Note: Descriptions are shown in the official language in which they were submitted.
1333584
The present invention relates to screening machines
utilizing rotating tumblers.
Machines that have tumblers are known in the art, for
example, the present applicant's U.S. Patent No. 4,167,975
shows a basic machine substantially similar in framework and
rotating tumbler to that disclosed herein, but which does not
include the refinements necessary for making it work for a
dirt screening machine. Patent No. 4,167,975 is a beach
cleaning apparatus having a rotating drum for screening with
a single brush in the interior of the drum for keeping the
screen openings clean. Because sand is a free flowing
material, the problems associated with screening are less
than with dirt.
U.S. Patent No. 3,825,018 also shows a machine using a
rotating drum having a screen with a brush on the outside.
The present invention relates to screening machines that
can be used for screening black dirt efficiently and rapidly.
The machine utilizes a rotating tumbler that has cleaning and
mixing mechanisms. Additionally, the input to the screening
machine preferably has a holding bin and conveyor that is
constructed in a unique manner so that loads of dirt to be
screened can be dumped into the holding bin through a large
grate (grizzly bars) that will provide removal of large rocks
and the like. The grate can be inclined and/or swung out of
the way when desired. The dirt that is placed in the holding
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1~335B~
bin can be stored and then conveyed to a dirt pulverizer, and
then conveyed to the screening tumbler. The pulverizer and
the holding bin both have grates or grizzly bars associated
therewith for separating out rocks of substantial size to
provide classification of materials that are to be passed
through the screening machine.
Additionally, the holding bin bottom conveyor belt has
cleaners on the interior surface which contact the belt drive
rollers. The conveyors for the holding bin are individually
driven from one or more separate motors, and the components
for the screening machine can be driven from a gasoline
engine mounted directly on the screening machine assembly.
The screening machine assembly is supported above the ground
a desired distance, and the material can fall down into a
pile or be carried away with a conveyor belt underneath the
screening machine.
In one aspect, the invention provides a screening
machine for earth materials comprising: a frame member; a
screening drum mounted on said frame member and rotatable
about a longitudinal axis; said screening drum having a
screen peripheral wall with openings therethrough to separate
the materials being screened as to size; means to support
said drum for rotation about the longitudinal central axis
with ends of the drum open to receive and discharge material
to be screened; a first rotary brush having an axis parallel
to the longitudinal axis and mounted on the interior of the
screening drum and having bristles engaging the screen
peripheral wall; a second rotary brush having an axis
parallel to the longitudinal axis and mounted on the exterior
of the screening drum and having bristles engaging said
screen wall, the second brush being offset along the
circumference of the screen peripheral wall from the first
A
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brush; beater means mounted for rotation on a central shaft
within said screening drum and having a plurality of spaced
beater flaps thereon, each comprising a flexible material
flap fixed to the shaft and hammer means fixed to outer ends
of the flap to engage material being screened; and means for
rotating said beater means independently of rotation of the
drum at a speed to cause the beater flaps to extend radially
under centrifugal force to break up clods of the earth
material, and the beater flaps being of size and mounted to
move in a path adjacent to but clear of said screen
peripheral wall of the screening drum and clear of the first
brush as the beater means is rotated.
In a further aspect, the invention provides a screening
machine for earth materials comprising: a frame member; a
screening drum mounted on said frame member and rotatable
about a longitudinal axis; said screening drum having a
screen peripheral wall with openings therethrough to separate
the materials being screened as to size; means to support
said drum for rotation about the longitudinal axis with ends
of the drum open to receive and discharge material to be
screened; beater means mounted for rotation on a central
shaft within said screening drum and having a plurality of
spaced beater flaps thereon, each comprising a flexible
elongated material flap fixed to the shaft at one end and
hammer means fixed to outer ends of the flaps to engage
material being screened; and means for rotating said beater
means independently of rotation of the screening drum off set
from the axis of the screening drum and at a speed to cause
the beater flaps to extend radially under centrifugal force
to break up clods of the earth material, and the beater flaps
being of size and mounted to move in a path adjacent to but
clear of the screen peripheral wall of the screening drum as
the beater means is rotated.
