Note: Descriptions are shown in the official language in which they were submitted.
CA 02603658 2007-10-22
PORTABLE SCREENING MACHINE
FIELD OF THE INVE'N'.I'JON
The present invention relates to a portable system for screening materials
comprising a rotary trommcl which is chain driven at a discharge end thereof
and has a
slacking conveyor belt at a forward end of the portable screening machine
which may he
a radial stacker for use with the portable screening machine or used solely as
a stand
alone conveyor.
BRIEF DESCRIPTION OF TFIE DRAWINGS
Figure 1 is a perspective view of the portable screening machine of the
instant
invention;
Figure 2 is a side view of the portable screening machine of Figure I ;
Figure 3 is a side view of a forward portion of the portable screening machine
of
is Figure I with a radial stacker in an extended operating position;
Figure 4 is a rear view of the portable screening machine showing the motor
and
chain drive at the discharge end;
Figure 5 is a top view of the motor and drive sprocket configuration of Figure
4;
Figure 6 is a perspective view of the radial stacker support structure;
30 Figure 7 is side view of the radial stacker support structure; and,
Figure 8 is a side view of the radial stacker Support structure in transition
toward
an upper position stored position,
CA 02603658 2007-10-22
DETAILED DESCRIPTION OF THE- PREFERRED EMBODIMENTS
The portable screening machine 10 of the present invention depicted in the
drawings provides a rotary trommel, which is driven by a chain and sprocket
arrangement
at a discharge end of the tronnmel, According to one embodiment depicted in
Figures 1-
7, a portable screening machine IO is depicted having a chassis I I defined by
at least a
lower frame portion 12 and an upper frame portion 30, As depicted in the
instant
embodiment the lower frame portion 12 and the upper frame portion 30 may be
formed
of channel beams or other suitable structure separated by a plurality of
.structural ribs.
The chassis I I comprises a forward end 14, where a tractor or other towing
machine may
be connected to the portable screening machine 10, and a rearward end 16.
Depending
from the rearward end 16 may be a suspension 18. Rotatably connected to the
suspension
18 may be wheel assemblies 28 providing a means for transporting the screening
machine
10 to and from various positions. The suspension 18 may farther comprise a
strut for
stiffening the machine 10 during travel. It should be understood that it is
well within the
is contemplation of the instant invention that various types of suspension
systems may be
implemented herewith including coil springs, air bladders, or other known
suspensions.
Connected about the periphery of the chassis I I are a plurality Of log's 34.
Tile
legs 34 each have a nested inner leg portion 36 therein which may he extended
between
an operating position, shown in Figure 3 and a traveling position, shown in
Figure 2. At
a lower portion of each inner leg 36 is a foot 37 providing a stable platform
from which
the screening machine 10 operates when the inner leg portion 36 is extended.
Connected
to mounting higs 42 on each leg 34 and substantially parallel to each leg 34
are cylinders
38. The cylinders 38 may he air cylinders, hydraulic, or some other type fluid
driven
CA 02603658 2007-10-22
cylinder, The cylinders 38 are connected at an upper end to the upper Frame
portion 30.
Slidably positioned within each cylinder 38 is a piston 40 which is connected
to the foot
37 and provides for movement of the foot 37 and inner leg portion 36 between
the
operating position and the traveling position. Preferably, the inner leg
portions 36 are
extended downward so that fbe. fket.37.can. fully support the portable
screening machine
during operation.
Referring now to Figure 1, mounted above the upper frame portion 30 is a
hopper
40. The hopper 40 has an open upper portion, an open lower portion, and
tapered
sidewa))s such that the upper portion has a larger perimeter and cross-
sectional area than
10 the lower portion. The hopper 40 may he formed of various materials
including but not
limited to steel plate, rubber lined steel plate, diamond plate, other
abrasion resistance
steel plate or polymeric material depending on the products tieing screened
and sized
using the screening machine 10. The hopper 40 receives material from a
conveyor belt,
front end loader, or other industrial equipment and directs the material to a
feed conveyor
52 disposed beneath the hopper 40 and best shown in Figure 2. The hopper 40
may
further comprise a grate extending across tipper open portion in order to
break tip clumps
of material before they reach the feed conveyor 52.
