Note: Descriptions are shown in the official language in which they were submitted.
CA 02799271 2012-12-19
CONVERTIBLE TRAILER
FIELD OF THE INVENTION
[0001] The present invention relates generally to the field of
transportation. More
particularly, the present invention relates to a trailer for the
transportation of compacted
garbage and/or bulk material.
BACKGROUND OF THE INVENTION
[0002] Garbage, waste, or any other materials, which are compacted for
transportation, require the use of fixed walled containers or trailers, which
allow the
transportation of materials in compacted form or the compacting of the
material in the
container or trailer itself. These types of trailers cannot backhaul any bulk
goods on the way
back from the unloading site, as their fixed and closed top does not allow
loading from the
top using a conventional loader, similar to an open-top trailer.
[0003] With the rising cost of fuel, the disposal of garbage becomes
increasingly
expensive, especially when the trailer cannot backhaul any goods to reduce the
cost of
waste disposal, and thus, returns empty from the unloading site.
[0004] On the other hand, open top trailers, even those which include a
cover, cannot
be used for compacting or for the transport of loosely compacted material.
[0005] United States Patent Application Publication No.2007/0126209
(Wolfe)
describes a trailer that converts into a shed. The trailer of Wolfe includes a
convertible roof
comprising two panels. However, the panels cannot be locked, and the walls are
not rigid
enough to withstand compressed materials.
[0006] European Patent Application No. 1,120,363 and United Kingdom
Patent
Application No. 2,429,006 (Sumpter) describe a trailer for the collection of
waste comprising
a chassis and a container. The container comprises a roof including an
aperture closeable by
a cover that slides over the aperture by means of a channel assembly. The
cover may be a
partly or fully retractable flexible sheet.
[0007] The structure of Sumpter does not allow the trailer to be used for
transporting
loosely compressed materials because the materials are distributed in the
container using
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reciprocating slats, not a compactor. Furthermore, the cover disclosed in
Sumpter is flexible
and would thus not be able to withstand any pressure from within the
container. Sumpter
clearly does neither teach nor suggest using the container disclosed for
transport of loosely
compacted materials.
[0008] Neither Wolfe nor Sumpter deal with loosely compacted materials,
and thus,
fail to recognize the structural challenge created by internal pressures in a
trailer upon
compression of loose materials therein.
[0009] It is, therefore, desirable to provide a trailer that can accept
and contain
loosely compacted material, and which can also backhaul bulk goods on the way
back from
the unloading site in order to reduce the cost of transportation, which bulk
goods are loaded
from the top.
[0010]
SUMMARY OF THE INVENTION
[0011] It is an object of the present invention to provide a trailer
which can hold
loosely compacted material or allows material to be compressed inside the
trailer, but can
also be loaded from the top to backhaul bulk goods on the way back from an
unloading site.
[0012] This specification refers to loosely compacted materials which are
compacted
and maintained in the compacted condition solely by the trailer without any
secondary
containment or bundling structures. Thus, loosely compacted materials
continuously exert an
expansion force on the containment structure in which they are held.
[0013] In an aspect, the invention provides a container for a convertible
trailer
comprising a chassis for carrying the container and a set of wheels for
rollably supporting the
chassis on the ground, the container comprising a floor, a wall, and a roof,
and an access
door for loading loosely compressed materials into the container. The roof
includes a pair of
opposite rigid panels, respectively pivotally connected to opposite side walls
of the container
by multiple hinges for movement between a closed position wherein each panel
forms part of
a solid roof for loading of the container with loosely compressed materials
from the access
door, and an open position wherein the container can be loaded from the top
with bulk
material. The container includes a plurality of spaced apart locking bars
distributed in
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longitudinal direction of the roof, for securing the panels in the closed
position and for
strengthening the wall against outward pressure exerted by the loosely
compressed
materials when loaded in the container. Due to the uneven outward pressure
distribution
along the length of the trailer when compacting pressure is applied from the
access opening,
it is important that a spacing of the locking bars is smaller proximal to than
distal from the
access door.
