Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This invention relates generally to a method for re-
claiming strip mined land. In particular, it relates to a method
for operating an apparatus comprising a leading tractor and a
trailing tractor and an elongated angularly disposed side casting
dozer blade adjustably mounted therebetween and operable on an
, elongated spoil bank to shift materials therefrom into adjacent
depressions.
Strip mining operations to obtain coal or other min-
erals are often carried out on land which originally has a gen-
erally level substantially horizontal grade. After the stripmining operation is carried out the land is left in the condition
of having generally parallel spoil banks having crests spaced
apart, for example, about 120 feet and extending, for example,
15 to 20 feet above the original grade, with a depression, trough
or valley between each adjacent pair of spoil banks and extending,
for example, 15 to 20 feet below the original grade. A side of a
~, spoil bank and the side of the valley therebelow merge into a
; common slope called the "repose slope". The "repose angle" is
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the angle the repose slope makes with the horizontal and is
determined by the particles of material settling into a state of
~'i repose under the force of gravity. Typically, the repose angle
may ke in the range of 26 to 38 from the horizontal, depending
on the nature of the material forming the spoil bank and the age
of the spoil bank. Heretofore it was the practice to employ
~; conventional bulldozers or specialized forms of earth moving
machinery to restore the land to its original condition by
pushing or conveying the materials forming the spoil bank into
the adjacent valleys. However, since a considerable volume of
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- material needs to be moved, the use of conventional existing
machinery and techniques can be very time consuming, costly and
hard on equipment. It is known that land reclamation can be
carried out more efficiently, by, for example, a bulldozer having
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! a blade of substantially greater width than is conventionally
employed in most earth moving operations. ~owever, the power
¦ available in a single tractor and the problem of balance limits
3 the size of blade that can be used. It is also known to employ
two or more tractors to push a single blade of relatively greater
width, and Patent 3,661,214 shows an arrangement wherein three
tractors are disposed in side by side relationship and coupled
¦ together by a bracing structure to maintain a forced parallelism
and a predetermined longitudinal relationship while they operate
to push a common bulldozer blade. U. S. Patent 3,552,497 teaches
¦ a generally similar arrangement. Tests have also been carried
I out starting in July, 1972 wherein test apparatus comprising two ~J
separate tractors of about 385 horsepower each, each having its
own driver, were employed to move a common blade which was on
the order of about forty feet long and disposed at an angle of
about 40 with respect to the path of travel, one tractor pushing
the blade and the other *ractor acting to pull the blade by means
of a flexible wire cable about two inches in diameter connected
between the leading tractor and the leading end of the blade.
The principal function of the leading tractor was to help counter-
act the side thrust forces i~posed upon the blade. In the afore~
mentioned tests the tractors exerted a combined force of about
770 horsepower on the blade. In the aforementioned test appara-
tus all controls for effecting changes in the position of the
blade were provided between the blade and the trailing tractor
and were controlled by the operator on the trailing tractor.
Apparatus and method are provided for reclaiming strip
~I mined land. The apparatus generally comprises a leading tractor
and a trailing tractor and an elongated adjustable side casting
blade angularly disposed between and connected to the tractors.
Control of both tractors and blade adjustment is carried out by
remote control by an operator on the leading tractor. Means are
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104Q42~
provided for connecting the rear end of the leading tractor to
the leading end of the blade and such means allow blade pivoting
; in all directions, as well as vertical adjustment of the leading
end of the blade. Means are provided for connecting the trailing
tractor to the blade at some distance from the trailing end of
the blade and such means serve to stabilize the connection be-
tween the trailing tractor and the blade and enable the blade
angle, pitch, tilt, and vertical position to be adjusted.
The method generally comprises the steps of driving
the apparatus along a spoil bank crest near one side thereof in
one direction to make one pass to effect side casting of material
down one repose slope of the spoil bank into the adjacent valley
~, and then driving the apparatus along the spoil bank crest near
the other side thereof in the opposite direction to make another
pass to effect side casting of material down the other repose
slope of the spoil bank into the other adjacent valley. Two such
passes constitute one complete cycle. The blade angle is in-
creased to cut a wider swath, the depth of cut is decreased, and
the blade tilt is decreased for each successive cut.
