Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF INVENTION
~a~ Field of the Invention
The present invention rela-tes to a system
and method for unloading bulk cornmodity from a con-
tainer wherein the bulk commodity is unloaded by
pulling a pleated liner from an end thexeof so that as
the pleats of the liner unfold sequenticllly, the com-
modity is discharged.
(b) Description of Prior Art
Many systems are known for discharging bulk
commodity from shipping containers such as tractor
~ trailers, railway cars, or the like, but require
costly equipment to effect the unloading or else the
loading is very time-consuming. For example, referring
to U.S. Patent No. 3,696,952 issued on October 10, 1972
and relating to a bulk cargo handling system and method,
it can be seen that in order to unload bulk cargo from
the container, it is required to provide a costly tilt
mechanism which tilts the container towards its rear
open end whereby the material will be discharged by
gravity or by pressure. Such tilting mechanism is
quite expensive~ bulky~ and can only be adapt~d to
specific types of containers and could not be used, for
example, with freight railway cars. However, attempts
have been made to discharge cargo without having to
tilt the vehicle. Such are disclos~d in British Patent
No. 527,916 published on October 18, 1940 and in U.S,
Patent No. 3,443,703 issued May 13, 1969 where there
is disclosed the use of a retractable floor liner on
which commodity is disposed and unloaded by retractiny
the liner from an open end. Recently, another such
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floor liner was disclosed in European Patent Applica-
tion 0 067 483 published December 22, 1982.
In the later referenced prior art, it is
necessary to calculate the size of folcls depending on
the nature of the commodity and to use special liner
material for proper unfolding and strength.
There exists the need to provide a discharge
mechanism which is easy and safe to use, economical,
and which does not require special liner material.
There also exists the need to provide an unloading
].iner which can be re-used, and which effects the dis-
charge quickly and which substantially unloads all
bulk commodity from the container be it a trailer or
freight car.
SUMMARY OF INVENTION
It is a feature of the present invention to
provide a system and method for unloading bulk commo-
dity which overcomesall of the disadvantages of the
prior art mentloned and which mee~q all of the above-
mentioned needs.
Another feature of the present invention is
to provide a system and method for unloading bulk com-
modity from a multitude of types of containers and
which is easy to install an~ which is re-usable.
Another feature of the present invention is
to provide a bulk commodity unloading liner which is
easy to install over the bottom wall~of the container
or inside an inflatable liner,~w~ich is strong without
the rec~irement of special liner fabrics.
According to the above features, from a
broad aspect ~the;present invention provides a system
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for unloading bulk commodity from a container having a
flat bottom wall. The system comprises a rectanyular
sheet disposed over the bottom wall wi-th a load of -the
bulk commodity disposed over the sheet. The sheet has a
plurality of pleats pre-formed therein side by side and
widthwise in at least a portion of the length of the
sheet which is disposed over the bottom wall. The pleats
are folded over a top face oE the sheet and have a
predetermined width calculated in dependency of the weight
of the load to be disposed thereon. The pleats are
maintained folded by a heat seal spot formed between the
pleats. At least one reinforcing strap-like member is
secured to the liner lengthwise thereof. The sheet has an
end flap at a rear end thereof and an attachment flap at a
forward end thereof. Pulling means is provided for pull-
ing the sheet from a rear end thereof over the bottom wall
to displace and discharge the load of commodity from
adjacent the rear end as the pleats are unfolded sequen-
tially and the sheet is drawn from its rear end.
According to another broad aspect of the present
invention there is provided a bulk commodity unloading
liner comprising a rectangular sheet having a pl~rality
of pre-formed pleats formed side by side widthwise
throughout a predetermined length thereof. The pleats are
folded over a top face of the sheet and have a predeter-
mined width calculated in dependency of the weight of a
load to be disposed thereon. The pleats are maintained
folded by a heat seal spot formed between the pleats. At
least one reinforcing strap-like member is secured to the
liner lengthwise thereof. The sheet has an end flap at a
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rear end thereof and an attachment flap at a forward end
thereo~. The sheet is constructed of a material of
sufficient strength and proper texture to permit a
load thereon to be shifted by pulling the sheet lying
on a supporting surface with the pleats unfolding
sequentially.
