Note: Descriptions are shown in the official language in which they were submitted.
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CONTAINER HAVING TEXTURED GRIP AND ENHANCED WALL INTEGRITY
BACKGROUND OF THE INVENTION
Field of Invention
The present invention relates to an improved nestable container, such as for
food or beverages. More particularly, the present invention is directed to a
nestable
container having enhanced wall integrity, increased rim strength, and improved
tactile
engagement.
Description of Related Art
A variety of thermoplastic containers, such as containers for food and
beverages, are well known in the art. Such thermoplastic containers are
relatively
inexpensive and disposable; and tllerefore are extremely popular. Such
containers are often
used at parties, picnics, gatherings, and other occasions where little or no
clean-up is desired.
Although thermoplastic containers offer consumers many benefits, there are
certain drawbacks affiliated with manufacture and use of thermoplastic
containers. For
instance, such a container can have a weak or flimsy side wall, as well as a
weak rim. For
instance, many consumers using thermoplastic drinking cups have experienced
collapsing or
crushing of the side wall when the container is grasped by the consumer.
Similarly, the rim
of such container can flex inward when a cup is gripped around the periphery
of the rim.
Conventional containers, which have side walls and rims that exhibit little
crush resistance,
therefore can cause messy spills and unwanted waste.
Another problem associated with thermoplastic containers is the lack of
grippability due to condensation forining on the sidewall of the container, as
well as the
insufficient coefficient of friction of the material of the container.
Conventional containers
typically have a sidewall made of a smooth outer surface. Such a smooth outer
surface can
be very slippery when wet, for example, by condensation. Thus, it is difficult
for a
consumer to obtain a comfortable and sufficient grip on a container having a
smooth outer
surface, unless extra force is used to grip the container. However, as
mentioned above, the
typical container can have a sidewall that lacks sufficient crush resistance
to withstand the
extra gripping force required.
Numerous attempts have been made to develop and improved container
having suitable crush resistance and improved tactile engagement without
increased
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manufacturing costs. For example, U.S. Patent No. 6,554,154, the contents of
which is
incorporated herein by reference, discloses a container having a double set of
annular ribs to
provide a side wall container. Although suitable for its intended purpose,
there remains a
need for a container having the desired characteristics without the limitation
of required ribs.
SUMMARY OF THE INVENTION
The purpose and advantages of the present invention will be set forth in and
apparent from the description that follows, as well as will be learned by
practice of the
invention. Additional advantages of the invention will be realized and
attained by the
methods and systems particularly pointed out in the written description and
claims hereof.
Containers having enhanced wall integrity and improved gripping features are
disclosed herein. Generally, each of the disclosed containers of the present
invention has a
base defining a closed bottom and a side wall extending upwardly from the
base. The side
wall has an outer surface and at least one recess formed in the outer surface.
The recessed
surface has a texture that is different than the surface texture of the outer
surface of the side
wall.
In accordance with one aspect of the invention, the at least one recess is
defined by a boundary edge. In one preferred embodiment, the boundary edge has
a
curvilinear shape. In a furtller preferred embodiment, the boundary edge has a
parabolic
shape. However, the boundary edge can be configured to have alternative
shapes, if desired.
In one aspect of the invention, the container includes at least three recesses
formed in the side wall. For example and not limitation, a preferred container
has recesses
formed in the side wall. The at least three recesses can be disposed equally
about the
periphery of the side wall of the container. Each of the at least three
recesses can be defined
by a boundary edge having a similar curvilinear shape and size. However, it is
to be
understood that at least some of the recesses can have a shape or size that is
different than
another recess of the same container.
In one embodiment, the at least one recess forms a recessed surface having a
texture that increases tactile engagement. Although a variety of textures can
be used, a
preferred texture has a multidirectional surface pattern capable of increasing
tactile
engagement generally in any direction. In a preferred aspect of the invention,
the
multidirectional surface pattern includes an irregular surface pattern of
protrusions and/or
indentations, such as bumps, peaks and valleys. For example and not
limitation, the texture
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can extend circumferentially, axially, or diagonally across the recessed
surface. In
accordance with a further preferred aspect of the invention, the texture
extends entirely
across the recessed surface.
