Note: Descriptions are shown in the official language in which they were submitted.
BACKG:ROUND OF THE I~IVF,NTION
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1. FIELD OE' THE INVE.NTION
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This invention relates generally to makerial handliny
systems, and more particularly, to a novel axle construction
for portable radial stackers.
2 . DESCRIPTION OF THE PRIOR ART
Conveyor systems and devices used to stack or pi.le
material are well known in the art. These devices utilize
various principles of the conveying art, including augers,
conveyor belts, buckets and similar conveying means. The
material may be moved intermittently or may be moved continuously
to a stockpile ~nd in fact, may include movement in th0 vertical,
horizontal or inclined directions.
One of the specific applications for the conveyor
system is to stockpile loose bulk material including such
i material as earth, coal, sand, ore, grain. These materials
are generally stockpiled by using a conveyor system which
transports the material from the material loading position
at an angle inclined upwards and then the material is dropped
off the end of the conveyor (the material unloading position).
As this material is loose material, it will form a conical-
shaped pile of its own accord
More recently, in order to minimize the area necessary
to stockpile this loose material, radial stackers have been
used. Radial stackers are conveyor systems wherein the terminal
end can pivot in an arc around the point where the material is
load~d onto the conveyor. Thus, the material is stockpiled in
an arc thereby allowing much more of the material to be stockpiled
within a specified area than would be stacked if separate piles
were used.
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1 Recently, r~dial stackers have been desiyned to be
portable, that is, desiyned to be abLe to be transported frorn
one location to another. These devices are attached to the
rear of a truck or other transporting vehicle and are towed
from one location to another. A supporting means is provided
which, in addition to supporting the stacker at the desired
angle during use, provides a set of wheels upon which the
rear portion of the stacker is supported during transporting.
This has removed the necessity of placing the stacker on a bed
1~ during transportation and has increased the utility of the stacker
tremendously.
Many of these constructions utilize telescopic axles
to allow the stacker to lie flat during transport but- they ~ -
suffer from the disadvantage that the load concentration
point during stacking and the carrying concentration point
during transporting are the same. This is, the concentration
point of the axle during both the loading stage and the trans-
portation stage is located at the balance point of the conveyor.
Thus; when the stacker is transported, uplifting will occur
2~ at the fifth wheel pin of the truck creati~g an unstable and
dangerous condition. This is particularly prevalent when the
stacker is transported over rough roads and terrain. The impact
impulses which are caused by the rough road creates a lifting
actian at the fifth wheel pin of the truck which will cause
breakage and is very hazardous.
It has been proposed to reduce thi~ uplifting effect
by moving the wheels of the stacker more towards the rear.
However, this will decrease the stockpiling capacity of the
stacker for two essential reasons. If the wheels are moved
rearward, the material which is toakp~.led will bury the wheels
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1 if the same angle o~ inclinatic)n is used for the stacker. If
the angle is raised, more elaborate machinery is necessary and
the wheels of the stacker will still be buried durirly use.
If the wheels of the support means of the stacker are
moved forward towards the front of the stacker to increase the
stockp7ling capacity, this creates very hazardous road conditions
during transpor~.ing the stacker as the upli~ting o~ the fifth
wheel pin on the truck is increased. It is possible to re-
inforce the fifth wheel pin on the transporting vehicle however
this increases the costs substantially and decreases the safety
factor during transportation of the stacker.
The effect of the impact impulses caused by the
road conditions during the transporting of the stackers is a
very serious problem. Some of the impulses may be absorbed
by the tires themselves but it has been found with the devices
presently in uæe that the tires manufactured today cannot
absorb all the impulses created by the road conditions during
the transportation of these stackers. Blow-outs of the tires
are very ~ommon and irreperable damage is done to the tires.
The average weight of one of these stackers is 20,000 lbs.
thus putting a load of ahout 10,000 lbs. per tire. ~ery heavy
tires with sufficient reinforcements are required to prevent
these blow-outs which is not satisfactory from a design or
cost aspect.
It has also been suggested that two tires may be used
to increase the safety factor during transportation of these
stackers. However, if two tires are used with the devices of
- the prior art, when the stacker is put into the operating
position, only one tire will be on the ground and the weight
is not distributed equally. A further drawback to using two
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1 tires is the accompanyiny increase in the width o~ the stack~r.
Most jurisdictions placed a maximum of 12 ~eet for the ~7idth
of a vehicle on the roads. The use of a double tire wi11
increase the width of many stackers beyond this legal limit
and thus prevent them from being transported on public roads.
SUMM~RY OF THE IMVENTION
Accordingly, it is an object of the present invention
to at least partially overcome these disadvantages by providing
a novel axle construction for radial stackers which allo~s the
maximum stockpiling capacity to be obtained during the operation
stage and also, during the transportation stage, the safety
fackor to be increased without increasing construction costs
of the stacker.