A
- 13335~g
- 2b -
In a still further aspect, the invention provides a
screening machine for earth materials comprising: a frame
member; a screening drum mounted on said frame member and
rotatable about a longitudinal axis; said screening drum
having a screen peripheral wall with openings therethrough to
separate the materials being screened as to size; means to
support said drum for rotation about the longitudinal axis
with ends of the drum open to receive and discharge material
to be screened; a rotary brush having an axis parallel to the
longitudinal axis of the drum and mounted to the frame and
having bristles engaging the openings in the screen
peripheral wall; beater means mounted for rotation on a
central shaft within said screening drum and having a
plurality of spaced beater flaps thereon, each comprising a
flexible elongated member fixed to the shaft and hammer means
fixed to outer ends of the elongated member to engage
material being screened; and means for rotating said beater
means independently of rotation of the screening drum at a
speed to cause the beater flaps to extend radially under
centrifugal force to break up clods of the earth material,
and the beater flaps being of size and mounted to move in a
path adjacent to but clear of the screen peripheral wall of
the screening drum as the beater means is rotated.
Figure 1 is a fragmentary schematic perspective view of
a screening plant made according to the present invention;
Figure 2 is a sectional view taken generally along line
2--2 in Figure 1 illustrating schematically the mounting of a
screening drum and its construction;
Figure 3 is a top plan view of the typical arrangement
of Figure l;
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Figure 4 is a vertical sectional view of the screening
drum shown in Figure 2;
Figure 5 is a fragmentary perspective view of a beater
bar used in the screening drum;
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133358~
Figure 6 is a part schematic sectional view of the upper
portion of a holding bin and grizzly bar assembly showing an
adjustment device therefore;
Figure 7 is a fragmentary side sectional view of an
input conveyor section and dirt pulverizer hopper taken on
line 7-7 in Figure 3;
Figure 8 is a front view of a dirt pulverizer shown in
Figure 7;
Figure 9 is a vertical section view of the dirt
pulverizer hopper of Figures 7 and 8;
Figure 10, with Figure 3, is a part schematic to
sectional view showing the interior of the conveyor belt
forming the bottom of the holding bin shown in Figures 1 and
3;
Figure 11 is a perspective view of a support for the
grizzly bars on the holding bin used with this invention; and
Figure 12, with Figures 6 and 7, is a schematic side
view showing the conveyor arrangement at the back of the
holding bin of the present invention.
A screening machine indicated generally at 15 includes a
mobile frame screening machine 16 that contains the drum and
other components for actually screening the dirt, and as
shown it is supported on overhead frames 17 which are
supported on suitable feet 19. The overhead frames have
hoists or winches 20 to raise the machine upwardly and
support is at a desired raised position above the ground
sufficient to provide for clearance of conveyors and the
like.
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~333~
The hoists can be conventional chain hoists or
powered hoists used conventionally.
A holding bin 22 is provided at the input
end of the machine for permitting material to be
05 dumped from a loader, and stored and fed smoothly to
the screening machine. The holding bin 22 is a
separate trailer assembly, having a conveyor bottom
and an upwardly inclined output conveyor 23 that will
receive material from the bottom conveyor of the
holding bin and deposit material to be screened into
a pulverizer assembly 35, or directly onto another
conveyor belt that will convey material to the
screening drum.
A truck 25 can be placed at the output end
of the screening machine 15 to receive material from
the output conveyor 26 of the screening machine. The
overhead frames 17 each have upright posts 18 at
opposite ends of a cross member 18A. The cross
members 18A are supported by the posts 18. The
hoists or winches 20 are mounted onto the cross
members 18A, and have chains or the like that will
attach to the screening machine frame 16 for lifting
and lowering the screening machine 15.
As shown, the screening machine frame 16 has
fore and aft extending frame members 28 on opposite
sides thereof, which carry suitable sleeves 29 that
are slidably mounted on the posts 18,18 so that the
screening machine 15 is guided upwardly as the hoists
20 are operated.
The screening machine frame 16 is of
substantially the same design as that shown in prior
Patent No. 4,167,975, and thus the frame is shown
only schematically. It does include longitudinal
frame member 28A parallel to the member 28 and as
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-- 5 --
many cross members as needed for support. The
mounting of the screening drum is substantially the
same in general as that shown in prior U.S. Patent
No. 4,167,975. The present device uses vibrating
05 support rollers for the drum. As shown in Figure 3,
the longitudinal frame members 28 and also using
inner longitudinal frame members 28A support walkways
30 on opposite sides of the machine 15 so that an
operator can walk along the screening machine during
operation. A gasoline engine 31 is mounted on the
forward end of the frame and is used as a power
source.
The engine 31 can drive through suitable
gear boxes 32, to drive the various components.
Mechanical drives such as universal joint shafts,
belts or chains may be used, and the drives are shown
only schematically in that they can be any desired
form. Remote hydraulic motors operated by valves and
powered from a hydraulic pump, in turn powered by
engine 31, may be used as well.