In accordance with another aspect of the invention, the container is stackable
with a second container of similar shape. In this aspect of the invention,
each container
includes an engaging portion to engage an adjacent container of similar shape,
which is
received in the mouth of the first container. The engaging portion includes at
least one
depression formed substantially proximate the base of the container. The at
least one
depression is configured to interlock with the adjacent container and thus
inhibit the
independent rotation of each container, with respect to the adjacent
container, if necessary or
desired. In one einbodiment, the engaging portion includes a plurality of
depressions spaced
from the base and disposed about the periphery of the side wall of the
container.
Alternatively, the engaging portion can include a plurality of depressions
disposed about the
base of the container. The plurality of depressions can be aligned with or
disposed between
adjacent recesses. At least one depression can have a height less than the
height of the at
least one recess. In this regard, and in a preferred embodiment, the container
includes
alternating recesses and depressions along the periphery of the side wall, the
height of each
depression being less than the height of each adjacent recess.
In another aspect of the invention, the base of the container includes an
upstanding base wall extending from the closed bottom, and the engaging
portion includes a
shoulder defined between the upstanding base wall and the side wall of the
container. The
shoulder defines a ledge along an inner surface of the container, such that
either the bottom
wall or the shoulder of an adjacent container, as desired, engages the ledge
of the first
container to maintain a defined spacing therebetween. In one embodiment, the
base further
includes at least one indentation formed in the upstanding base wall along a
periphery of the
closed bottom. In one aspect, the indentation is axially aligned with a
depression, if
provided.
In another aspect of the invention, a stack of nestable containers is
provided.
The stack comprises a first container and a second container received within
the first
container. Each of the containers is substantially similar in shape and
includes the one or
more of the same features described above.
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It is to be understood that both the foregoing general description and the
following detailed description are exemplary and are intended to provide
further explanation
of the invention claimed.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a schematic perspective view of a first representative embodiment of
a
container in accordance with the present invention.
FIG. 2 is a schematic side view of the container of FIG. 1 in accordance with
the
present invention.
FIG. 3 is a schematic top view of the container of FIG. 1 in accordance with
the
present invention.
FIG. 4 is a schematic bottom view of the container of FIG. 1 in accordance
with the
present invention.
FIG. 5 is schematic view of another embodiment of a container in accordance
with
the present invention.
FIG. 6 is a side view of the container of FIG. 5 in accordance with the
present
invention.
FIG. 7 is a top view of the container of FIG. 5 in accordance with the present
invention.
FIG. 8 is a bottom view of the container of FIG. 5 in accordance with the
present
invention.
FIG. 9 is a cross section of the container in accordance of FIG. 1 in
accordance with
the present invention.
FIG. 10 is schematic view of a first representative embodiment of a stack of
nested
containers in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference will now be made in detail to the present preferred embodiments of
the invention, an example of which is illustrated in the accompanying
drawings.
The present invention provides for a container having enhanced wall strength
and improved tactile engagement such that the container is configured to be
capable of being
gripped from substantially any direction. Such containers generally include
but are not
limited to beverage cups and food containers.
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In accordance with the invention, a container is provided having a base
defining a closed bottom, and a side wall extending upwardly from the base.
The sidewall
includes an outer surface and an inner surface. The closed bottom and the
sidewall
extending from the base define a receptacle space. The sidewall defines a
mouth formed
opposite the closed bottom. In accordance with the invention, the container
further includes
at least one recess having a recessed surface formed in the sidewall of the
container. The
recessed surface has a texture to increase tactile engagement therewith. In
accordance with a
particular aspect of the invention, the textured surface is configured to
increase tactile
engagement when grasped from substantially any direction.
For purpose of explanation and illustration, and not limitation, an exemplary
embodiment of the container in accordance with the invention is shown in FIG.
1 and is
designated by reference character 100. Additional features, aspects and
embodiments of a
container in accordance with the invention are provided in FIGS. 2 -10, as
will be described.
