
operations and the end use of the land. All metal detectors need a
comprehensive in-
country technical evaluation. The SOPS must contain the procedures for
operation, action on
troubleshooting faults, maintenance and battery checking. The minimum depth of
clearance
is 200 mm therefore detectors should be able to detect mines to at least this
depth.
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e) Trip Wire Drills. A visual inspection is necessary in the zone that is
being cleared.
This may also be accompanied by a tripwire feeler drill. Methods of use are to
be outlined in
the SOPs.
SUNINIARY OF THE INVENTION
High-pressure water jets are used directly against the ground to both remove
surface
cover of dirt and natural or applied cover over land mines or other buried
explosives, and the
high-pressure water jets also cut through the mines, mine fuses, or mine
detonators, disabling
them in many cases or causing them to explode in other cases. The water jets
are preferably
provided as a series of spaced apart nozzles (or jets as they are referred
to). The nozzles are
provided in a distributing that can be directed towards the ground (or in the
embodiment
where the device is used as a suspected container of explosive that is not on
the ground or a
wrecked vehicle from which persons are sought to be removed with minimal
danger of
igniting fuel) or towards the target to be cut. Generally for mine
removal/detection/disarming, the nozzles should be capable of being directed
downwardly
(towards the ground) towards the path that is to be cleared of mines. The
nozzles may be
provided on a planar support surface (that is so that the ends of the nozzles
are lying
preferably along a plane so that they are equidistant from the ground. In
other circumstances
or methods of operating in the vicinity of mines, it can be desirable to have
the nozzles
presented towards the ground at different distances. For example, the nozzles
most forward
in the direction the system is moving may be elevated higher above the ground
then the
nozzles furthest from the direction of movement. In this way, the higher
elevated nozzles
2S may expose mines over a slightly wider area, and the lower height nozzles
may focus their
jets more intensely to slice through the mines. Looking at the face of a
support for a
multiplicity of nozzles, the nozzles may be seen to be positioned in a pattern
or randomly as
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horizontally spaced apart nozzles. It is preferred to have spacing dimensions
between nozzles
that assure that even the smallest land mines will be cut by the water jets.
The nozzles are
relatively inexpensive and readily replaceable, so that in the event that any
accidental
detonation damages a nozzle, it may be readily replaced. The water jet system
may also be
extensible and may be moved horizontally in two dimensions (forward and back
and also left
to right). The device is preferably mounted on a vehicle or may be mounted on
its own
carriage. Many different liquids may be used, but water from available
supplies and/or water
laden or entrained with abrasive may also be used as the liquid emittent. The
water need not
be pure, and in fact the addition ofabrasives to the liquids can be desirable.
Some filtration
may be desirable to assure that too large particles or stones from ambient
sources of water do
not enter the jet stream and clog the jets. The water jet system may be
carried on a moving
system such as a cart optionally fitted with motor, water storage, pumps,
energy source or
convertor.
BRIEF DESCRIPTION OF THE FIGURES
Figure I shows both a side view ofa folded water jet system for deactivating
land
mines but water jet cutting of the mines either on site or in situ.
Figure 2 shows a side view of a partially to completely extended water jet
system for
detecting and/or deactivating land mines by water jet cutting of the mines
either on site or in
situ.
Figure 3 shows a side view of a further partially extended water jet system
for
deactivating land mines or cutting through surfaces by water jet cutting of
the mines either on
site or in situ, the arm carrying the jet nozzle extended upwardly to reach an
elevated target.
Figure 4 shows a side view of a fully horizontally extended water jet system
for
deactivating land mines by water jet cutting of the mines either on site or in
situ.
Figure 5 shows an alternative side view of a telescopically extended water jet
system
for deactivating land mines but water jet cutting of the mines either on site
or in situ.
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Figure 6 shows details of a heat exchanger piping with tubing from a
compressor (not
shown) for fluid temperature control within a power system for the landmine
detection/deactivation system of the invention.
Figure 7 shows a partial cutaway side view ofa section of the power system for
a land
5 mine detection/deactivation system from the engine building water pressure
to the pump for
the water.
DETAILED DESCRIPTION OF THE INVENTION
A process for the in situ and on-site deactivation of land mines comprises at
least one
high-pressure water jet that is directed against the ground to remove cover
from the land mine
10 and (subsequently or simultaneously) cut through the land mine,
deactivating the mine or
reducing its effective capability. The water jet or a series of water jets is
moved over the
surface area to be cleared of mines, tracing a path or series of paths that
will intersect at
positions that will overlap a high percentage of mines, hopefully one hundred
percent of
mines. If there is foreknowledge of the type of mines available or buried in
an area to be
1 S cleared, the spacing or movement of the water jets may be tailored for
those particular mines.
