Container with expandable side walls

A container, such as a transfer trailer, a roll-off container, or other container that can be transported, has expandable side walls. The walls are hydraulically, or otherwise, forced outward to increase the inside width dimension of the container. A loading device, such as a garbage route collection truck or other similar vehicle can then be backed into the container whereby the solid material waste or other commodities can be directly loaded into the container. Once the container has been loaded, the side walls can be retracted to their original positions, such that the container maintains its standard regulated width dimension.

I. BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention pertains to containers, such as transfer trailers, used for 
transporting solid material loads. 
2. Description of the Related Art 
Waste disposal within a community has typically been accomplished by using 
community landfills. Garbage route collection trucks pick up garbage from 
houses and local businesses and would transport the garbage to community 
landfills. This was an acceptable method when waste disposal for an entire 
community could be accommodated by smaller landfills. 
With the ever increasing production and accumulation of garbage, however, 
community landfills are no longer adequate to accommodate disposal of an 
entire community's waste. Consequently, regional landfills are being 
increasingly developed and used to receive waste from multiple 
communities. 
Regional landfills have made the transporting of garbage by garbage route 
collection trucks to the landfills impractical. Regional landfills are 
often located great distances from the communities in which the garbage 
route collection trucks pick up garbage. Thus, many areas have begun using 
transfer trailers or other containers, such as, for example, roll-off 
containers to transport solid waste material initially collected by 
garbage trucks to the regional landfill. This prevents the need for many 
smaller trucks making the same journey to the regional landfill. Thus, the 
use of transfer trailers or other containers to haul waste to a regional 
site is a more efficient and cost-effective method of transporting waste 
once it has been collected from homes and local businesses. 
Typically, the garbage collected by a garbage route collection truck is 
taken to a transfer facility where the garbage is unloaded and then 
reloaded to a transfer trailer or other container using some type of 
loading machine. Garbage route collection trucks generally cannot dump 
their loads directly into transfer trailers or other containers because 
the maximum inside dimension of such containers is not larger than the 
outside dimension of the garbage route collection trucks. Thus, directly 
loading waste from the garbage route collection truck into the containers 
results in a large amount of waste being spilled. The width of transfer 
trailers and other containers is regulated by federal statutes and 
therefore, cannot be permanently enlarged to accommodate the size of 
garbage route collection trucks. On the other hand, efficiency demands 
require maximizing the amount of garbage that each individual garbage 
route collection truck can hold, thereby making it impractical to reduce 
the dimensions of the garbage route collection trucks. 
What is needed is a transfer trailer or other container that can be 
efficiently transported, which is designed to accommodate the size of 
garbage route collection trucks for directly loading waste contained in 
the garbage trucks into the containers with minimal spillage of the waste. 
II. SUMMARY OF THE INVENTION 
According to a preferred embodiment of the present invention a container 
having expandable side walls is provided. The side walls of the container 
are expanded outwardly to increase the inside width dimension of the 
container. A garbage route collection truck can then back its end up into 
the container and load its waste directly into the container. Once the 
waste is loaded into the container, and the empty garbage truck pulls 
away, the side walls of the container are retracted to their original 
positions, thereby decreasing the width dimension of the container to its 
standard regulated size.

IV. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
With reference now to the various drawing figures in which identical 
elements are numbered identically throughout, a description of the 
preferred embodiment of the present invention will now be provided. 
Referring to FIG. 1, a truck 2 is shown having a tractor 4 with a trailer 
10 attached to a chassis 6. Tractors, such as the tractor 4 shown in FIG. 
1 are well known in the art and can be of any type that allows a trailer 
for hauling solid material waste or other commodities to be attached 
thereto. The trailer 10 provides a container for receiving the solid 
material waste or other commodity in a container area within the trailer 
10. 