For purposes of illustration and not limitation, as embodied herein and as
depicted in FIG. 1, the container 100 has a base 112 defining a closed bottom
103, and a
base wall 112a extending upwardly from the base. In one preferred embodiment,
the base
wall 112a has a reverse taper. That is, the basewall 112a has an upwardly and
inwardly
taper. A mouth 105 is formed opposite the closed bottom 103. The base 112 and
side wall
114 define a receptacle space capable of holding contents in the container
100.
The sidewall, embodied herein, is substantially cylindrical, and more
preferably frustoconical, in shape, as shown generally in FIGS. 1 to 4.
However, the
sidewall can be configured to have a variety of other shapes, including but
not limited to
rectangular, hexagonal, or octagonal polyhedronal shapes. In one preferred
embodiment, as
depicted in FIGS. 2 and 4, the sidewall 114 has an upwardly and outwardly
taper.
Accordingly, the diameter of the mouth 105 is greater than the diaineter of
the closed bottom
103. Alternatively, however, the sidewall 114 can be configured such that the
diameter of
the mouth 105 can be substantially the same as closed bottom 103, if desired.
The dimensions of sidewall 114 depend on the particular application. For
example and not limitation, if the container is an 18 ounce beverage cup,
sidewall 114 can
have a height approximately 4.5 inches, and a radius at the base of
approximately 1 inch and
a radius at the mouth of approximately 2 inches.
In accordance with a further aspect of the invention, container 100 further
includes a first portion 130 and a second portion 132, as depicted in FIG. 2.
First portion
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130 includes at least a first section of sidewall 114a disposed proximate base
112 and
extending upwardly to second portion 132 of container 100. The second portion
132
includes at least a second section of sidewall 114b disposed proximate mouth
105. In one
preferred embodiment, sidewall 114a of first portion 130 has a shape different
than sidewall
114b of second portion 132 of container 100.
For the purpose of illustration and not limitation, and as depicted in FIG. 2,
sidewall 114a can have a substantially frustoconical shape, and sidewall 114b
can have a
substantially bowl-like shape. In this manner, sidewall 114a is proximate base
112 and
extends upwardly at a constant taper or angle to a location 162 proximate
second portion 132
of container 100. The portion of sidewall 1 14b has a radius that extends
outwardly greater
than the radius achieved by sidewall 114a. The greater radius of sidewall 114a
thus can
define in part a wider mouth 105 as well as a contoured surface ergonomically
shaped for a
user's hand. Preferably, the first portion extends between about 50% to about
75% the height
of the sidewall. Although the shape of sidewall 114a and sidewall 11 4b are at
least in part
dictated by the radii of base 112 and mouth 105, respectively, sidewall 114a
and sidewall
1 14b can have a variety of alternative shapes. Further, the shape of sidewall
114a and
sidewall 114b can have substantially the same shape and radius to provide a
continuous
tapered or non-tapered container, if desired.
In accordance with a further aspect of the invention, the side wall 114 has at
least one recess 120 formed in the side wall. The at least one recess is
configured to increase
crush resistance of the side wall 114. The term "crush resistance" as used
herein refers to the
resistance to inward deflection of the sidewall of the container. In
particular, the wall
integrity of the container 100 is increased by the recess, thereby reducing
the occurrences of
sidewall collapse when container 100 is grasped. In a preferred embodiment,
container 100
can have a plurality of recesses. For example and not limitation, in one
preferred
embodiment, container 100 has four recesses.
The at least one recess includes a recessed surface 121 defined by a boundary
edge 122, as depicted in FIG. 1. In one preferred embodiment, the boundary
edge 122 has a
curvilinear shape, and more preferably a continuously curved shape.