If there is no basis for anticipating the specific type or size of mines
present, the water jets
may be spaced to assure contact with all known dimensions for mines, which is
a minimum
diameter of about 7.5 cm. Thus the water jets may be spaced at a minimum of 3
cm apart
(center of jet to center of adjacent jet of adjacent path). The water jet
(especially if there is a
20 single row of jet nozzles) is moved at a sufficiently stow pace (e.g., 1
cm/sec or less) to
assure that the volume and emission rate ofthe fluid from the jet will remove
the cover from
any mines and cut through the mine to deactivate or detonate the mine. The
system may also
be operated at a faster speed to uncover mines and then deactivate the mines
by the same set
of nozzles or with differentiated nozzles for exposing and then cutting the
mines. Sensing
systems (e.g., optical capture systems, scanners, cameras) may be used to
convey images
back to a control site so that the system needs to operate at a slower speed
only after the
mines have been exposed or sensed by the system or operator. The sensing
system may be
completely automatic with recognition technology used to identify a mine
shape, may be
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completely under the control ofa distal observer, using visual recognition to
spot uncovered
mines and direct the system (especially the later described robotic system),
or a combination
of computer observation and personnel observation. As the covering on mines
tends to be of
minimal structural importance, except for avoiding detection or providing
shrapnel upon
explosion, the water jets are generally able to cut through the mines rather
easily, even when
a composite or non-magnetically responsive metal cover is used. At an absolute
minimum,
mines may be clearly exposed by the water jet and then the water jet can be
particularly
positioned over the mine to cut through it, at whatever speed is needed to
assure deactivation.
The system can therefore both expose mines and deactivate them.
The spacing between water jets is most easily achieved by mounting a number of
water jets (e.g., at least 2, at least 3, at least 4, at least 5, at least 6
and up to twenty or thirty
or more water jets on a single support. A single or double set of water jets
that are
independently movable may also be provided to assure that if mines) are
exposed but not
detonated, a readily positionable set of water jets) or even single water jet
may be positioned
over the exposed and still active mine. At present, the preferred system uses
between 5 and
jets, leaning towards the lower end to conserve water where that becomes a
limiting factor
(in the desert) in the continuous operation of the system. The relative
position of the water
jets on the support may be slidable, expandable, or otherwise readily
adjustable to assure that
appropriate spacing is effected. For example, expandable joints, accordion
joints, slide joints,
20 telescoping joints, and the like may be used to allow side-to-side spacing
of the water jets to
assure the proper spacing to deactivate mines.
The methods and apparatus of the present invention may be generally described
as
follows. A method of deactivating land mines buried in ground comprises
projecting high-
pressure water jets into ground, cutting through ground with the high-pressure
water jets, and
cutting through at least one land mine that had been under the ground, the
cutting of the land
mine reducing the performance of the land mine. The method may reduce the
performance of
the land mine by rendering the land mine inactive to normal detonation
procedures for the
land mine. It is preferable that at least two high-pressure water jets are
spaced apart are used
to cut through the ground. It is reasonable to use 2, 3, 4, 5, 6, 7, 8, 9, 10
or more individual
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jets in an array to practice the cutting effects of the invention. The jest
may be in a single line
or in a pattern designed to distribute the effect of the jets. The method may
be practiced with
the high-pressure water jet being carried on a vehicle and cutting is done in
a line that is
formed at least in part by movement of the vehicle over the ground while the
high-pressure
water jet is cutting ground. That is, the movement of the vehicle determines
the primary
movement of the nozzles at the ends of the device. Alternatively, the high-
pressure water jet
may be supported on a vehicle and cutting is done in a line that is formed at
least in part by
movement of an assembly supporting the water jet on the vehicle while the
vehicle remains
stationary. The vehicle may of course have the at least two high-pressure
water jets that are
spaced apart as part of the system used to cut through the ground. Reducing
the performance
of the land mine consists essentially of rendering the land mine inactive to
normal detonation
procedures for the land mine. By reducing the performance or capability of the
landmine to
normal detonation means that either the total explosive force capable of being
provided by
the land mine is reduced or the ease of detonation by a designed detonation
system is reduced
or deteriorated. It is preferred that the explosive device be rendered
substantively inactive to
pressure or influence detonation. However, the ability of the explosive charge
to explode by
heat, electrical charge, or collateral explosion need not be destroyed, which
would require
removal of the explosive material itself. It is a primary objective to remove
the explosive
capability of the mine, which is the major concern of land mines. Once the
mine's functional
capability of triggering has been degraded, manual removal upon observation of
the mine
becomes a much less dangerous and simple task. It is preferred that the high-
pressure water
jet has a pressure of at least 18,000 pounds per square inch.