FIGS. 2 and 3 show a partial side view of the trailer 10 having wheels 11.1 
through 11.3. The trailer 10 has a front trailer portion 16 having two 
side walls 18 and 18' and a floor 20. The front side walls 18 and 18' are 
non-movable portions of the trailer 10, in that they cannot expand 
outwardly. The trailer 10 also has a rear trailer portion 22 having two 
side walls 24 and 24' and a floor 26. In a preferred embodiment, the 
floors 20 and 26 comprise a movable floor, wherein multiple slats extend 
side-by-side from a front end 12 of the trailer 10 to a rear end 14 of the 
trailer 10. Each of the slats is longitudinally slidable relative to the 
side walls 18, 18', 24 and 24'. Such a floor enables material loads loaded 
into the trailer at the rear end 14 to be moved forward toward the front 
end 12 so that more can be loaded into the trailer 10 at the rear end 14. 
An example of such a movable floor which is used in the preferred 
embodiment is the Keith Running Floor II.TM. movable floor system by Keith 
Manufacturing Co. of Madras, Oregon. Although the movable floor system is 
used in the preferred embodiment, stationary floors or other types of 
floors can also be used in this invention. Furthermore, the alternative 
preferred embodiment of a roll-off container disclosed hereafter, 
typically does not utilize a movable floor system, because such containers 
are generally shorter in length than standard sized trailers and use a 
hoist system for unloading the containers. 
The trailer 10 has a top covering 15 and a rear door 17 for containing the 
materials loaded into the trailer 10. In the preferred embodiment, a roll 
tarp, which is well known in the art, is used as the top covering 15. Also 
in the preferred embodiment, split doors with vertical hinges, which are 
well known in the art, are used for the rear door 17 of the trailer 10. It 
will be apparent to those in the art that a variety of different 
embodiments, beyond those disclosed with reference to the preferred 
embodiment of this invention, could be utilized for both the top covering 
15 and the rear door 17. Other suitable embodiments of both a top covering 
and a rear door must be removable or sufficiently movable so as not to 
prevent loading devices, such as garbage collection trucks, from backing 
into the trailer rear end 14 and dumping their loads directly into the 
trailer 10. 
Connecting the rear trailer portion 22 with the front trailer portion 16 
are connector mechanisms 28 and 28'. Connector mechanism 28 has a front 
hinge 30 pivotally connected to front side wall 18 and a rear hinge 32 
pivotally connected to rear side wall 24. A cross member 29 is pivotally 
connected between the front hinge 30 and the rear hinge 32. The connector 
mechanism 28' is essentially a mirror image of connector mechanism 28 
connecting front side wall 18' with rear side wall 24'. A top view of 
connector mechanism 28' is shown in FIG. 3. 
A more detailed view of the preferred embodiment of the connector 
mechanisms 28 and 28' is shown in FIGS. 4A and 4B. FIGS. 4A and 4B show a 
detailed top view and a detailed side view, respectively, of the rear 
hinge 32 of the connector mechanism 28. The preferred embodiment is a 
typical hinge, utilizing multiple bushings, partially represented by 34.1, 
34.2, 34.3, and 34.4, placed end-to-end and having a pin 36 disposed 
therethrough. The bushings 34 are alternately welded to the rear side wall 
24 and the cross member 29. For example, bushings 34.1 and 34.3 are welded 
to rear side wall 24 and bushings 34.2 and 34.4 are welded to the cross 
member 29. The welded portion of bushings 34.1 through 34.4 are 
represented as 38.1 through 38.4, respectively. FIGS. 4A and 4B show that 
the portions of the rear side wall 24 and the cross member 29, adjacent 
and welded to the bushings, are made of vertical square tubes 19.1 and 
19.2, respectively. The front hinge 30 of connector mechanism 28 is 
identical to the rear hinge 32 shown in FIGS. 4A and 4B. In addition, it 
will be apparent that the connector mechanism 28' connecting rear side 
wall 24' to front side wall 18' is a mirror image of the connector 
mechanism 28. 
It will be apparent to one skilled in the art that a single hinge connector 
mechanism could be used rather than the dual hinge connector mechanism 
shown and described with reference to the preferred embodiment of FIGS. 2 
through 4. The dual hinge connector mechanism allows the side walls to 
expand outwardly, remaining parallel to their retracted positions. 
However, with a single hinge connector mechanism the side wall would pivot 
outwardly at an acute angle to the plane defined by the side wall while in 
the retracted position. In addition, other connector mechanisms allowing 
outward expansion of the side wall during loading are also possible. 