Particularly, and in
accordance with a preferred aspect of the invention, the boundary edge defines
a parabola
with an apex located opposite the base. Hence, the at least one recess has a
bottom portion
and a top portion. The width of the bottom portion of the at least one recess
is greatet than
the width at the top portion of the at least one recess, such that the width
decreases with
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increasing height along the container 100, and the top portion of the at least
one recess forms
an apex. In this manner, recess 120 also has a curvilinear shape. However,
boundary edge
122 can be configured to have alternative shapes, for example and not
limitation, polygonal
shapes, as deemed suitable or desirable for the intended purpose.
In further accordance with an additional aspect of the invention, the boundary
edge 122 defines an edge surface 123 extending between the recessed surface
121 and the
sidewall 114. As depicted herein, the edge surface is parabolic in shape and
angled relative
to the recessed surface and the sidewall, respectively.
For the purpose of illustration and not limitation, as embodied herein and
depicted in FIG. 2, the at least one recess 120 has a height generally
perpendicular to closed
bottom 103 that is between about 50% to about 80% of a height of sidewall 114.
In one
preferred embodiment, the at least one recess extends upwardly from base 112
and is formed
in the first portion 130 of sidewall 114. Further preferred, at least a
portion of boundary
edge 122 such as the edge surface can extend to at least the second portion
132 of sidewall
114 of container 100, as depicted in FIG. 2.
As described further below, and in accordance with another aspect of the
invention, the base 112 can include a base wall 112a extending upwardly from
the closed
bottom. The base wall 112a and the sidewall 114 define an annular shoulder 146
therebetween. As embodied herein, and as depicted in FIG. 2, the at least one
recess can
extend from the annular shoulder 146 upwardly of sidewall 114. Alternatively,
the at least
one recess 120 can extend from closed bottom 103 of container 100 upwardly
along a height
of sidewall 114, if desired or if no annular shoulder is provided.
In accordance with yet another aspect of the invention, the recessed surface
can define a generally partial cylindrical, frustoconical, or even-bowl shaped
surface
configuration, as desired. For example, and as depicted in FIG. 2, the
sidewall can extend
upwardly at a first angle to define a frustoconical surface configuration, and
the recessed
surface of the at least one recess can extend upwardly at a second different
angle to define a
portion of a second frustoconical surface configuration. By providing
different angles or
configurations therebetween the at least one recess can be further defined
from the sidewall
and the strength of the sidewall can be further enhanced. In yet another
alternative, the
sidewall and the at least one recess can extend upwardly at substantially the
same angle in a
spaced relationship. In this manner, the at least one recess can be further
defined from the
sidewall by providing a step in the sidewall.
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In accordance with a further aspect of the invention, the recessed surface of
the at least one recess is configured for increased tactile engagement by a
user. Particularly,
and as embodied herein, the recessed surface 121 is provided with a texture
124 to increase
tactile engagement. A variety of textures can be incorporated, either
individually or in
combination. Such textures include ribs, protrusions and indentations. In
accordance with a
preferred aspect of the invention, the textured surface is configured to
increase tactile
engagement when gripped from virtually any direction. The textured surface
therefore is
preferably defined or formed by a multidirectional surface pattern of
protrusions and/or
indentations, such as but not limited to a regular or irregular pattern of
protrusions defining
peaks and valleys. In accordance with the invention, the multidirectional
surface patterns
can extend circumferentially, axially, or diagonally across the recessed
surface 121. In
accordance with yet another aspect of the invention, the recessed surface can
include a
combination of ribs and a multidirectional surface pattern texture. For
example and not
limitation, the recessed surface can include ribs or ridges having a textured
surface thereon
or therebetween. The ribs or ridges can be arranged in any suitable pattern,
for example and
not limitation, the ribs can form a linear array or alternatively form a
circular pattern, with
the multidirectional surface pattern extending circumferentially axially or
diagonally.