An apparatus for the reduction in effectiveness of land mines buried in ground
may
comprise a self contained push-cart unit or a unit attached or attachable to a
vehicle. A
complete system would comprise a vehicle having a source of liquid, a high-
pressure pump to
move the liquid under high-pressure, a nozzle directing a liquid jet path for
the liquid, a
support for the nozzle, and nozzle being controllable to direct the liquid
towards the ground
while the nozzle is fixed relative to the vehicle. Again, the at least two
nozzles are provided
on the vehicle so that they direct the Liquid towards the ground while the at
least two nozzles
are fixed relative to the vehicle. By fixed, it is meant that the height and
orientation of the
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nozzles is controllable and does not waiver so significantly with vehicle
movement that the
path of cutting cannot be controlled within the design parameters of the
cutting/demining
pattern. For example, the at least two nozzles are fixed at a distance of less
than one meter
from the ground (e.g., lm, 0.8m, 0.7Sm, 0.6m, O.Sm, 0.4m, 0.3m, 0.25m, 0.2m,
O.lm, O.OSm
and the like. Extensibility of the nozzles from the vehicle may be effected at
least in part by
water carrying tubes that bend with respect to each other, as by using rotary
actuators or
telescoping tubes carrying the water. The moving cart may be positioned at a
location and
the arms carrying the jets may be articulated to sweep over an area at a
constant height or
controlled and variable height to sweep and uncover mines and to deactivate
the mines.
Commercially available water jet systems and nozzles may be used. Cutting
various
materials by means of jets of high-pressure water is a well known technique in
modern
manufacturing engineering. Focused jets of high-pressure water from 2,000
pounds per
square inch pressure ("psi") or less, up to 60,000 psi or more, are capable of
cutting virtually
any material. The term "high pressure" therefore means water pressure of at
least 2,000 psi
1 S in the tip of the waterjet. Preferably the water pressure is at least
4,000 psi, at least 5,000 psi,
at least 8,000, or more preferably at least 10,000 psi. Thick sheets of steel
are capable of
being cut by means of high-pressure water, as are much thinner sheets of soft
or sticky
material inconveniently cut by mechanical means. Cutting by means of water
jets has several
advantage including: su .fficiently high quality cut providing for sharp
inside corners,
reduction in or elimination of slag or burr following the cutting operation
(typically requiring
a subsequent "deburring" operation following conventional cutting procedures),
highly
accurate contouring resulting in less wasted material, and water jet cutting
allows the cut to
be initiated at any point along the path to be cut on the workpiece.
The customary term in the field is "water jet cutting." However, abrasive
additives
2S may be added to the stream of water comprising the jet to increase cutting
eiTectiveness
(although wear on the nozzle is likewise increased). For the cutting of
metals, abrasive grit is
typically added to the stream after the jet is formed but prior to the impact
of the jet on the
workpiece. Water jets including abrasives can accomplish the cutting of
intricate slots,
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through cuts and curves cut in metals, glass, stone, ceramics, artificial and
natural abrasives,
composites and similar materials.
Fluids other than water can also be employed if materials cannot be in contact
with
water but cutting with a jet of fluid is still the preferred cutting
technique. For economy of
language we will refer herein to "water jet cutting" or "high-pressure water"
and the like, not
intending to exclude cutting by jets of fluid other than water, and not
intended to exclude jets
of fluid containing abrasive or other additives.
The typical technique for cutting by means of water jets is to mount the piece
to be
cut (hereinafter "workpiece") in a suitable jig, die or other means for
securing the workpiece
into position. One or more water jets are typically directed onto the
workpiece to accomplish
the desired cutting, generally under computer or robotic control. The cutting
power is
typically generated by means of a single intensifier connected to the cutting
head through
high-pressure tubing, hose, piping, accumulators and filters. Typical units
may have powers
of at least 20 horsepower ("hp"), 50 hp, 250hp up to I OOOhp.
1 S The typical mode of water jet cutting is to employ a single water jet
cutting head, but
this is not an inherent limitation. A fine stream ofwater, typically traveling
at two to three
times the velocity of sound, is directed onto the workpiece. The stream of
cutting fluid is
typically pinhole size in diameter, but a jet slightly larger than (1/16) inch
in diameter
produces nearly 50 hp when concentrated. Hereinafter we will refer to
workpiece and cutting
tool in the singular, not intending thereby to exclude the use of a plurality
of cutting heads
and/or a plurality of workpieces.
Fluid jet devices are often used to cut metal parts, fiber-cement siding,
stone and
many other materials. A typical fluid jet cutting machine has a high-pressure
pump to provide
a high-pressure fluid source, and a nozzle is coupled to the high-pressure
fluid source to
generate a cutting jet from the nozzle. The nozzle is also attached to a
carrier assembly that
moves the nozzle along a desired cutting path, and a catch tank is aligned
with the nozzle
throughout the cutting path. An abrasive particle source may be coupled to the
nozzle to
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impart abrasive particles to the cutting jet. The fluid is typically water,
and the abrasive
particles are typically garnet.
In operation of such a fluid jet cutting machine, a work-piece is positioned
between
the nozzle and the catch tank. The carrier assembly moves the nozzle along the
cutting path,
and the high-pressure fluid source and abrasive particle source generate an
abrasive cutting-
jet projecting from the nozzle. As the cutting jet passes through the work-
piece, the catch
tank receives the wastewater and abrasive particles of the spent cutting jet.
The abrasive
particles generally accumulate in the catch tank, and the waste water
generally flows out of
the catch tank.