[0014] The container is preferably rectangular including a rear wall, a
front wall and
opposite sidewalls. In an embodiment, each locking bar is preferably secured
to one of the
panels at one end and includes a structure for releasably fastening an
opposite end to the
other panel when the panels are in the closed position, for releasably locking
the panels in
the closed position. In another embodiment, each locking bar is preferably
provided adjacent
and substantially aligned with a pair of hinges respectively connecting one of
the panels to
the associated sidewall, for connecting the opposite sidewalls to each other
by way of the
locking bars and against the outward pressure exerted by the loosely
compressed materials
compacted in the trailer. Preferably, the locking bars are positioned on the
roof panels to be
in symmetrical contact with the roof panel on each side. The locking bars may
be releasably
fastened at each end in order to allow for the complete removal of the locking
bars for
opening of the roof panels in restricted space situations, or to allow the
roof panels to be
opened with the locking bars attached to one or the other of the roof panels.
[0015] In another aspect, the container includes a mid span tie bar
connecting a top
edge of the sidewalls mid span of the trailer for added structural strength of
the basic trailer
structure, and a locking bar located directly above the tie bar. In another
aspect, the number
of locking bars between the tie bar and an access door end of the container,
the access door
half of the roof, is higher than the number of locking bars between the tie
bar and the other
end on the trailer. The number of locking bars on the access door half is
preferably at least
double the number on the other half. Most preferably, there are at least 6
locking bars on the
access door half of the roof for added stability, resistance to movement and
twisting and for
resistance to compacting pressure exerted from the access opening.
[0016] In a further aspect of the invention, a rubber seal is provided
between each
roof panel and edges of the container walls adjacent the panel in its closed
position to
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minimize spillage of materials carried in the trailer and intrusion of
moisture and dirt into the
container when the roof is closed. A rubber seal is preferably also provided
between the
panels at their meeting edges. Finally, a seal is preferably provided at the
tie down bolt
locations in order to minimize ingress of contamination into the container,
especially during
inclement weather conditions.
[0017] In another aspect of the invention, the roof panels are extruded
panels and
include edge extrusions for overlapping and interlocking engagement of the
roof panels at
their meeting edges when in the closed position. The edge extrusions are
preferably
constructed as a bottom overlap extrusion extending along the meeting edge of
one panel
and a top overlap extrusion extending along the meeting edge of the other
panel and
complementary to the bottom overlap extrusion. Most preferably, the roof
panels are
extruded aluminum panels.
[0018] In a further aspect of the invention, each locking arm has an
attached half,
which is rigidly welded to a first of the pair of roof panels and a free half
for resting against
and releasable attachment to the second of the pair of roof panels, when the
roof panels are
in the closed position. A rubber seal is preferably provided on the free end
for cushioning
between the free half and the second panel to prevent grinding of the locking
bar against the
second panel. A further rubber seal profile is preferably provided between the
extruded
aluminum roof panel and the mid top tie bar for cushioning.
[0019] In still another aspect of the invention, the free end of the
locking bar is
respectively releasably fastened to the second roof panel by a tie down
assembly. The
assembly preferably includes a nut and bold connection, with the nut welded to
one of the
roof panel and the locking bar and the bolt extending through the other of the
roof panel and
the locking bar for engaging the nut and fasten the locking bar to the roof
panel when the bolt
is tightened in the nut.
[0020] Other aspects and features of the present invention will become
apparent to
those ordinarily skilled in the art upon review of the following description
of specific
embodiments of the invention in conjunction with the accompanying figures.