The apparatus and method in accordance with the present
invention offer several advantages over the prior art. For
example, both tractors use standard hydraulic cylinders and con-
trols for performing their respective control functions. The
remote control means and the means for interconnecting the blade
and the tractors are easily disconnectable to allow each tractor
to be employed separately in a conventional manner. ?he means
for interconnecting the tractors and the blade insures stable
mounting of the blade while enabling freedom of relative move-
ment between the two tractors and the blade. The blade is
greatly positionable to provide a cut or pass of the required
width and depth. The method of employing the apparatus allows
continuous forward travel of the apparatus and continuous side
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casting of a large volume of material from the spoil bank there-
by resulting in more efficient and economical reclamation of
land.
From a broad aspect, the present invention relates to
a method for laterally shifting material from an elongated spoil
bank down the slopes thereof into elongated valleys on opposite
sides of the spoil bank by means of apparatus which comprises an
adjustable slde casting blade and means for moving the blade.
The method comprises the steps of moving the apparatus in one
direction along one side of the top of the spoil bank with the
blade adjusted at a predetermined blade angle, at a predetermined
depth of cut and at a predetermined tilt angle, whereby the
material is shifted laterally down one slope of the spoil bank
into one of the valleys. The blade is readjusted to change the
blade angle, the depth of cut, and the blade tilt angle. The
apparatus is moved in a direction opposite to the said one direc-
tion along the opposite side of the top of the spoil bank, where-
by the material is shifted laterally down the other slope of the
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spoil bank into the other of the valleys.
Other objects and advantages of the invention will
hereinafter appear.
The present invention will now be described with refer-
~' ence to a preferred embodiment as illustrated in the accompanying
- -~ drawings in which:
Figure 1 is a side elevational view of apparatus
in accordance with the present invention, including a leading
tractor, a trailing tractor, and a side casting blade connected
to and between both tractors,
Figure 2 is a top plan view of the apparatus shown in
; 30 Figure 1 and also showing in phantom lines, the trailing trac-
, tor and the side casting blade in an alternate position,
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Figure 3 is a schematic top plan view of a portion of
a geographic area which has been strip mined and showing the
relative position of spoil banks and valleys thereat, and
Figure 4 is an enlarged schematic view taken on line
4-4 of Figure 3 and showing a cross-sectional view of one spoil
bank and its two adjacent valleys and further showing a method
in accordance with the invention of making cuts along the spoil
bank by means of apparatus in accordance with the present inven-
` tion.
Referring to Figures 1 and 2, apparatus in accordance
with the invention generally comprises a leading tractor 1, a
trailing tractor 12, and an adjustable side casting dozer blade
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assembly or blade 10 connected to and between the tractors.Blade 10, for example, is on the order of 60 feet long and
8-1/2 feet high. The tractors 1 and 12 are substantially iden-
tical and each is of the conventional type and comprises a frame
22, a pair of tracks 24 and an engine 26 mounted on the frame
` for driving the tracks and for operating conventional hydraulic
pumps tnot shown) for powering conventional hydraulic actuators
or cylinders on the tractor, as hereinafter described.
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It is to be understood that both tractors 1 and 12
are to be operated or are under the control of a tractor operator
located at the operator's station on the lead tractor 1, and
means are provided whereby the operator can control
all functions of lead tractor 1 by direct control and whereby he
can remotely control all functions for trailing tractor 12 and
for blade 10. Remate control of the trailing tractor engine
throttle, drive line disengagement (the steering clutches), first
gear forward and reverse transmission shift, the blade hydraulics
~except those at the lead end of blade assembly 10) are under-
stood to be carried out by means of air or hydraulic control
lines 21 from the operator's station on the lead tractor 1. The
control of the lead end of blade assembly 10 is understood to
be carried out directly by means of conventional hydraulic con-
trols on the leading tractor 1 which are normally used for con-
trolling a conventional ripper. It is to be understood that
`~( the remote control lines 21 are disconnectable so that each
tractor 1 and 12 may be employed independently by separate opera-
; tors in a conventional manner.
~ 20 Lead tractor 1 is provided with optional dozer equip-
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ment generally designated by the numeral 11 which, for example,
includes a standard dozer blade and hydraulic actuators and con-
trol means therefor.
Means are provided for connecting the rear end of
leading tractor 1 to the leading end of blade 10, and such means
allow the blade to pivot universally in all directions, as well
as include a means for effecting vertical adjustment (raising
and lowering) of the leading end of the blade. The leading
tractor 1 has a drawbar 2 attached to the rear end of its frame
22 and the drawbar is connected by means of a universal pivot
connection 3 with one end of a rigid tongue or member 4 that
; extends rearwardly. The other end of tongue 4 is connected by
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means of a transverse (horizontal) pivot connection 5 to a
vertically disposed rigid hitch member 6. Hitch member 6 is
provided at its lower end with a ground-engaging breaker point
7 which facilitates blade engagement with the spoil bank at the
proper depth. Hitch member 6 is pivotally connected by means
of a vertical axis pivot pin connection 9 to the leading end of
blade 10. An extendable and retractable hydraulic lift cylinder
; 8 is pivotally connected at one end by means of a transverse
pivot connection 42 to the forward end of tongue 4. Cylinder 8
is extendable and retractable to effect raising and lowering,
respectively, of the leading end of blade 10.