FIG. 5 shows a controller 40, which is a hydraulic system, used in the 
preferred embodiment in the present invention to control the expansion and 
retraction of the rear side walls 24 and 24'. Hydraulic systems are well 
known in the art and therefore, those skilled in the art will readily 
understand this system and its possible variations. As shown in FIG. 5, 
the cylinders 42.1 and 42.2 have extension members 43.1 and 43.2 which are 
forced outwardly from the cylinders to expand the side wall 24 and pulled 
inwardly into the cylinders 42.1 and 42.2 to retract the side wall 24. As 
shown in FIG. 5, expansion and retraction of rear side wall 24' is also 
controlled by identical cylinders 42.1' and 42.2'. A two-spool valve 50, 
which is well known in the art, is mounted beneath the truck and has two 
levers or switches for actuating the hydraulic system. One lever actuates 
the cylinders 42.1 and 42.2 through hydraulic lines 44 and 46. The other 
lever actuates cylinders 42.1' and 42.2' through hydraulic lines 44' and 
46'. In the preferred embodiment the two-spool valve 50 is connected to 
the tractor 4, by hydraulic lines 47, 48 and 49, which supplies oil for 
operating the hydraulic system. A detailed side view of the cylinder 42.1' 
is shown in FIGS. 8A and 8B, with FIG. 8A showing the cylinder 42.1' in an 
actuated position and FIG. 8B showing the cylinder 42.1' in a non-actuated 
position. A detailed end view of the cylinder 42.1' is shown in FIG. 6. 
The extension member 43.1' of the cylinder 42.1' is shown pivotally bolted 
with a pin 45.1' through two support beams 41.1' and 41.2' in the rear 
side wall 24'. The other cylinders 42.1, 42.2 and 42.2' are configured in 
the same manner. 
Referring now to FIG. 7 an end view of the rear trailer portion 22 of the 
truck is shown. Sealing flanges 52 and 52' are connected to the rear side 
walls 24 and 24', respectively. FIG. 5 shows that the sealing flanges 52 
and 52' extend along the entire length of the rear side walls 24 and 24' 
respectively. An enlarged rear view of the sealing flange 52' attached to 
rear side wall 24' is shown in FIG. 8A wherein the rear side wall 24' is 
in the retracted position. FIG. 8B is the same view of the sealing flange 
52' attached to the rear side wall 24' as in FIG. 8A, but shows the rear 
side wall 24' in the expanded position. A back side 54' of the sealing 
flange is fixedly attached to the rear side wall 24'. A bottom side 56' of 
the sealing flange 52' is substantially parallel to and spaced from the 
floor 26. A top side 55' of the sealing flange 52' tapers from the rear 
side wall outwardly toward the opposing rear side wall 24 and downwardly 
toward the floor 26. 
A front side 53' of the sealing flange 52' is shown in FIGS. 3, 9A and 9B. 
The front side 53' opposes a connector sealing flange 62' attached to the 
connector mechanism 28'. The front side 53' tapers downward from the top 
side 55' of the sealing flange 52' toward the connector sealing flange 
62'. In addition, a lower front edge 57' of the sealing flange 52', 
extending outwardly from the rear side wall 24' toward the opposing rear 
side wall 24, tapers away from the connector sealing flange 62', forming 
an acute angle with the rear side wall 24'. This creates a space between 
the sealing flange 52' and the connector sealing flange 62'. 
Sealing flanges 62 and 62' are also connected to connector mechanisms 28 
and 28' respectively, as shown from a top plan view in FIG. 5. A cutaway 
drawing of sealing flange 62' is shown in more detail in FIGS. 9A and 9B. 
As shown in FIG. 9A, a top member 65' and a bottom member 66' are attached 
to the connector mechanism 28' along their edges 67' and 68' respectively. 