Still referring to Figure 2, the teed conveyor 52 includes a belt 51 extending
between a head pulley 54 and a tail pulley 56 and comprises a plurality of
idling rollers
58 for supporting a bed of material being moved by the feed conveyor 52. The
feed
conveyor 52 may also include at least one return roller for engaging the
return side of the
conveyor 52 and providing sonic tension in the belt. In addition, the feed
conveyor 52
may further include centering rollers 80 inhibiting the feed conveyor from
"walking" or
CA 02603658 2007-10-22
.,creeping" along the idling rollers 58 beyond a predetermined tolerance. In
addition, it a
chute may extend between the feed conveyor 52 and a lower edge portion of the
hopper
40 in order to keep dust at a minimum and inhibit material spillage at the
transfer point
between the hopper 40 and the feed conveyor 52.
Referring stow to Figures 1, 2. and 4, at the discharge end of the teed
conveyor 52
near the head pulley 54 is cylindrical screening machine, which is also known
as a rotary
screening trornmel 70 in the industry. 'I he rotary tromnmel 70 is
substantially cylindrical
in shape having a feed end receiving material from the feed conveyor 52 and a
discharge
end at a rearward portion of the chassis 11. The rotary trommel 70 is oriented
so that the
1t) feed end is higher than the discharge end. This may he accomplished by
raising the
forward end 14 of the machine 10 to a higher elevation than the rearward end
16, or
raising the feed end of the trotnrnel 70 higher than the discharge end. In
either event, it is
preferable to have the feed end of the trommel 70 higher than the discharge
end so that
material .moves from one end to the opposite end during rotation of the
trommel 70. The
rotary trommel shape is defined by a screening material 78 having a
preselected screen
size which allows material less than the preselected size to fall there
through while
retaining oversized product material within the trommel 70 for continuous
removal at the
discharge end. The screening material is preferably lbrrned of a steel mesh
having a
preselected wire size and aperture size dependent upon sizing characteristics
desired firr
_0 the material- The screening material 78 may also be corrosion resistant if
such a
characteristic is desired. The rotary trommel 70 is rotatably positioned on a
plurality of
bearing assemblies, preferably tour, each having either a forward roller 72 or
a rearward
roller 74 and allowing rotation of the trommel 70. According to the instant
design two
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forward rollers 72 and two rearward rollers 74 are used to support the trommcl
70. At
least one trommel ring 76 extends about the trommel 70 at forward and rearward
ends
and each is aligned for rotation on the forward and rearward rollers 72.74. 1n
addition, a
thrust bearing may be used near a lower discharge end of the trommel 70 since
the
trommel is oriented having a downward slope from the feed end to the discharge
encl.
As shown in Figures I and 4, at least one brush 79 is shown rotatably
contacting
the trommcl 70, and more specifically the trommcl screen 78. The at least one
brush 79
preferably has a plurality of bristles which clear the trommel screen 78 to
provide proper
screening during operation. The brush 79 is rotatably connected to a
structural arm 77
which properly spaces the brush 79 from the trommel screen 78 for proper
operation
during screening. A. scraping device may also extend from the structural arm
77 to clear
clumps of material from the rotary screening trommel 70.
Referring now to Figures 2, 4, and 5, the rotary trommel 70 is rotated by a
chain
drive positioned at a rearward or discharge end of the trominel 70. Extending
about the
trammel 70 adjacent the rearward roller ring 76 is a trommel sprocket 102. A
motor 96 is
disposed on the chassis 1 I above the suspension 18 at the rearward end
portion of the
chassis 16. The motor 96 has a shaft with a sprocket 98 aligned with the
trommel
sprocket 102. A chain 100 extends about the motor sprocket 98 and trammel
sprocket
102 so that the motor 96 can drive the rotary trommel 70.
The rear chain drive configuration of the present invention provides two
distinct
advantages over prior art trommcts which do not include rear chain drive
configurations.
The real- drive configuration has a low primary load height which is very
important in the
screening industry. Prior art screening machines are not rear drive systems as
in the
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present invention. In order to provide clearance for prior art drives, the
drum must be
raised which requires that conveyors and hoppers also be raised. By raising
the hopper,
larger front end loading equipment is required which is very expensive and may
be cost
prohibitive.
