U.S. patent application number 11/247060 was filed with the patent office on 2006-05-25 for methods of reducing the stacking height of containers, lids, and bases.
Invention is credited to James N. Gomoll, Thomas J. Hayes, H. Bernard Kirkland.
Application Number | 20060108254 11/247060 |
Document ID | / |
Family ID | 36177458 |
Filed Date | 2006-05-25 |
United States Patent
Application |
20060108254 |
Kind Code |
A1 |
Gomoll; James N. ; et
al. |
May 25, 2006 |
Methods of reducing the stacking height of containers, lids, and
bases
Abstract
A method for forming a reduced-height stack of containers
wherein the containers stacked contain at least one undercut and at
least one undercut receiving structure. The first container having
an undercut at a first position and an undercut receiving structure
at a second position. The second container having an undercut at a
third position and an undercut receiving structure at a fourth
position. The containers may be arranged so that the at least one
undercut of the first container at the first position aligns with
and fits into the at least one undercut receiving structure at the
fourth position of the second container below the first container
in the stack.
Inventors: |
Gomoll; James N.;
(Lindenhurst, IL) ; Hayes; Thomas J.; (McHenry,
IL) ; Kirkland; H. Bernard; (Lindenhurst,
IL) |
Correspondence
Address: |
PACTIV CORPORATION;c/o JENKENS & GILCHRIST
225 WEST WASHINGTON STREET
SUITE 2600
CHICAGO
IL
60606
US
|
Family ID: |
36177458 |
Appl. No.: |
11/247060 |
Filed: |
October 11, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60617733 |
Oct 12, 2004 |
|
|
|
Current U.S.
Class: |
206/509 |
Current CPC
Class: |
B65D 21/0234
20130101 |
Class at
Publication: |
206/509 |
International
Class: |
B65D 21/00 20060101
B65D021/00 |
Claims
1. A method for forming a reduced-height stack of a plurality of
containers comprising: providing a first container having at least
a first undercut and at least one undercut receiving structure, the
at least a first undercut being located at a first position, the at
least one undercut receiving structure being located at a second
position; providing a second container having at least a second
undercut and at least one undercut receiving structure, the at
least a second undercut being located at a third position, the at
least one undercut receiving structure being located at a fourth
position, the third position being a different location from the
first position, the fourth position being a different location from
the second position, the first and second containers being of
generally equal sizes; and arranging the first and second
containers to form a stack of a plurality of containers, wherein
the at least a first undercut of the first container at the first
position aligns with and fits within the at least one undercut
receiving structure of the second container at the fourth position
so as to reduce the stack height.
2. The method of claim 1 wherein the first and second containers
are made using a forming process.
3. The method of claim 1 wherein the first and second containers
are thermoformed.
4. The method of claim 1 wherein the first and second containers
are injection molded.
5. The method of claim 1 wherein the first and second containers
are polymeric containers.
6. The method of claim 1 wherein the first and second containers
are made of molded fiber.
7. The method of claim 1 further comprising: providing a plurality
of first containers; providing a plurality of second containers;
and arranging a plurality of two-container stacks, the respective
undercuts of the plurality of first containers at the first
position being aligned with and fitted within with respective
undercut receiving structures of the plurality of second containers
at the fourth position so as to reduce the stack height.
8. A method for forming a reduced-height stack of containers
comprising: providing a mold base comprising at least a first mold
cavity having a first design and a second mold cavity having a
second design, the first and second designs being different; making
a first container in the first mold cavity, the first container
having at least one undercut located at a first position and at
least one undercut receiving structure located at a second
position; making a second container in the second mold cavity, the
second container having at least one undercut located at a third
position and at least one undercut receiving structure located at a
fourth position, the third position being a different location from
the first position, and the second position being a different
location from the fourth position; removing the first and second
containers from the respective first and second mold cavities; and
arranging the first and second containers to form a two-container
stack, wherein the at least a first undercut of the first container
at the first position aligns with and fits within the at least one
undercut receiving structure of the second container at the fourth
position so as to reduce the height of the two-container stack.
9. The method of claim 8, wherein the mold base further comprises a
third mold cavity having a generally identical design as the first
mold cavity, the third mold cavity being rotated within the mold
base relative to the first mold cavity; making a third container in
the third mold cavity, the third container having at least one
undercut located at a fifth position and at least one undercut
receiving structure located at a sixth position; removing the third
container from the third mold cavity; and arranging the third
container with the first and second containers to form a
three-container stack, wherein the at least a first undercut of the
third container at the fifth position aligns with and fits within
the at least one undercut receiving structure of the first
container at the second position so as to reduce the height of the
three-container stack.
