U.S. patent application number 10/273421 was filed with the patent office on 2003-08-28 for molded container assembly for transporting bulk materials.
Invention is credited to Knutson, Thomas, Kovash, Dean, Reiter, William P..
Application Number | 20030160049 10/273421 |
Document ID | / |
Family ID | 25071979 |
Filed Date | 2003-08-28 |
United States Patent
Application |
20030160049 |
Kind Code |
A1 |
Reiter, William P. ; et
al. |
August 28, 2003 |
Molded container assembly for transporting bulk materials
Abstract
A container assembly for transporting bulk materials that
includes a molded, one-piece completely integral non-metallic
container insert and a frame supporting the container insert. The
container insert can be molded of polyolefin. It can include walls
having varying thicknesses, a bottom wall having a thickness
greater than the side walls, and/or reinforcing structures molded
within the walls. The container assembly can be constructed to
provide a fixed truck box or dump truck box.
Inventors: |
Reiter, William P.;
(Dickinson, ND) ; Knutson, Thomas; (Dickinson,
ND) ; Kovash, Dean; (Manning, ND) |
Correspondence
Address: |
MUETING, RAASCH & GEBHARDT, P.A.
P.O. BOX 581415
MINNEAPOLIS
MN
55458
US
|
Family ID: |
25071979 |
Appl. No.: |
10/273421 |
Filed: |
October 17, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10273421 |
Oct 17, 2002 |
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09535284 |
Mar 24, 2000 |
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6478176 |
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09535284 |
Mar 24, 2000 |
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08764852 |
Dec 13, 1996 |
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6076693 |
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Current U.S.
Class: |
220/9.1 |
Current CPC
Class: |
B60P 1/286 20130101 |
Class at
Publication: |
220/9.1 |
International
Class: |
B65D 030/10; B65D
033/02 |
Claims
What is claimed is:
1. An apparatus for transporting bulk materials, the apparatus
comprising: an open support frame formed of spaced-apart frame
members; and a non-metallic container insert located substantially
within the support frame, and further wherein the container insert
comprises at least a front wall, a bottom wall, and opposing side
walls that are provided as a molded, one-piece, completely integral
unit.
2. An apparatus according to claim 1, further comprising at least
one flange located on an exterior surface of at least one of the
side walls of the container insert, wherein the at least one flange
extends generally longitudinally along a longitudinal axis of the
container insert, and further wherein the at least one flange rests
on one of the spaced-apart frame members of the support frame.
3. An apparatus according to claim 1, further comprising retaining
structure on an exterior surface of the container insert, wherein
the retaining structure, the container insert and the support frame
cooperate to retain the container insert within the support
frame.
4. An apparatus according to claim 3, wherein the retaining
structure is molded integral with the exterior surface of the
container insert.
5. An apparatus according to claim 3, wherein the retaining
structure further comprises at least one eyelet on an exterior
surface of the container insert.
6. An apparatus according to claim 3, wherein the retaining
structure is located along a single axis transverse to the
longitudinal axis of the container insert, wherein the container
insert can expand and contract along the longitudinal axis
independent of the support frame.
7. An apparatus according to claim 1, wherein the container insert
further comprises means for retaining the container insert within
the frame.
8. An apparatus according to claim 1, wherein the container insert
includes at least one wall of varying thickness.
9. An apparatus according to claim 1, wherein the bottom wall of
the container insert has a thickness that is greater than the
thickness of at least one of the opposing side walls.
10. An apparatus according to claim 1, wherein the container insert
is formed of at least one polyolefin material.
11. An apparatus according to claim 1, wherein at least a portion
of the container insert comprises a reinforcing structure molded
therein.
12. A truck box comprising: an open support frame formed of
spaced-apart frame members; and a non-metallic container insert
located substantially within the support frame, and further wherein
the container insert comprises at least a front wall, a bottom
wall, and opposing side walls that are provided as a molded,
one-piece, completely integral unit.