The top and bottom members 65' and 66' extend outwardly from the connector 
mechanism 28' toward the opposing rear side wall 24. The bottom member 66' 
is substantially perpendicular to the connector mechanism 28'. The top 
member 65' tapers downward from the connector mechanism 28' and joins the 
bottom member 66' at a lower outer edge 64'. The lower outer edge 64' of 
the sealing flange 62' forms an acute angle with respect to the cross 
member 29'. It will be apparent to those in the art that the appropriate 
angle is determined based upon the distance that the attached rear side 
wall 24' can expand. In the preferred embodiment, a rear side 63' of the 
connector sealing flange 62' opposes the front side 53' of the sealing 
flange 52'. The rear side 63' extends outwardly from the connector 
mechanism 28' toward the opposing rear side wall 24, and tapers away from 
the sealing flange 52'. Finally, a plate 59' is connected to the bottom 
side 56' of the sealing flange 52' and extends outwardly toward, and 
slightly lower than, the bottom member 66' of the connector sealing flange 
62'. The distance between the plate 59' and the bottom member 66' is 
sufficiently small to contain solid material waste or other commodities 
within the trailer. 
In the preferred embodiment, the sealing flange 52 attached to the rear 
side wall 24 is a mirror image configuration of sealing flange 52' 
attached to the rear side wall 24'. Likewise, the connector sealing flange 
62 attached to the connector mechanism 28 is a mirror image configuration 
of the connector sealing flange 62' attached to the connector mechanism 
28'. 
Referring back to FIGS. 8A and 8B, a slide member 58' is fixedly attached 
to the floor 26 by means of a bottom rail 69'. The slide member 58' is 
substantially in the shape of a rectangular box and slidably contacts the 
bottom side 56' of the sealing flange 52' and the bottom member 66' of the 
connector sealing flange 62'. Thus, the slide member 58' extends along the 
entire lengths of the sealing flanges 52' and 62'. In the preferred 
embodiment the slide member 58' is approximately 3 inches wide and is made 
of Ultra High Molecular Weight (U.H.M.W.) plastic to provide a surface 
against which the sealing flanges 52' and 62' will smoothly slide when the 
rear side wall 24' is expanding or retracting. Slide member 58 which 
contacts sealing flanges 52 and 62, is configured in the same manner as 
slide member 58'. 
Referring now to FIG. 10, a side view of an alternative preferred 
embodiment of the present invention is shown. The alternative embodiment 
is a roll-off container 70 having expandable side walls. A roll-off 
container is a container, generally shorter in length than a typical 
transfer trailer, that is attachable to a tractor and that can be rolled 
off the tractor before being loaded with solid waste materials or other 
commodities. Once the roll-off container is loaded, it can be hoisted back 
onto the tractor for transporting the loaded commodities. The structure of 
the roll-off container 70 having expandable side walls, shown in FIG. 10, 
can be configured in the same manner as the trailer 10 described herein. 
Such a configuration allows expansion and retraction of the side walls to 
minimize spillage when directly loading solid material waste or other 
commodities into the container from a loading apparatus such as a garbage 
route collection truck. 
The parts of the roll-off container 70 shown in FIG. 10, 11A and 11B are 
numbered identically to the parts of the trailer 10 shown in FIGS. 1 
through 9. The container 70 is configured for receiving the solid material 
waste or other commodity in a container area within the container 70. The 
roll-off container has expandable vertical side walls 24 and 24' that are 
connected to non-movable portions shown generally at 18 and 18'. Connector 
mechanisms 28 and 28' connect the expandable side walls 24 and 24' with 
the non-movable portions 18 and 18', respectively. The connector 
mechanisms 28 and 28' each have a front hinge 30 and 30' pivotally 
connected to the non-movable portions 18 and 18'. Rear hinges 32 and 32' 
are pivotally attached to the vertical side walls 24 and 24' respectively. 
Finally, sealing flanges 52 and 52' are attached to vertical side walls 24 
and 24' respectively, while connector sealing flanges 62 and 62' are 
attached to connector mechanisms 28 and 28' respectively. A container 
floor 26 is substantially perpendicular to the vertical side walls 24 and 
24'. 
It will be understood that the hydraulics and the side walls and the 
sealing flanges discussed with reference to the preferred embodiment of 
trailer 10, are implemented in the same manner in this alternative 
embodiment of a roll-off container 70 and in other similarly configured 
containers. In addition, it will be understood that the references to 
alternative configurations or variations with respect to the trailer 10 
also apply to other similarly configured containers, such as the roll-off 
container 70. 
