Note: Descriptions are shown in the official language in which they were submitted.
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VEHICLE AND TANKS FOR HYDRO EXCAVATION
This invention is in the field of excavating equipment and in particular hydro
excavating
equipment where high pressure water is used to loosen soil, which is then
vacuumed out
of the hole to create the excavation.
BACKGROUND
Hydro excavation is popular, especially when excavating around existing buried
pipes,
cables, and the like. A high pressure water stream is used to loosen soil, and
a vacuum
system sucks up the slurry of water and loosened soil and deposits same into a
slurry
tank. A typical vehicle, either a truck or trailer bed, that is equipped for
hydro excavation
carries a water tank to supply water, and a slurry tank for collecting the
mixture of soil
and water that is removed by the vacuum. Hydro excavating equipment is
disclosed for
example in United States Patent Numbers 5,295,317 to Perrot and 5,408.766 to
Pobihushchy.
On a typical hydro excavation vehicle, such as the TornadoT" Hydrovac truck
manufactured by Tornado Corporation of StettlerõAlberta, Canada the water and
slurry
tanks are provided by placing a divider in a horizontal cylindrical tank such
that the front
portion of the tank holds water and the rear portion holds the slurry. The
tank capacities
range from 550 gallons of water and 4.0 cubic yards of slurry to 2366 gallons
of water
and 13.0 cubic yards of slurry.
It can be seen that initially the water tank will he full, and the slurry tank
will be empty,
and that during operation water will be drawn out the water tank and slurry
will be drawn
into the slurry tank. Thus the balance of weight carried on the vehicle will
shift during
the excavation process from the front to the rear. This shifting of weight can
adversely
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affect the handling of the vehicle, and the shift of weight can cause one axle
of the
vehicle to become overloaded while another is under-loaded.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a vehicle and tank
apparatus for hydro
excavation that overcomes problems in the prior art.
The present invention provides a vehicle and tank apparatus for hydro
excavation. The
apparatus comprises an inner tank, and an outer tank substantially enclosing
the inner
tank such that a water space is created between walls of the inner and outer
tanks. A
water pump is operative to draw water from the water space and direct same to
a pressure
nozzle, and a vacuum system is operative to draw a mixture of water and
excavated soil
into the inner tank. A vehicle bed mounted on wheels for movement along the
ground
supports the inner and outer tanks, water pump, and vacuum system.
Enclosing the inner slurry tank inside the outer tank forms a water storage
space between
the tank walls. This arrangement allows the tanks to be configured so that as
water is
drawn out of the water space during operation, and slurry is vacuumed into the
inner
slurry tank, the center of gravity of the tank assembly remains at the same
location on the
vehicle bed, as opposed to prior art tank arrangements where the weight
distribution
shifts during operations. Improved stability and weight distribution on the
vehicle wheels
is improved significantly. The apparatus is readily configured to achieve
desired
proportions of the capacities of the inner and outer tanks for slurry and
water
DESCRIPTION OF THE DRAWINGS
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While the invention is claimed in the concluding portions hereof, preferred
embodiments
are provided in the accompanying detailed description which may be best
understood in
conjunction with the accompanying diagrams where like parts in each of the
several
diagrams are labeled with like numbers, and where:
Fig. I is a schematic cut away side view of an embodiment of a vehicle and
tank
apparatus of the present invention for use in hydro excavation operations;
Fig. 2 is a schematic front view of the embodiment of Fig. 1;
Fig. 3 is schematic sectional view along line 3-3 in Fig. I;
Fig. 4 is a schematic side view of an alternate embodiment of the vehicle and
tank
apparatus of the present invention configured such that the axis of the tanks
is
vertically oriented;
Fig. 5 is a schematic top view of the embodiment of Fig. 4;
Fig. 6 is a schematic cut away side view of an alternate embodiment of a
vehicle and
tank apparatus of the present invention where the tanks are oriented
horizontally and
have the same length.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
Figs. 1 - 3 schematically illustrate an embodiment of a vehicle and tank
apparatus 1 of the
present invention for use in hydro excavation operations. The apparatus I
comprises an
inner tank 3, and an outer tank 5 substantially enclosing the inner tank 3
such that a water
space 7 is created between walls of the inner and outer tanks 3, 5. A water
pump 9 is
3
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operative to draw water from the water space 7 and direct same to a pressure
nozzle 11,
and a vacuum system 13 is operative to draw a mixture of water and excavated
soil 15
into the inner tank 3. A vehicle bed 17 is mounted on wheels 19 of a truck or
trailer for
movement along the ground and supports the inner and outer tanks 3, 5, water
pump 9,
In the illustrated apparatus 1 the inner and outer tanks 3, 5 are cylindrical
and are oriented
with axes A thereof substantially horizontal. The cylindrical shape of the
inner tank 3
provides the strength necessary to resist the pressure exerted thereon by the
vacuum
Front and rear end portions 3F, 3R of the inner tank 3 extend about an equal
distance
outward from corresponding first and second ends 5F, 5R of the outer tank 5,
and front
and rear annular cover plates 21 are fastened between the ends 5F, 5R of the
outer tank 5
The front and rear annular cover plates 21 support the inner tank 3 above a
bottom wall
of the outer tank 5, such that the tanks do not contact each other, avoiding
damage from
.7)5
Because the center of gravity CG of the inner and outer tanks 3, 5 is at the
same location
on the vehicle bed 17 midway between the front and rear ends of the inner tank
3, it can
be seen that as water is drawn out of the outer tank 5 and the mixture of
water and
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excavated soil 15 is drawn into the inner tank 3, the center of gravity CG of
the assembly
of inner and outer tanks 3, 5 will stay at the same location. The weight on
the wheels 19
will change but the proportion on each will remain about the same as well.