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BRIEF DESCRIPTION OF THE DRAWINGS
[0021]
Embodiments of the present invention will now be described, by way of
example only, with reference to the attached Figures, wherein:
Figure 1 is a top view of a convertible trailer in accordance with an
embodiment of the invention;
Figure 2 is a rear view of the container of the trailer when the panels are 90
degrees open;
Figure 3 is a rear view of the container of the trailer when the panels are
fully
open and the trailer is being loaded from the top;
Figure 4 is an exploded view illustrating an embodiment of the invention, in
which, the locking bar is provided at both panels;
Figure 5 illustrates the rotation mechanism of the panels;
Figure 6 illustrates a top plan view of a preferred container roof
construction;
Figure 7 illustrates a perspective top view of an end of the roof construction
shown in Figure 6;
Figure 8 illustrates an enlarged view of one of the locking bars shown in
Figure 7;
Figure 9 illustrates a cross-sectional view of the roof structure shown in
Figure
6, at the location of one of the locking bars;
Figure 10 is a bottom perspective view of the mid portion of the roof
construction shown in Figure 6 and illustrating the mid span tie bar;
Figure 11 illustrates a corner detail of the cross-sectional view of Figure 9;
Figure 12 illustrates a center detail of the cross-sectional vie of Figure 9;
Figure 13 illustrates a hinge detail of the perspective view of Figure 8;
Figure 14 is a cross-sectional view of an end of the roof construction of
Figure
8;
Figure 15 is a cross-sectional view of a reverse tie down bolt construction in
the roof construction illustrated in Figure 7;
Figure 16 is a cross-sectional view of a variant of the tie down bold
construction of Figure 15; and
CA 02799271 2012-12-19
Figure 17 is a cross-sectional view of the tie down bolt construction used to
engage the mid span tie bar.
DETAILED DESCRIPTION
[0022] Generally, the present invention provides a container for loosely
compacted
materials which is convertible to a top loading bulk good container. In a
preferred
embodiment the invention provides a trailer comprising a chassis, a set of
wheels for rollably
supporting the chassis on the ground, and a rigid container carried by the
chassis. The rigid
container comprises a floor, a sidewall, an access door for loading/unloading
materials into
the container, and a convertible rigid roof. The convertible roof is movable
between a closed
position which permits waste or other materials to be compressed into the
trailer, and an
open position which permits the trailer to be loaded with bulk goods from the
top. The
convertible roof includes movable rigid panels, and a locking bar for holding
the panels
closed and connecting the opposite sidewalls of the trailer to each other
against the
expansion pressure exerted by loosely compressed materials transported in the
trailer. The
panels may be rotating panels hinged to a wall, or may be provided as sliding
panels running
in tracks.
[0023] Figure 1 illustrates by way of example, a top view of a
convertible trailer 100 in
accordance with an embodiment of the invention. In the embodiment shown in
Figure 1, the
roof of the trailer is made of two movable panels 102 and 104. When the panels
102 and 104
are in a closed position, as illustrated in Figure 1, the convertible trailer
100 may be loaded
with loosely compressed materials, such as garbage, from the access door using
a
compactor (not shown). The compactor applies pressure on the materials loaded
in order to
remove gaps for the most efficient use of the space inside the trailer. When
the compactor is
operated, the roof must be closed and rigid in order to withstand the outward
expansion
pressure exerted by the loose materials being compacted.
[0024] Once the convertible trailer 100 is unloaded at the unloading
site, it may be
loaded again to backhaul bulk goods on the return trip, in order to reduce
transportation
costs. If uncompressed bulk goods are to be transported, the convertible roof
of the trailer
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- =
100 may be opened to allow the loading of the convertible trailer 100 from the
top. For
instance, the trailer 100 may be loaded with bulk goods like sand, gravel, or
the like using a
conventional loader 110. Figure 2 is a rear view of the container of
convertible trailer 100
when the panels 102 and 104 are 90 degrees open, and the access door 202 is
closed, while
Figure 3 is a rear view of the container of the convertible trailer 100 when
the panels 102 and
104 are fully open (270 degrees), and the trailer is being loaded from the
top.
[0025] As shown in Figures 1 to 3, panels 102 and 104 are movable
between a
closed position, in which, the panels are substantially parallel and coplanar
so as to form a
solid hard roof as shown in Figure 1, and an open position, in which, the
panels are 270
degrees rotated from the closed position and, in which, the panels are
substantially parallel
to the left and right sidewalls of the trailer, as shown in Figure 3.