10 Waterjet systems are used for cutting many types of materials. A waterjet
system
includes a waterjet head that is supplied with liquid at an ultra-high-
pressure (IIHP), for
example 10,000 to 60,000 pounds per square inch (psi) up to even 100,000 psi
or more. The
LTHP liquid is discharged from the head in a high velocity stream against a
workpiece. The
liquid stream is used to cut through materials such as wood, paper and foam.
An abrasive
I 5 particulate material can be added to the stream, and the liquid/abrasive
stream can be used to
cut through composites, metals and other dense materials. The stream typically
is
concentrated in a small area, for example, for example as small as 0.05 inch
diameter and has
a high flow rate of perhaps one to three gallons per minute (gpm). Because of
their high
energy concentrations, such waterjet streams cannot be used for surface
treatment operations
20 such as cleaning, polishing or milling. A typical waterjet liquid or
liquid/abrasive stream cuts
too deeply and rapidly into the workpiece surface if it is stationary for even
a small fraction
of a second, and uniform surface treatment has not been possible. In the
operation of the
invention, as suggested earlier, water may be jetted at one pressure to
uncover mines and then
jetted at a higher pressure to cut through the mines. This would help conserve
water, where
25 that was an important factor.
It has been recognized that a continuously and rapidly moving, and accurately
controlled, waterjet stream could be used for surface treatment operations if
the energy
dissipation could be uniformly spread over the workpiece surface area.
However, there has
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been a longstanding and unsolved problem with providing an apparatus or method
for
achieving this result.
Waterjet systems normally incorporate a head drive arrangement, such as a
computer
numerically controlled (CNC) X-Y-Z drive system intended to move the waterjet
head in a
programmable pattern for making preprogrammed accurate cuts in a workpiece.
These known
drive systems cannot move the head continuously and quickly enough in a
controlled fashion
to carry out a satisfactory surface treatment operation without damaging the
workpiece
surface.
In an attempt to solve this problem, it has been proposed to provide a
waterjet head
incorporating a discharge nozzle with an angled outlet passage and a swivel
arrangement for
rotating the nozzle. The intent of this approach is to provide a UHP stream
that rotates at high
speed to increase the workpiece surface area contacted by the stream and
reduce the energy
concentration ofthe stream. U.S. Patent No. 4,669,760 discloses such a swivel
fitting
arrangement for a UHP liquid stream, and U.S. Patent Nos. 4,854,091 and
4,936,059 disclose
swivel assemblies for liquid/abrasive streams.
Prior art waterjet systems are commercially available from sources including
EASB
Cutting Systems, 411 Ebenezer Road, Florence, S.C. 29501-0504. A further
description of
the prior art system 10 can be found at the title pages and pages 2-4, 2-5, 2-
7, 2-8, 2-12, 4-29,
4-30 and 2-24 through 6-26 ofESAB Cutting Systems manual No. F14-135 dated
May, 1999,
and incorporated herein by reference (and found in U.S. Patent No. 6,283,832).
U.S. Patent No. 6,280,302 describes a method and apparatus for controlling the
coherence of a high-pressure fluid jet directed toward a selected surface. In
one embodiment,
the coherence is controlled by manipulating a turbulence level of the fluid
forming the fluid
jet. The turbulence level can be manipulated upstream or downstream of a
nozzle orifice
through which the fluid passes. For example, in one embodiment, the fluid is a
first fluid and
a secondary fluid is entrained with the first fluid. The resulting fluid jet,
which includes both
the primary and secondary fluids, can be directed toward the selected surface
so as to cut,
mill, roughen, peen, or otherwise treat the selected surface. The
characteristics of the
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secondary fluid can be selected to either increase or decrease the coherence
of the fluid jet. In
other embodiments, turbulence generators, such as inverted conical channels,
upstream
orifices, protrusions and other devices can be positioned upstream of the
nozzle orifice to
control the coherence of the resulting fluid jet. For example, direct drive
pumps capable of
generating pressures up to 50,000 psi and pumps with intensifiers capable of
generating
pressures up to and in excess of 100,000 psi are available from Flow
International
Corporation of Kent, Wash., or Ingersoll-Rand of Baxter Springs, Kans.
Water jet cutting nozzles are well known in the art as disclosed in U.S.
Patent Nos.
4,545, I57; 4,648,215; 4,478,368; 4,707,952 and 4,723,387. With each of these
devices
pressurized water and a stream of abrasive particles are introduced separately
into the mixing
chamber of a cutting nozzle. The high velocity jet of water comes in contact
with the abrasive
particles and momentum is transferred from the water to the particles to form
a high velocity
stream of abrasive particles entrapped within the stream of water that exits
the cutting tip of
the nozzle assembly. The abrasive water jet stream is then used in a variety
of cutting
operations, such as cutting rock, concrete, asphalt and metals such as
reinforcung rod.