10. The method of claim 8, wherein the mold base further comprises
a third mold cavity and a fourth mold cavity, the mold cavities
being arranged in two rows and two columns, the first and second
mold cavities comprising a first column of mold cavities, the third
and fourth mold cavities comprising a second column of mold
cavities, the design of the third mold cavity being different from
the design of the fourth mold cavity, the method further
comprising: making a third container in the third mold cavity, the
third container having at least one undercut being located at a
fifth position and at least one undercut receiving structure being
located at a sixth position; making a fourth container in the
fourth mold cavity, the fourth container having at least one
undercut being located at a seventh position and at least one
undercut receiving structure being located at an eighth position,
the fifth position being a different location from the seventh
position; removing the third and fourth containers from the
respective third and fourth mold cavities; arranging the third and
fourth containers to form a two-container stack, the at least one
undercut of the third container at the fifth position being aligned
with and fitted within the at least one undercut receiving
structure of the fourth container at the eighth position so as to
reduce the height of the two-container stack.
11. A method for forming a reduced-height stack of containers
comprising: providing a mold base comprising at least a first mold
cavity and a second mold cavity, the design of the first mold
cavity being substantially identical to the design of the second
mold cavity, the second mold cavity being rotated in the mold base
relative to the first mold cavity; making a first container in the
first mold cavity, the first container having at least one undercut
being located at a first position and at least one undercut
receiving structure being located at a second position; making a
second container in the second mold cavity, the second container
having at least one undercut being located at a third position and
at least one undercut receiving structure being located at a fourth
position, the first position being a different location from the
third position relative to the mold base; removing the first and
second containers from the respective first and second mold
cavities; and arranging the first and second containers to form a
two-container stack, the at least one undercut at the first
position of the first container being aligned with and fitted
within the undercut receiving structure at the fourth position of
the second container so as to reduce the height of the
two-container stack, without further rotating the containers after
removing the containers from the mold cavities.
12. The method of claim 11, wherein the mold base further comprises
a third mold cavity having a design different than the first mold
cavity; making a third container in the third mold cavity, the
third container having at least one undercut located at a fifth
position and at least one undercut receiving structure located at a
sixth position; removing the third container from the third mold
cavity; and arranging the third container with the first and second
containers to form a three-container stack, wherein the at least a
first undercut of the third container at the fifth position aligns
with and fits within the at least one undercut receiving structure
of the first container at the second position so as to reduce the
height of the three-container stack.
13. The method of claim 11, wherein the mold base further comprises
a third mold cavity and a fourth mold cavity, the mold cavities
being arranged in two rows and two columns, the first and second
mold cavities comprising a first column of mold cavities, the third
and fourth mold cavities comprising a second column of mold
cavities, the design of the third mold cavity being substantially
identical to the design of the fourth mold cavity, the method
further comprising: making a third container in the third mold
cavity, the third container having at least one undercut being
located at a fifth position and at least one undercut receiving
structure being located at a sixth position; making a fourth
container in the fourth mold cavity, the fourth container having at
least one undercut being located at a seventh position and at least
one undercut receiving structure being located at an eighth
position, the fifth position being a different location from the
seventh position; removing the third and fourth containers from the
respective third and fourth mold cavities; arranging the third and
fourth containers to form a second two-container stack, the
undercut of the third container located at the fifth position being
aligned with and fitted within the undercut receiving structure of
the fourth container located at the eighth position so as to reduce
the height of the second two-container stack, without further
rotating the containers after removing them from the third and
fourth mold cavities.
14. A stack of containers comprising: a first container comprising
a locking mechanism including at least one undercut at a first
position and at least one undercut receiving structure at a second
position; and a second container comprising a locking mechanism
including at least one undercut at a third position and at least
one undercut receiving structure at a fourth position, the first
and second containers are stacked such that the at least one
undercut at the first position is aligned with the at least one
undercut receiving structure at the fourth position, and the at
least one undercut at the first position contacts the undercut
receiving structure at the fourth position thereby reducing the
stack height.
15. The stack of containers of claim 14 further comprising a third
container, the third container comprising a locking mechanism
including at least one undercut at a third position and a least one
undercut receiving structure at a fourth position, wherein the
third container is stacked such that the at least one undercut at
the third position is aligned with the at least one undercut
receiving structure of the first container at the second position,
and the at least one undercut at the third position contacts the
undercut receiving structure at the second position thereby
reducing the stack height.
16. A stack of containers comprising: a first container wherein the
first container comprises a locking mechanism including at least
one undercut at a first position and at least one undercut
receiving structure at a second position; and a second container
wherein the second container comprises a locking mechanism
including at least one undercut at the first position and at least
one undercut receiving structure at the second position; a third
container wherein the third container comprises a locking mechanism
including at least one undercut at a third position and at least
one undercut receiving structure at a fourth position; a fourth
container wherein the fourth container comprises a locking
mechanism including at least one undercut at the first position and
at least one undercut receiving structure at the second position;
and a fifth container wherein the fifth container comprises a
locking mechanism including at least one undercut at the first
position and at least one undercut receiving structure at the
second position, wherein the second container is aligned such that
the at least one undercut at the first position is aligned with the
at least one undercut at the first position of the first container,
the third container is aligned such that the at least one undercut
at the third positioned is aligned with and fitted within the at
least one undercut receiving structure at the second position of
the second container, the fourth container is aligned such that the
at least one undercut at the first position of the fourth container
is aligned with and fitted within the at least one undercut
receiving structure at the fourth position of the third container,
and the fifth container is aligned such that the at least one
undercut at the first position of the fifth container is aligned
with the at least one undercut at the first position of the fourth
container, such the stack height between the second, third, and
fourth containers is minimized and the overall stack height is
reduced.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional
Patent Application Ser. No. 60/617,333, entitled "Methods of
Reducing the Stacking Height of Containers, Lids, and Bases" filed
on Oct. 12, 2004, which is incorporated herein by reference in its
entirety.