[0026] When panels 102 and 104 are in the closed position, at
least one locking bar
106 secures both panels to each other. The locking bar 106 may be provided on
one of the
panels or on both. Figure 4 is an exploded view showing by way of example the
locking bar
106 provided at both panels, in accordance with an embodiment of the
invention. The locking
bar 106 may be welded or permanently secured to one of the panels at one side
and has one
or more openings 400 at the other side, as illustrated in Figure 4. The
openings 400 provided
in the locking bar overlap one or more threaded openings 402 in the other
panel when the
panels are in closed position for releasably securing the locking bar 106 to
the other panel
using bolts or the like.
[0027] Panels 102 and 104 are connected to the sidewalls 112, 114
of the trailer by
hinges 108 as shown in Figures 1 and 4. The locking bar 106 is provided
adjacent, and
preferably aligned with the hinges 108 for connecting the sidewalls 112 and
114 to each
other against the outward expansion pressure exerted by the loose materials
being
compacted for preventing the sidewalls and the roof from bulging out and
deforming.
[0028] Panels 102 and 104 are provided with a rotation mechanism
that allows them
to move between the closed position shown in Figure 1, and the open position
shown in
Figure 3. Figure 5 illustrates, by way of example, an embodiment of the
rotation mechanism
that rotates the panels. As shown in Figure 5, the rotation mechanism includes
a bracket 502
and a worm drive or any other suitable rotating means 504. The bracket 502 is
provided at
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the side of each of panels 102 and 104, and connected to the panel at one end
and to the
motor 504 at the other end.
[0029] In a preferred embodiment of the roof construction of the trailer
100, as shown
in Figures 6 to 9, the roof 600 includes a pair of opposite rigid panels 102,
104, respectively
pivotally connected to opposite side walls of the container by multiple hinges
108 for
movement between a closed position as shown, wherein each panel forms part of
a solid
roof for loading of the container with loosely compressed materials from the
access door, and
an open position (not illustrated) wherein the container can be loaded from
the top with bulk
material. The container includes a plurality of spaced apart locking bars 106,
distributed in
longitudinal direction of the roof 600, for securing the panels 102, 104 in
the closed position
and for strengthening the sidewalls 112, 114 (see Figs. 2 and 9) against
outward pressure
exerted by the loosely compressed materials when loaded in the container, a
spacing of the
locking bars 106 being smaller proximal to than distal from the access door
202 (see Fig. 2).
[0030] Each locking bar 106 is preferably secured to one of the panels
102, 104 at
one end and includes a structure 700 for releasably fastening an opposite end
to the
remaining structure of the container in such a way that the panels are
reliably maintained in
the closed position. For example, the opposite end of the locking bar can be
releasably
fastened to the other of the panels 102, 104 when the panels 102, 104 are in
the closed
position, for releasably locking the panels 102, 104 in the closed position.
However, the other
end of the locking bar 106 may also extend around the top edge of the sidewall
and come to
rest against the sidewall for releasable attachment thereto, when the roof
panels are in the
closed position.
[0031] For added stability, each locking bar 106 is preferably provided
adjacent to
and substantially aligned with a pair of hinges 108 respectively connecting
one of the panels
102, 104 to the associated sidewall 112 or 114, for connecting the opposite
sidewalls 112,
114 to each other by way of the locking bars 106 and against the outward
pressure exerted
by the loosely compressed materials compacted in the trailer. The locking bars
106 may be
releasably fastened at each end in order to allow for the complete removal of
the locking bars
106 for opening of the roof panels 102, 104 in restricted space situations, or
to allow the roof
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panels 102, 104 to be opened with the locking bars 106 attached to one or the
other of the
roof panels 102, 104.