The system may be design as a push-cart system or as a system that may be
installed
on the front of a vehicle such as a car, truck, van, tractor, tank or other
land vehicle. Larger
vehicles are desired for improved stability. The water jet system may be
provided in
components such as single water jets, sets of water jet and the like, with a
mounting system
water flow system, control system (e.g., microprocessor, computer, software,
sensors, and the
like), abrasive addition controls, filter arrays, visual sensors to observe
mines as they are
exposed, sensors to identify malfunction of individual nozzles or tubes, flow
control systems,
self contained water systems, ambient water access systems (for accessing
water from
streams, seas, lakes, ponds, rivers, and the like), and other accessories as
needed.
The nozzles may have openings conveniently sized to effect exposure and
deactivation of the mines. The size of the jets exiting the nozzles may range,
for example,
from about O.Smm to Scm, although the higher dimension would require an
inordinate fluid
flow, so that more intermediate jet diameters, such as O.Smm to 1 cm, or 1 mm
to 1 cm, or 1.5
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mm to I cm, or I.5 mm to SO mm are particularly useful jet sizes, which tend
to correspond
to nozzle opening sizes (although jets may expand as much as 20% upon exiting
nozzles, so
nozzle sizes should be appropriately considered with regard to their
dimensions). The liquid,
as previously noted, may be stored water, ambient water, or any other
available fluid, with
water being the least expensive and most available liquid. Liquid alone may be
used, or
abrasive materials may be added to the liquid, usually by a separate addition
system (that is,
not stored with the water) such as a solids dispersing addition, addition of a
concentrated
dispersion of the abrasive, solids injection system into the water stream,
etc. Sand is a
convenient abrasive to be added to the fluid flow exiting the nozzles of the
water jet, or more
appropriately, the fluid jet. These and other aspects of the invention will be
further described
with reference to the Figures.
Figure 1 shows a side view of a folded water jet system 2 according to one
aspect of
the invention. The water jet system 2 comprises a base 4 with a tread-based
drive system 6
having wheels 8 and 10 that drive the treads or belt 6 and a droppable
platform 12 that can
I 5 stabilize the system 2 against undesired movement when in cutting mode.
Support element
14 can swivel to assist in positioning the system 2. Water can be conveying
into pipe opening
16 and moves through a first tube 18. The water is lead through the first tube
18 to a first
rotary actuator 20 connected to a second water conveying tube 22. Water (not
shown) carried
within the second water conveying tube 22 is carried into a second rotary
actuator 24 and
then into a third water carrying tube 14. The water is then passed through the
third rotary
actuator 28 which can be used to finely direct the jet head 30. Water passes
into the third
water conveying tube 26 after passing through articulating water joints 32 and
34. The water
passes from the third water conveying tube 26 into the water jet nozzle head
30. The water
jet nozzle system comprises the nozzle 36, a rotating control element 28.
Water exits out of
jet nozzle 36.
Figure 2 shows a partially extended water jet system 202 according to the
present
invention. The same elements of Figure I are shown as a base 4 with a tread-
based drive
system 6 having wheels 8 and 10 that drive the treads or belt 6 and a
droppable platform 12.
Water (not shown) carried within the first water conveying tube 210 is carried
into a first
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29
rotary actuator 212 and then into a second water carrying tube 214. The water
is then passed
through the second rotary actuator 216 and into the third water conveying tube
218. The
water passes from the third water conveying tube 218 into the water jet nozzle
system 220.
The water jet nozzle system comprises the nozzle 228, a rotating control
element 228 and a
valve support element 226. Water exits out of the nozzle 248 of the jet nozzle
system 220.
The arc of rotation 230 of the support element 240 is shown. Water passes
through the
hollow portions 242, 244 and 246 of the system 2. Articulating water joints
232 and 234 are
shown.
Figure 3 shows a further partially extended water jet system 302 according to
the
present invention. The same elements of Figure 1 are shown as a stationary
base 304 with a
water conveying valve 306 leading to a first rotary actuator 308 connected to
a first water
conveying tube 310. Water (not shown) carried within the first water conveying
tube 310 is
carried into a second rotary actuator 312 and then into a second water
carrying tube 314. The
water is then passed through the third rotary actuator 316 and into the third
water conveying
1S tube 318. The water passes from the third water conveying tube 318 into the
water jet nozzle
system 320. The water jet nozzle system comprises the nozzle 322, a rotating
control
element 324 and a valve support element 326. Water exits out of the emission
surface 328 of
the valve 322.
Figure 4 shows a fully extended water jet system 402 according to the present
invention. The same elements of Figure 1 are shown as a base 404 with a water
conveying
valve 406 leading to a first rotary actuator 408 connected to a first water
conveying tube 310.
Water (not shown) carried within the first water conveying tube 310 is carried
into a second
rotary actuator 412 and then into a second water carrying tube 414. The water
is then passed
through the third rotary actuator 416 and into the third water conveying tube
418. The water
passes from the third water conveying tube 418 into the water jet nozzle
system 420. The
water jet nozzle system comprises the nozzle 422, a rotating control element
424 and a valve
support element 426. Water exits out of the em fission surface 428 of the
valve 422.