FIELD OF THE INVENTION
[0002] The present invention generally relates to the packaging
industry. More particularly, the present invention relates to
reducing the stacking height of a stack of containers, lids, or
bases.
BACKGROUND OF THE INVENTION
[0003] The packaging industry has produced a number of containers,
lids, and bases to be used in applications such as egg cartons,
carry-out containers, fruit trays, and other container types. These
containers, lids, and bases are typically transported from a
manufacturer to an entity that utilizes a container, lid, or base.
The containers often have locking mechanisms between its bases and
lids. A container that is not securely closed could open
inadvertently and spill the contents of the container. Typically
this locking mechanism is controls the design of the stack height.
These containers, lids, and bases are often transported by being
stacked inside boxes. The size of these transportation boxes is
often referred to as the cube of the outer packaging.
[0004] Referring now to prior art FIG. 1, a portion of a stack 30
that includes a plurality of containers 10 is shown. The distance
indicated by arrow A is the stack height between two containers.
The term "stack height" as used in this application means the
distance between identical features of adjacent containers in a
stack. It can be observed in prior art FIG. 1 that the stack height
A is governed by a lead-in surface 18 of the locking mechanism of
the top container of the stack 30 resting on an undercut rim 16 of
the locking mechanism of the bottom container of the stack 30.
[0005] Similarly, in prior art FIG. 2 a portion of a stack 40 that
includes a plurality of containers 20 is shown. The distance
indicated by an arrow B is the stack height between two containers.
The stack height B of prior art FIG. 2 is driven by an undercut rim
26 of the locking mechanism of the first container resting on a
lead-in surface 28 of the locking mechanism of the second container
in the stack 40.
[0006] A greater stack height results in a larger cube for the
transportation boxes. A typical stack may include several hundred
or even several thousand containers, lids, bases, and combinations
thereof. Having an inefficient stacking of containers, lids, and
bases is costly because of the higher transportation costs
involved. Additionally, potential storage costs may be incurred by
the entities that use such items because of the inefficient
stacking. Further, a large stack also requires additional store
shelf-space, which increases the cost associated with marketing the
containers. Such costs are ultimately passed onto the end user of
the containers, lids, and bases.
[0007] A need therefore exists for a method to stack containers
that results in a reduced stack height for an equal number of
containers.
SUMMARY OF THE INVENTION
[0008] A method for forming a reduced-height stack of a plurality
of containers provides a first and second container. The first
container has at least a first undercut and at least one undercut
receiving structure. The at least a first undercut is located at a
first position. The at least a first undercut receiving structure
is located at a second position. The second container has at least
a second undercut and at least one undercut receiving structure.
The at least a second undercut is located at a third position. The
at least one undercut receiving structure is at a fourth position.
The third position is a different location from the first position.
The fourth position is a different location from the second
position. The first and second containers are generally equal in
size. The method arranges the first and second container to form a
stack of a plurality of containers. The at least a first undercut
of the first container aligns with and fits within the at least one
undercut receiving structure of the second container at the fourth
position to reduce the stack height.
[0009] According to another method of the present invention, a
method of forming a reduced-height stack of containers provides a
mold base that comprises at least a first mold cavity that has a
first design and a second mold cavity that has a second design. The
first design is different from the second design. This method makes
a first container in the first mold cavity that has at least one
undercut located at a first position and at least one undercut
receiving structure located at a second position. The method also
makes a second container in the second mold cavity that has at
least one undercut located at a third position and at least one
undercut receiving structure located at a fourth position. The
third position is a different location than the first position. The
fourth position is a different location than the third position.
This method removes the first and second containers from the
respective first and second mold cavities. The method arranges the
first and second containers to form a two-container stack. The at
least a first undercut of the first container at the first position
aligns with and fits within the at least one undercut receiving
structure of the second container at the fourth position to reduce
the height of the two-container stack.
[0010] According to a further method of the present invention, a
method of forming a reduced-height stack of containers provides a
mold base that comprises at least a first mold cavity and a second
mold cavity. The design of the first mold cavity is substantially
identical to the design of the second mold cavity. The second mold
cavity is rotated in the mold base relative to the first mold
cavity. This method makes a first container in the first mold
cavity that has at least one undercut located at a first position
and at least one undercut receiving structure located at a second
position. The method also makes a second container in the second
mold cavity that has at least one undercut located at a third
position and at least one undercut receiving structure located at a
fourth position. The third position is a different location than
the first position. This method removes the first and second
containers from the respective first and second mold cavities. The
method arranges the first and second containers to form a
two-container stack. The at least one undercut of the first
container at the first position aligns with and fits within the
undercut receiving structure at the fourth position of the second
container to reduce the height of the two-container stack. The
containers align without further rotation of the containers after
they are removed from the mold cavities.
