Note: Descriptions are shown in the official language in which they were submitted.
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TITLE
PIPELINE PADDING SYSTEM
This invention relates to apparatus for
backfilling a pipeline laid in a trench. It is more
particularly concerned with such apparatus which can be
moved along a trench by a carrier vehicle and which
accepts unclassified fill and deposits it on the pipe in
layers; finer fill, referred to as "padding", directly in
contact with the pipe, and coarser material, in layers of
ascending larger size thereon.
BACKGROUND OF THE INVENTION
It is well known to cantilever backfilling
apparatus over a pipeline trench from a crawler type
tractor or the like which travels parallel to the trench.
A recent patent for such apparatus is that of
McClain et al. U.S. Patent 4,664,791 of May 12, 1987.
The apparatus theredescribed has a chute into which is
loaded backfill, such as material previously removed from
the trench. The material is dropped in batches onto a
vibrating screen; the size which passes through the
screen is deposited on the pipe within the trench and the
material of the batch which does not pass through the
screen is mixed with the following batch; accumulating
oversize is disposed of from time to time by dumping it
away from the trench. The prior art patents cited
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against McClain et al., which are listed on the patent,
disclose other more or less similar devices designed for
like purposes.
Apparatus of that type must be loaded by a
bucket elevator or the like which charges successive
bucketfuls of backfill into the chute. Each load falls
as a batch onto the screen, blocking or overloading it
until an appreciable fraction has been disposed of by the
screening action. If the chute has a grizzly at its
discharge end, the operation of the apparatus must be
stopped periodically until the oversized material is
removed. If the pipeline is laid up and down hills, as
not infrequently happens, the delivery of padding
material from the screen may vary substantially between
uphill and downhill travel.
SUMMARY OF THE INVENTION
The apparatus of my invention is carried by a
crawler tractor or like vehicle in somewhat the same way
as that of McClain. The apparatus of my invention is
contained in a frame or chassis which is pivotally
cantilevered on a hitch affixed to the crawler tractor
and which allows the hitch to be positioned on either
side of the trench. A hydraulic cylinder varies the
attitude of my chassis, that is, the angle between the
chassis and the hitch. My machine embodies a hopper
fixed in the chassis into which unclassified backfill
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material is loaded. The hopper mouth is provided with
grizzly bars which deflect the large rock and masses of
clay fill not readily broken up. The grizzly is hinged
to a frame which can be attached to the hopper at its
mouth. In one embodiment the hopper mouth is as wide as
it is long so that the grizzly, by proper positioning,
may optionally be inclined toward the rear of my
apparatus, or to either side. A variable speed conveyor
conveys fill material from the bottom of the hopper to a
higher elevation where it is discharged through a
shredder onto a downwardly inclined vibrating screen.
The speed of the conveyor and the attitude of my machine
are varied by the operator to maintain a uniform flow of
backfill onto the vibrating screen. The shredder is a
rotary device which beats the fill material with flails,
breaking up larger lumps into smaller lumps. The screen
is preferably double-decked. Fine material of padding
size falls through both screens and into the trench in
front of my chassis onto the pipe. Pieces which pass
through the upper screen, which screen has a coarser mesh
than the lower screen, but not the lower screen, travel
over the lower screen into a chute and are directed
rearwardly thereby into the trench onto the padding fill.
Pieces too large to fall through the upper screen may
travel over that screen into another chute, if desired,
which directs them into the trench onto the layer of fill
from the lower screen. A further chute may also be
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provided to receive large pieces of fill which will not
pass through the grizzly on the hopper and direct them
rearwardly into the trench or otherwise as desired. My
apparatus, as above-described, forms a uniform padding
layered classified fill from unclassified fill material.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a front end elevation of a first
embodiment of my apparatus mounted on a carrying vehicle.
Figure 2 is a side elevation of the chassis of
my apparatus of Figure 1 removed from its carrying
vehicle, taken parallel to the trench.
Figure 3 is a rear elevation of my apparatus, as
shown in Figure 2, together with a portion of the
carrying frame shown in Figure 1.
Figures 4 and 5 are details of the shredder
shown in Figure 2.
Figure 6 is a rear elevation of a second
embodiment of my apparatus.
DESCRIPTION OF PREFERRED EMBODIMENT
As it is shown in the figures, my apparatus is
mounted in a chassis 10 comprising two identical side
frames 11, each having a top rail 12, a vertical rear end
rail 13, vertical front end rail 14, bottom rails 15, 16
and 17 and intermediate braces 18 extending from each end
of bottom rail 16 to top rail 12. In my first embodiment
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a fixed position hopper 19 is mounted between side frames
11, having a mouth 20 parallel to rails 12 fitted with a
grizzly 21. The grizzly 21 is pivotally mounted on the
rear edge of mouth 20 and inclined thereto so that
oversize material which does not fall through the grizzly
rolls off the grizzly to the rear of my hopper 19. Any
fill r~m~ining on the grizzly is discharged by tilting
it. Below hopper 19 is a frame 23 affixed to side frames
11 and inclined upwardly from rear 13 to front 14
supporting a belt conveyor 24 which passes around front
end roll 25 and rear end roll 26 and is carried over
intermediate rolls 27, all of which rolls are carried by
frame 23. Conveyor 24 forms the bottom of hopper 19.
