Note: Descriptions are shown in the official language in which they were submitted.
CA 02697311 2010-03-18
EGG CONTAINER WITH STACK-SPACING SYSTEM
FIELD OF THE APPLICATION
The present application relates to containers for
receiving frangible objects such as eggs, and to structural
components of such containers for allowing the stacking of
such containers in an opened position.
BACKGROUND OF THE ART
Egg containers of all kinds have been developed
for the transportation and sale of frangible items such as
eggs. As eggs are relatively fragile, the egg containers
must protect the eggs from the various manipulations
involved from the packaging of the eggs to the consumer's
refrigerator.
One significant improvement in egg containers is
the use of thermoformed plastics as material for the egg
containers. Thermoformed plastics are typically
transparent, which allows the eggs to be visible, and are
relatively inexpensive to produce. As they can inspect the
eggs by seeing through the material of the egg container,
the consumers do not need to open the egg container, as is
the case with cardboard egg containers, for instance. In
the case of cardboard boxes, it may occur that the boxes are
not closed properly after inspection. This may cause the
breakage of eggs if the improperly closed egg container is
subsequently manipulated by another consumer.
One of the advantages with containers of
thermoformed plastics pertains to the stacking of the
containers in an open position. Containers in the open
position may be nested one into the other to form stacks
requiring a relatively small volume when compared to stacks
of closed containers. However, the separation of containers
nested one into the other is often performed by automated
equipment. Accordingly, containers must have components to
ensure that stacks of open containers are upright.
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Moreover, an equidistant spacing between a plurality of open
containers nested one into the other facilitates their
separation by the automated equipment.
SUMMARY OF THE APPLICATION
It is therefore an aim of the present disclosure
to provide a container for frangible items addressing issues
associated with the prior art.
Therefore, in accordance with the present
application, there is provided a container for receiving
frangible items comprising: a sheet of polymer formed into:
a base portion having a plurality of item-receiving cavities
for supporting frangible items; at least one cover portion
having at least one item-covering concavity for covering the
frangible items, the cover portion having a generally flat
top wall and peripheral walls concurrently defining the at
least one item covering concavity; a first hinge between the
base portion and the cover portion for rotating the cover
portion onto the base portion to hold the frangible items
captive in the item-receiving cavities; at least one
abutment spacer formed at an edge between the peripheral
walls and the top wall, the at least one abutment spacer
comprising an abutment surface projecting into the concavity
from one of the peripheral walls, and support walls relating
the abutment surface to the top wall, with at least one of
the support walls being in an acute angle relation with the
top wall; at least one alignment channel in at least one of
the peripheral walls defining an alignment protrusion
through the sheet of polymer, the alignment
channel/protrusion being oriented vertically for guiding the
nesting of an upper one of the cover portion descending into
a lower one of the cover portion, by the alignment
protrusion of the upper one received in the alignment
channel of the lower one, when a stack of the containers in
an opened state is formed, whereby a spacing between nested
containers is defined by the abutment spacers of the upper
one seated on the abutment spacers of the lower one.
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Further in accordance with the present
application, there is provided a container for receiving
frangible items comprising: a sheet of polymer formed into:
a base portion having a plurality of item-receiving cavities
for supporting frangible items, with a post centered between
each set of four of the item-receiving cavities, the post
projecting upwardly from the base portion to support a
structural component of the cover portion when the container
is closed; at least one cover portion having at least one
item covering concavity for covering the frangible items,
and a structural component extending into the concavity for
contacting the post when the container is closed; a first
hinge between the base portion and the cover portion for
rotating the cover portion onto the base portion to hold the
frangible items captive in the item-receiving cavities;
spacers formed between at least one of the posts and the
four item-receiving cavities surrounding the post, the
spacers each defining a subcavity on one side of the sheet
of polymer and a bump on the other side of the sheet of
polymer, the spacers having a wider central portion for
narrower ends along a vertical axis of the container, such
that the nesting of an upper one of the base portion
descending into a lower one of the base portion results in
the spacers of the upper one seated on the spacers of the
lower one when a stack of the containers in an opened state
is formed, whereby a spacing between nested containers is
defined by the spacers of the upper one seated on the
spacers of the lower one.