[0011] According to yet another method of the present invention, a
method of forming two reduced-height stacks of containers provides
a mold base that comprises at least a first mold cavity, a second
mold cavity, a third mold cavity, and a fourth mold cavity. The
mold cavities are arranged in two rows and two columns. The first
and second mold cavities comprise a first column of mold cavities.
The third and fourth mold cavities comprise a second column of mold
cavities. The design of the first mold cavity is different than the
design of the second mold cavity. The design of the third mold
cavity is different than the design of the fourth mold cavity. This
method makes a first container in the first mold cavity that has at
least one undercut located at a first position and at least one
undercut receiving structure located at a second position. The
method also makes a second container in the second mold cavity that
has at least one undercut located at a third position and at least
one undercut receiving structure located at a fourth position. The
third position is a different location than the first position. A
third container is made in the third mold cavity that has at least
at least one undercut located at a fifth position and at least one
undercut receiving structure located at a sixth position. A fourth
container is made in the fourth mold cavity that has at least at
least one undercut located at a seventh position and at least one
undercut receiving structure located at an eighth position. The
fifth position is a different location than the seventh position.
This method removes the first, second, third, and fourth containers
from the respective first, second, third, and fourth mold cavities.
The method arranges the first and second containers to form a
two-container stack. The at least one undercut of the first
container at the first position aligns with and fits within the
undercut receiving structure at the fourth position of the second
container to reduce the height of the two-container stack. The
method arranges the third and fourth containers to form a
two-container stack. The at least one undercut of the third
container at the fifth position aligns with and fits within the
undercut receiving structure at the eighth position of the fourth
container to reduce the height of the two-container stack.
[0012] According to yet a further method, a method of forming two
reduced-height stacks of containers provides a mold base that
comprises at least a first mold cavity, a second mold cavity, a
third mold cavity, and a fourth mold cavity. The mold cavities are
arranged in two rows and two columns. The first and second mold
cavities comprise a first column of mold cavities. The third and
fourth mold cavities comprise a second column of mold cavities. The
design of the first mold cavity is substantially identical to the
design of the second mold cavity. The second mold cavity is rotated
within the mold base relative to the first mold cavity. The design
of the third mold cavity is substantially identical to the design
of the fourth mold cavity. The fourth mold cavity is rotated within
the mold base relative to the third mold cavity. This method makes
a first container in the first mold cavity that has at least one
undercut located at a first position and at least one undercut
receiving structure located at a second position. The method also
makes a second container in the second mold cavity that has at
least one undercut located at a third position and at least one
undercut receiving structure located at a fourth position. The
third position is a different location than the first position. A
third container is made in the third mold cavity that has at least
at least one undercut located at a fifth position and at least one
undercut receiving structure located at a sixth position. A fourth
container is made in the fourth mold cavity that has at least at
least one undercut located at a seventh position and at least one
undercut receiving structure located at an eighth position. The
fifth position is a different location than the seventh position.
This method removes the first, second, third, and fourth containers
from the respective first, second, third, and fourth mold cavities.
The method arranges the first and second containers to form a
two-container stack. The at least one undercut of the first
container at the first position aligns with and fits within the
undercut receiving structure at the fourth position of the second
container to reduce the height of the two-container stack. The
first and second containers align without further rotation of the
first and second containers after they are removed from the mold
cavities. The method arranges the third and fourth containers to
form a two-container stack. The at least one undercut of the third
container at the fifth position aligns with and fits within the
undercut receiving structure at the eighth position of the fourth
container to reduce the height of the two-container stack. The
third and fourth containers align without further rotation of the
third and fourth containers after they are removed from the mold
cavities.
[0013] According to still another method of the present invention,
a method of forming a reduced-height stack of containers provides a
mold base that comprises at least a first mold cavity and a second
mold cavity. The design of the first mold cavity is substantially
identical to the design of the second mold cavity. This method
makes a first container in the first mold cavity that has at least
one undercut located at a first position and at least one undercut
receiving structure located at a second position. The method also
makes a second container in the second mold cavity that has at
least one undercut located at a third position and at least one
undercut receiving structure located at a fourth position. The
third position is a different location than the first position.
This method removes the first and second containers from the
respective first and second mold cavities. At least one of the
containers rotates after it is removed from the mold cavity. The
method arranges the first and second containers to form a
two-container stack. The at least one undercut of the first
container at the first position aligns with and fits within the
undercut receiving structure at the fourth position of the second
container to reduce the height of the two-container stack.
[0014] According to one embodiment, a stack of containers comprises
a first container and a second container. The first container
comprises a locking mechanism. The first container locking
mechanism includes at least one undercut at a first position and at
least one undercut receiving structure at a second position. The
second container comprises a locking mechanism. The second
container locking mechanism includes at least one undercut at a
third position and at least one undercut receiving structure at a
fourth position. The first and second containers stack such that
the at least one undercut at the first position is aligned with the
at least one undercut receiving structure at the fourth position.
