Note: Descriptions are shown in the official language in which they were submitted.
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IMPROVED BULK MATERIAL CARRYING TRUCK
Field of the Invention
The invention relates to an improved truck for carrying bulk materials
such as earth, sand, coal and grain. It is applicable with particular advantage
to trucks used in the construction industry, for carrying earth and the like.
Back~round art
Typically bulk materials are transported in tipper trucks, or dump
trucks. They are available in both rigid and articulated configuration.
Traditionally a dump truck body which carries bulk material is pivotally
mounted at the rear, with the material being discharged by tipping the body,
by means of extending hydraulic rams fitted to the front of the body. The
rear of the body includes a hydraulically operated bottom tailgate which may
also hold shut a top tailgate.
Such trucks are commonly used for the transport of bulk materials, and
are used in the construction industry where the vehicles are often off road
vehicles. A conventional dump truck cannot discharge its load in areas of
restricted height such as tunnels or under overhead cables. It is also liable toroll over sideways whilst tipping on uneven ground due to its centre of gravity
being raised significantly and the uncontrolled way in which the bulk material
is discharged.
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Moreover, when the load is sticky, for example earth, merely tipping
the body is not sufficient to clear the body completely of the load - some may
adhere to the body walls, especially in the corners.
S Su~nm~rv of the Invention
According to one aspect of the present invention there is provided a
bulk material truck of the type suitable for carrying earth or the like, the truck
comprlsing
a load carrying vessel for receiving the bulk material. the vessel having
a discharge port for discharging the bulk material; and
a plurality of wheels positioned substantially underneath the load
15 carrying vessel,
characterised by comprising a discharge plate mounted to move within
the vessel to push the bulk material towards and through the discharge port
to discharge the bulk material without pivoting the load vessel.
Preferably, the discharge plate is capable of moving within the load
carrying vessel to clear the bulk material out of the vessel without requiring
the vessel to tip.
This avoids the problems encountered with the conventional tipping
dump truck in that the stability of the truck of the present invention may be
substantially unaffected during unloading. Further, the present truck may be
usable in confined spaces.
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Preferably, there is provided a means for driving the discharge plate,
the arrangement being that the discharge plate moves in response to the means
for driving the discharge plate.
Preferably, the means for driving the discharge plate comprises an
hydraulic cylinder or ram.
Preferably, said means for driving the discharge plate comprises a multi
stage hydraulic cylinder.
However, it may also comprise a screw drive or a wire rope
mechanism, or any means to power drive the plate.
Preferably, said discharge port is positioned at a rear of the load
carrying vessel, and said discharge plate is arranged to move from the front
of the truck to the rear of the truck.
Said discharge plate may comprise a front wall of the load carrying
vessel.
The vessel may be a four walled vessel with a separate plate mounted
to move within it to form the discharge plate.
By making the discharge plate and the front wall of the vessel one and
the same, trapping of bulk material at the front of the vessel may be avoided.
Moreover, the discharge plate can be arranged such that it fully clears out the
load carrying vessel to ens~lre that no bLllk material is retained within the load
carrying vessel.
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Preferably, the discharge plate extends across an entire cross section
of the load carrying vessel.
By arranging the discharge plate to extend wholly across the load
5 carrying vessel, complete clearance of all of the bulk material out of the
discharge port may be obtained.
Preferably, said discharge plate is mounted upon a plurality of rollers.
Preferably, said discharge plate is mounted upon a lower set of rollers,
arranged to run along a base of the vessel, and on an upper set of rollers
arranged to run along a wall of the vessel.
Preferably, there is provided a tailgate arranged to close said discharge
port.
The discharge port preferably comprises the entire rear face of the
vessel which is closed by a tailgate.
Preferably, said tailgate is hydraulically operable.
Preferably, said tailgate is rotatable for opening said discharge port.
Preferably, there is provided an hydraulic mechanism arranged to
25 operate in response to movement of said discharge plate, so that as said
discharge plate moves towards said discharge port, said tailgate opens.