13. A truck box according to claim 12, wherein the bottom wall is
thicker than at least a portion of at least one of the opposing
side walls.
14. A truck box according to claim 12, wherein at least one of the
opposing side walls of the container insert has a varying
thickness.
15. A truck box according to claim 12, wherein further comprising
at least one eyelet on an exterior surface of the bottom wall of
the container insert.
16. A truck box according to claim 15, wherein the eyelet is
located proximate a rear of the container insert.
17. A truck box according to claim 12, further comprising at least
one flange located on an exterior surface of at least one of the
side walls of the container insert, wherein the at least one flange
extends generally longitudinally along a longitudinal axis of the
container insert, and further wherein the at least one flange rests
on one of the spaced-apart frame members of the support frame.
18. A truck box according to claim 12, further comprising retaining
structure on an exterior surface of the container insert, wherein
the retaining structure, the container insert and the support frame
cooperate to retain the container insert within the support
frame.
19. A truck box according to claim 18, wherein the retaining
structure further comprises at least one eyelet on an exterior
surface of the container insert.
20. A truck box according to claim 18, wherein the retaining
structure is located along a single axis transverse to the
longitudinal axis of the container insert, wherein the container
insert can expand and contract along the longitudinal axis
independent of the support frame.
21. An apparatus for transporting bulk materials, the apparatus
comprising: an open support frame consisting essentially of
spaced-apart frame members; and a non-metallic container insert
located substantially within the support frame, and further wherein
the container insert comprises at least a front wall, a bottom
wall, and opposing side walls that are provided as a molded,
one-piece, completely integral unit.
22. A truck box comprising: an open support frame consisting
essentially of spaced-apart frame members; and a non-metallic
container insert located substantially within the support frame,
and further wherein the container insert comprises at least a front
wall, a bottom wall, and opposing side walls that are provided as a
molded, one-piece, completely integral unit.
Description
RELATED APPLICATIONS
[0001] This is a continuation of U.S. patent application Ser. No.
08/764,852 filed on Dec. 13, 1996, which is incorporated herein by
reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of shipping and
trucking containers. More particularly, the present invention
includes a container assembly including a molded, one-piece,
completely integral non-metallic container insert and frame.
BACKGROUND OF THE INVENTION
[0003] A wide variety of containers are used to transport bulk
materials. Typically, containers for transporting bulk materials
are constructed of sheet metal either fashioned into a tank or an
open container such as a fixed truck box, pivoting dump truck box,
or roll-off container. As used in connection with the present
invention, "containers" includes open containers such as pivoting
dump truck boxes, fixed truck boxes, roll-off containers detachable
from a truck, intermodal containers designed to be transported by
ship, train or truck, substantially enclosed tanks for use in
transporting bulk liquids, and any other container assembly for
transporting bulk materials that is adapted to be attached to a
truck, truck-like vehicle, or trailer. Containers within the
meaning of that term as used in connection with the present
invention are designed to transport bulk materials in loads ranging
from one-half ton or more. The materials can include soil, rocks,
grains, foods, liquids, etc.
[0004] The containers are typically manufactured using sheet metal
(typically steel) attached to a framework of structural members.
Sheet metal is used to manufacture the boxes because of its
strength and resistance to wear--both properties that are required
during typical use of the trucks. In spite of the durability and
toughness provided by the sheet metal boxes, there are drawbacks
associated with metal truck boxes and other containers.
[0005] One problem is that the truck boxes and other containers
manufactured with sheet metals are themselves typically relatively
heavy which limits the loads that can be transported by the trucks.
Furthermore, the sheet metal used to manufacture the truck boxes
and containers typically corrodes easily, reducing the useful life
of the containers. In addition, it may not be desirable or
allowable to allow some materials to come into contact with the
sheet metal, thereby requiring the use of expensive liners or other
methods to prevent contact between the materials and the sheet
metal.