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BRIEF DESCRIPTIO~ OF DRAWINGS
A preferred embodiment of the present inven-
tion will now be described with reference to the
examples thereof illustrated in the accompanying draw-
ings in which:
FIGURE 1 is a perspective view of a container
showing the bulk commodity unloading liner at its rear
open end thereof,
FIGURE 2 is a perspective view of a container
showing the bulk commodity unloading liner properly
positioned over the bottom wall of the container;
FIGURE 3 is a perspective view of a container
showing the unloading liner positioned over the bottom
wall of an inflated liner in which bulk commodity is
blown;
FIGURE 4 is a perspective view of a container
showing the unloading of the bulk commodity therein,
FIGURE 5A is a fragmented perspective view
showing the pleated unloading liner,
FIGURE 5B is a perspective view showing the
liner with reinforcing strapping and formed of stiff
material:
FIGURE 6 is a perspective view of a container
showing the position of the liner after it has been
- fully unpleated after the load of commodity has been
unloaded,
FIGURE 7 is a perspective view of a railway
freight car showing the unloadin~ liner of the present
invention adapted to an unloading device;
FIGURE 8 is a perspective view of -the railway
freight car showing the unloading device located under
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the floor of the car and further illustrating the
position of the unloading liner after the bulk commodity
has been unloaded:
FIGURE 9 is a perspective view of the discharge
device as used with the railway freight cars,
FIGURE 10 is a top view of Figure 9:
FIGURE 11 is a transverse section view of
Figure 9, and
FIGURE 12 is a schematic illustration of the
drive and clutch mechanism for the discharge device.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now to the drawings and more particu-
larly to Figures 1 to 5, there is shown genarally at 10
the bulk commodity unloading liner of the present inven-
tion and its use. T~le liner 10 consists of a rectangular
sheet formed o-f suitable strong material having surface
properties which will permit unpleating of the sheet with
a load positioned thereover and which will resist tearing
as the sheet is pulled from a rear end thereof with a load
commodity thereover. Preferably, but not e~clusively, the
sheet is constructed of corrugated board, reinforced paper
or plastic sheet material. For added rigidity, one or
more, herein three, reinforcing strap-like members 9 are
secured lonyitudinally of the sheet. The members 9 may
be formed by plastic, woven, longitudinal fibers or steel
straps. As better illustrated in Figure 2, a plurality
of folds or pleats~ll are formed side by-side widthwise
of the shePt throughout a predetermined length thereof
which is~to be positioned over the bottom wall 12 of con-
tainer 13. The pleat= 11 are fGlded over a top face of
the sheet.
At the Iear end of the sheet, there is provided
an end flap~14. At the opposite end of the sheet,
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there is provided an attachment flap 15. The attach-
ment flap is of suf~icient length to lie over a front
wall 16 of the container 13 and is provided with attach-
ment means in the form of eyelets or loops 17 to be
secured adjacent the top end 16' of the i~ront wall 16.
The end flap 14 has two purposes as will be.
described with reference to Figures 3 and 4. As shown
in Figure 3, the open end 18 of the container is pro-
vided with a retaining wall or bulkhead 19 having a
discharge slot opening 20 at the bottom end thereof
adjacent the bottom wall 12. This slot is 2 :to 8 inches
in width and permits the emptying of the commodity 21
being placed into the container 13 over the pleats 11
of the sheet 10. As shown in Figure 3, the commodity
21 is blown into the container by a convection tube 22
and the container is fitted with an inflated liner 13
to protect the cor~modity from the interior wall of the
container. The front flap 15 may be taped, wi~h pres-
sure release tape, to the liner 13' front wall and will
detach automaticaIly by pulling after the commodity is
unloaded.
