Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02305909 2000-04-17
S B.aCKGROUND OF THE INVEYTIOIY
Field of the Invention
The invention relates to a waste container, and, more specifically, to a
waste container having a reinforced bottom.
Related Art
Current residential waste containers comprise a container body having
an open top and a closed bottom. A handle is typically located near the open
top and a
wheel assembly is typically located near the bottom of the container body. The
top is
closed by one or more lids, which are hingedly connected to the body or a
divider in
the body. Most residential waste containers have a relatively large capacity
of 30
1S gallons or more. It is also common for the waste container to be injection-
molded out
of a suitable plastic.
A common problem for this type of waste container is that the weight
of the contents held by the container body can bow the waste container bottom
downwardly a sufficient amount so that it contacts the ground, resulting in
increased
wear and tear on the container body bottom as the waste container is moved
about
during its lifetime. Ultimately, the excess wear and tear on the container
body bottom
results in a premature failure of the container. ~ Although this problem can
be reduced
by increasing the thickness of the bottom wall; this solution increases the
cost of the
container due to increased material costs and increased cycle time and may
also result
in undesirable stresses in the container body due to differential cooling
during the
molding process.
An additional problem arises from the current container bodies having
a relatively narrow draft in order to obtain the greatest amount of volume in
the
smallest plan form. The narrow draft often makes it difficult to remove the
container
body from the injection mold because of the tendency for a vacuum to form
between
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the container bottom and the mold. To aid in the removal of the container
body, air is
injected between the mold and the container bottom. The injected air has a
tendency
to extend the container bottom upwardly into the container body cavity. Since
the
container body is still relatively warm during removal, the force of the
injected air can
cause a permanent stretching or arching of the bottom, which exacerbates the
tendency
of the bottom to contact the ground when the container body is loaded with
waste and
the bottom inverts from the load.
SUMMARY OF THE INVENTION
The invention relates to a waste container for the storage and collection of
residential or commercial waste, comprising an open top body closeable by a
cover
pivotally mounted to the body, a wheel assembly provided near the bottom of
the body
and a handle extending from the body. The body has a bottom wall with a
peripheral
edge and a peripheral wall extending upwardly from the bottom wall peripheral
edge
and terminating in an upper edge to define a waste compartment with an open
top. An
inner rib projects downwardly from a bottom surface of the bottom wall and a
plurality of corrugations are formed in the bottom wall and extend from the
bottom
wall peripheral edge to the inner rib wherein the corrugations and inner rib
cooperate
to form a structural support for the bottom wall.
Preferably, the corrugations comprise elongated indentations, which have a
thickness substantially the same as the bottom wall thickness. Each of the
elongated
indentations preferably define a longitudinal axis and have a U-shaped Gross
section
transverse to the longitudinal axis. When arranged in groups, the combined U-
shaped
Gross sections of the elongated indentations form a truncated sinusoidal-like
wave
form. Some of the elongated indentations can extend past the rear edge of the
bottom
wall and at least partially up the peripheral wall.
The inner rib can circumscribe an interior portion of the lower surface of the
bottom wall. The bottom wall peripheral edge is substantially rectangular and
defines
a front edge, a rear edge, and side edges connecting the front and rear edges
to form
corners at the junctions of the front and rear edges with the side edges, with
corner
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indentations having an elongated arcuate profile positioned in the bottom wall
near the
corners and extending between adjacent groups of elongated indentations.
The body can include an outer peripheral rib projecting downwardly from the
peripheral edge of the bottom wall along at least a portion of the bottom wall
peripheral edge and at least some of the groups of elongated indentations
extending
between the outer rib and the inner rib.
The wheel assembly preferably comprises an axle mounted to the body and a
pair of wheels mounted to the axle, with at least the axle being rotatable
relative to the
body or the wheels being rotatable relative to the axle.
The invention also relates to a waste container for the storage of waste,
comprising a body having a bottom wall with a peripheral edge and a peripheral
wall
extending upwardly from the bottom wall peripheral edge and terminating in an
upper
edge to define a waste compartment with an open top. An inner rib projects
downwardly from a bottom surface of the bottom wall and a plurality of
corrugations
are formed in the bottom wall and extend from the bottom wall peripheral edge
to the
inner rib wherein the corrugations and inner rib cooperate to form a
structural for the
bottom wall.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a left-front upper perspective view of a waste container with
an open-top body having reinforced bottom according to the invention and a
cover for
closing the open top of the body and a wheel assembly;
FIG. 2 is a right-rear upper perspective view of the waste container of
FIG. I with the cover removed and the wheel assembly shown in exploded;
FIG. 3 is a left rear lower perspective view of the waste container of
FIG. 1 illustrating the corrugations in the waste container bottom with the
cover and
wheel assembly removed;
FIG. 4 is a top view of the waste container of FIG. 1 illustrating the
bottom wall corrugations;
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FIG. 5 is a bottom view of the waste container of FIG. 1 illustrating the
bottom wall corrugations;
FIG. 6 is a enlarged partial perspective view of the corrugations in the
bottom wall of the waster container; and
FIG. 7 is a sectional view taken along line 6-6 of FIG. 5 and illustrating
the Gross-sectional shape of the corrugations.
DETAILED DESCRIPTION
FIGS. 1-3 illustrate a waste container 10 according to the invention.
The waste container 10 comprises a waste container body 12 from which extends
a
handle assembly 14 to which is pivotally mounted a cover 15. A wheel assembly
16
is mounted to a rear lower portion of the body.
The waste container body 12 comprises a peripheral wall that is
defined by a front wall 18, a rear wall 20, and side walls 22, 24, which
extend
upwardly from a bottom wall 26 to define a waste compartment 28 to which
access is
provided through an open top 30. The open top 30 is bounded by a peripheral
lip 32.