The input of the screening plant is through
the dirt pulverizer or shredder 35 (see Figures 7, 8
and 9), and will be more fully explained. Dirt and
other material from the pulverizer drops through a
grate member 36 comprising a pivoting grizzly bar
assembly, onto an upwardly inclined conveyor 37,
which in turn has its rear end positioned to deposit
material into the interior of the screening drum 40.
The screening drum 40 as shown in Figures 2
- 30 and 4, is a screening drum member having a plurality
of longitudinally extending frame members or
stringers, indicated at 42, with a screen or mesh
material 43 on the interior of the drum frame. A
plurality of annular frame support bands 44 are used
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1333~1
-- 6 --
for welding the longitudinally extending members
together. At the input end of the drum 40 there is a
flanged track 45 that is used for mounting a
plurality of drive belts 46 that are driven from a
05 pulley 47 as shown in Figure 2. The pulley in turn
is driven from the main engine 31 through a suitable
shaft 48, or if desired, a hydraulic motor can be
used. The belts 46 extend around the drum and rotate
it about its central axis when powered. The drum
itself is supported independently, and as can be
seen, there is a second flanged track 50 at the rear
portion of the drum. Support rollers 51,51 shown
schematically in Figure 2 are rotatably mounted on
the frame 16 and are positioned to support the
screening drum through annular bands 44. The rollers
51 are mounted on side frame member 28A in suitable
bearings.
The screening drum rotates relative to front
and rear frame plates and a rotating seal is desired
at both the front and rear of the screening drum.
The seal is mounted on the interior of the drum and
extends out slightly to engage a frame member.
Schematically as shown in Figures 4 and 7, a frame
plate 49 is positioned adjacent the respective end of
the screening drum to form a desired enclosure.
The seal, shown at 50 is made of an
initially flat strap of steel 50A and having a band
of belting or other tough, flexible seal material
fixed thereto. This assembly of the steel band and
flexible strap are formed into a hoop and placed into
the screening drum at each end. The ends of the
strap 50B are bent up to form lugs and a threaded
adjustment stud 50C is inserted through the lugs.
Suitable nuts 50D are mounted on the stud and are
1 3333-~
threaded outwardly to expand the hoop and tighten it
against the interior of the screening drum. The hoop
is expanded sufficiently to clamp it in place. This
expanding force also helps to clamp the screen in
05 place in the end bands 44 and 45.
The seal is capable of being changed easily
by loosening nuts 50D and removing the steel band.
The band can be made in two or more sections that
encircle the interior of the drum for ease of
assembly.
As can be seen in Figures 2 and 6, the
support rollers 51 have axial extending, annularly
spaced ribs 53 forme~ thereon on the outer surface at
desired intervals, in order to provide for a
vibrating or shaking action as the drum 40 is rotated
through the drive belts 46. The drum 40 will rotate
in direction as indicated by the arrow 54 in Figure
2, and as it is rotated the ribs 53 on the support
rollers 51 will vibrate and shake the drum 40 so that
material, such as dirt being screened, will tend to
fall through the screen openings onto a conveyor 52,
which is standard and shown only schematically, and
not merely clog the screen openings.
The drum 40 has an interior brush 55 having
a shaft mounted in bearings attached to a suitable
cross members 56 of the frame which in turn are
supported on side uprights 56A. The uprights 56A are
supported on frame member 28A. The cross members 56
are at the front and rear ends of the drum 40. The
brush 55 is mounted in substantially the same manner
as on the machine shown in U.S. Patent No. 4,167,975.
The brush 55 is driven from the rear end of
the drum 40. The drive is accomplished by providing
a long drive shaft that extends rearwardly to a
133358~
transfer case or gear case 57 (Figure 3) mounted on
the side of the rear conveying elevator 26. The
transfer case 57 has output shafts that drive a power
take-off shaft (a universal joint type shaft) 57A
05 (Figures 3 and 4) that in turn connects through a
universal joint 58 (Figure 4) to the shaft 59
mounting the brush 55.
A second segmented brush indicated at 60
(Figures 2 and 4) is mounted for free wheeling
rotation on the outside of the drum 40, and the
bristle tips are substantially tangential to the drum
40. Brush 60 has a shaft 61 rotatably mounted in
suitable bearings at its opposite ends which are
supported from cross member 56 with uprights 56B.