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Figure 5 is a side view of a fully extended telescoping water jet system 502
for
deactivating land mines but water jet cutting of the mines either on site or
in situ. The
telescoping system 502 comprises a stationary base 504 (the motorized base may
also be used
with this telescoping system), a water conveying element 506, a rotating water
conveying
5 connector or actuator 508 that is fluid conveying connected to first fluid
(water) conveying
tube 510. The first water conveying fluid tube 510 has a telescoping joint 512
that
controllably extends second fluid conveying tube 516 by gearing 514. The
gearing 512 is
desirable to prevent high water pressure from extending the telescoping
elements so strongly
as to cause them to freeze or jam. The second fluid conveying tube 516 has a
telescoping
10 joint 518 that controllably extends a third fluid conveying tube 522 by a
second set of gearing
520. At the end of the third fluid conveying tube 522 is a nozzle system 524
that comprises a
rotating control element 530, the nozzle 526, and end support element 532. The
nozzle 526 is
shown with the fluid emitting surface 528 rotated towards a relatively
downward position.
The rotating water conveying connector 506 should have fairly complete
rotational
15 capability, such that the first water conveying tube 510 can be moved
vertically and side-to-
side to assure proper positioning. Only a single telescoping water jet element
is shown, but in
a preferred embodiment, sets of at least two, up to 10 or more such
telescoping elements may
be joined into a single unit. The individual telescoping units may be
individually rotated to
provide a control of the spread or separation of the individual nozzles at the
ends of the units.
20 Control of the position of the nozzles is preferably provided by computer
control rather than
manual control ofeach individual unit.
These waterjet detection and deactivation systems may be integrated into a
completely integrated deactivation system. That integrated system may comprise
a cart base
on wheels. The cart base may support a water storage tank, an energy source
(e.g., fuel
25 burning system, battery system, solar powered system or other energy
sources that may be
used singly or combined) One particularly useful system is a diesel engine,
which can use
widely available fuels. This energy system powers a high-pressure pump. There
would be a
water source and a hose for carrying high-pressure water to the high-pressure
directing robot
subcomponent shown in Figure 1. The water-cutting tips would then be directed
towards an
30 Identified Explosive Device (1ED), or towards the ground in its
detection/uncovering mode
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before deactivation. An optional abrasive hopper may be provided to feed
abrasive to be
mimed with water from the water storage tank before it is fed through the
pump. An
important attribute of this integrated system is that the high-pressure
directing robot
subcomponent is free of electrically motivated elements, and is operated by
pneumatic
S controls, using minimal amounts of the water pressure for motivation force.
The hose may
also have pneumatic control hoses (not individually shown) associated with it,
the pneumatic
control hoses being connected to controls in the high-pressure directing robot
subcomponent
to control general movement, directional movement, arm movement, tip
positioning, and
other necessary controls for the operation of the high-pressure directing
robot subcomponent.
Also attached to the hose may be sensor connectors (not shown), such as
optical fibers to
connect to optical sensors, thermal sensors, or other sensing elements that
may be positioned
near, but not in front of the cutting tips. The sensors are positioned a8er
the jets so that 'the
area passed over by the jets can be viewed and to minimize collateral damage
to the system
should a mine explode under force of the jets. The absence of electrical
components reduces
the potential for vapors or other accessible explosive or flammable materials
being detonated
by electrical sparks or heat generated by electrical flow. This also makes the
system highly
desirable for cutting into vehicle wrecks or storage tanks or unidentified
packages as ignition
potential is minimized. The larger components ofthe system are segregated from
the high-
pressure directing a robot subcomponent onto a trailer or cart base. This
structure allows for
many different variations in system design and particularly allows for
elimination of
electrical components in the high-pressure directing robot subcomponent.
Figure 7 shows a partial cutaway side view of a section of the system 700 from
the
engine 702 to the pump 704. Figure 7 shows more detail in the system 700 such
as a three-
quarter inch (1.9 cm) garden hose connector 706, a 1.5 inch (3.8 cm) first
hose assembly 710
to a charge dump (not shown), and a hose assembly 708 from the dump valve 712,
a base for
the motor slide 714, a self priming diaphragm water pump 716, a thirty-five
gallon (130 liter)
water tank assembly 718, air hoses 720 and 722, a pad mounting assembly 724,
water filter
assembly 726, charge pump stand 728, and other recognizable features such as
hose
connectors and assemblies. Element 91 is an inlet tube for an outside source
of liquid or gas.
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A pressure release vent 85, exhaust vents 35, and 39, housing cover 90, pump
access port 94
are also shown.
Figure 6 shows the details of the heat exchanger piping 900 with tubing 902
from a
compressor (not shown), adaptor 904, adaptor elbow 906, hose assembly 908 from
an air
filter (not shown), hose clamp 910, heat exchanger 912, hose 914 to unloader
valve (not
shown) on top ofair tank (not shown), elbow adaptor 916, reducing bushing 918,
elbow
adapter 920, and hose assembly 922 to the water storage tank (not shown).