To this end, in one of its aspects, the invention
provid~s a novel axle assembly for use with a portable radial
stacker for stockpiling a material including a
conveying mean~ adapted to convey said materia~ from a material
loading position to a material unloading position, a support
means adapted to support said conveying means a~ an upwardly
inclined angle during the stockpiling stage and in the horizontal
position during the transporting stage, and an axle assembly
adaptëd to support one end of the support means on the ground
and to move said xadial stacker in an arc about the material
loading po~ition, said axle assembly also adapted to support
and move said stacker during the transporting stage from one
place to another place,
said axle assembly comprising:
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(a) a transverse member secured to the end of the support means
proximate the ground and aliyned transverse to the directlon
of the conveying means;
(b) two pairs of tires, each pair of tires having an axle
bar therebetween;
(c) two torsion levers, one end of each torsion lever secured
to 'che central portion or -the axle har between each pair of tires
and the opposite end of each torsionlever pivotally connected
to one end of said transverse member,
wherein each tire has an independent suspension mounting on each
respective end of each axle bar.
In another of its aspects, the invention further
provides a portable radial stacker for stockpiling a material
comprising:
ta) a conveying means adapted to con~ey sa:id material from
a material loading position to a :material unloading positioni
(b) a support means adapted to support said conveying
means at an upwardly inclined angle during the operational
stage, and horizontally during the transportation stage;
(c) an axle assembly adapted to support one end of the
support means on the ground and to move said radial stacker
in an arc about the material loading position during the
: operational stage, said axle assembly also adapted to
support and move said stacker during transportation of
said stacker from one place to another place, said axle
assembly comprising:
(a) a transverse member secured to the end of the support
means proximate the ground and aligned transverse
to the direction of the conveying means;
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1 (b) two pairs of tire~, each pair o~ tires having an
axle bax therebetween;
(c) two torsion levers, one end of each torsion lever se-
cured to the central portion of the axle bar between each
pair of tixes and the opposite end of each torsion lever
pivotally connected to one end of said first transverse
member,
wherein each tire has an independent suspension mounting
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on each respective e.nd of each axle bar, and wherein the :
. 10 pivotal connection between each torsion lever and each respect-
ive end of said txansverse member is adapted to align the
tires parallel to said conveying means when said stacker~is
being transported and transverse to said conveying means
when said stacker is stacking said material, the width ... :
; between the outer peripheral edges of the tires durin~
: transportation is less than 12 feet. :.
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BRIEF DESCRIPTION OF THE DRAWINGS
~ Further objects and advantages of the invention will appear
2~ from the following description taken together with the accompany- : ~`
. ing drawings in which: .
FIGURE 1 is a schematic representation of a stack of
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. material which has been stacked by a radial stacker;
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; FIGURE 2 is a top plan of the wheel and axle assembly
of the present invention in the operati.ng and in the travelling
positions;
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FIGURE 3 is a side view of a radial stacker in the
travelling position embodying the present invention;
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` FIGURE 4 is a side view of a radial stacker in the
; ~ 30 : operating position embodying the present invention;
FIGURE 5 is a side view of one wheel and axle assembly
; ~ of the present i.nvention;
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1 FIGURE 6 is a side view of the wheel assembly opposite
to the assernbly o~ Fiyure 5;
FIGURE 7 is a top plan view showing the novel ax]e
and wheel assembly of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
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Reference is first made to Figure 1 which is a
schematic representation of a stack of material which has been
stacked by a radial stacker. The radial stacker comprises a
first stationary portion 2 and a pivoting portion 4. Material
6 is loaded onto the terminal end of portion 2 and conveyed
to the pivoting portion 4. Portion 4 of the stacker pivots
in an arc and deposits the material 6 in the configuration
generally indicat d as 8. In order to demonstrate the
advantages o a radial stacker when compared to a circular
stockpile, the following table illustrates the increased
amount of material which may be stacked in the same area when
compaxed to a circular stockpile. In the table, A represents
the width-of the stack; B represents the distance from the pivot
2~ point of the stacker to the inner edge of the stack; C xepresents
the distance from the pivot point of the stacker to the centre
line of the highest point in the stack: and D represents the
diameter of the stack. The length of the pivoting portion 4
is referred to under the column "radial stackers" and the
height of the stack is in the column indicated as "height".
A comparison is made between a 270 radial stack and a circular
stockpile assuming that the material stacked weighs 100 lbs/cu~ ft.
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It is quite evident from the results shown in Table 1
that radial stacks are capable of stacking much more material
than circular stockpiles.
Referring now to Figure 4 there is shown a side view
of a radial stacker in the operating position, embodying the
present invention.