Brush segments 62 are positioned in between the
support bands 44 for the screening drum. The brush
60 is free wheeling, as stated, and rotates in the
direction shown by the arrows in Figure 2. The brush
rotates under power in the direction as also
indicated by the arrow.
Additionally, in order to break up dirt and
material shown generally at 65 on the interior of the
screening drum 40, a beater bar indicated at 66 is
suitably mounted on supports 67 at opposite ends of
the drum extending from the cross members 56. The
beater bar comprises a rotating shaft 68 that has
angle iron supports 69 attached thereto, which extend
longitudinally along the drum 40, and each of the
angle iron supports mounts a plurality of heavy
belting flaps 70, each of which extends about four
inches along the axis. The flaps have hardened steel
hammers or weights 71 attached to the outer ends of
the flaps. The flaps 70 extend radially out from the
angle irons 69 and are of sufficient length so the
1 3 ~
end hammers 71 engage and tend to break up dirt or
other material in the screening drum. The beater bar
66 is rotated under power through a universal joint
drive indicated at 72 in Figure 4. The construction
is shown in Figure 5 as well. The shaft 68, with the
angle iron supports 69 attached thereto can be seen
in perspective. The flaps 70 and hammer 71 will
rotate in the direction shown by the arrows 72A and
the hammers 70 will mix into the dirt 65 and tend to
break up clods and thus help to urge the dirt through
the openings in the mesh or screen of the screening
drum 40. The flaps 70 and steel hammers 71 break up
the materials quickly and thoroughly with a minimum
amount of wear.
As can be seen in Figures 3, 7, 8 and 9, the
dirt pulverizer or shredder assembly 35 includes a
hopper indicated generally at 80 is mounted onto
frame members 81 and frame member 81A, which are
supported from the main frame side member 28A of the
screening machine. The dirt shredder hopper 80
comprises two hopper sections. The first hopper
section is a stationary section indicated at 82 in
Figures 8 and 9, held stationary relative to the
frame, and the second hopper section is a movable
section indicated at 83. The pulverizer frame 81
includes cross frame members 84 which are of
sufficient size and strength to support the hopper
section 83 in position through a pair of pivoted arms
85. The arms 85 are pivoted as at 86 on brackets
fixed to one of the cross frame members 84. The
stationary hopper section 82 has side plates that are
spaced laterally apart and will receive material from
the input conveyor 23 of the holding bin 22. The
movable hopper section 83 also has sides that fit on
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l~3~4
-- 10 --
the interior or the side plates of the stationary
section 82. The arms 85 carry the hopper section 83
and also support a powered rotating drum 88. The
drum 88 has a shaft 89 that is mounted in suitable
bearings on the ends of the arms 85, and this shaft
05 89 is powered through a power take off shaft 90 that
has universal joints at its ends and which is driven
from the engine 31 in a suitable manner.
The arms 85 have stop members 85A at the
ends thereof adjacent the roller or drum 88, and a
stationary member 82, as shown in Figure 8, has
adjustable stop bolts 85B carried thereon. The stop
bolts will engage the members 85A when the roller or
drum 88 is adjacent the lower panel of the hopper 80
to maintain the desired clearance. This prevents the
drum 88 from striking the bottom of the hopper when
in use, but pèrmits the drum 88 to move away from the
hopper bottom to permit larger rocks to pass through
without damaging the roller or hopper and drop onto a
grizzly bar assembly below the hopper.
,20 As shown in the side view of Figures 7 and
9, a frame 92 is mounted onto the cross members 84,
and carries a spring 93 that tends to exert a load
tending to lift the arms 85 and the roller 88. The
roller 88, as shown in Figure 7 has a plurality of
lugs on its outer surface at spaced intervals, and as
the drum is rotated, it will tend to pulverize
material and cause the material to drop down onto
grizzly bars 95 that are supported on the rear one of
the cross members 84 on a suitable pivot pipe 96
using adjustable hubs 96A that can be set screwed in
place and selectively loosened to permit changing the
spacings of the grizzly bars. The grizzly bars also
are supported in a suitable manner onto a cross
13335~
-- 11
member shown at 97 on a frame 98 which is attached to
the main frame above the conventional conveyor 99 for
conveying material into the rotating drum 40. The
cross member 97 also has hubs 97A that can be
05 adjusted along the support 97 for changing the bar
spacing. These grizzle bars 95 are made with a long
section 95A that bolts to support sections on hubs
97A and 96A as shown at 95B so the long sections 95A
can be replaced if they bend.