To the contrary, the present invention overcomes these problems and provides
several advantages. First, by relocating the chain drive to the rear end of
the trommel 70,
the hopper 40 and in-feed conveyor 52 are lowered to provide a lower primary
load
height which does not require larger loaders. Second because the hopper 40 is
lowered, a
larger hopper 40 may be used than iii prior art designs. Third, a maintenance
panel may
be provided at the rear of the screening machine 10 to provide access to the
chain drive
for maintenance rather than having maintenance personnel laying on an
undersize
product belt 130 to perform maintenance on the drive. Fourth, the rear chain
drive
configuration allows a lower height for the trommel 70 which may relate to a
lower
height for the undersized conveyor 130 providing clearance between the
undersized
product conveyor 130 and the in-feed conveyor 52. Finally, the rear chain
drive
configuration allows for lower undersized product belt height providing
additional
clearance between the lower portion of trommel 70 and the material piles on
the
undersized product belt 131.
Referring now to Figures 1 and 2, at a discharge end of the trommel 70 is an
oversized product conveyor 110 receiving oversized material which fails to
pass through
the screening material 78. The oversized product conveyor is rotatably
connected to the
chassis 11 such that the conveyor i 10 may be pivoted upward about a
horizontal axis
through connection 119 into a traveling position or for storage shown in
Figure 2 or
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CA 02603658 2007-10-22
pivoted downward and extended for operation shown in Figure 1. The oversized
product
conveyor I 10 includes a. head pulley for driving the conveyor and tail pulley
and may
also include idling rollers, return rollers, and tensioning rollers. The
oversized product
conveyor 1 [0 is preferably driven by a, motor and drive wherein the motor may
be a
hydraulic motor or an electric motor and the drive may be a belt drive, chain
and sprocket
drive, gear reducer, or other known drive system for transmitting torque from
the motor
to the conveyor 110. The oversized product conveyor 1 10 comprises a First
cylinder 1 12
having a piston 114 slidably extending from the cylinder 112. The first
cylinder 112 may
be pivotably connected on the chassis 11 and the piston 114 has a distal end 1
14
connected to a conveyor support aria 118. When the piston 114 is extended the
conveyor
1 10 pivots about connection 1 19 to an upper folded and stored position
depicted in Figure
2. however, when the piston 114 is retracted the conveyor support arm 118
pivots about
connection 119 into an extended operational position depicted in Figure 1. At
an
opposite second end of the conveyor support arm I I8, is a second cylinder and
piston
is 120. The second cylinder-piston arrangement 120 is disposed in an extended
position
when the conveyor 1 10 is in a stored position but moves to a. retracted
position when the
conveyor 11 0 may be moved to an extended operating position, In such an
extended
position, the oversized product conveyor 110 is inclined or directed. in an
upward
direction to allow for stacking of the oversized product received from the
rotary trommel
70. Alternatively, the orientation of the oversized product belt 110 may be
adjusted to
extend horizontal ly or downward if desired. .According to at least one
embodiment, the
oversized product conveyor 1.10 is driven by a hydraulic motor although it i.s
well within
the scope of the present iriverition to use an electric motor.
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CA 02603658 2007-10-22
Referring now to Figures 2 and 3, extending from the rearward end 16 of the
chassis I I to the forward end 14 is the undersized product conveyor or fines
conveyor
130 located beneath the trommcl 70 and receiving undersized material which
passes
through the screen 78. The undersized product conveyor 130 comprises a head
pulley
(32 at a forward end 14 of the ehassi 11--, a tail pllllcv-t34 of ii rearward
cad 16 iii the
chassis I I , idler rollers 136, and return rollers 138 The head pulley 132
an./or tail
pulley 134 may also have a turnbuckle or other tensioning device in order to
adjust the
tension on the undersized product belt 131. The undersized product conveyor
130 is
preferably driven by a motor and drive wherein the motor may be a hydraulic or
electric
motor and the drive may be a belt drive, chain and sprocket drive, gear
reducer, or other
known drive system for transmitting torque from the motor to the conveyor 130.