The at least one undercut at the first position contacts the
undercut receiving structure at the fourth position to reduce the
height of the stack.
[0015] According to another embodiment, a stack of containers
comprises a first container, a second container, a third container,
a fourth container, and a fifth container. The first container
comprises a locking mechanism. The first container locking
mechanism includes at least one undercut at a first position and at
least one undercut receiving structure at a second position. The
second container comprises a locking mechanism. The second
container locking mechanism includes at least one undercut at the
first position and at least one undercut receiving structure at the
second position. The third container comprises a locking mechanism.
The third container locking mechanism includes at least one
undercut at a third position and at least one undercut receiving
structure at a fourth position. The fourth container comprises a
locking mechanism. The fourth container locking mechanism includes
at least one undercut at the first position and at least one
undercut receiving structure at the second position. The fifth
container comprises a locking mechanism. The fifth container
locking mechanism includes at least one undercut at the first
position and at least one undercut receiving structure at the
second position. The second container aligns so that the at least
one undercut at the first position of the second container aligns
with the at least one undercut at the first position of the first
container. The third container aligns so that the at least one
undercut at the third position of the third container aligns with
and fits within the at least one undercut receiving structure at
the second position of the second container. The fourth container
aligns such that the at least one undercut at the first position of
the fourth container aligns with and fits within the at least one
undercut receiving structure at the fourth position of the third
container. The fifth container aligns so that the at least one
undercut at the first position of the fifth container aligns with
the at least one undercut at the first position of the fourth
container. The stack height between the second, third, and fourth
containers is minimized, and the total stack height is reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Other advantages of the invention will become apparent upon
reading the following detailed description and upon reference to
the drawings.
[0017] FIG. 1 is a sectional view of a prior art stack of
containers;
[0018] FIG. 2 is a sectional view of another prior art stack of
containers;
[0019] FIG. 3 is a sectional view of a locking mechanism for a
container according to one embodiment of the present invention;
[0020] FIG. 4 is a sectional view of a locking mechanism for a
container according to another embodiment of the present
invention;
[0021] FIG. 5a is a schematic view of a stack of two containers
according to one embodiment of the present invention;
[0022] FIG. 5b is a sectional view of a stack of two containers
according to another embodiment of the present invention;
[0023] FIG. 6 is a functional diagram of a mold base to be used to
manufacture containers according to one embodiment of the present
invention;
[0024] FIG. 7 is a functional diagram of a mold base to be used to
manufacture containers according to another embodiment of the
present invention;
[0025] FIG. 8 is a functional diagram of a mold base according to a
further embodiment of the present invention;
[0026] FIG. 9 is a functional diagram of a mold base according to
yet another embodiment of the present invention;
[0027] FIG. 10 is a sectional view of a stack of five containers
according to yet another embodiment of the present invention;
and
[0028] FIG. 11 is a functional diagram of a mold base according to
yet a further embodiment of the present invention.
[0029] While the invention is susceptible to various modifications
and alternative forms, specific embodiments thereof have been shown
by way of example in the drawings and will herein be described in
detail. It should be understood, however, that it is not intended
to limit the invention to the particular forms disclosed but, on
the contrary, the intention is to cover all modifications,
equivalents, and alternatives falling within the spirit and scope
of the invention as defined by the appended claims.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT
[0030] Turning now to the drawings, FIG. 3 shows a locking
mechanism 12 of a container 1 in the closed position. As used in
this application the word "container" is defined herein as
including, trays, lids, bases, bowls, combinations of lids and
bases, combinations of lids and bowls, bases with hinged lids,
bowls with hinged lids, and combinations thereof. The locking
mechanism 12 comprises a rim flange 14 and a corresponding undercut
16. The locking mechanism 12 functions by having the undercut 16 go
over the rim flange 14 so as to close the container 1. The undercut
16 of FIG. 3 includes a lead-in surface 18.
[0031] Referring to FIG. 4, a locking mechanism 22 of a container 2
is shown in the closed position according to another embodiment.
The locking mechanism 22 comprises a rim flange 24 and an undercut
26. The locking mechanism 22 functions by having the rim flange 24
inserted into the undercut 26 so as to close the container 2. The
undercut 26 has a lead-in surface 28.
[0032] FIG. 5a shows a schematic view of a two container stack 50
that includes a first container 52 and a second container 54. The
first and second containers 52, 54 comprise respective locking
mechanisms 22, 32 that further comprise an undercut receiving
structure 56 and an undercut 58. The undercut receiving structure
56 is designed to allow the undercuts 58 of the locking mechanisms
22, 32 of the containers 52, 54 in the stack 50 to be in closer
proximity to each other, thus reducing stack height C (FIG. 5b) of
the stack 50. The undercut receiving structures 56, as well as the
undercuts 58, of the locking mechanisms 22, 32 of the containers
52, 54 are offset relative to each other in stack 50. This offset
allows the undercut receiving structure 56 of the locking mechanism
32 of the container 54 to align with the undercut 58 the locking
mechanism 22 of the container 52 in the stack 50.