The radial stacker generally indicated as 8 consists of
a conveying means 10 which in this embodiment, is an endless
conveyor belt upon which the material 12 to be stacked,is
placed at the end 14 of the stacker which rests on the ground.
The conveying means 10 may be of any well-known construction
and Ls not limited to a conveyor belt. The means 10 may include
augers, conveyor ~elts, buckets, sections or any other conveying
means well-known in the art.
The material 12 to be stacked is loaded onto the
conveyor means 10 and conveyed to the opposite end 15 of the
stacker where it is stockpiled in a conical shaped-pile
generally indicated at 16. The pile 16 will achieve its own
material shape and size depending in part on the material to
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be stacked and also the height of the end 15 of the stacker
above the ground. It is seen from Figure 4 that the maximum
amount of material which can be stacked is achieved when the
height of the stacker end 15 above the ground causes the material
to flow and stack such that the peripheral edge of the stack
- ~ 18 is ad3acent to but not in contact with the wheels 20~of the
stacker.
If the height of the end lS of the stacker is raised
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higher, the material will cover the wheel 20. It will then be
impossible to remove the stacker from the stacking position
once the stacking operation is completed if the wheel 20 is
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1 buried. If the end 15 is lowered, ~he pile itself will be lower
and less material can be stacked in t:he same stacking area.
The stacker assembly 8 comprises a conveying means
lO to convey the material 12 to be stacked and a ~upporting
structure 22. The supporting structure comprises a main ~rame
24, rear pulleys 26,front pulleys 28 and, as sh~wn in Figure
4, an endless conveyor belt lO. The belt may be driven in any
desired manner by a driving motor 30 such as an electric
motor, a gasoline motor or the like.
The main frame 24 of the stacker may be~ as shown in
Figure 4, comprised of two foldable sections 32 and 34 with the
centre section 36 therebetween. As shown in Figure 3, these
foldable sections 32 and 34 fold over the centre section 36
during the transportation stageO
The frame 24 of the stacker is supported by a pair of
arms 38, 40; arm 38 is an affixed or statio~ary arm and arm 40 is
I telescoping arm, these arms being com~ected to the peripheral
; portions of the centre section 36 of 1~he main frame 24 at
points 42, 44. The arms 38, 40 and ~le points 42~ 44 allow the
ao main frame 24 of ~he stacker to ba xaised and lowered as desired
and secured in the operating position at the desired height.
; Each of the arms 38, 40 are affixed to the novel wheel
and axle assembly of the present invention which will be explained
hereinafter.
Arm 38 is an arm of fixed length. The arm may pivot
at point 42 and also pivots at the wbeel assembly itself. Arm 40
is a telescoping arm whose length is adjustable. The telescoping
means may be any means well known in the art including an inner
arm and an outer sheath~ When the length of the arm 40 is
3~ compared in the operating position ~Figure 4) and the travelling
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1 posi-tion (Figure 3), it is seen that the telescoping is necessary
to raise the end 15 to a height to allow the material 12 to be
stacked and -then to lower the end 15 for transportation. The
angle between the ground and the main frame 22 i9 yenerally
between 6 and 20 but this is dependent upon the material to be
stacked. Thus, the distance between points 42 and 44 i5 fixed;
the distance between point 42 and wheels 20 is fixed; the distance
between point 44 and wheels 20 is variable.
The height of the end lS of the stacker depends upon
1~ the material to be stacked. If a ma~erial of mixed coarseness
is discharged at a great height, the finer material will separat,e
from the coarser material because the heavier coarse material falls
faster. Also, with heavy coarse material, a much more compact
pile is obtalned. The telescoping arm 40 therefore lends greater
flexibility to the stacker.
Figure 3 shows the stacker of Figure 4 in one
travelling position and affixed to the fifth wheel pin 46 of
the truck 48. In the travelling position, the foldable section~
32 a~d 34 are ~olded over the centre sectio~ 36 and secured
20 thereto. The telescoping arm 40 is telescoped to allow the -'~
main frame 24 of the sta~ker to lie in a substantially horizontal
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position and arm 38 pivots at point 42 if re~uired. '~
In both the travelling (Figure 3) and in the
operating position (Figure 4), the stacker 8 is supported
on the ground by the wheel and axle assembly. The present ~'
invention provides a novel assembly whereby dual wheels-are
provided which may be rotated for travelling and operating ' -'
positions but which maintain the maximum capacity of the stacker ' '~
while achieving safe road conditions. ,~ '
Referring now to ~igure 2 there is shown a top plan ~'
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view of the wheel and axle assembly of the pr~sent application.