Conveyor 24 is driven by motor 29 coupled to roll 25.
Below the conveyor 24 and extending forward to roll 25 is
a vibrating screen 30 mounted on chassis element 31 which
is pivotally affixed in rails 15 at its front end. A
telescoping brace 33 suspends the rear end of vibrating
screen 30 from conveyor frame 23 so that by adjusting the
length of brace 33 the inclination of screen 30 may be
adjusted. Below roll 25 of conveyor 24 at the front end
of vibrating screen 30 is mounted a rotating shredder 34,
details of which are shown in Figures 4 and 5, driven by
a motor 35.
The operating member of shredder 34, as shown in
Figure 4, is the shaft 37 which is mounted in suitable
bearings and is driven by motor 35. The central portion
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38 of shaft 37 is flat-sided and in clevises 39 affixed
to those flat sides are mounted rows of flails 40, either
fixed or pivoted, as are shown in Figures 4 and 5.
Vibrating screen 30 is double-decked, having an
upper deck screen 42 with larger apertures than its lower
deck screen 43. Screens 42 and 43 are vibrated by motor
44. The small size material which passes through screen
43 falls directly onto the pipe in the trench. The
material passing over screen 43 is delivered into
rearwardly inclined chute 48 which directs it onto the
padding materials on the pipe. The material which passes
through screen 42 falls on the screen 43. The material
which passes over screen 42 also exits in rearwardly
inclined chute 48 or, if desired, into a second chute,
not shown, and is delivered therefrom onto the previously
deposited fill material above mentioned. The large
pieces which pass over the grizzly 20 of hopper 19, when
the grizzly is positioned on the hopper as is shown in
Figure 3, fall from its lower edge into rearwardly
inclined chute 50 and complete filling of the trench. It
may be desirable to fit a short discharge chute 54, in
Figure 3, to a lower edge of the mouth of grizzly 20 so
as to insure that the discharge material from that
grizzly falls into chute 50 above mentioned, or to the
sides of the trench, and to fit outwardly flared panels
or wings 55, shown in Figures 1, 2, and 3, to the edges
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of the grizzly mouth to funnel incoming fill into the
grizzly.
Alternatively, as is shown in Figure 6, grizzly
20 may be adjusted to dispose of the grizzly oversize on
either side of the trench.
My invention includes the transverse support bar
52, shown in Figures 1, 2, 3, and 6. which is part of
hitch 56 fitted to a crawler tractor or the like.
Essentially hitch 56 is of the type shown in U.S. Patent
4,664,791 mentioned. The motors of my apparatus are
preferably hydraulic. Hitch 56 carries a hydraulic oil
tank 57, a diesel engine 58, and a multi-stage pump 59
which supplies oil to the previously described motors of
my apparatus through hydraulic hoses 60, and controls 61.
A hydraulic cylinder 69 is attached at one end
to frame 11 through member 62 and at the other to hitch
56, Figure 3. Cylinder 69 is supplied with oil from
variable volume pump 59 through hose 60 and can be
operated to adjust the angle of attitude of chassis 10,
that is, between chassis 10 and hitch 56, in accordance
with the slope of the ground.
Chassis 10 is pivotally mounted on transverse
support bar 52 by a lug 63 on each side affixed to cross
members 64 between vertical braces 18. The lugs have
aligned holes 65. Transverse support bar 52 of hitch 56
also has upstanding lugs 67 spaced apart the width of
chassis 10 provided with aligned holes 68, Figure 6.
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Chassis 10 is mounted on support bar 52 by inserting pins
62 through each pair of mating holes 65 and 68 so that
the chassis pivots on those pins. Support bar 52 may be
inserted through chassis 10 from either side, permitting
the carrying vehicle to be positioned on either side of
the trench.
In a second embodiment of my invention, shown in
Figure 6, chassis 10 is identical with its illustration
in Figure 2 except that the mouth of hopper 70 is made as
wide as it is long. Grizzly 20 is hinged at one side of
the hopper to a frame 45 which has a square bottom mating
with the mouth of hopper 70 but may have a pair of
triangular parallel sides 46. The grizzly is hinged so
that it is sloped when it is resting on frame 45. A
hydraulic cylinder 47 is attached on each side between
chassis 10 and grizzly 20 to raise and lower the grizzly.
Frame 46 is detachably mounted on the mouth of hopper 70
and may be positioned to cause grizzly 20, when it is
elevated by cylinder 47, to discharge alternatively on
either side of chassis 10 or to the rear thereof. This
structure, in addition to the structure which allows the
carrier vehicle to support the chassis from either side,
considerably increases the versatility of my machine.
In the operation of my machine the backfill
material is loaded into the hopper 70 by conventional
means. Material at the bottom of the hopper falls onto
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belt conveyor 24 which is operated to move material
uphill from hopper 70. The rate at which material is so
moved is affected by the speed of the conveyor and the
attitude, or the inclination, of chassis 10, both of
which factors are controlled by the operator of the
machine through controls 61. The operator can thus cause
my machine to maintain an even flow of backfill material
to screen 30 or an even flow of padding material from
backfill which varies in consistency.