[0006] Furthermore, the sheet metal can make unloading difficult in
some situations. For example, in colder climates moisture in the
materials may cause them to freeze to the interior of the
container, typically requiring hand labor to dislodge the material.
In some situations, the entire container may need to be heated to
facilitate unloading and/or pressurized water may be required to
completely unload the container. All of these actions raise the
cost of transporting materials using conventional containers
manufactured from sheet metal.
[0007] In addition to freezing, friction between the materials and
the sheet metals used in the containers can also make unloading
difficult, requiring the operator, in some situations, to rapidly
accelerate and decelerate the containers (which may be mounted to
pivot about the end of the truck) in an attempt to jar the
materials loose. Such actions add unnecessary stress and wear to
the containers as well as the hydraulic lifts used to pivot them,
adding the cost to repair any damage and potentially reducing the
useful life of the containers and/or hydraulic lifts.
[0008] In addition to causing difficulty in unloading when the load
remains in the container, such situations may also result in
personal injury or damage to the truck because the probability of,
for example, a dump truck tipping over is greatly increased when
its box is raised to dump a load of material. The probability of
tipping is increased because the load typically stays in the front
end of the box (which is raised the highest). The raised load may
raise the center of gravity of the truck above a point at which the
truck is stable, particularly in locations, such as construction
sites, where the ground is uneven or unstable.
[0009] To address the issue of friction between the load and truck
box, some users may coat the interior of the truck box with a
release agent, such as diesel fuel, that assist in removal of the
load during dumping. That practice can cause undesirable
environmental contamination as the materials unloaded from the
container invariably carry with them some of the diesel fuel or
other release agent.
SUMMARY OF THE INVENTION
[0010] The present invention provides a container assembly for
transporting bulk materials that includes a molded, one-piece
completely integral non-metallic container insert and a frame
supporting the container insert. The advantages provided by the
invention include reduced weight as compared to container
assemblies manufactured with sheet steel, reduced corrosion,
improved release properties, and the ability to easily replace a
worn container insert while retaining the supporting frame.
[0011] In one aspect, the present invention comprises a container
assembly for transporting bulk materials including a substantially
rigid frame formed of spaced-apart members; and a molded,
one-piece, completely integral non-metallic container insert having
at least one wall with an exterior surface, the container insert
located substantially within the frame, the exterior surface
including a retaining structure for attaching the container insert
to the frame, wherein the retaining structure is molded integral
with the exterior surface of the container insert.
[0012] The container insert is preferably molded of a non-metallic
material, such as a polyolefin. It can include walls having varying
thicknesses, a bottom wall having a thickness greater than the side
walls, and/or reinforcing structures molded within the walls. The
container assembly can be constructed to provide a substantially
enclosed tank, a roll-off container, intermodal container, a fixed
truck box, or a dump truck box.
[0013] In another aspect, the present invention comprises a truck
box for transporting bulk materials, the truck box including a
substantially rigid frame formed of spaced-apart members; and a
molded, one-piece, completely integral nonmetallic container insert
having at least one wall with an exterior surface, the container
insert located substantially within the frame, the exterior surface
including a retaining structure for attaching the container insert
to the frame, wherein the retaining structure is molded integral
with the exterior surface of the container insert.
[0014] These and other various features and advantages of the
present invention are described in more detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a perspective view of one container assembly
according to the present invention.
[0016] FIG. 2 is a perspective view of the frame used in the
assembly of FIG. 1.
[0017] FIG. 3 is a side view of the container assembly of FIG.
1.
[0018] FIG. 4 is a front end view of the container assembly of FIG.
1.
[0019] FIG. 5 is a perspective view of the container insert used in
the assembly of FIG. 1.
[0020] FIG. 6 is a cross-sectional view along line 6-6 of the
container assembly as shown in FIG. 4.
[0021] FIG. 7 is a partial cut-away view of a portion of one
container insert according to the present invention.