By sealing one of the annular cover plates 21 to the inner tank walls by
caulking or the
like instead of welding same, the bolts on the flanges 23 can be removed, and
the inner
tank 3 removed from the outer tank 5 to allow for repair and maintenance of
the outer
tank 5 if necessary.
It is contemplated as well that, as in the apparatus 101 schematically
illustrated in Fig. 4,
the inner and outer tanks 103, 105 could be oriented with axes A thereof
substantially
vertical on the vehicle bed 117. In the illustrated apparatus 101, the inner
tank 103
extends above a top edge of the outer tank 105, and an annular cover plate 121
between
the top edge of the outer tank 105 and .the inner tank 103 seals the top of
the outer tank
105. The water space 107 is between the walls of the tanks 103, 105, and inner
and outer
access ports 125, 127 through the tank walls are provided for connection of
the water
pump and vacuum system
The center of gravity of the apparatus 101, as in the apparatus 1 described
above, remains
in the same location on the vehicle bed 117 as material moves into and out of
the tanks
103, 105. Fig. 5 illustrates a top view of the apparatus 101, showing that the
outer tank
105 can he rectangular instead of cylindrical. So long as the outer tank 105
is located
with a center thereof located on the axis A of the cylindrical inner tank 103,
the center of
gravity will remain at the same location. To vary the proportions of the
capacities of the
inner and outer tanks 103, 105 the diameter, length, width, and height thereof
can be
varied.
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Orienting the tanks 103, 1.05 vertically limits the size of the tank, since
width and height
restrictions generally apply on public roads where the vehicle will be
travelling. The
horizontal orientation of Fig. 1 allows one or both of the tanks 3, 5 to be
lengthened to
increase the capacity thereof, since allowable vehicle lengths are
considerably greater
than allowable heights. The inner and outer tanks 3, 5 can be lengthened or
shortened
relative to each other to achieve a desired proportion of the capacity of the
inner tank 3 to
the capacity of the outer tank 5.
Fig. 5 schematically illustrates an apparatus 201 where the inner and outer
tanks 203, 205
are oriented horizontally on the vehicle bed 217, and are the same length. A
full cover
assembly 229 is attached to each end of the inner and outer tanks 203, 205 and
is
operative to close the ends of the inner and outer tanks 203, 205 and support
the ends of
the inner tank 203 above the bottom wall of the outer tank 205. The full cover
assembly
229 could include an existing end wall of the inner tank 203, with lugs or the
like
extending inward from a plate to support the inner tank 203, with the plate
bolted to the
flanges 223 on the outer tank 205. The inner tank 205 would then be removable.
Other
cover assemblies that would occur to a person skilled in the art could be used
as well.
To vary the proportions of the capacities of the inner and outer tanks 203,
205 the
diameters thereof could be varied, or alternatively Fig. 5 also shows that one
end 203A of
the inner tank 203 could extend outward from the end of the outer tank 205, as
in the
apparatus I described above. Such a configuration may be desirable in some
circumstances, however the center of gravity will shift somewhat as material
moves in
and out of the tanks 203, 205.
The water space 207 is between the walls of the tanks 203, 205 and inner and
outer
access ports 225, 227 are provided through the full cover assembly 229 for
connection of
the water pump and vacuum system.
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The vehicle and tank apparatus of the present invention for use in hydro
excavation
operations of the present invention provides a vehicle with improved stability
and weight
distribution. The apparatus is readily configured to achieve desired
proportions of the
capacities of the inner and outer tanks for slurry and water.
The foregoing is considered as illustrative only of the principles of the
invention.
Further, since numerous changes and modifications will readily occur to those
skilled in
the art, it is not desired to limit the invention to the exact construction
and operation
shown and described, and accordingly, all such suitable changes or
modifications in
structure or operation which may be resorted to are intended to fall within
the scope of
the claimed invention.
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