The conveyor 99 comprises a ~heavy duty belt
that is powered in a suitable manner, such as that
shown in the beach cleaning machine shown in Patent
No. 4,167,975. The frame 98 is supported on conveyor
side plates which are also shown in U.S. Patent No.
lS 4,167,975. The conveyor 99 carries the prescreened
materials that have been pulverized by drum 88 up
into the screening drum 40. he grizzly bars 95 are
spaced a desired distance apart so that large rocks
will roll off the front of these bars onto the ground
and be discarded. When the screening machine is
raised to its working position as shown in Figure 1,
a substantial pile of rocks and other debris can be
collected before it is necessary to remove the pile
of such rocks and debris.
The holding bin 22 has a conveyor belt
bottom and an upwardly inclined discharge conveyor
23. The conveyor belts in the holding bin can be run
independently of the other components of the
screening machine, so that the conveyor 23 as well as
the bottom conveyor belt of the holding bin 22 can be
operated as desired to convey material toward the
screening plant.
1~33~8~
As shown, the holding bin hopper 109 has a
trailer frame 110, and spaced side walls 111,111 of
heavy duty reinforced construction. The conveyor 23
is mounted in a suitable manner to the rear portions
05 of the holding bin 22. The frame 110 has a tongue
113 extending forwardly, which is supported in a
suitable manner with a jack or other support 114 when
the holding bin 22 is in use. Wheels 115 are used
for providing support for the frame so that the
holding bin can be moved to different locations. A
suitable separate engine 116 is mounted on the
holding bin for providing power. As shown in Figures
1 and 10, schematically, the bottom of the bin
comprises a conveyor belt 121 that is mounted on
suitable rollers 122,122 at opposite ends of the
holding bin. The rollers 122 are supported in a
suitable manner to the lower edge portions of the
side walls 111 of the holding hopper 109. The
rollers 122 are powered from the engine 116 in a
suitable manner, for example, by driving a hydraulic
system so the conveyor can be run intermittently.
For simplicity of showing a hydraulic motor 120 is
illustrated for driving the conveyor belt 121. The
upper length of the conveyor belt 121 will be
supported on support slats 121A (or a plate) which
are supported on the side walls 111 of the holding
bin hopper, to hold the belt 121 in proper position
when dirt is placed in the holding bin hopper 109.
Conveyors with support plates or slats for the
conveyor belt are well known. A very high molecular
weight polyethylene sheet is placed under all
conveyor belts to lessen friction and to reduce the
amount of dirt build up under the belts.
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- 13 -
The rear portions of conveyor belt 121 are
positioned above the conveyor belt 129 o~ the
conveyor 23, as shown in Figure 12, so that material
coming off the upper reach of the conveyor belt 121
05 will be deposited onto the upper length of belt 130,
and then conveyed upwardly as shown to be dropped
into the dirt shredder hopper 80. The conveyor belts
in the holding bin hopper can have suitable lugs 133
thereon for insuring that the material will be moved
positively up into the dirt shredder hopper 80.
The side walls 111 of the holding bin hopper
109 are reinforced, and a shield or deflector plate
126 is mounted onto the top edge of one of the side
walls 111, and extends outwardly and at an angle
downwardly from the upper edge. The shield plate 126
is reinforced with s~itable braces 127.
This shield plate 126 prevents rocks in the
material from falling down onto the wheels 115 of~the
holding bin, and also provides a slide for dumping
the rocks that will collect on a grizzly bar or grate
assembly indicated generally at 130 ~hat is supported
on this plate 126. As can be seen in Figure 11, the
plate 126 has supports thereon that mount hubs 131,
in which a pipe 132 is rotatably mounted. The pipe
25 132 extends down along the edge of the side wall 111,
and a plurality of elongated bars 135 are mounted
with suitable adjustable hub members 136 (held with
heavy clamp screws 136A) onto pipe 132. The hub
members 136 may be loosened to change the spacing of
the grizzly bars and the clamp screws 136A
retightened.