BRIEF DESCRIPTION OF DRAWINGS
Fig. 1 is a schematic perspective view of a two-
fold egg container;
Fig. 2 is a schematic perspective view of a three-
fold egg container;
Fig. 3 is a top plan view of a three-fold egg
container with a stack-spacing system in accordance with an
embodiment of the present disclosure;
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Fig. 4 is an enlarged fragmented view of a top
cover portion of the egg container of Fig. 3;
Fig. 5 is a sectional view of two of the top cover
portions of Fig. 4, nested one into the other, with the
stack-spacing system; and
Fig. 6 is an enlarged perspective view of an
abutment spacer of the stack-spacing system.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to the drawings and more particularly to
Fig. 1, a container for frangible items is generally shown
at 10, and is referred to as an egg container. The egg
containers described hereinafter are preferably made of
transparent or translucent plastics, for instance, using a
thermoforming process or other molding process. In one
embodiment, the egg containers are formed from a single,
flat sheet of plastic. Other materials and/or processes may
be used as well. The containers described hereinafter may
be used to contain eggs or any other frangible items (e.g.,
tomatoes), in any suitable number (e.g., 6, 12, 18, 24).
The egg container 10 of Fig. 1 is a two-fold egg
container, as it has two portions hinged to one another.
The egg container 10 has a base portion 11 having a
plurality of egg-receiving cavities 12 (e.g., 6, 12, 18, 24,
or any other suitable number), with each cavity 12
supporting an egg. A top cover portion 13 is hinged to the
base portion 11 by hinge 14, in a longitudinal dimension of
the egg container 10. The top cover portion 13 presents a
flat top surface part of a top wall as in Fig. 1, with or
without strengthening components (e.g., arches, posts).
Although not shown, mating connectors or any other suitable
type of connectors are provided on the periphery of the base
portion 11 and top cover portion 13 for interlocking them
when the egg container 10 is closed.
Referring to Fig. 2, a three-fold egg container is
generally illustrated at 10'. The egg container 10' is
similar to the egg container 10 of Fig. 1, but has an
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intermediate cover portion 15. The intermediate cover
portion 15 is hinged to the base portion 11 by hinge 16, in
a longitudinal dimension of the egg container 10'. The
hinges 14 and 16 are preferably on opposite edges of the
base portion 11. The intermediate cover portion 15
typically has egg cavities 17 to cover a top portion of the
eggs supported by the egg-receiving cavities 12. Although
not shown, mating connectors or any other suitable type of
connector are provided on the periphery of the top cover
portion 13 and the intermediate cover portion 15 for
interlocking them when the egg container 10' is closed.
The egg containers 10/10' of Figs. 1 and 2 may
have peripheral flanges 20-22, that lie one against the
other when the egg containers 10/10' is closed. The flanges
20-22 provide structural stability to stacks of closed
containers, by spreading the weight between base portion 11,
top cover portion 13 and intermediate cover portion 15, if
applicable.
In order to close the egg container 10', the
intermediate cover portion 15 is firstly hinged into contact
with the base portion 11, as illustrated by arrow A. The
top cover portion 13 is then hinged onto the intermediate
cover portion 15, as illustrated by arrow B.
The egg containers of the present disclosure may
contain any suitable number of item-receiving cavities. One
suitable material for the egg containers of the present
application is polyethylene terephthalate (PET). PET has
many advantages, as this material can be transparent or
opaque and can be produced at high volume and at low cost.
Wall thicknesses of PET cases in a contemplated embodiment
are 0.0175 inch in thickness, but other thicknesses as low
as 0.012 to as high as 0.022 inch are also contemplated.
However, this thickness may vary, for instance, once the
sheet is formed into the egg container 10/10'.
Referring concurrently to Figs. 3 and 4, a stack-
spacing system is shown in the top cover portion 13, for the
stacking of top cover portions 13. The stack-spacing system
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is present in a top cover portion of the type having a top
wall 30 that is generally flat and horizontal when the egg
container 10/10' is open or closed and rests on a horizontal
surface. In Figs. 3 and 4, the top wall 30 is illustrated
as defining a single flat surface, but may alternatively be
separated into multiple surfaces, or may be disrupted with
ribs or other protuberances projecting into the top cover
portion 13.
Peripheral walls 31 are provided between the top
wall 30 and the peripheral flange 22. The peripheral walls
31 are concurrently tapered from the peripheral flange 22 to
the top wall 30 for nesting of top cover portions 13 one
into another. An inner concavity 32 of the top cover
portion 13 is defined concurrently by the top wall 30 and
the peripheral walls 31, and covers a top portion of
frangible items received in the egg-receiving cavities 12
(Fig. 1 and 2).
Components of the stack-spacing system are now
described. The components are described with reference to
the inner concavity 32. Due to the thin-wall nature of the
material used in the containers 10/10', these components
projecting into the inner concavity 32 are indentations from
an exterior of the top cover portion 13.
Referring to Figs. 3, 4 and 6, abutment spacers 40
are provided in the inner concavity 32. In an embodiment,
the abutment spacers 40 are at the intersection of the top
wall 30 and the peripheral walls 31. Each of the abutment
spacers 40 has an abutment surface 41 and support walls 42.