The complete system may be taken to a potential operation site, with water fed
from
an outside source (where convenient) or carried to the site in a tank with
supply capability
(e.g., a water truck). The trailer (carrying the power system) is positioned
at a respectful
distance from the actual point of operation, and sufficiently close so that
the robot pneumatic
system can reach the unexploded device or other point of operation, yet the
trailer (which
may often carry fuel) is still sufficiently distant from the operation site so
as not to be
compromised if there is a mine detonation by the system. The robotic element
is moved to a
forward position at the site (with remote control preferred and with pneumatic
control
preferred) and moved into its initial position. The tips are appropriately
directed, high
pressure water sent through the tips, and the high-pressure water operation
begun. Remote
sensing should be used, as with optical fibers, cameras (either distal or
proximal to the robot),
infrared sensoTS, or the like to monitor the operation and local effects of
the robotic system.
The initial cutting operation I begun and by programming, manual remote
control or a
combination of the two, the cutting process is continued under distal
direction, as from the
trailer where controller personnel are located. In the event of a premature
detonation or
booby trap that cannot be addressed by the cutting device, personnel and the
majority of the
system is safe and the robot can be replaced.
There are numerous situations that can be addressed by the cutting system of
he
invention, either using a standard unit or with specialized units that can be
modified at the
site, in transit to the site, or at a central location. For a mine field, the
robotic unit would be
positioned at an edge position to the field, and then the robotic unit, with
the high-pressure
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cutting tips aimed towards the ground, would sweep the area. A slight overlap
in the
sweeping path would be suggested, with the sweep speed (both mass movement of
the
robotic device and controlled movement of the tips on the extended arms in
three dimensions)
being controlled from the trailer (either by a processor and/or human
controller) to effectively
disarm individual mines in a sweep of the ground and progress over the field
to deactivate all
mines. By actually addressing the entire surface area of the field, all mines
can be
deactivated. The robotic device may move at relatively slow speeds in the
process and its
speed may be controlled. For example, when monitors show that no mine is
present , the
speed of the robotic element may be relatively fats (e.g., 3-5 centimeters per
second or faster
if the visualization, response and stopping capabilities are compatible with
the higher speeds),
and then the speed is slowed down to assure that the mines are cut through.
Different mines
require different degrees and times of cutting, so observed control is
important. For example,
plastic cover, composition cover or other non-metal covers can be cut through
in a matter of
seconds, while old fashioned, thick metal clad mines, may be cut at a rate of
only millimeters
per second (e.g., 0.1 to 10 mm/second or more or less as needed). Although
these speeds are
relatively moderate, the efficiency of the method, the safety of workers, and
its speed
compared to the presently most efficient process (the grunt groping on the
ground with a
probe) is a slower method, because speed cannot be altered without endangering
the worker
and reducing efficiency significantly.
Other site operations may be performed differently than with mine field
clearance.
For example, the cutting device may be used for victim extraction at a damaged
site or wreck.
The high-pressure water cutting system has a distinct advantage in wreck
situations where
drill or flame cutting devices cannot be used because of local fuel spillage.
The device may
be locally monitored under this situation, with an operator at the sire or
distally located. The
device I brought into a local position, small amounts of eater may be expelled
from the tips
(e.g., at high or reduced pressure) to assure correct targeting, and then high-
pressure cutting is
begun). All o fewer than alt tips ma[y be in operation, and the number of tips
in operation
may be modified during use. The cutting is performed on the wreck site and
moved
according to the local cutting needs.
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With a possible toxic local site, evacuators may also be associated with the
tips to
vent any residue of toxic material at the site. This can be done through
vacuum tubes or other
venting systems in the distal end of the tube, adjacent the cutting tips. When
toxic waste is
encountered, the water may be temporarily cut off or pressure reduced to
assist in removal of
the toxic material without continuing to introduce water to the site. With cut
off of the high
pressure water, all vapors at the tip site can be influenced by applied vacuum
or reduced
pressure.
The tips of the high-pressure water cutting tips of the invention are
preferably able to
provide shaped jets of water, as with Rankin Shaped Jets~ tips from Aqua-Dyne,
Inc. Such
jets are described generically in U.S. Patent No. 5,170,946 fox cleaning and
cutting purposes.