[0032] In another aspect, the container as illustrated in Figure 10,
includes a tie bar
120 connecting a top edge of the sidewalls 112, 114 mid span of the trailer
for added
structural strength of the basic trailer structure, and a locking bar 106
located directly above
the tie bar. In another aspect, the number of locking bars 106 between the tie
bar 120 and an
access door end 204 of the container, the access door half of the roof, is
higher than the
number of locking bars 106 between the tie bar 120 and the other end on the
trailer. The
number of locking bars 106 on the access door half is preferably at least
double the number
on the other half. The tie bar 120 is located mid span of the trailer and is
always bolted at two
locations to the structural top cross member 122 (see also Fig. 11) that is
located at the top
of the trailer sidewalls 112, 114 and which spans from sidewall 112 to
sidewall 114.
[0033] As illustrated in Figs. 11 and 13, each hinge 108 includes an
outer hinge
profile 108a welded to an outer surface 105 of one of the roof panels 102, 104
and a middle
hinge profile 108b welded to the top rail 122 of one of the sidewalls 112,
114. A rubber seal
124 is inserted into a seal slot 125 on the extruded roof panel 102 or 104.
The rubber seal
124 has a curved profile allowing it to curl on top of the top rail 122 and
rest on the top rail
122 when the roof panel 102, 104 is closed. The rubber seal 124 acts as a seal
to prevent fill
in the trailer escaping from the container and to prevent humidity entering
the container.
[0034] As illustrated in Figure 12, the roof panels 102, 104 respectively
include at
their meeting edges a bottom overlap extrusion 126 and a top overlap extrusion
128. The top
and bottom overlap extrusions 126, 128 overlap and interlock when the panels
102, 104 are
in the closed position, as shown in Figure 12. The top overlap extrusion 128
is provided with
a rubber seal extrusion 127 and a rubber seal 130, which runs the length of
the top overlap
extrusion 128 and engages the opposite roof panel to prevent material from
exiting or
entering the container in the meeting area of the roof panels 102, 104, when
the panels are
in the closed position. A rubber seal cap 132 is provided on the lip 134 of
the bottom overlap
extrusion 126 to provide a seal between the top and bottom overlap extrusions
126, 128 and
to prevent metal to metal contact at the meeting edge of the panels 102, 104.
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[0035] Figure 14 illustrates the end construction of the roof of the
container of the
invention and shows a rubber seal extrusion 136 mounted to a bottom surface of
the roof
panel 102, 104 and a rubber seal 138 inserted into the extrusion to seal the
gap between the
roof panel 102, 104 and the top of the end wall, here represented by the angle
bracket 142,
which is welded to the end wall (not shown). A bolt 140 can be used to secure
the roof panel
102, 104 to the end wall by fastening it to the angle bracket 142. Angle
bracket 142 is welded
to a structural rear header (not shown) located at the rear of the trailer.
The rear header
spans from structural post to structural post on the trailer body. This allows
the placement of
two bolts at the very rear of the roof to anchor the roof to a structural
member of the
container body. Delta clad is welded to the angle bracket allowing a nut to be
welded in
place, which allows the tie down bolt to fasten the roof in place. The front
end construction is
assembled accordingly with the angle bracket attached to a front header.
Rubber seals are
provided at the front end as well.
[0036] As illustrated in Figures 15 to 17, the tie down assembly 300 is
an upside
down assembly which allows a tie down bolt to be tightened from inside the
trailer, obviating
the need for the operator to climb on top of the trailer to lock down the
roof. It would of
course also be possible to install the tie down bold in an upright orientation
in which the tie
down bolt is fastened from on top of the roof.
[0037] The illustrated tie down assembly 300, includes the locking bar
106 and the tie
down bolt assembly 320. The locking bar 106 is an aluminum extrusion 302 with
a generally
C-shaped cross-sectional profile with hollow arms 304 and bottom grooves 306
incorporated
into the arms of the extrusion for receiving and holding a rubber seal 308.