Means are provided for connecting trailing tractor 12
to blade 10 at some distance from the trailing end of the blade
and such means serve to stabilize the connection between the
trailing tractor and the blade and also enable the blade angle,
pitch, tilt, and vertical position to be adjusted. The trailing
tractor 12 is provided with a C-frame 13 which is mounted by
means of conventional trunions 14 to the tractor. C-frame 13
can be raised and lowered by means of a pair of conventional
laterally spaced apart lift cylinders 15 which are mounted in a
conventional manner on opposite sides of trailing tractor 12.
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Each lift cylinder 15 has its piston rod pivotally connected by
means of a lateral pivot connection 26 to the front of C-frame
13. Extension or retraction of the cylinders 15 causes the blade
10 to be lowered or raised, respectively.
A universal connection 16 is provided for connecting
a point near the right front corner of C-frame 13 to a point on
the rear of blade 10 which is located a substantial distance
inwardly from the trailing end of the blade and near the lower
edge portion of the blade.
An extendable and retractable hydraulic blade angle
cylinder 17 is connected at one end to the left hand forward
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part of the C-frame 13 by means of a universal connection 28 and
has its other end connected by means of a universal connection
30 to a point near the middle rear of blade 10. The blade angle
cylinder 17 and its universal connections 28 and 30 serve as a
universally adjustable strut-type connection between C-frame 13
and blade 10. Operation of blade angle cylinder 17 enables the
blade angle of blade 10 to be changed with relation to the
trailing tractor 12. When cylinder 17 is fully retracted, as
shown in solid lines in Figure 2, a maximum attack angle of 50
for blade 10 is possible. A maximum width of cut if provided
for. When blade angle cylinder 17 is fuily extended, as shown
in broken lines in Figure 2, a minimum attack angle and minimum
width of cut are provided for.
A pitch/tilt cylinder 18 is connected to the forward
upper center of a tractor radiator guard 32 of trailing tractor
12 by means of a universal connection 34. Pitch/tilt cylinder
18 has its other end connected by means of a vertical pivot
connection 36 to a point on the upper edge of blade 10 directly
above universal connection 16. The pitch/tilt cylinder 18 pro-
vides both pitch control and tilt control of blade 10 and also
provides for blade stability.
Extension or retraction of pitch/tilt cylinder 18
results in a pitch and tilt motion of blade 10 about an axis of
rotation 20 that passes through the center of the universal
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connections 3 (on leading tractor 1) and 16 (on C-frame 13 of
trailing tractor 12). Therefore, at any selected vertical
position of blade 10, which is established by means of operation
of tongue cylinder 8 (on leading tractor 1) and the lift cylin-
ders 15 (on C-frame 13 of trailing tractor 12), when the pitch/
tilt cylinder 18 is retracted the leading end of blade 10 will
be lowered and the trailing end of the blade will be raised.
This action is reversed if the pitch/tilt cylinder 18 is extended.
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1al40421
This arrangement and capability make possible a simple and
accurate means for coordinating the application of tractor draw-
bar pull applied to blade 10 under varying load conditions.
Pitch/tilt control gives the operator a simple and
convenient means of coordinating the power output of the two
tractors 1 and 12 when used in combination with the trailing
! tractor throttle control.
The apparatus shown in Figures 1 and 2 is operated in
the following manner, for example, to reclaim strip mined land
of the character shown in Figure 3. Figure 3 is a schematic
top plan view of a portion of a geographic area which has been
strip mined and shows the relative position of a plurality of
generally parallel similar spoil banks 68, 50, 70 and 72 which
are understood to be formed when strip mining operations are
carried out on the land. As Figures 3 and 4 show, the spoil
bank 50 is seen to comprise a first side or slope 52 on one side
of the spoil bank crest line 54 and a second side or slope 56 on
the other or opposite side of the crest line. The first slope 52
terminates at a line 58 defining the deepest portion of a first
valley 60 on one side of spoil bank 50, and the second slope 56
terminates at a line 62 defining the deepest portion of a second
valley 64 on the opposite side of the spoil bank 50.