[0022] FIG. 8 is a cross-sectional view of one door assembly useful
in connection with the container assembly shown in FIG. 1.
[0023] FIG. 9 is a perspective view of an alternative container
insert for a container assembly according to the present
invention.
[0024] FIG. 10 is a perspective view of another alternative
container insert for a container assembly according to the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] The present invention provides a container assembly
incorporating a non-metallic container insert supported within a
frame having spaced-apart members. FIG. 1 is a perspective view of
one container assembly 10 according to the present invention
including a frame 20 and a non-metallic container insert 30. The
container assembly 10 is adapted for attachment to a vehicle (not
shown), typically a truck such as a dump truck or fixed bed truck
(including a pickup truck), so that it can be transported with a
load of material located within the container insert 30. In many
instances, the container assembly 10 will be mounted for pivotal
movement about its back end 12 such that materials located in the
container insert 30 can be removed by raising the front end 14 of
the container assembly 10 relative to the back end 12.
[0026] Referring now to FIGS. 2-4, the frame 20 includes a bottom
22 formed from spaced-apart longitudinally extending members 21. A
series of transverse bottom frame members 23 are provided to
support the container insert 30 as well as to maintain the spacing
between members 21. At the front end, the longitudinally extending
members 21 are attached to a pair of front upright members 24. At
the rear end, the longitudinally extending members 21 are attached
to a rear frame bottom member 26. The rear frame bottom member 26
supports a pair of rear upright members 27. The rear upright
members 27 and front upright members 24 are attached to side
supports 28 that extend along both sides and around the front end
14 of the container assembly 10.
[0027] It is preferred that the frame 20 be constructed of
substantially rigid materials such as structural steel, although
any other suitable materials could be provided. The exact
dimensions of the members and their arrangement will be based on
the intended use of the container assembly 10. It should be
understood that the although a specific embodiment of the frame 20
is depicted in the figures, any suitable frame construction
incorporating spaced-apart frame members designed to support a
non-metallic container insert 30 could be provided in connection
with the present invention.
[0028] An important feature of the invention is that the frame 20
is constructed of spaced-apart members adapted to support and
enclose the nonmetallic container insert 30 such that it retains
its shape when loaded with a bulk material. As a result, the
spaced-apart frame members of the frame 20 will typically define a
volume within which the container insert 30 is located and
supported. By providing that combination, a container assembly 10
according to the present invention offers a relatively light weight
assembly for transporting bulk materials that is still structurally
sound.
[0029] FIG. 5 depicts the container insert 30 removed from the
frame 20 of the container assembly 10. The container insert 30 is
constructed from nonmetallic materials that provide the required
strength (when supported in frame 20) to transport the desired
loads. Among suitable non-metallic materials for the container
insert 30 are polyolefins (including blends thereof). One
particularly preferred material for container insert 30 is high
density polyethylene (HDPE) because of its rigidity, strength,
chemical resistance, and high-release, low-friction surface
properties. It will be understood that any non-metallic material
having the properties necessary to form a container insert 30 in a
container assembly 10 according to the present invention could be
substituted for the preferred materials. Furthermore, although the
entire container insert 30 of the preferred embodiment is formed of
HDPE, it may be possible to provide different portions of the
container insert 30 of different materials. It may also be
desirable to provide container inserts having walls constructed of
layers of different materials to enhance strength, abrasion
resistance, impact resistance, etc. In additional, it will also be
understood that additional components may be included in the
materials, such as UV stabilizers, release agents, etc.
[0030] The container insert 30 includes a bottom wall 32, opposing
side walls 34 and a front wall 36. The rear of the container insert
30 preferably includes a flange 31 adapted to butt against the rear
of the frame 20. Opposing pairs of raised ribs or flanges 38 are
also provided on the exterior surfaces of the side walls 34 and the
front wall 36. Each opposing pair of flanges 38 defines a slot
within which one of the side supports 28 can be located to assist
in supporting the container insert 30 as well as assist in
retaining the container insert 30 in the frame 20.