Operation 
FIG. 5 shows the expansion of the rear side walls 24 and 24' when the 
cylinders 42.1, 42.2, 42.1' and 42.2' are actuated. The expanded positions 
of the rear side walls 24 and 24' are represented by phantom lines, 
whereas the retracted positions of the rear side walls 24 and 24' are 
represented by solid lines. Similarly, the cylinders 42.1, 42.2, 42.1' and 
42.2' are shown in actuated positions by phantom lines, and are shown in a 
non-actuated positions by solid lines. When the rear side walls 24 and 24' 
are in the retracted positions, they lie substantially in the same plane 
defined by the front side walls 18 and 18', respectively. Similarly, when 
the rear side walls 24 and 24' are in the retracted positions, the 
connector mechanisms 28 and 28' lie in substantially the same plane 
defined by front side walls 18 and 18', respectively. 
To expand either of the rear side walls 24 or 24', the appropriate lever of 
the two spool valve 50 is engaged. When the lever for actuating the rear 
side wall 24 is engaged, pressurized oil flows through hydraulic line 46 
to cylinders 42.1 and 42.2. The extension members 43.1 and 43.2 exert 
pressure upon the rear side wall 24, shown in solid lines. As the force 
against the rear side wall 24 increases, the connector mechanism 28 begins 
to pivot at the front hinge 30 and the rear hinge 32, and the rear side 
wall 24 expands outwardly and substantially parallel to its retracted 
position. The outward expansion causes some contraction of the length of 
the rear side wall 24. This is caused by the rear side wall 24 moving 
slightly toward the front trailer portion 16 as the rear side wall 24 
expands. The extension members 43.1 and 43.2 of the cylinders 42.1 and 
42.2, respectively, remain substantially perpendicular to the rear side 
wall 24 as it expands, because the extension members 43.1 and 43.2 pivot 
about the pins 45.1 and 45.2 shown and described with reference to FIGS. 2 
and 6. Expansion of rear side wall 24' occurs in the same way as expansion 
of rear side wall 24. 
After the rear side wall 24 has expanded, the lever for actuating the 
hydraulic cylinders 42.1 and 42.2 will default to a neutral position, 
allowing the rear side wall 24 to remain in the expanded position until 
the lever is disengaged. When the lever is disengaged, the oil returns 
through hydraulic line 44 to the two-spool valve 50 and then through 
hydraulic lines 48 and 49 to the tractor 4. As pressure from the extension 
members 43.1 and 43.2 is reduced, and the extension members 43.1 and 43.2 
are pulled back into the cylinders 42.1 and 42.2, respectively, the rear 
side wall 24 is pulled back into the retracted position. The rear side 
wall 24' can be moved between the expanded position and the retracted 
position in the same manner as rear side wall 24. A separate lever, 
however, is provided on the two-spool valve 50 to actuate the cylinders 
42.1' and 42.2' for controlling the movement of the rear side wall 24'. 
Finally, the levers controlling the rear side walls 24 and 24' can be 
engaged simultaneously or separately. The operation of hydraulic systems 
in the above-described manner is well known in the art. 
In one alternative embodiment, only one of the rear side walls 24 or 24' 
would be expandable. It will be apparent that in an embodiment utilizing a 
single hinge connector mechanism, all of the cylinders used would be 
placed toward the rear end of the trailer 10, causing the rear side walls 
24 and 24' to pivot outwardly at an angle to the plane defined by their 
retracted positions. 
It will be apparent to those in the art that the hydraulics could be 
controlled by a hydraulic system in the truck, such as, for example, the 
hydraulically controlled running floor. In addition, the hydraulics could 
also be controlled by a hydraulic system separate and apart from the 
truck. It will be further apparent to one skilled in the art that the 
operation of the controller 40, of expanding and retracting the side 
walls, could be performed in a variety of ways. For example, electronics 
could be used for electrical control, a manual crank could be used for 
manual control, or air cylinders could be used to control movement of the 
side walls. Although hydraulics are used in the preferred embodiment, this 
invention is not limited by the method used to control expansion and 
retraction of the side walls. 