Figure 4 is an enlarged cross-sectional view of spoil
bank 50 and its adjacent valleys 60 and 64 taken along line 4-4
in Figure 3. In Figure 4 the original grade line of the geo-
graphic area is designated 74 and a vertical center line or
plane extending lengthwise through spoil bank 50 is designated
76. It may be assumed that the repose angles of the sides 52
and 56 of spoil bank 50 are each on the order of 35 from the
horizontal, as indicated by angle in Figure 4.
Figure 4 depicts the manner in which successive cuts
or passes are made lengthwise of spoil bank 50 by the apparatus
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in accordance with the invention when employed in accordance
with the method of the present invention. As Figure 4 makes
clear, alternate passes or cuts are made in opposite directions
along the length of spoil bank 50, commencing downwardly from
the top thereof so as to cut and laterally shift material from
the spoil bank so that it descends under the force of gravity
~¦ down a repose slope and into the appropriate adjacent valley
60 or 64. For example, a first pass is made along the length of
spoil bank 50 substantially to one side of the center plane 76
:. 10 to remove the material in the area designated A in Figure 4, and
this material slides down the repose slope 52 and comes to rest
: to occupy the cross-sectional area designated A'. After the first
pass is completed, the apparatus is turned 180, the side casting
blade 10 is readjusted, and the apparatus is then moved in the
~ opposite direction along the length of spoil bank 50 substan-
: tially to the other side of center plan 76 to remove material
in the area designated B in Figure 4, and this material slides
down the repose slope 56 and comes to rest to occupy the area
designated B'. Subsequently, successive passes or cuts are made
in opposite directions on opposite sides of the center line 76
and in the areas designated C, D, E, F, G, H, I, J and K in
Figure 4. The material shifted from such areas comes to rest to
occupy the corresponding cross-sectional areas designated C'
throuqh K', respectively, as shown in Figure 4.
It will be noted that for each successive pass or cut
blade 50 is readjusted by changing (increasing) the blade angle
to increase the effective width of the blade slightly so that
the width of each successive pass is greater than the preceding
pass, and this is shown, for example, in the depiction in Figure
4. Furthermore, blade 10 is readjusted by raising it slightly
aftcr each pass so that the depth of cut is reduced slightly for
each successive cut or pass. This readjustment is necessary
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i because, as Figure 4 shows, blade 10 is required to move a mass
i of material of relatively greater width during each successive
¦ cut or pass. Furthermore, the tilt angle of blade 10 is changed
¦ (reduced) for each successive pass or cut, as Figure 4 makes
clear. It may be assumed, for example, that for making the
initial pass or cut to remove material in area A in Figure 4,
the blade tilt angle is 15 from the horizontal and this angle
is reduced by approximately 2 for each successive pass until
blade 10 is horizontal when making the final pass or cut for
area K.
It will be observed from Figure 4 that, after the two
~_J passes for areas A and B are carried out, each succeeding pass
for the areas C through J involves movement of material initially
comprising the spoil bank 50, as well as a small additional
amount of material on the repose slopes which was deposited
thereat by each preceding pass or cut. However, the amount of
material which is required to be moved more than once in accor-
-~ dance with the present invention amounts, for example, to approx-
imately 12% of the total amount of material being moved, and
this is a relatively conservative figure when compared to present
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methods of reducing or reclaiming spoil banks.
It is to be understood that in accordance with the
present method the pass for area A is made in one direction and
principally on one side of center line 76 of spoil bank 50, and
the pass for area B is made in the opposite direction and sub-
stantially on the other side of center line 76. Two such passes
comprise one cycle of operation. Five and one-half cycles are
required in Figure 4. It is to be further understood that the
passes C, E, G, I and K are made in the same direction as pass A
and the passes D, F, H, and J are made in the same direction and
substantially on the same side of the center line as pass ~.
The method in accordance with the invention enables
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¦ fast, efficient continuous side casting of material in the spoil
banks. The slope of the cut made on each pass and the cross-
¦ sectional shape of the area of the material removed on each pass
¦ tends to counter the side thrust of the angled side casting
¦ blade 10 and also reduces the amount of material required to be
moved more than once by approximately 12%.
The apparatus in accordance with the present invention
is so constructed that is can be turned 180 after each pass or
cut in a very small turning radius. Furthermore, it will be
apparent that it is advantageous for the single machine operator
who is in full control of the apparatus to be located on leading
tractor where he has a good forward view of the terrain on which
~-f he is operating.
This application is a divisional of Canadian Patent
Application Serial No. 240,856 filed December 1, 1975. ~
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