Referring now to Figures 1-3, a second embodiment of the present invention is
depicted. In addition to the rear drive trommel design previously discussed,
the portable
screening machine I 0 also comprises either a permanently attached stacker
1.50 as shown
in Figure 1, or a removable radial stacker 260 as shown in Figures 2 and 3,
such that
either configuration may be provided to an end user. Referring first to Figure
1,
extending from the forward end 14 of the chassis 1 1 are first and second
pairs of pivot
plates 151 which may be used to connect either the radial stacker 250 or the
non-radial
stacking, conveyor 150 to the portable screening machine 10. Still referring
to Figure 1,
the first exemplary embodiment of the alternative stacking devices comprises
the non-
radial stacking conveyor 150 which is pivotably connected between each pair of
pivot
plates 15 1. Pivotably attached to the pivot plates 151 is a first embodiment
of a pivoting
stacker arm 168 for upward and downward pivotal rotation about a horizontal
axis. The
s
CA 02603658 2007-10-22
stacker arm 168 pivots at the pivot plate 151 such that the radial stacking
conveyor 150
may be directed upwardly through a range of angles to permit stacking of
undersized
product at various heights. The stacker conveyor 1 50 also comprises a hinge
162 in the
conveyor frame providing pivoting about a horizontal axis for folding the
conveyor
during storage or travel.
Referring now to Figures 2, 3. 6, and 7. an exemplary removable radial
stacking
conveyor 250 and support structure is shown wherein the stacking conveyor 250
may be
used either with the portable screening machine I 0 or as a stand-alone
stacking conveyor
separate from the portable screening machine 10. The radial stacking conveyor
250
t0 preferably has a range of motion through a horizontal plane ofup to about
200 degrees
when attached to a stacking arm 268 of the portable screening machine 10.
Prior art
radial stackers which are integral with a screening machine have typically
been limited to
less than 180 degrees of rotation. However, the structure of the present
design does not
limit rotation to 180 degrees but instead allows a greater range of rotation.
Pivotably
connected to the pivot plates 151 is a second embodiment of a stacking arm 268
having
an integral lever arm 280 and shaft collar 290. According to the second
embodiment of
the stacking conveyor, the stacking arm 268, the shaft collar 290 and lever
arm 280 are
welded together to provide a unitary stricture. The stacking arm 268, lever
arm 280, and
shaft collar 290 arc connected to the pivot plates by a shaft 291 allowing
pivotal rotation
of the radial stacker 250 about a horizontal axis defined by the shaft 291
such that the
radial stacking conveyor 250 can rotate upward about a. horizontal axis.
Hereinafter,
referral to the stacking arm 268 can be assumed to also include referral to
the shaft collar
290 and lever arm 280. The stacking arm 268 is connected to the pivot plates
151 at a
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higher pivoting position on the plates 151 than the first embodiment stacker
150 as best
shown in Figure 3 in order to provide clearance for parts disposed beneath the
radial
stacker 250. Disposed at a lower portion of a stacker arm 268 is a ball-joint
266
providing for a pivoting movement about a vertical axis between the stacking
arm 268
and the stacking conveyor 250. Thus, the stacking an-ii 268 in combination
with the ball-
.joint 266 provide for movement of the conveyor 250 about a horizontal axis
and about a
vertical axis. Disposition of the ball-joint 266 at a lower portion of
stacking arm 268
allows greater rotation than available with prior art machines such that the
stacking
conveyor 250 does not conic into contact with the chassis l i as readily as
prior art
to machines. The radial stacking conveyor 250 comprises a frame 260 having a
head
pulley 252 at a first end and a tail pulley 254 at a second end. The frame 260
is formed
of a plurality of structural beams which may be, for instance, 1-beans or
channel beams.
Extending upwardly from the frame 260 between the head pulley 252 and tail
pulley 254
are a plurality of idler rollers 256 for supporting a load of material being
conveyed along
the stacking conveyor 250. Also extending upward from the frame 260 may be a
fines
conveyor hopper 267 which, in the operating position shown in Figure 3, is
located
beneath the head pulley 132 of the undersized product belt 130. In this
configuration the
tines conveyor hopper 267 inhibits spillage of material 1'roni the transfer
between the
undersized product belt 1 30 and the stacking conveyor 250 and further
contains dust.