[0033] Turning to FIG. 5b, a partial section view of the container
stack 50 is shown. The stack height C of the stack 50 is reduced
because the undercut 58 of the locking mechanism 32 of the
container 54 aligns with the undercut receiving structure 56 of the
locking mechanism 22 of the container 52. The depth of undercut
receiving structure 56 of the locking mechanism desirably
corresponds with the height of the undercut 58 of the locking
mechanism. For example, a deeper undercut receiving structure 56,
up to the depth of the undercut 58, reduces the stack height C by a
greater amount, while a shallower undercut receiving structure 56
reduces the stack height C by a lesser amount. The shape of the
undercut receiving structure 56 may vary from that depicted in FIG.
5b, so long as the shape of the undercut receiving structure 56 is
capable of stacking on the undercut 58 of the container below it in
the stack and of receiving the undercut 58 of the container above
it in the stack. Methods of obtaining the offset of the undercut
receiving structure 56 of the locking mechanism 32 of the container
54 relative to the undercut 58 of the locking mechanism 22 of the
container 52 are shown in FIGS. 6 and 7.
[0034] FIG. 6 shows a mold base 60 comprising mold cavities 62a-d
for producing containers. The containers produced by the mold
cavities 62a-d are shown to be an approximately square shape. Other
shapes are contemplated, such as rectangular, or polygonal. The
mold base 60 is a two by two mold base because it has two columns
and two rows of mold cavities, and may mold four containers at
once. Each of the mold cavities 62a-d is shown with four undercut
receiving structures 64 and four undercuts 66. According to one
process, once the containers have been molded, they are removed
from the mold base 60 and trimmed to the proper shape. The trimmed
containers are then stacked. It is contemplated that the container
stack order may be from bottom to top as follows: the container
from the mold cavity 62a, the mold cavity 62b, the mold cavity 62d,
and the mold cavity 62c. Stacking the containers in this order
reduces the stack height, because the undercuts 66 of the locking
mechanisms of the containers are aligned with the undercut
receiving structures 68 of the locking mechanisms of the container
directly preceding it in the stack. It is contemplated that the
containers produced by mold cavities 62a-d of several cycles of
mold base 60 may be stacked in the order described above so that a
stack with more than four containers is produced.
[0035] Other stack orders are also contemplated in the present
invention. An alternate container stack order may be from bottom to
top as follows: the container from the mold cavity 62a, the mold
cavity 62d, the mold cavity 62c, and the mold cavity 62b. This
order reduces the stack height, but the reduction in stack height
is not as significant as the prior stacking order. The stack height
is not reduced as much in this stacking order because undercut to
undercut contact occurs in the stack of containers.
[0036] It is further contemplated that larger mold bases, such as a
four by two cavity mold base, or an eight by four cavity mold base
may be used in the current invention. It is also contemplated that
a stack of containers would be formed from each column of the mold
base 60. According to one process, the order of the first stack of
containers may be from bottom to top as follows: the container from
the mold cavity 62a, the mold cavity 62c. The order of the second
stack may be from bottom to top as follows: the container from the
mold cavity 62b the mold cavity 62d. It is contemplated that the
containers of several cycles of mold base 60 may be stacked in this
order to produce two stacks with more than two containers per
stack. It is further contemplated that a non-matrix mold may be
used.
[0037] The embodiment depicted in FIG. 7 is similar to that
depicted in FIG. 6 except that the mold base 70 produces containers
that have a generally circular shape in mold cavities 72a-d. Other
shapes are contemplated, such as oval or oblong. The mold base 70
depicted in FIG. 7 is a two by two mold base because it has two
columns and two rows of mold cavities and may mold four containers
at once. Each of the mold cavities 72a-d is shown with three
undercut receiving structures 74 and three undercuts 76. According
to one process, once the containers have been molded, they are
removed from the mold base 70 and trimmed to the proper shape. The
trimmed containers produced by the mold cavities 72a-d are then
stacked. It is contemplated that the stack order may be from bottom
to top as follows: the container from the mold cavity 72a, the mold
cavity 72c, the mold cavity 72b, and the mold cavity 72d. Stacking
the containers in this order reduces the stack height, because the
undercuts 76 of the locking mechanisms of the containers are
aligned with the undercut receiving structures 78 of the locking
mechanism of the container directly preceding it in the stack. It
is contemplated that the containers of several cycles of mold base
70 would be stacked in the order described above so that a stack
with more than four containers was produced.
[0038] Other stack orders are also contemplated in the present
invention. Using the mold 70, an alternate stack order may be from
bottom to top as follows: the container from the mold cavity 72a,
the mold cavity 72b, the mold cavity 72c, and the mold cavity 72d.
This order reduces the stack height, but the reduction in stack
height is not reduced as much as the prior stacking order using
containers formed from mold 70, as undercut to undercut contact is
taking place.