The multidirectional surface pattern enhances tactile engagement and
improves grippability of the container. For the purpose of illustration and
not limitation, the
protrusions provide greater surface area for tactile engagement by a user, and
the
indentations can provide a plurality of troughs to house and wick away
condensation. In this
manner, the multidirectional surface pattern increases tactile engagement by
reducing
slippage when a container in accordance with the present invention has
condensation
formation on its outer surface. Further, the greater surface area and/or
coefficient of friction
provided by the multidirectional surface pattern enhances tactile engageinent
and improves
grippability of a container having a dry surface. Additionally, because the
texture is a
multidirectional pattern of, for example, bumps, protrusions, dimples, and
indentations, or
grid-like cross hatching, the container is configured for increased tactile
engagement
regardless of the direction in which it is grasped. That is, a discrete
pattern of ribs or ridges
generally provides tactile engagement in a single direction. In this regard,
the particular
direction or orientation of the ribs or ridges on the surface of the container
dictate the
direction in which the container should be grasped if improved grippability is
to be attained.
By contrast, the use of a multidirectional pattern in accordance with the
present invention
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provides a surface on the container for increased tactile engagement despite
the orientation
of the container when grasped. Further, the texture in accordance with the
present invention
can be provided with an increased coefficient of friction when measured in a
variety of
directions, unlike a discrete pattern that may only provide an increased
coefficient of friction
in a limited number of directions. The greater coefficient of friction of the
multidirectional
pattern of protrusions and/or indentations enhances tactile engagement and
grippability when
container 100 is grasped by a consumer.
A variety of multidirectional patterns are suitable for the present invention.
For example, the multidirectional pattern can be provided in the form of a
regular pattern of
offset bumps or intersecting raised cross hatching. Alternatively, an
irregular pattern of
bumps or protrusions can be used, as preferred and embodied herein.
Additionally, the texture in accordance with this aspect of present invention
can provide the advantage of eliminating at least one step in the
manufacturing process, so as
to provide a more efficient and less costly procedure. By providing the
texture with an
irregular pattern, for example, imperfections otherwise visible with a regular
or symmetrical
pattern are not relevant. That is, each irregular pattern is unique, and not
limited by
symmetry. In this regard, the manufacturing process to form a container 100 in
accordance
with the present invention does not require an additional quality control
inspection to ensure
that each container produced on the assembly line includes a texture having an
identical
pattern. In contrast, the manufacturing process to form containers having a
regular pattern,
such as a pattern including ribs or ridges, generally requires a step in the
process for visual
inspection of each container to ensure that the regular pattern is maintained
for each
container. Other advantages of providing a container having a texture in
accordance with the
present invention is that the texturing eliminates blemishes from the
moldings, so as to
conceal heat-check marks, sink marks, and flow marlcs.
In accordance with another aspect of the invention, the texture is coextensive
with the entire recessed surface. In this manner, and unlike a discrete or
isolated raised rib,
an increased tactile engagement can be accomplished anywhere within the
boundary of the
recessed surface. Such an arrangement increases the predictability in grasping
the container
with the recesses provided. The container can further include additional
suitable surface
treatments as lcnown in the art.
A variety of techniques can be used for forming the texture on the recessed
surface in accordance with the invention. For the purpose of illustration and
not limitation,
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container 100 can be provided having texture 124 on a surface of recess 120 by
a textured
mold. In this manner, a metal mold, for example but not limitation, an
aluminum mold body
can be configured with a multidirectional, and preferably, an irregular
pattern in accordance
with the present invention. For example, but not limitation, the metal mold
can be acid
etched to defme a texture pattern. In this regard, an acid can be applied to a
portion of the
metal mold to degrade the metal material in a particular or desired pattern.
Alternatively, a
hobbing process can be used, in which a master having a particular texture is
applied with
force to a metal mold, such as for example an aluminum mold. The particular
pattern on the
master displaces portions of the metal mold to create the desired texture. The
textured mold
is then used to fabricate the container in accordance with the present
invention. In a
preferred embodiment, the mold is configured to provide an irregular pattern
of protrusions,
similar to that depicted in FIGS. 1 and 5, to define a depth of approximately
0.008" and a
draft angle of approximately 12 minimum. Such textured molds can be formed
and
provided by, for example, a variety of texturing suppliers known in the art.