The tie down bolt
assembly 320 includes the threaded tie down bolt 322, a handle 324 welded to
the bolt 322
for ease of rotation and tightening of the bolt 322, and a nut 326 for
threaded engagement by
the bolt 322. An access opening 328 is cut into the extrusion 302 at the
location of the tie
down bolt assembly 320 to recess the assembly into the locking bar 106 to
allow for an
optimum volume of the trailer (due to overall height restrictions). A top
stiffener plate 330 is
welded to the extrusion 302 in the access opening 328 to stiffen up the
locking bar 106
where the arm will be tightened down by the tie down bolt assembly 320. A
bottom stiffener
plate 332 is welded to the underside of the roof panel 102, 104 to stiffen up
the panel where
CA 02799271 2012-12-19
the panel will be engaged by the tie down bolt assembly 320. Both stiffener
plates 330, 332
are preferably provided with a slot profile 334 for receiving the bolt 322, in
order to allow for
adjustment of the bolt location during bolt installation as well as to absorb
some shifting in
the roof fore and aft during twisting and turning of the container. The nut
326 for engagement
by the bolt 322 is welded to the top stiffener plate 330. A washer 336 is
welded to the bolt to
prevent the bolt from falling through the roof during bolt release from the
nut 326.
[0038] At
least one of the stiffener plates 330, 332 is preferably made of deta-clad
material, which is an explosion welded sandwich of aluminum and steel, in
order to avoid
electrolytic corrosion between the steel and aluminum portions of the
assembly. If the top
stiffener plate 330 is made of deta-clad material (see Fig. 15), the edges
330a of the deta-
clad material are preferably beveled to allow for welding it inside the access
opening 328 to
the inwardly projecting arms 303 of the extrusion 302. If the bottom stiffener
plate 332 is
made of deta-clad material (see Fig. 16), the nut 326 is welded to a flat
steel washer 327,
which rests on top of the top stiffener plate 330.
[0039]
The rubber seal 308 is inserted into the bottom grooves 306 of the locking arm
extrusion 302 to allow for some cushioning between the locking arm 106 and the
roof panel
102, 104 to avoid metal resting on metal.
[0040] A
slot profile 340 is cut through the roof panel 102, 104 to accommodate the
tie down bolt 322. The slot profile 340 runs from the front to the back to
allow for some
movement in the locking bar 106 front to rear of the trailer.
[0041] At
the location of the mid span tie bar 120, the tie down bolt 322 extends not
only through the roof panel 102, 104, but also through the tie bar 120 and the
bottom
stiffener plate 332 is welded to the bottom surface of the tie bar 120 (see
Fig. 17). Rubber
seal profiles 344 rest between the extruded aluminum roof panel 102, 104 and
the mid span
tie bar for cushioning between the panel and the tie bar.
[0042]
Although tie down arrangements in the form of a nut and bolt assembly are
disclosed in detail, other tie down arrangements which provide for a reliable
and releasable
fastening of the free half of the locking bar to the second roof panel can be
used. For
example, the tie down arrangement may be provided by a pair of eyelets, one
each on the
free end of the locking bar and on the second the roof panel (not
illustrated), which are
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positioned to be adjacent and co-centric when the roof is closed, and by a
locking bar which
is movable between a locked position in which it fittingly extends through
both eyelets and an
unlocked position in which the locking bar is positioned clear of both
eyelets. Other tie down
arrangements which reliably and releasably lock the roof panels in the closed
position can
are also
[0043] While the embodiments shown in Figures 1 to 13c illustrate a
longitudinal
container, it is possible to implement the convertible roof of the invention
in a trailer having
oval, cylindrical, or any polygonal shaped container including a floor, a
sidewall, and an
access door for loading compressed materials when the convertible roof is in
closed position.
[0044] Furthermore, different locks may be used for locking the panels in
closed
positions for connecting opposite sidewalls by the locking bar against the
outward pressure
of the compressed materials. The implementation and details of such locks are
known in the
art, and will not be described in detail herein.
[0045] In the preceding description, for purposes of explanation,
numerous details
are set forth in order to provide a thorough understanding of the embodiments
of the
invention. However, it will be apparent to one skilled in the art that these
specific details are
not required in order to practice the invention.
[0046] The above-described embodiments of the invention are intended to
be
examples only. Alterations, modifications and variations can be effected to
the particular
embodiments by those of skill in the art without departing from the scope of
the invention,
which is defined solely by the claims appended hereto.
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