The function of the sealing flanges 52 and 52' can be explained with 
reference to FIGS. 5, 8A, 8B, 9A and 9B. FIG. 8A shows the rear side wall 
24' in the retracted position, whereas FIG. 8B shows the rear side wall 
24' in the expanded position. As the rear side wall 24' expands, the 
bottom side 56' of the sealing flange 52' moves across the slide member 
58'. As the rear side wall 24' moves away from the bottom rail 69', a gap 
is created between the rear side wall 24' and the bottom rail 69'. Because 
the sealing flange 52' extends along the entire length of the rear side 
wall 24' as shown in FIG. 5, the sealing flange 52' prevents the waste or 
other commodities being loaded onto the trailer from falling into the gap. 
The sealing flange 52 attached to the rear side wall 24, functions with 
respect to movement of the rear side wall 24 in the same way as sealing 
flange 52' functions with respect to movement of the rear side wall 24'. 
Referring back to FIG. 5, the operation and function of the sealing flanges 
62 and 62' is similar to the sealing flanges 52 and 52'. However, sealing 
flanges 62 and 62' seal gaps created between the connector mechanisms 28 
and 28' and the bottom rails 69 and 69', respectively. The gaps are 
created when the connector mechanisms 28 and 28' pivot outwardly at an 
angle to the bottom rails 69 and 69' respectively, as the rear side walls 
24 and 24' expand. The lower outer edges 64 and 64' of the sealing flanges 
62 and 62' are appropriately angled with respect to the cross members 29 
and 29' such that, as the rear side walls 24 and 24' expand, the lower 
outer edges 64 and 64' move to a position substantially parallel to the 
longitudinal axes of the bottom rails 69 and 69'. The sealing flanges 62 
and 62' are sufficiently extended to ensure that the gaps between the 
connector mechanisms 28 and 28' and the bottom rails 69 and 69', created 
when the rear side walls 24 and 24' are in the expanded positions, are 
closed. 
FIGS. 9A and 9B show the cooperation between the sealing flange 52' and the 
connector sealing flange 62'. FIG. 9A shows the sealing flanges 52' and 
62' when the rear side wall 24' is in the retracted position. The plate 
59' extends from the bottom side 56' of the sealing flange 52', across the 
space between the sealing flanges 52' and 62', to beneath the connector 
sealing flange 62'. This configuration of the plate 59' results in 
containment of solid material waste and other commodities within the 
trailer 10. As the rear side wall 24' expands, the sealing flange front 
side 53' and the connector sealing flange rear side 63' move toward each 
other. FIG. 9B shows the flanges 52' and 62' when the rear side wall 24' 
is completely expanded. When expanded, the sealing flanges 52' and 62' are 
configured such that the lower front edge 57' of the front sealing flange 
52' lies adjacent and substantially parallel to the rear side 63' of 
connector sealing flange 62'; and the plate 59' is positioned adjacent to 
the connector sealing flange bottom member 66'. The tapered configuration 
of the front side 53' of the sealing flange 52' prevents waste or other 
commodities from becoming trapped between the flanges 52' and 62' as they 
move toward each other. It will be apparent to those in skilled in the art 
that the sealing flanges 52' and 62' could be configured in a variety of 
ways to allow expansion and retraction of the side walls while preventing 
spillage of waste. The sealing flanges 52 and 62 are configured to 
cooperate during expansion and retraction of rear side wall 24 in the same 
manner as the sealing flanges 52' and 62' cooperate during expansion and 
retraction of the rear side wall 24'. 
The preferred embodiments of this invention as shown and described above, 
in addition to alternative embodiments referenced, provide a trailer or 
other container for loading garbage or other commodities directly from a 
garbage route collection truck or other similar vehicle. This invention 
minimizes the spillage of garbage or other commodities when being directly 
loaded into the trailer. While the invention has been disclosed with 
reference to the preferred embodiments, it will be appreciated that 
modifications and equivalents of the disclosed concepts may be apparent to 
those skilled in the art having the benefit of the teachings of the 
present invention. It is intended that the scope of the present invention 
not be limited by the specific embodiments shown above, but shall include 
such modifications and equivalents.