The front wall 18 can be provided with an alcove 34 or similar
structure, which is often used to aid in the lifting of the container into a
collection
vehicle. Similarly, the intersections of the front, rear, and side walls are
rounded 38 to
define a series of shoulders 40. The rounded side walls 38 and the shoulders
40
combine to form a lifting surface for a mechanical lifting device. The
peripheral lip
32 can also be used as a lifting surface.
The rear wall 20 includes an alcove 42 located near the intersection of
the rear wall with the bottom wall 26. A series of mounting webs 44 are formed
in the
alcove 42 of the rear wall 20 to permit the mounting of the wheel assembly 16,
which
includes an axle 45 received in openings in the webs 44, with wheels 46
mounted to
the shaft by a fastener 47, which is enclosed by a cover 48. Such a wheel
assembly is
disclosed in U.S. Patent No. 5,716,107, which is incorporated by reference.
Referring to FIGS. 3-5, the bottom wall 26 has an outer peripheral
wear rib 50 that extends along the side walls 22, 24 and across the front wall
18. An
inner wear rib 52 extends from the lower surface of the bottom wall 26 and
defines a
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central support area 64. Preferably, the inner wear rib 52 has a generally
rectangular
shape, but it could also define other geometric enclosed shapes (circle,
triangle,
hexagon, etc.) and non-enclosed shapes.
A series of corrugations 54 are formed in the bottom wall to provide it
with increased rigidity. For description purposes, the corrugations 54 can be
divided
into sets or groups based on their location: side wall corrugations 56, front
wall
corrugations 58, rear wall corrugations 60, and corner corrugations 62. The
side wall
corrugations 56 and front wall corrugations 58 all extend from the outer wear
rib 50 to
just past the inner wear rib 52. The rear wall corrugations 60 extend from the
inner
wear rib 52, around the junction of the rear wall 20, and the bottom wall 26,
and
partially up the rear wall 20 within the alcove 42. The corner corrugations 62
effectively connect the adjacent sets of side wall corrugations 56, front wall
corrugation 58, and the rear wall corrugation 60. L-shaped side support ribs
53 are
arranged in pairs and extend from the front, rear and side walls to the bottom
wall.
As best seen in FIGS. 6 and 7, all of the corrugations are elongated
indentations with a generally inverted U-shape profile comprising side walls
66, 68
connected by a bottom wall 70. The corrugations extend upwardly into the waste
compartment 28. The side walls 66, 68 are preferably canted outwardly away
from
the bottom wall 70, which is preferably arcuate, to form a continuous arc with
the
bottom wall 70. A flat portion of the bottom wall connects the adjacent
indentations,
resulting in a group of the corrugations having a wave-like Gross section in
the form of
a truncated sinusoidal-like wave form. The corrugations of the preferred
embodiment
also have a substantially constant thickness, which is also preferably equal
to the
bottom wall thickness.
The corrugations can take a number of different Gross-sectional shapes,
including triangular and rectangular Gross sections. Also, the thickness of
the
corrugations can vary relative to the thickness of the bottom wall.
Preferably, the
corrugations have a relatively thin Gross section since the thicker the
material, the
greater the cooling time and the greater the likelihood that stresses will
build up in the
bottom wall.
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The U-shaped Gross section of the corrugations 54 increases the
surface area of the bottom wall 26. The surface area of the waste container
bottom
illustrated in FIGS. 1-7 is up to two times greater than the surface area
without the
corrugations 54. The corrugations 54 also provide extra rigidity to the bottom
wall 26
because of their Gross-sectional shape which resists bending better than a
planar
bottom wall. Also, since the corrugations in general extend from the outer
wear rib 50
to the inner wear rib 52, the combination of the wear ribs (which also provide
a
strengthening function) with the intersecting corrugations 54 provides an
interlocking
web of strengthening elements that greatly increase the overall rigidity of
the bottom
wall.
Functionally, the rear wall corrugations 60 provide a fluid channel
from the rear wall to the bottom wall since the corrugations 60 extend around
the
intersection of the rear wall and bottom wall. The fluid channel formed by the
rear
wall corrugations help eliminate the likelihood of a vacuum forming between
the
bottom wall and the mold during removal of the container body from the mold
during
the injection molding process.
The corrugations 54 provide multiple advantages over the prior art. In
addition to the increased rigidity of the bottom wall, the corrugations also
provide an
increased bottom wall surface area that provides for faster cooling of the
bottom wall
during the molding process making it more uniform with the cooling rate of the
material in the rest of the cart. Another advantage of the corrugations is
that they
provide airflow channels for the flow of air between the mold and the bottom
wall
during the molding process to improve the ease of removal of the waste
container
body 12 from the mold. The combination of the increased rigidity and the
airflow
channels make it less likely that the bottom wall 26 of the container body 12
stretch or
deform when air is injected between the bottom wall 26 and the mold during
removal
of the container body 12 from the mold, which reduces the likelihood of the
bottom
wall sagging during operation which can cause the premature failure of the
waste
container. The increased cooling rate attributable to the increased surface
area also
reduces the likelihood of molded-in stresses.
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Reasonable variation and modification are possible within the scope of
the foregoing disclosure without departing from the spirit of the invention
which is
defined by the appended claims.
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PARTS LIST
waste container 38 rounded
12 waste container body 40 shoulder
14 hand assembly 42 alcove
16 wheel mount assembly 44 mounting webs
18 front wall 46
rear wall 48
22 side wall 50 outer wear rib
24 side wall 52 inner wear rib
26 bottom wall 54 corrugations
28 waste compartment 56 side wall corrugations
open top 58 front wall corrugation
32 peripheral lip 60 rear wall corrugation
34 alcove 62 corner corrugations
36 64 central support
area
60033997. DOC