The fines conveyor hopper 267 may be formed of various abrasion resistant
materials
including but not limited to rubber, synthetic rubber, abrasion resistant
molded polymeric
materials, steel, or abrasion resistant steel. Within the area, surrounded by
the hopper 267
and beneath conveyor belt 250 is at least one support roller 269 which support
the
CA 02603658 2007-10-22
stacking conveyor belt 250 as material is dumped thereon. Depending from a
lower side
of the frame 260 is at least one return roller 258 providing tension on the
conveyor belt
and inhibiting excessive sagging on the return side. Also depending from the
conveyor
frame 260 are a plurality of conveyor support beams 262, 264. A first conveyor
support
beam 262 is pivotably attached to the frame 260 at a first end for pivotal
motion about a
horizontal axis and a wheel assembly 263 at a second end. Near the second
distal end of
the beam 262 is a slide block 270 which is attached to the first conveyor
support beam
2()2. A second conveyor support beam 264 is pivotably connected to the
conveyor frame
260 at a first distal end, substantially adjacent the tail pulley 254, forming
a triangular
shaped support structure in combination with the frame 260 and the first
conveyor
support beam 262. In order to provide for folding of the stacking conveyor
250, the slide
block 270 has a collar 271 through which the second conveyor support beam 264
passes
in sliding fashion. In other words, the slide block 270 slidably connects the
second
conveyor support beam 264 to the first conveyor support beam 262. It)
addition, the
collar 271 pivots from the portion 270 in order to provide the folding motion.
As shown
in Figure 8, as the stacking conveyor 250 pivots toward an upper stored
position, gravity
forces the wheel assembly 263 toward the conveyor frame 260 and the second
support
beam 264 slides through the slide block collar 271 until the conveyor support.
structure is
disposed against the conveyor frame 260 as shown in Figure 2.
Referring now to Figures 2, 1, and 6-7, the radial stacker conveyor 250
support
structure is shown in various positions. As previously described beams 262,264
provide
support for the radial stacker 250 which is shown in the extended operating
position in
Figure-3-. A-siabi.l.izor beam 265 extends Iron] the frame 260 where it is
positioned on the
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wheel assembly 263. The beam 265 need not he connected to the wheel assembly
263 or
beam 262 but instead may rest upon wheel assembly 263. The stabilizer beam 265
provides a stabilizing function inhibiting radial movement of the radial
stacker 250 about
a vertical axis when the radial stacker 250 is pivoted from a transport
position to an
operating position. The stabilizer beam 265 is pivotably connected to the
frame 26(1 at a
distal end so that the beam 265 pivots about a horizontal axis between a first
position
shown in Figure 3 and a second position shown in Figures 6 and 7. At a second
distal
end the stabilizing beam 265 has a pin connector 261 which is used to connect
the
stabilizing beans 265 to a shaft collar 290 with integral lever arm 280 and
stacking arm
268. When the stabilizer beam 265 is positioned as shown in Figure 3, the
bean? 265 may
simply rest on the wheel assembly 263. When the stabilizing beam 265 is
positioned as
shown in f.7igures 2, 6, and 7, the beam 265 is connected to shaft collar 290
and inhibits
the slacker 250 from moving radially about a vertical axis rc)ative to the
chassis 11. In
this configuration, the stacker 250 may be moved to the stored frill-length
position or
configuration rather than folding the stacker conveyor 250. To allow for such
a locked
configuration, the stabilizing beam 265 connects to a shaft collar 290 with a
pinned
connection shown in Figures 6 and 7. The shaft collar 290 is connected to a
shaft 291
extending from the pivot plates 151 in order to provide rotatable motion.
Extending
between the stacker ann 268 and the shaft collar 290 is the lever arm 280. The
lever arnti
280 is connected to a hydraulic cylinder 292 which is disposed in an extended
position
when the radial stacker 250 is being stored as shown in Figure 2. When the
cylinder 292
is retracted, the radial stacker is moved to an extended operating position.