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Preferably, said discharge plate comprises an upright headboard
mounted at an upper end of the discharge plate.
Although the invention could be applied to a truck in which the load
5 carrying vessel has a closed top, the majority of cases of a load carrying
vessel will have an open top. The discharge plate may include at its top a
pivotally mounted head board and the truck also includes means to
hydraulically pivot the head board from an inclined position facing towards
the front of the truck to an upright position when the discharge plate is
10 pushing the bulk material towards and throu~h the discharge port.
Brief Description of the Drawin~s
A specific embodiment of the invention will now be described by way
15 of example only, with reference to the accompanying drawing, in which:-
Figure I shows a truck in accordance with the invention beforedischarge, fully loaded with material, with the multi stage hydraulic cylinder
fully retracted and the tailgate hydraulically locked shut;
Figure 2 shows the truck of figure 1 during discharge and illustrates the
moving discharge plate mnning on sets of rollers top and bottom and the
tailgate hydraulica~ly powered up;
Figure 3 shows the truck of figure 1 after discharge and illustrates the
multi stage hydraulic cylinder fully extended and the position of the moving
discharge plate and tailgate after unloading all the material; and
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Figure 4 shows in rear view, the truck of figures 1 to 3 on uneven
ground.
Description of the Pref'erred Embodiment
The drawings illustrate an off road truck used in the construction
industry, primarily for moving earth which would replace the conventional
dump truck.
The truck 1 comprises a chassis 2 having at a front end thereof a cab
and driving portion 30~ an engine, and a plurality of driven wheels comprising
a set of front wheels 40 on a front axle and at a rear end of the chassis, a setof rear wheels 41 on first and second rear axles, and a load carrying vessel
3 arranged over the rear wheels, and having a centre of gravity, when loaded
above the rear axles. The load carrying vessel 3 is defined by two vertical or
upright side walls 5, 7, a base 9, a discharge plate l l and movable tailgate
13. The load carrying vessel 3 is capable of receiving bulk material lS
through an open top 17.
The discharge plate 11 is mo~lnted to move within the vessel 3 to push
the bulk material 17 along the vessel towards and through discharge port 19
defined when tailgate 13 is opened.
The side walls 5, 7 include at their upper edges a projecting lip 21.
The discharge plate 11 forms the front wall of the vessel 3 and extends across
the cross section of the vessel 3 between the side walls 5, 7 and the base 9.
The discharge plate 11 is mounted upon a set of lower rollers 23 and a set of
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upper rollers 25. The lower rollers 23 run along the base 9, and the upper
rollers run along the lips 21.
The discharge plate 11 extends across the width of the load vessel 3.
5 In side view as shown in figures i to 3 the discharge plate may be of a
substantially "I" shape, comprisin~ an upright plate member 40 extending
between the ~lpper and lower rollers, at an upper end of the plate 40, an upper
roller mounting plate 41 extends in a direction along the length of the vessel
3. and at a lower end of the plate 40, a lower roller mounting plate 42, also
10 extending in a direction substantially along the main length of the vessel 3,first and second upper rollers 44, 45 of the upper roller set being spaced apartfrom each other along the main len~th direction of the vessel and similarly,
first and second lower rollers 46, 47 of the lower roller set being spaced apartfrom each other along the main length direction of the load vessel 3.
In its fully retracted position (shown in figure l), the discharge plate
11 stands at the front of vessel 3.
A multi stage hydraulic cylinder 27 ram is mounted between a fixed
20 bracket 29 extending upwardly from chassis 3 l of the truck and the discharge plate 11.
The multi stage hydraulic cylinder 27 extends to urge the discharge
plate 11 along the main length of the load carrying vessel from a front of the
25 vessel to a rear of the vessel, and thus to urge the bulk material towards the
discharge port. The multistage hydraulic cylinder 27 may be contracted to
draw the discharge plate 11 back along the load vessel 3 in a direction from
the rear of the vessel back towards the front of the vessel.