[0031] The relationship between the flanges 38 and side supports 28
can be best seen in the cross-sectional view of FIG. 6 (taken along
line 6-6 in FIG. 3). As shown, the slots defined by each pair of
flanges 38 at least partially receives a side support 28. It is
preferred that the slots defined by the flanges 38 and side
supports 28 have complementary shapes as shown to assist in their
ability to cooperate to retain the container insert 30 within frame
20. They may also include other attachment means such as mechanical
fasteners, etc. It is however, preferred that any such methods of
attachment provide for movement of the container insert 30 relative
to the frame 20 due to thermal expansion/contraction.
[0032] FIG. 6, along with FIG. 2, depict one preferred retaining
structure 40 located near the rear of the container insert 30. The
retainers 40 are essentially eyelets that fit within cooperating
slots 42 in the rear frame bottom member 26 (see FIG. 2). Openings
44 (see FIGS. 2 and 3) provided in the rear frame bottom member 26
align with openings 46 (see FIG. 5) in the retainers 40 to allow
for the insertion of a pin or rod 48 through member 26 and
retainers 40 to retain the container insert 30 within frame 20.
[0033] It is helpful to attach the container insert 30 to the frame
20 at a single point (or along a single axis transverse to the
longitudinal axis of the container assembly 10) due allow the
container insert 30 to expand and contract in response to
temperature variations without inducing stresses due to the
differential expansion rates of the frame 20 and the container
insert 30. Although one mechanism for attaching the container
insert 30 is depicted, it will be understood that many other
mechanisms could be provided to accomplish the same result.
[0034] The container insert 30 is preferably a molded, one-piece,
completely integral object to avoid introducing areas of weakness
or stress concentrations from attaching components to the container
insert 30 through welding, adhesives, mechanical fasteners, etc. It
should be understood, however, that additional minor components
could be attached after molding, but they are preferably not
structurally integral with the container insert 30. One example of
a component that may be added to the container insert 30 is the cab
protector 31 best seen in FIG. 1. The protector can be attached to
the upper edge of the container insert 30 by any suitable means,
including, but not limited to: welding, adhesives, mechanical
fasteners, etc.
[0035] To provide a molded one-piece, completely integral container
insert 30, it is advantageous to employ a rotational molding
process. One such process is described in U.S. Pat. No. 5,316,701
to Payne. Rotational molding services are provided by a number of
companies, including Snyder-Crown Industries, Lincoln, Nebr., as
well as Assmann Corporation, Garrett, Ind. Other molding methods
could also be used including compression, injection, etc.
Regardless of the molding process used, it is preferable to mold
the structures used to retain the container insert 30 within the
frame 20, such as flanges 38 and retainers 40, integrally with the
remainder of the container insert 30 to reduce any potential
problems associated with welding or other means of attaching such
structures to the container insert 30.
[0036] One advantage of molding the container insert 30 as a
one-piece integral unit is that the corners, i.e., the junction
between the bottom 32, side walls 34 and front wall 36 can be
provided in a smoothly rounded shape as seen in, for example, FIG.
5. Those smoothly rounded corners help reduce the incidence of
materials gathering and remaining in the container insert 30 after
unloading. That problem is particularly acute when the materials
being transported have high moisture contents, such as grains,
etc.
[0037] It is also desirable to provide the container insert 30 with
varying wall thicknesses to enhance the weight and strength
advantages of the container assembly 10 according to the resent
invention over conventional container assemblies. It is preferred
that any variations in wall thickness are gradual, i.e., not
step-wise or discrete, to avoid inducing any areas of stress
concentration in the walls. The use of varying wall thicknesses in
a molded, one-piece, completely integral container 30 provides
enhanced strength, impact resistance, and ability to endure wear
without premature failure that could not be provided if the
container insert 30 was, for example, constructed of various pieces
of material attached together through welding.