Befoxe the commodity 21 is placed into the
container, the end flap 14 is secured upwardly, as shown
by arrow 23, and reta1ned over the rear wall 19 by
fastening means, such as staples, whereby the end flap
14 substantially obstructs the discharge slot opening
20 to prevent commodity~from falling out during the
loading of the corNmodity. After the container is-
loaded, the rear doors 24 o~ the oontainer are closed
over the rear opening 18.
As shown in Figure 4, in order to unloacl the
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commodity from the container, a discharge device 25 is
usedO The device 25 constitutes a pulling means for
the sheet and comprises a sheet wind~r constitutec by
a spool 26 to which the end flap 14 is secured and which
is axially rotatable to pull the sheet from the rear end
thereof over the bottom wall 12 whereby to discharge the
commodity through the discharge slo-t opening 20 as the
pleats unfold sequentially from the rear end thereof
and the sheet is drawn outwardly of -the container through
the discharge slot opening.
The discharge device shown in Figure 4 con-
sists of a frame 27 which is herein shown secured to a
stationary surface. In use, the container 13 is placed
adjacent the discharge device whereby the rear flap can
be secured to the winding spool 26 which is adjustably
securable in height by adjustment means 27' whereby to
adapt to containers having their bot om wall at different
heights from the ground surface. A hopper bin 28 is
positioned under the spool 26 and rearwardly thereof
whereby the commodity being conveyed outwardly of the
container by the winding of the sheek 10 will fall into
the bin 28. A conveying means, in the form of a spiral
screw 29, is positioned in the bin 28 and directs the
commodity into a conveying tube 30 where the commodity
is fed to a remote storage means ~not shown).
As shown in Figure 6, after the sheet has been
completely unpleated, most of the commodity has been
discharged from the container. However, when the sheet
is completely unpleated, the winder roll will pull it
taut whereby the sheet extends diagonally across the
container from the top end of the *ront wall 16 to the
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bottom discharge slot opening 20 of the rear end. This
arrangement of the sheet provides a slide to cause the
residual commodity to slide down the sheet towards the
opening. When the sheet reaches this position, the
winder roll is stopped and it may be rec:iprocably
rotated whereby to impart a vibration to the sheet to
cause any further commodity to slip down the sheet and
out through the discharge slot. As also shown in Figure
6, the discharge device ~5 is herein shown as securable
adjacent the rear bottom edge of the container. It
also consists of a screw conveyor 29 ~isplaced in a bin
28 supported adjacent the spool 26 to convey ma-terial
through a flexible tube 30' securable to a sleeve 31
provided at one end of the housing 28 in reyistry with
the spiral screw conveyor 29O
As shown in Figure 5A, in order to maintain
the pleats 11 in position, a small heat weld 32 may be
formed at the position shown. This heat weld will have
very little resistance and would become undone as soon
as a pulling force is app~ied to the top layer portion
11' of the pleat. Alternatively, a single stitch 33
may be provided for the same purpose and becomes easily
undone as soon as a pulling force is applied to the pleat.
Referring now to Figure 5B, there is better
shown the construction of the unloading liner 10. As
herein shown, the reinforcing strapping or tapes 9 is
secured spaced apart longitudinally of the liner. The
straps 9 may be made of reinforcing tape, plastiç strap-
ping, or steel strapping. Such strapping provides the
necessary longitudinal strength to pull the liner out
of the container when it is fully loaded. Also, with
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this strapping, it is not necessary to use special fold
patterns or to have special slip surface fabrics to
eEfect the unfolding. Thus, the strapping is c~ite
advantageous.
As above stated, with the strapping 9, many
types of plastic or woven fabrics can be used to form
the liner. It is also possible to use corrugated
board as the liner. If corrugated board or a stiff
plastic is used, the pleats 11 can remain in a vertical
position and closely spaced to one another in accordion
fashion. As the liner is pulled out, -the pleats 11
would flatten out to draw out the commodity. This type
of liner would be particularly useful with granular
commodity such as flour, grain, etc~, where the pleats
would not be damaged in their uprig'ht position when
commodity is dropped thereon.