These Rankin-Shaped Jets~ tips are disclosed as being capable of providing
shaped water
jets to assist in controlling cleaning and cutting parameters in high pressure
systems. These
tips are conventionally used in hand-held systems, with an operator holding
the hand-held
device and cutting or cleaning a surface under direct and close visual
supervision by the
operator. These tips provide high volume flow at high pressure such as at
least 5
gallons/minute (18.52L/minute) at pressures of at least 5,000 PSI, 8
gallons/minute
(29.62L/minute) at pressures of at least 7,000 PSI, 10 gallons/minute
(37.04L/minute) at
pressures of at least 10,000 PSI, and 13 gallons/minute ( 48.13L/minute) at
pressures of at
least 8,000, 10,000, or at least 12,000 PSI, with described conventionally
used pressure of at
least 40,000 PSI being shown. These tips are used in the industry as an
environmentally
friendly alternative to sandblasting or grinding; internal cleaning of pipes
and heat
exchangers, concrete removal; and as a cutting alternative to saw blades and
laser cutting
machines for parts fabrication. Hole diameters in the tips generally range
from 0.001 to
0.071 inches (0.025 to 1.803 mm), although both larger and smaller holes may
be used. The
hole shapes are nominal in that shapes other than circular shapes with a
constant diameter
may be used. The holes may be slits (e.g., rectangles, narrow rectangles,
pointed ovals, etc.),
or polygon shapes, particularly triangles, equilateral triangles, isosceles
triangles, irregular
triangles, squares, etc. to provide an edge to the jet. The shaped jets also
tend to maintain the
jet in a cohesive stream for a longer emission distance than does a
conventional circular hole
in the jet tip.
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The preferred tip available from Aqua-Dyne is a diamond hole tip, although the
composition of the tip merely affects longevity of the tip and not its
immediate performance.
The tip is actually a small diamond (e.g., industrial or natural diamond) with
a precision,
shaped hole cut through the diamond. Other strong materials, e.g., tungsten
carbide, metal
5 alloys, etc.) may also be used, with the material merely controlling
longevity and being an
economic design choice.
The present invention also provides a core method for strategically
neutralizing a
potential bio-chemical weapon of mass destruction remotely while viewing and
monitoring
the procedure from a safe distance is the use of an ultra-high water jet in
combination with an
10 anti-bio-agent foam as developed by Sandia Labs. Once the bio-chemical
target has been
identified, it is surrounded with a dike or parameter to ensure that the foam
and discharged
water solution is kept in the immediate area. Then the weapon is rendered safe
by the foam
and water additives. This can be practiced, for example, as follows:
A pressurized canister device containing anti-bio-agent foam may be attached
to the
15 manipulator will be described. A delivery tube for foam dispersal runs to
the end of the arm
adjacent to the waterjet cutting tip. The arm is strategically aimed with the
use of cameras
(which may be positioned on the nozzle support or a water carrying tube that
is aligned with
the waterjet, or on a moveable camera) at a determined location on the
suspected bio-
chemical object, and the foam is remotely triggered until the object and the
tip of the
20 manipulator arm together are completely covered by a sufficient amount of
anti-bio-agent
foam. By foaming the entry site and the surrounding barrier with foam it is
possible to
contain any escaping hazardous materials. The water jet is activated while
being entrained
with a bleach solution, and breaches the casing ofthe target and vents the
internal materials
into the foam. The foam and solution kills or neutralizes the hazardous
materials. The
25 amount of total water jetted solution introduced can be as little as I or
two gallons. The
device then can also be used to render safe any explosive device that may have
acted as an
accelerant or distribution method for propelling the hazardous materials into
the environment.
Mounted in front of the remote motorized tracks may be a hydraulic rack that
is 10
feet long by 10 feet wide (3.1m x 3.1m). A 12" (30.5 cm) row of 13 nozzles
located in a
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36
straight row I inch (2.54 cm) apart moves from left to right beginning near
the front of the
tracks. It moves at the correct rate for 10 feet (3.1 m) to the other side of
the rack to cut into
the landmines in the soil below, thereby rendering them harmless. The arm then
advance 12
inches (30.5 cm) forward and moves from right to left to repeat the process.
This is done 10
times until the row of nozzles is at the front of the hydraulic rack.. At this
time the entire unit
advances 10 feet (3.1 m), stops and repeats the process.
In the case of highly vegetated areas that are generally found in mine fields
about
60% of the time, the following process occurs simultaneously as the entire
unit moves
forward. Two 4 ft. (1.4 m) to 6 ft. (1.9 m) arms in front of the hydraulic
rack each has a
rotary nozzle at the end that rotates from 200 to 300 RPM containing 2 to 6
nozzle jets each.
One arm points directly ahead horizontal to the ground, and the other points
down at
approximately a 45 degree angle. The arms move together at a determined rate
back and
forth from one side of the front of the hydraulic rack to the other; from left
to right or visa-
versa. The straight arm completely obliterates any vegetation in its path
while the angled arm
I 5 penetrates to the necessary depth (8 inches to 24 inches; 20.3 cm to 61
cm) and destroys any
roots while up-rooting and exposing any landmines. The surface ground is left
amazingly
dry. In the rare event that a mine is activated, it is sufficiently far enough
from the shielded
track system that little or no damage occurs.
In the case where small trees are in the way, sound detecting devices on the
robotic
track system cause the system to stop advancing, and the arms to automatically
reverse
immediately at the outer end of the tree. This process is repeated until the
tree is mowed
down.
As can be seen, the system of the invention has wide-ranging and alternative
uses that
are beneficial to public health and safety.