The bars 135 are of sufficient length to
span the width of the holding bin 22, and the ends of
the bars opposite from the pipe 132 are fixed to and
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- 14 -
supported on a longitudinal pipe 140 (see Figure 3)
with hubs and set screws as well to permit
adjustment. The pipe 140 is not attached to the
holding bin wall. As shown, the bars 135 are spaced
05 a desired width apart (for example nine inches) and
can be changed easily. The grizzly bars will
separate out large rocks indicated at 141 when bulk
material is dumped into the holding bin. The larger
rocks will stay in place when the bars 135 are
horizontal or roll off if the assembly is inclined as
shown in Figure 6. The grizzly bar assembly 130 can
be raised upwardly, for example with the bucket of a
loader by lifting under the pipe 140 and tilting the
grizzly bar assembly 130 upwardly. Safety chains are
provided to prevent pivoting the grizzly bar assembly
130 too far, so it would go over center. Also, as
shown in Figure 6, the grizzly bars can be supported
at a desired incline by supporting the assembly 130
on the end walls of th,e holding bin. Braces 141 are
used between the assembly 130 and the side wall of
the holding bin, as shown in Figure 6. The angle of
inclination is capable of being changed by bolting
the braces 141 in selected positions to suit existing
conditions. The grizzly bar assembly 130 thus can be
inclined so rocks will roll off. Also, as shown in
Figure 6, the grizzly bars may be bolted to hubs at
the ends with bolts 142 so the grizzly bar sections
in the center can be removed for straightening as
they bend.
The grizzly bar assembly 130 can be held or
locked in a position with the grizzly bars raised,
with the mechanism shown in Figure 11. The plate 126
has at least two locations with spaced apart pairs of
clips 146 thereon, and the pipe 132 has latch lugs
1333~ 1
- 15 -
147 welded thereon which move to position between the
two clips 146 forming a pair. As can be seen, the
clips 146 have openings 148 which will align with
openings 149 in the lugs 147, so that the grizzly bar
05 assembly 130 can be pinned in an open position as
shown in Figure 11. The grizzly bars 135 are then
out of the way when material that does not have rocks
is being dumped into the holding bin. The grizzly
bar assembly 130 also can have upright end plates at
the front and rear ends to prevent material from
falling off the assembly.
The holding bin bottom conveyor is run at
selected speed so that the conveyor belt 121 will
convey material to the upright conveyor 23. A
variable speed valve 120A (Figure 10) can be used for
controlling the motor 120 to run at a very slow speed
or a fast speed as desired. The upright conveyor 23
also can be powered from the engine 116, through a
drive indicated schematically at 150 in Figure 3
which has a clutch for stopping the device, or
through a separate hydraulic motor shown
schematically in Figure 12 at 133A, and when it is
run at a selected speed the conveyor 23 will be
effective to regulate the amount of material being
dumped into the dirt shredder hopper 80. The
conveyor 23 also can be run at a desired speed by
operating a valve 133B to control motor 133A.
The use of two grizzly bar assemblies
permits graduated removal of rocks. In other words,
the grizzly bar assembly 130 on the holding bin 22
takes out the very large rocks, and when they are
dumped they will be dumped into a pile shown at 160
in Figure 3. The grizzly bars 95 receiving material
from the pulverizing hopper 80 can be adjusted to
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133358~
- 16 -
remove smaller rocks. The size of classification of
the rocks can be adjusted so that clods of dirt will
still pass through. Of course, the pulverizing drum
88 will tend to break up dirt clods and pulverize and
05 shred the dirt so that the screening job takes less
time, and the screen itself has less of a tendency to
plug up and less material has to go through the
rotating screen or tumbler.
One of the problems with holding bins that
transfer black dirt where conveyor belts are used is
that the conveyor belt will tend to get dirt on the
interior where it engages the drive rollers. In
addition to use of a polyethylene layer, as shown in
Figure 10, an elongated brush indicated at 165 is
positioned at an angle with respect to the
longitudinal axis of the holding bin, as shown in
dotted lines in Figure 3, and brush 165 is mounted on
a shaft 166 that is supported in suitable bearings at
its opposite ends. The shaft 166 is driven from a
hydraulic motor 167, in a suitable manner as shown
schematically in Figure 10. The angle of the brush
axis insures that dirt, small rocks and other
material will be brushed off and moved off the side
of the conveyor belt 121 from the bottom of the
holding bin hopper. The brush 165 has relatively
stiff bristles and as shown is substantially the same
size as the rollers 122 that mount the conveyor belt
121.
Additionally, interior belt scrapers are
used on the upright conveyor belt 130, as well as the
conveyor 26. ~he conveyor 26 at the output end of
the machine is substantially the same as on that
shown in the beach cleaning machine described in
Patent No. 4,167,975.
1333S~4
Suitable adjustments can be utilized for raising and
lowering the conveyors and adjusting the angles thereof so
that they will be above truck boxes, for example, the truck
indicated at 25 in Figure 1 and also in Figure 3. The
material that has been screened can be deposited directly in
a truck and transported to its desired location.
- 17 -
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