Referring now to Figures 7 to 12, there is
described another embodiment of the present invention
whereby the system is adapted to a railway freight car
container 35. Such containers are usually provided
with a side door opening 36 providecl in a side wall 37
of the freicJht car. As herein shown, the discharge
device 25' is slightly altered ancl is secured over the
bottom wall 38 of the railway car and extends trans-
versely over the bottom wall adjacent the side door
opening 36. The discharge device is providecl with two
spaced apart rotatable spools 39 and 40 which are sup-
ported în the discharge device across the o,pposed side
walls 41 thereof. The device 25' is secured to the
bottom wall 38 by attachment flanges 4~. Suitable fas-
teners are driven through the flanges and into the bottom
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wall making it easy to install and remove from -the
bottom wall.
The spools 39 and 40 are each located inside
the housing under an angulated side wall 43 which is
hinged at a lower end 44 thereof to permit access to
the spools. The side wall or side door 43 is held in
a position shown in Figure 11 by abutment flanges 45
and terminates short of a top edge 46 of a discharge
bin 47. Thus, a slot 48 is formed between the top
edg~ of the discharge bin 47 and the top edge of the
side wall 43 whereby to permit the sheet 10 to be drawn
therethrough. The top edge of the side wall 43 may have
a roller 49 secured thereto or else be rounded whereby
to provide for said sheet 10 to be easily drawn by the
rotation of the spool 40.
A spiral screw conveyor 50 is disposed bet-
ween the end walls 41 and extends substantially parallel
to the spools 40 and is positioned adjacent the bottom
wall 51 of the discharge binO A coupling flange 52 is
remova~ly secured to the end wall 41 whereby to attach .
a conveyor line (not shown) thereto when discharging
the commodity from the freight car.
Figure 12 illustrates a conventional motor
drive which may be conveniently secured to the discharge
device 25' and it consists essentially of a motor 52
having a drive shaft 53 and a drive gear 54. A clutch
arrangement displaces the drive gear whereby to engage
with a drive gear of the spiral screw conveyor 50 or a
drive gear 55 or 56 of the first and second spools 39
and 40. The clutch mechanism 60 can therefore engage
the spiral screw conveyor 50 without engaging any of the
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spools or else could engage either one of the spools
or both spools simultaneously with the spiral screw
conveyor. It is pointed out that instead of having a
motor drive, the discharge device 2S' may be provided
with the necessary gearing inside an end wall 41 and
have a drive pinion (not shown) extending through the
wall 41 and engag d by an industrial portable rotary
motor. A clutch lever (not shown~ would prov1de for
the selection o~ the drives.
When discharging the commo'dity from the
freight car, it is firstly necessary to rotate the
spiral conveyor screw whereby the load above the dis-
charge bin 47 will be discharged without the need to
activate either of the spools 39 or 40. After that
portion of the load is discharged, the first or second
spool or both spools are operated whereby the remainder
of the commod~ty from each side of the discharge device
25' will be conveyed to the discharge bin. The con-
veying of the load on each side of the container is
done the same way as described previously with the ;~
discharge of the container 13 by withdrawing the pleated
liner from its rear end direction. After both spools
have been wound, the liner on both sides will lie dia-
gonally, as shown in Figure 8, whereby most of the com-
modity will be removed from the freight car.
Although in Figure 7~the discharge device 25'~
is shown as secured on top of the bottom wall 38, it
may be secured under the bottom wall 38 below the~floor
as shown in Figure 8. Many freight cars,have sllding
doors in their' bottom wall for bot~tom discharge and the
device may be suitably adapted thereto.
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~he gearing ratio of the drive shown in
Figure 12 may vary to provide various ratios between
the speed of the spiral screw and the speed of the
spools. For example, the screw conveyor 50 can rotate
at a speed much higher than that of the spools to assure
that all of the commodity conveyed to the discharge bin
is removed quickly to prevent build-up. Also, the gear
coupling between the spools and the drive from the motor
should be such as to prevent overloading the drive shaft
of ~-he motor.
It is within the ambit of the present inven-
tion to cover any obvious modifications of the examples
of the preferred embodiment described herein provided
such modifications fall within the scope of the appended
claims.
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