During
operation. the cylinder 292 is retracted moving the lever arm 280 and in turn
pulling the
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stacker arm 268 downward as well as the shaft collar 290 downward. As
previously
describer, the stacker arni 268, shaft collar 290, and lover arm 280 are,
according to the
present exemplary embodiment, a unitary structure. Once the radial stacker 250
is moved
into an operating position, the stabilizing beam 265 is disconnected from the
shaft collar
290 by a releasable connection and pivoted to the position shown in Figure 3
and Figure
7 in dotted line. When the stabilizing beam 265 is moved to the lower position
the radial
stacker 250 is released from a locked position and is free to pivot about a
vertical axis
relative to the chassis I I at ball joint connection, When the screening
operation is
complete the stabilizing beam 265 is moved as Shown in Figure 7 and connected
to the
shaft collar 290.
According to this embodiment the design allows the rotation of the stacking
conveyor 250 for storage or travel as shown in Figure 2. The conveyor support
beams
262, 264, 265 may be formed or various structure shapes including but not
limited to
channel beams, angle irons, or other shapes. Positioned adjacent the
connection of the
first and second conveyor support beams 262.264 may be a wheel assembly 263.
The
wheel assembly 263 allows for radial movement of the stacking conveyor 250
relative to
the chassis 11 which in turn provides for larger stockpiles of product.
Located at the forward end of the chassis 1 I is a power compartment I80. The
power compartment 190 may comprise various pieces of equipment allowing the
portable
screening trommel to operate self-sufficiently. For example, the power
compartment 180
may comprise a diesel engine as well as a hydraulic pump for providing fluid
pressure to
various hydraulic motors and cylinders. In an alternative embodiment, an
electric
generator may be located in a power con:ipartment 180 providing power for the
various
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conveyor motors and trommel motor 96. In addition, the power compartment 180
may
have an air compressor providing compressed air to an air system for blowing
off belts or
providing compressed air for other uses.
Extending from the chassis 11, and more specifically the upper frame portion
30,
are ribs 92. The ribs 92 extend outwardly a first preselected distance and
then upwardly a
preselected distance. Extending between the ribs 92 are removable access
panels 94
which serve several functions. First, the access panels 94 inhibit hands or
other body
parts from being injured by contacting moving feed conveyor 52 parts or the
rotary
trommel 70. Second. the removable panels 94 provide access to various
components of
the portable screening machine 10 allowing for maintenance and necessary
repairs. In
addition, the panels contain material spillage from the feed conveyor 52 and
rotary
trommel 70.
To use, the portable screening machine 10 is connected to a fifth-wheel or
other
hitch apparatus of a tractor or other towing vehicle at which time it may be
towed to a
screening location. Once the screening machine 10 is positioned for use, the
components
located in the power compartment are started providing at least hydraulic
fluid power.
The inner legs 36 are then lowered by hydraulic cylinders 38 so that the feet
37 stabilize
the machine for operation. Once the hydraulic systems are started the
oversized product
conveyor 110 and the stacking conveyor 150 are lowered from their stored
positions to
extended operating positions. Next, the conveyor belts are started as well as
the motor
l'or the trommel 70. Once the conveyor belts and trommel are operating, the
hopper 40
may be loaded by some mobile equipment including a front-end loader, a
baekhoe, or
other such equipment utilizing a bucket. Alternatively, a portable
conveyor.may be
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positioned adjacent the screening machine 1.0 having a discharge end
positioned above
hopper 40 such that the hopper 40 receives material From the portable
conveyor. Once
received in the hopper 40, the material is directed to the feed conveyor 52
and further
directed into the trommel 70 where the material may be sized according to the
screen size
of the mesh screening material 78. The oversized material, which does not fit
through the
screen 78 is stacked to the rear of machine 10 by the oversized product
conveyor 1 10,
which receives material from the interior of the trommel 70. The undersized
material,
which falls through the trommel screen 78 to the undersized product conveyor
belt 130, is
directed to the front or forward portion 14 to the stacking conveyor 1 50 or
radial stacker
250. Once the screening process is completed, the machine 110 may be cleaned,
if
necessary, and the stacking conveyor 250 and oversized conveyor 110 moved to
stored
positions. Finally, the screening machine 10 may be towed. to a new position
f'or
screening.
it is apparent that variations may be made to the screening machine design of
the
present invention in regards to specific design elements thereof. Such
variations however
are deemed to fail within the teachings of the present invention as generally
modifications may be made to placement of the particular structure described
herein
while falling within the general teachings hereof.
is