The abutment surface 41 may be generally horizontal when the
egg container 10/10' is closed or opened, whereas the
support walls 42 are slanted. As best seen in Fig. 6, the
support walls 42 taper toward the top wall 30, thereby
defining an acute angle relation with the top wall 30,
whether connected to the top wall 30 or distanced from the
top wall 30. Therefore, the abutment spacers 40 are said to
be negative spacers (i.e., negative stops) . Accordingly,
when the top cover portions 13 are nested one into the
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other, a top one of the abutment spacers 40 is seated on a
bottom one of the abutment spacers 40. More specifically,
an edge between the top wall 30 and the support wall 42 for
the top one is seated on the abutment surface 41 of bottom
one. The height of the support walls 42 is selected as a
function of a desired spacing between top cover portions 13.
More specifically, the height of the vertical surfaces 42 is
selected as a function of the desired spacing between nested
top cover portions 13, which spacing is for instance equal
to the spacing between base portions 11 when nested one into
the other. .
The abutment spacers 40 may be positioned at any
point along the edge between the top wall 30 and the
peripheral walls 31, or in the peripheral walls 31. In one
embodiment, the abutment spacers 40 are positioned at the
edge that is farthest from the base portion 13. In placing
the abutment. spacers 40, a positioning of a label should be
taken into consideration, as labels covering the full width
of the top wall 30 are commonly used for identification,
labeling and/or marketing purposes. As shown in Fig. 3, the
positioning of the abutment spacers 40 at corners of the top
cover portion 13 provides little interference for a wide
label positioned therein.
The stack-spacing system of the top cover portion
13 also features a plurality of alignment channels 50
defined in the peripheral walls 31, which channels 50 may be
from an interior or an exterior of the top cover portion 13,
with a corresponding alignment protrusion formed on the
other of the. interior or exterior of the top cover portion
13, due to the fact that the container 10/10' is formed from
a sheet. The alignment channels 50 are in the peripheral
walls 31 so as to ensure that the abutment spacers 40 are
vertically aligned when the top cover portions 13 are
brought one into the other. This reduces the risk that the
abutment spacers 40 of nested top cover portions 13 lock one
into the other.
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As seen in Fig. 3, the alignment channels 50 may
have a tapering shape by way of edges 51 tapering from the
peripheral flange 22 to the top wall 30. Accordingly, when
one alignment channel 50 is lowered toward another alignment
channel 50, the tapering edges 51 result in mating
engagement and gradual alignment of the channels 50 one into
the other. The tapering shape of the channels 50 also
facilitates the denesting of a top cover portion 13 from
another by pivoting movement about the base portion 11. The
edges 51 may also be parallel to one another.
Referring to Fig. 5, the alignment channels 50
define a projecting portion such as a projecting edge 52,
projecting toward an exterior of the peripheral walls 31.
The projecting edges 52 are generally horizontal. The
projecting edges 52 are used to ensure that the alignment
channels 50 fit one into the other despite the presence of a
label 60. More specifically, the projecting edge 52 of the
top cover portion 13 nested into another will push the
material of the label 60 into the alignment channel 50 of
the bottom top cover portion 13. Alternatively, any shape
of projection may be used. Although the projecting edges 52
are shown projecting toward the exterior as part of the
channels 51, the projecting edges or portion 52 may extend
into the concavity 32 if used with channels defined from an
exterior of the egg container 10/10'.
Referring to Fig. 3, tear-shaped post spacers 70
are provided at central posts between four egg-receiving
cavities 12. The spacers 70 define the spacing between base
portions 11 nested one into the other and intermediate cover
portion 15 nested into the other, if applicable. The tear-
shaped spacers 70 are at four corners of the central posts,
as the central posts are the main structural members inside
the egg containers 10/10', and thus bear a substantial part
of the weight of closed egg containers stacked thereon. The
spacers 70 may be in the egg-receiving cavities 12, on the
post, or at the intersection between cavities 12 and post.
The tear shape of the spacers 70 is suited for spacers 70 to
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sit one on another, with the wide central section and
narrower ends, along a vertical axis of the container
10/10'. In Fig. 3, the spacers 70 are in the form of a
subcavity with respect to an interior of the container
10/10', and thus result in a bump from an exterior of the
container 10/10', due to the generally uniform thickness of
the sheet. However, the bump may be inward of the container
10/10' while the subcavity is outward of the
container 10/10'.
In an embodiment of the present disclosure, the
containers 10/10' are provided with all of the abutment
spacers 40, the alignment channels 50 (and corresponding
protrusions), and the post spacers 70. Although the egg
containers 10/10' need not have all these components
simultaneously, the stacking of open containers 10/10'
featuring all of these components is efficient. The
abutment spacers 40 and the post spacers 70 are concurrently
sized so as to cause a uniform spacing between cover
portions 13 and base portions 11, such that stacks of open
containers 10/10' are substantially upright.