In accordance with a further aspect of the invention, the container includes
an
engaging portion configured to engage a second container of similar shape
received in a
nested relationship within the mouth of the container. The engaging portion is
generally
disposed proximate base. In accordance with one aspect of the invention, and
as previously
described, base 112 can include an upstanding base wall 112a extending from
the closed
bottom 103. As shown in FIG. 2, engaging portion 140 includes shoulder 146
defined
between upstanding base wall 112a and the sidewall 114. The shoulder defines a
ledge on
the inner surface of the container, as depicted in FIG. 3 and in the cross
section in FIG. 9.
The ledge can be configured to engage the bottom 103 of an adjacent container
received
within the first container so as to maintain a spaced relationship between the
two containers
as depicted in FIG. 10. Alternatively, the ledge can be configured to engage
the shoulder of
an adjacent container as described with regard to the embodiments of FIG. 5
below.
Additionally, or alternatively, the engaging portion of the invention can
include an anti-rotational interlock element to prevent relative rotation
between adjacent
containers received in a nested relationship. Particularly, and as embodied
herein, an anti-
rotational interlock element includes at least one depression 142 formed
proximate the base
112. The at least one depression 142 is configured to inhibit rotational
movement of a
container when engaged with a second container of similar shape.
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In a preferred embodiment, the at least one depression has a sufficient depth
to define or form a protruding shelf 144 extending from an inner surface of
sidewall 114
into the receptacle of container 100, as best can be viewed from FIG. 3 and a
cross section in
FIG. 9. The depth of the at least one depression can be constant across a
height of the at
least one depression. Alternatively, the depth of the at least one depression
can vary across a
height of the at least one depression. For example and not limitation, the at
least one
depression can have a depth that increases with an increase in height. The
protruding shelf
144 defined by the depth of the at least one depression is capable of engaging
a
corresponding depression of a second container of similar shape. The
engagement between
the depressions of adjacent containers thereby maintains proper alignment for
stacking and
prevents rotation therebetween. Further, the at least one depression can be
configured to
maintain an axial spaced relationship between the sidewall 114 of one
container and a
sidewall of a second container when in a stacked or nested orientation, if
desired.
For example, and as embodied herein as depicted in FIG. 3, the at least one
depression 142 includes a plurality of depressions formed in the side wall
proximate the base
112. Particularly, and as embodied herein, the at least one depression is
disposed in the
sidewall above the annular shoulder. As shown in FIG. 4, the plurality of
depressions are
disposed about the periphery of the side wall 114. In one preferred
embodiment, the at least
one depression 142 is disposed between two adjacent recesses 120.
Alternatively, however,
the at least one depression can be configured to be in axial alignment with at
least one recess
120.
As schematically shown in FIG. 4, the at least one depression has a height
less than the height of the at least one recess. Although the dimensions of
the at least one
depression can depend on the particular application. For example and not
limitation, for a
beverage cup, the at least one depression can have a height of approximately
0.4 inch and a
depth of approximately 0.045 inch to about 0.082 inch. In one aspect of the
invention, the at
least one depression can be configured to have a depth that increases with
increasing height.
In this manner, the at least one depression can have a depth of approximately
0.045 inch
proximate the base and a depth of approximately 0.082 inch at the height of
0.4 inch
upwardly from the base. In this manner, the at least one depression can have a
continuously
increasing depth across the height of the depression. Alternatively, the at
l.east one
depression can be configured to include a step to define an increased depth.
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Further, the base 112 can include indentation 116, which can best be seen in
FIG. 4, formed within the base wall 112a along a periphery of the closed
bottom 103. In one
embodiment, indentation 116 is axially aligned with a corresponding depression
142,
although alternative arrangements can be provided.
In another preferred embodiment, the at least one depression is formed in the
base wall 112a of base 112 below the annular shoulder 146, as depicted in FIG.