A pair of wheel assemblies 50, 52 each comprise two -
tires 54 and 56 mounted on an axle assembly 58. In the
operating position, the wheels are aligned substantially
perpendicular to the main frame 24 of the stacker 8. In the
travelling position, shown in dot-ted lines, the tires 54~ and
56A are aligned with the axle 58A parallel to the main frame
24 of the stacker 8. The axle assembly 58 pivots about point
60 as will be explained hereinafter.
Referring now to Figures 5, 6 and 7 there is shown the
construction of the axle and wheel assembly of the present
invention. Each wheel 54, 56 is mounted on its own independent
suspension 62. This is particularly important because it will
equalize the load distribution on each wheel. The load
distribution is dependent upon the independent suspension of
each wheel mounting and thus, reduces the effect of road impulses ~
` during travelling. -
The axle 64 between tires 54 and 56 is journalled in
a torsion lever 66 which i5 pivotally connected to the pin 68 which
is at piVQt point 60 (see Figure 2) of the transverse member 61. When
the position o~ the tires is desired to be ad~usted, the pin
is released and the torsion lever 66 is rotated.
In order to secure the pivotal connection and as a
safety precaution, a second pin 69 may be provided as shown
in Figures 6 and 7. Flange 71 is provided on the outer peripheral
` ~ surface of the torsion lever 66 and corresponds to a hole 73 in the
txansverse member 61. ~s shown in Figure 7, a second flange
75 is provlded for pin 69 when the wheels are pivoted into the
position as shown in dotted lines. Casing 67 ~figure 6) is
~30 provided to secure the upper and lower ends of the pin 69 to the
novel assembly. Thus, a second attachment of the wheels is
achieved in the desired position. As shown
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1 in Figure 5, a motor assembly 70 is drivabl~ af~ixed to one
wheel. This motor is used to drive the stacker in the operating
position about the arc to produce thè radial shaped stack of
material as depicted in Fiyure l.
The novel axle and wheel assembly provides a much
improved construction. In the travelling position, the tires
upon which the rear part of the stacker rests, have been moved
behind the balance point of the tire. This effectively
increases the load on the fifth wheel pin of the transporting
1~ vehicle which is a very desirable result. When impact impulses
from the road, are transmitted to the tires, there will be a
much reduced lifting action at the fifth wheel pin of the
transporting vehicle. Thus, the inventors have eliminated ~-
the need for reinforcement at the fifth wheel pin and have
increased the safety factor of the vehicle.
A second notable improvement is in the operation of
the torsion lever 66. When the stacker is being transported, ;
its weight bears directly on the wheels 54 and 56. When the ;
impact impulses of the road are transmitted to the stacker, the
,
-20 lever 66 creates a torsional movement and transfers the load
` direc~ly into the main carrierO The movement occurs in the trans
verse member 61 which ahsorbs any movement of the torsion lever and~
increases the fatigue limit of the stacker remarkably. This
` becomes extremely important and sometimes critical when the
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impact impulses occur on one side of the vehicle. The torsion
lever 66 hetween the wheels causes a flexin~`motion and transfers
the load to the main frame thereby reducing significantly the
efect of the impact impulses.
The independent suspension of the tires and the
~30 effect of the torsion lever 66 have reduced the shock felt by
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1 the tires upon .impact impuLses hy f:ifty percent. The independerlt
suspension oE the tires has also .increased the load limit of
the tires and helps to p:revent blow--outs f.roTn occurriny.
The increased safety of the stacker and the abili~y
to optimize the stacking capability is attributable to the
positioning of the wheels, the torsion lever, the independent
suspension of the tire and the presence o-f the dual wheels.
All these factors help to produce a better load distribution
on the vehicle.
The prior art has suggested that by puttiny dual tires
on a radial stacker, the same results may be achieved. However,
the inventors have found that if dual tires are used on stackers
of the prior art, the arms 38 and 40 must be reduced in size -
in order that the width between the outer edges of the tires is
equal to or less that the maximum allowable width for these
vehicles on public roadways. In most jurisdictions, this width
is 12 feet and by merely using dual tires with the devices
of the prior art, this width is exceeded. If as suggested, the
. arms 38 and 40 are reduced to accommodate the width between the
20 tires, the capacity of the stacker is necessarily reduced~ :
In effect, if dual tires are used in the devices o~ -
the prior art~ the flexibility and stability of the stacker
are significantly reduced thereby resulting in a reduction in
the stacking capability of the stacker. ~lso, if dual tires
are used in these devices, the wheels are not supported equally
. thereby resulting in hazardous road conditions.
: By the novel construction of the present inventian,
: the lnventors have utilized the maximum capacity of the stacker ~ -
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1 while reInaining within the allowable limits for transportation
and also, have increased the safetv fActors associated with the
transportation of the stacker.
Although the disclosure describes and illustrates
a preferred embodiment of the invention, it is to be understood
that the invention is not restricted to this particular er~odiment.
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