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In one optional embodiment~ a head board 33 may be pivotally
mounted to the top of the plate 11 and is actuable by a hydraulic cylinder (not
shown). ~n the front position of the plate 11, the head board 33 is in an
inclined position facing towards the front of the truck to retain the bulk
S material which is heaped over the walls of the vessel 3. When the hydraulic
cylinder 27 is actuated to move the discharge plate 11, at the same time the
head board 33 is rotated to a vertical position shown in figures 2 and 3 to
propel the bulk material 15.
However, in another elllbodilllellt, the head board is rigid and in a
permanently upright position.
The tailgate 13 is hydraulically actuated by hydraulic cylinders (not
shown). The tailgate 13 is pivotally mounted to the lip 21 at the top of the
15 walls, and is over centre mounted so that in its open position~ as in figures 2
and 3, the rear of the vessel is clear for discharge.
In order to discharge the bulk load material 15, the driver of the truck
operates a two way lever, situated inside the cab 35, which controls the
20 extending of the multi stage hydraulic cylinder 27, which then moves the
discharge plate 11 in a controlled and regulated nlanner as shown in figure 2.
The operation of the above two way lever simultaneously lifts the hydraulic
operated tail~ate 13. As soon as the driver releases the above two way lever,
the unloading operation StOpS.
Figure 3 shows the truck with its load fully discharged and illustrates
the multi stage hydraulic cylinder 27 fully extended and the position of the
moving discharge plate 11 and tailgate 13.
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To retract the multi stage hydraulic cylinder 27, the driver operates the
two way lever in the opposite direction to that used for extending it. It will
be possible to lock the level in position whell retracting in order to make surethe cylinder is always fully retracted. The lever may automatically release to
5 its central position as soon as the cylinder is fully retracted.
Figure 4 shows the truck in rear view with the tailgate 13 is in an open
position. The truck is shown on uneven ground. illustrating that a centre of
gravity of the load carrying vessel 3 remains above the wheel base of the
10 truck, between left rear wheels 41 and right rear wheels 42, as the bulk
material 15 is discharged.
Further, it is ill~lstrated that the truck may discharge its load within a
tunnel 50, or underneatll overhead cables 51, since the load is discharged in
15 a direction along the main length of the load vessel without raising the load vessel relative to the chassis.
The embodiments of the invention may have an advantage of providing
an off road d~mlp truck having high ground clearance underneath axles of the
20 truck, and having the axles and wheels of the truck underneath the load
carrying vessel, the centre of gravity of the load carrying vessel being above
the axles. The truck may have improved stability during discharging of the
load as compared to the conventional tipping dump truck in which the centre
of gravity of the load vessel is raised relative to the axles during tipping.
25 Further, the overall height of the d~mlp truck of the present embodiment may
remain constant during discharging of the dulllp truck, enabling operation
underneath overhead obstacles.
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- 10 -
The reader's attention is directed to all papers and documents which are
filed concurrently with or previous to this specification in connection with this
application and which are open to public inspection with this specification, andthe contents of all such papers and documents are incorporated herein by
S reference.
All of the features disclosed in this specification (including any
accompanying claims, abstract and drawings), and/or all of the steps of any
method or process so disclosed, may be combilled in any combination, except
10 combinations where at least some of such features and/or steps are mutually
exclusive.
Each feature disclosed in this specification (including any
accompanying claims, abstract and drawings), may be replaced by alternative
1~ features serving the same, equivalent or similar purpose. unless expressly
stated otherwise. Thus~ unless expressly stated otherwise, each feature
disclosed is one example only of a generic series of equivalent or similar
features.
The invention is not restricted to the details of the foregoing
embodiment(s). The invention extends to any novel one, or any novel
combination, of the features disclosed in this specification ~including any
accompanying claims~ abstract and drawings), or to any novel one, or any
novel combinatiom of the steps of any method or process so disclosed.