[0038] It will typically be desirable to provide thicker walls in
the bottom of the container insert 30 as well as at the junction
between the bottom wall 32 and the side walls 34 and front wall 36.
Those areas will typically be subjected to the greatest wear and
impacts as the container assembly 10 is loaded and unloaded. For
example, if HDPE is used to form the container insert 30 for a
container assembly designed for a dump truck, the side walls 34 and
front wall 36 could be provided with a thickness of about 5/8
inches (15.9 mm) while the areas such as the radius between the
bottom wall 32 and side walls 34 or front wall 36 as well as the
bottom wall 32 could be thicker, i.e., about 1 inch (25.4 mm), to
withstand the increased forces and wear likely to be encountered in
those areas. Alternatively, the container insert 30 could be
provided with more localized areas where the wall thickness is
increased, such as where fittings or other components may be
attached to the insert 30 after molding.
[0039] In addition to providing varying wall thicknesses in the
areas of wear, it may also be desirable to provide reinforcing
structures in the material such that the wall thickness can be
further reduced without excessively reducing the strength of the
walls. Examples of potential reinforcing structures that could be
included within the bulk of the material of the container insert 30
include fibers, netting, meshes, etc., or a combination of the
above. FIG. 7 depicts a partial cutaway view of a portion of a
container insert 30 including a reinforcing mesh structure 33. The
reinforcing structures could be constructed of any suitable
materials, although one particularly material is KEVLAR.TM.,
available from E. I. DuPont de Nemours, Wilmington, Del. The
reinforcing structures may also be provided in only selected areas
where severe impacts are to be expected, or throughout the
container insert 30.
[0040] The container assembly 10 may also include a door assembly
50 at the rear end to retain materials within the container insert
30 during transport as seen in FIG. 1. A conventional pivoting door
may be used in connection with the container assembly 10 according
to the present invention or, optionally, a door assembly 50
including a non-metallic door panel 60 on a frame 70 could be
provided, one embodiment of which is depicted in FIG. 8.
[0041] As with the container insert 30, the door panel 60 is also
preferably molded as a one-piece, completely integral object. The
materials described above for the container insert 30 would also
preferably be used for the door panel 60. FIG. 8 is a
cross-sectional view of the door assembly 50 including vertical
members 72 and cross-members 74. The cross-members 74 preferably
include 10 flanges 76 adapted to fit within slots 64 formed in
flanges 62 on door panel 60 as shown. The upper end of the outside
vertical members preferably include hinge plates 78 for hingedly
attaching the door assembly 50 to the container assembly 10.
Alternatively, the door assembly 50 could rotate about a side of
the container assembly 10 or about the bottom edge of the container
insert 30.
[0042] Such a door assembly may not be required where the container
insert is provided with a rear wall provided as a part of the
molded, one-piece, completely integral container insert. One such
design is depicted in FIG. 9 where the rear wall 135 is formed as
part of the container insert 130. A container 130 as depicted in
FIG. 9 may be useful for use in connection with side-dumping trucks
or trailers. Alternatively, the container insert 130 may also be
provided with a top wall to provide a substantially enclosed volume
for use in connection with an intermodal shipping container.
[0043] Another alternative is depicted in FIG. 110, where the
container insert 230 is formed as a molded, one-piece completely
integral object that substantially encloses a volume to provide a
tank. In such a design, it may be desirable to increase the wall
thickness in localized areas where fittings are to be attached to
the insert 230 to increase its strength. It may also be desirable
to include baffles in the tank to reduce movement of the liquids
during transport. It will also be understood that it may be
desirable to provide such a tank in a food-grade material suitable
for transporting, for example, drinking water, milk, or other
liquid food products.
[0044] Although various features and advantages of the present
invention have been described herein, it will be understood that
variations and substitutions can be made which do not fall outside
the scope of the invention as defined by the claims appended
hereto.
* * * * *