[0039] It is further contemplated that larger mold bases, such as a
four by two cavity mold base, or an eight by four cavity mold base
may be used in the current invention, or any other matrix mold base
may be used. It is also contemplated that a stack of containers may
be formed from each column of the mold base 70. According to one
process, the order of the first stack may be from bottom to top as
follows: the container from the mold cavity 72a, the mold cavity
72c. The order of the second stack may be from bottom to top as
follows: the container from the mold cavity 72b, the mold cavity
72d. It is contemplated that the containers of several cycles of
the mold base 70 may be stacked in this order to produce two stacks
with more than two containers per stack. It is also contemplated
that non-matrix mold base may be used.
[0040] Turning now to FIG. 8, a mold base 80 is shown that is
capable of producing three containers per cycle in mold cavities
82a-c. Mold base 80 is a 1 by 3 mold base because it has one column
of mold cavities and three rows of mold cavities. The mold cavities
82a-c are identical except that the first cavity 82a is at a first
angle D relative to the mold base 80, the second cavity 82b is at a
second angle E relative to the mold base 80, and the third cavity
82c is at a third angle F relative to the mold base 80. The first
angle D is from about 80.degree. to about 100.degree., the second
angle E is from about 50.degree. to about 70.degree., and the third
angle F is from about 20.degree. to about 40.degree..
[0041] Each of the mold cavities 82a-c is shown with three undercut
receiving structures 84 and three undercuts 86. According to one
process, once the containers are molded they are removed from the
mold base 80 and trimmed to the proper shape. The trimmed
containers are then stacked. It is contemplated that the stack
order may be from bottom to top as follows: the container from the
mold cavity 82a, the mold cavity 82c, and finally the mold cavity
82c. Stacking the containers in this order reduces the stack
height, because the undercuts 86 of the locking mechanisms of the
containers are in alignment with the undercut receiving structure
88 of the locking mechanism of the container directly preceding it
in the stack.
[0042] It is contemplated that the containers of several cycles of
mold base 80 would be stacked in the order described above so that
a stack with more than three containers is produced.
[0043] It is further contemplated that larger mold bases, such as a
two by three cavity mold base, or an eight by four cavity mold base
may be used in the current invention. It is also contemplated that
a stack of containers would be formed from each column of a
multi-column mold base. It is also contemplated that a non-matrix
mold base may be used.
[0044] It is additionally contemplated that the mold cavities as
shown in FIG. 8 may have a different shape from the generally round
shape depicted. For example, the mold cavities may be generally
polygonal. If generally polygonal mold cavities are employed, the
angle of rotation of the mold cavities within the mold base would
vary from that described in connection to FIG. 8. For example, if a
generally rectangular mold cavity is employed the angle of rotation
between each mold cavities is approximately one hundred and eighty
degrees (180.degree.).
[0045] It is additionally contemplated that the methods of using
mold bases 70, 80 may be combined such that a mold base with mold
cavities of varying geometry are combined with the rotation of the
mold cavities relative to the mold base to produce a stack of
containers with undercuts aligning with the undercut receiving
structures of the preceding container in the stack.
[0046] Referring to FIG. 9, a mold base 90 is shown comprising mold
cavities 92a-f. The mold base 90 of FIG. 9 is a two by three mold
base because it has two columns of mold cavities and three rows of
mold cavities and is capable of molding six containers at once.
Each of the mold cavities 92a-f of the mold base 90 is of an
approximately polygonal shape. Each of the mold cavities 92a-f is
shown with four undercut receiving structures 94 and four undercuts
96. According to one process, there are two mold cavity designs in
mold base 90 of FIG. 9. The mold cavities 92a, 92c, and 92e are the
first mold cavity design, and mold cavities 92b, 92d, and 92f are
the second mold cavity design. Once the containers have been molded
they are removed from the mold base 90 and trimmed to the proper
shape. The trimmed containers are then stacked. It is contemplated
that the stack order may be from bottom to top as follows: the
container from the mold cavity 92a, the mold cavity 92b, the mold
cavity 92c, the mold cavity 92d, the mold cavity 92e, and the mold
cavity 92f. Stacking the containers in this order will reduce the
stack height, because the undercuts 96 of the locking mechanisms of
the containers are in alignment with the undercut receiving
structures 94 of the locking mechanisms of the container directly
preceding it in the stack. It is contemplated that the containers
produced by mold cavities 92a-f of several cycles of mold base 90
would be stacked in the order described above so that a stack with
more than six containers is produced.
[0047] It is further contemplated that larger mold bases, such as a
four by two cavity mold base, or an eight by four cavity mold base
may be used in the current invention. It is also contemplated that
a stack of containers would be formed from each column of mold base
90. According to one process, the order of the first stack may be
from bottom to top as follows: the container from the mold cavity
92a, the mold cavity 92b, and the mold cavity 92c. The order of the
second stack may be from bottom to top as follows: the container
from the mold cavity 92d, the mold cavity 92e, and the mold cavity
92f. It is further contemplated that the containers of several
cycles of mold base 90 may be stacked in this order to produce two
stacks with more than three containers per stack.