5. As
depicted in FIG. 6, and can be best viewed in FIG. 7, the at least one
depression extends
radially inward beyond the ledge formed by the annular shoulder. In this
embodiment, the
base 112 of the container is configured to have a smaller diameter than the
internal diameter
provided by the ledge formed by the annular shoulder. In this regard, the
shoulder of an
adjacent container that is inserted into the mouth of a first container will
engage the ledge
formed by the shoulder of the first container. The depression 142 therefore
defines a shelf
for engagement by a corresponding depression in an adjacent container that is
inserted into
the mouth of the first container to establish the desired anti-rotational
interlock and /or
spacing features of the engagement portion. The ledge formed by the annular
shoulder also
can be configured to maintain a spaced relationship between the sidewall of
the container
and a sidewall of a second container when in a stacked orientation.
Alternatively, and in lieu
of an annular shoulder, the depression can be formed proximate the base in the
sidewall,
either between or aligned with the recesses. For the purpose of illustration
and not
limitation, the at least one depression can have a curvilinear shape, as
depicted in FIG. 2.
Alternatively, however, the at least one depression can be configured to have
any of a variety
of suitable shapes, such as for example, a square, rectangular, triangular or
other polygonal
shape, as depicted in FIG. 5.
Further in accordance with the invention, the mouth 105 of container 100
includes an annular lip 150. In a preferred embodiment, the lip has a
substantially planar top
surface 152, and a flange 154 angle laterally from the substantially planar
top surface 152, as
depicted in FIG. 1. The flange 154 is folded at least partially under the
substantially planar
top surface 152 such that the flange is configured at an angle of
approximately 25 and
greater, for example and not limitation 45 , relative to the substantially
planar top surface
152. The configuration of the annular lip therefore can have a substantially
triangular
configuration. In one preferred embodiment, the unique annular lip
configuration can be
formed by known lip forming techniques. In this manner, a lip forming machine
is used to
form a lip on the rim of the thermoformed containers, such as disposable cups,
food
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packages, and the like. A stack of nested containers is fed into a conveyor,
which directs the
containers into a space between a set of rotating feed rollers. The feed
rollers engage the rim
of the containers and rotate the stack of nested containers. The containers
are thereby
advanced into the interior of a heating oven having a heating source, such as
for example a
calrod. The stack of nested containers are heated in the oven, and then are
directed to a set of
rotating forming screws. The forming screws engage the heated rims of the
containers and
progressively fold a portion of the rim downward to create the triangular lip
configuration on
the rim of each container. However, the annular lip can also have other
configurations, such
as but not limited to a rounded, rectangular, or square configuration, or can
otherwise be
folded or rolled in a conventional manner.
The dimensions of the annular lip, including the substantially planar top
surface 152, and flange 154, as well as the particular angle at which the
flange is rolled will
depend upon the intended application of the container. For example and not
limitation, for a
beverage container, such as a cup, the planar top surface has a length of
approximately 0.15
inch, the flange 152 has a length of approximately 0.10 inch, and the flange
is preferably at
an angle of approximately 28 in relation to the planar top surface 152.
As shown in FIG. 2, sidewall 114 can be configured to include at least one
ridge 160 disposed circuinferentially about a surface of the sidewall, if
desired. For example
and not limitation, ridge 160 is disposed proximate to annular lip 150.
Alternatively,
however, ridge 160 can be disposed at other locations, if desired.
Additionally, a plurality of
ridges can be disposed circumferentially about the sidewall 114 of container
100.
Particularly, an 18 oz. disposable beverage container in accordance with the
present invention, and having a configuration similar to that of FIGS. 1 to 4,
was formed
with the following relevant dimensions: height 4.75 in.; base diameter 2.33
in.; mouth
diameter 4.00 in.; number of recesses 4; recess height including boundary edge
3.10 in.; and
a formed lip including a top planar surface having a length of 0.15 in., a
flange having a
length of 0.15 in., the flange forming an angle of 28 relative to the top
planar surface.
As mentioned above, the container in accordance with the present invention
has improved sidewall crush resistance or improved wall strength integrity, as
well as
improved lip strength. To demonstrate the improvement in strength of a
container in
accordance with the present invention a standard comparison deflection test
was performed
on the sidewall and the lip of a container in accordance with the present
invention and of a
commercially available container of generally similar size. Each container
sample tested
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was an 18 oz. beverage cup. The results of the comparative deflection test
illustrated that the
container in accordance with the present invention has about an 8% increase in
sidewall
strength as compared to the standard commercially available container. The
results also
illustrated that the container in accordance with the present invention has
about a 31 %
increase in lip strength as compared to the standard commercially available
container. Thus,
the results of the comparative deflection analysis illustrated the improvement
in structural
integrity of both the sidewall and the lip achieved by the container in
accordance with the
present invention.
In accordance with another aspect of the invention, a stack of nestable
containers 110 is provided. The stack of nestable containers includes a first
container 100
and an adjacent container 101 received within the -first container. Each
stackable container
has a substantially similar shape as described above.
For the purpose of illustration and not limitation, and as depicted in FIG.
10,
in a preferred embodiment, a second container 100' is received within the
mouth 105 of the
first container 100 such that the body of the second container extends
downwardly through
the mouth and into the receptacle of the first container. As discussed above,
and as depicted
in FIG. 10, the annular shoulder 146 of the first container 100 provides a
ledge along an
inner surface of the first container, such that when the second container 100'
is disposed
within the mouth 105 of the first container and extends downwardly through its
receptacle,
the bottom of the second container 100' engages the ledge on the inner surface
of the first
container 100 to maintain a defined spacing therebetween. Alternatively, and
as previously
noted with regard to the embodiment of FIG. 5, the bottom can be dimensioned
so as to be
smaller than the cross dimension of the ledge. In this manner, the bottom of
the second
container will be disposed within the volume defined by the upstanding base
wall of the first
container, and the shoulder of the second container will engage the ledge of
the first
container.
In accordance with one preferred embodiment, as depicted in FIG. 10, the
ridge 160 disposed circumferentially about the surface of the sidewall 114 of
the first
container 100 engages at least a portion of the annular lip 150 of the
adjacent container 101
when in a stacked orientation.
In accordance with a further aspect of the invention, the engaging portion 140
of the first container includes at least one depression to engage a
corresponding engaging
portion of the second container. In one embodiment, the at least one
depression 142 has a
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substantially constant depth and provides a protruding shelf 144 that extends
along an inner
surface of the first container 100. In this manner, the protruding shelf 144
provided by the at
least one depression 142 engages an outer surface of the at least one
depression 142 of the
second container 100'. The at least one depression 142 in conjunction with the
protruding
shelf 144 assist in providing proper alignment of the nested first and second
containers.
Further, the at least one depression and protruding shelf also inhibit
independent rotational
movement of each container, if needed. The anti-rotational feature provides
benefits during
manufacturing, for example, during lip forming, such that the stack of nested
container
maintain proper alignment Further, the at least one depression is configured
to maintain a
spaced relationship between the sidewall of the first container and the
sidewall of the second
container. The spacing and lack of rotational movement prevents extensive wear
on the
containers.
Any of a variety of suitable polymers can be used for container of the present
invention, including but not limited to polystyrenes and copolymers thereof,
propylene
polymers, such as, for example polypropylene homopolymers, polypropylene
random
copolymers, or polypropylene impact copolymers, ethylene polymers, such as,
for example,
high density polyethylene, medium density polyethylene, or low density
polyethylene,
polybutenes and copolymers thereof, polyesters, and mixtures or copolymers
thereof.
In accordance with a preferred embodiment, the container material can
include at least one colorant. The colorant can be any suitable material
capable of providing
a vivid color, including, but not limited to any color of the spectrum, as
well as white and
black, to the material of the container. The colorants that can be used in the
present
invention include, but are not limited to, pigments or dyes. The colorants may
be used in a
variety of modes, including but not limited to, dry color, conventional color
concentrates,
liquid color and precolored resin. The colorant is provided in a sufficient
concentration to
provide the desired color.
It will be apparent to those skilled in the art that various modifications and
variations can be made in the method and system of the present invention
without departing
from the spirit or scope of the invention. Thus, it is intended that the
present invention
includes modifications and variations that are within the scope of the
appended claims and
their equivalents.
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