[0048] FIG. 10 shows a partial stack 100 of containers produced by
a column of the mold base 90 of FIG. 9. The stack 100 comprises
containers 102-110, the containers are from three cycles of mold
base 90. The first container 102 is from the third cycle of the
mold base 90, the second, third, and fourth containers 104,106,108
are from the second cycle of the mold base 90, and the fifth
container 110 is from the first cycle of the mold base 90. The
container 102 at the top of the stack, and the container that is
second from the bottom of the stack 108 were produced in the third
mold cavity 92c of the mold base 90 of FIG. 9. The second container
from the top 104 of the stack 100 and the bottom container 110 of
the stack 100 were produced in the first mold cavity 92a of the
mold base 90 of FIG. 9. The middle container 106 of the stack 100
were produced in the second mold cavity 92b of FIG. 9.
[0049] The middle container 106 of the stack 100 is the only
container that is made by a mold cavity with the second mold cavity
design in this stack 100. Therefore, the undercuts of the locking
mechanism of the container 104 are in alignment with the undercut
receiving structures of the locking mechanism of the container 106,
and the undercuts of the locking mechanism of the container 106 are
in alignment with the undercut receiving structures of the locking
mechanism of the container 108. However, the undercuts of the
locking mechanism of the container 102 are in alignment with the
undercuts of the locking mechanism of the container 104, and the
undercuts of the locking mechanism of the container 108 are in
alignment with the undercuts of the locking mechanism of the
container 110. The overall height of stack 100 therefore is not
truly optimized, as undercut to undercut alignment is occurring
among the locking mechanisms of the containers. However, this
undercut to undercut alignment of the locking mechanisms is
unavoidable when an odd number of rows of mold cavities are present
in a mold base, and the shape of the containers prevents the
rotation of the containers when forming the stack 100.
[0050] This process reduces the stack height of the stack 100,
since locations are present where the undercuts of the locking
mechanism of one container are in alignment with the undercut
receiving structures of the locking mechanism of the preceding
container. For example, a stack height H between the second
container 104 from the top of the stack 100 and the middle
container 106 of the stack 100, and between the middle container
106 of the stack 100 and the second container from the bottom 108
of the stack 100 is the reduced stack height. A stack height G
between the top container 102 and the second container 104 from the
top of the stack 100 and between the second container from the
bottom 108 and the bottom container 110 is the full stack
height.
[0051] Referring to FIG. 11, a mold base 200 is shown comprising
mold cavities 210a,b. The mold base 200 of FIG. 11 is a one by two
mold base because it has one columns of mold cavities and two rows
of mold cavities and is capable of molding two containers at once.
Each of the mold cavities 210a,b of the mold base 200 is of an
approximately polygonal shape. Each of the mold cavities 210a,b is
shown with four undercut receiving structures 212 and four
undercuts 214. As shown in FIG. 11, each of the undercut receiving
structures 212 and each of the undercuts 214 are located generally
within each of the corners of the containers formed by the cavities
210a,b and are at a generally diagonal orientation. According to
one process, there are two mold cavity designs in mold base 200 of
FIG. 11. The mold cavity 210a is a first mold cavity design, and
mold cavity 210b is a second mold cavity design. Once the
containers have been molded they are removed from the mold base 200
and trimmed to the proper shape. The trimmed containers are then
stacked. It is contemplated that the stack order may be from bottom
to top as follows: the container from the mold cavity 210a, the
mold cavity 210b. Stacking the containers in this order will reduce
the stack height, because the undercuts 214 of the locking
mechanisms of the containers are in alignment with the undercut
receiving structures 212 of the locking mechanisms of the container
directly preceding it in the stack. It is contemplated that the
containers produced by mold cavities 210a,b of several cycles of
mold base 200 would be stacked in the order described above so that
a stack with more than two containers is produced.
[0052] It is further contemplated that undercuts and undercut
receiving structures located generally within a corner of a
container at a generally diagonal orientation may vary from that
depicted in FIG. 11. For example, it is contemplated that a mold
base may contain a first mold cavity that contains two undercut
receiving structures in a first corner and a second corner along a
first lateral edge, and two undercuts in a third corner and a
fourth corner along a second lateral edge, generally opposite the
first lateral edge. The mold base contains a second mold cavity
that contains two undercut receiving structures in a fifth corner
and a sixth corner along a third lateral edge, and two undercuts in
a seventh corner and an eighth corner along a forth lateral edge,
generally opposite the third lateral edge. A first container made
in the first mold cavity would be stacked with a second container
made in the second mold cavity such that the under cut receiving
structures of the second container align with the undercuts of the
first container.
[0053] It is further contemplated that various methods of reducing
the stacking height of containers may be combined. For example, it
is contemplated that a mold base may have three mold cavities,
wherein the first mold cavity and the second mold cavity have
generally identical designs that are at a different orientation
relative to each other, and the third mold cavity has a different
design.
[0054] It is still further contemplated that a mold base may have
three mold cavities, wherein the first mold cavity and the second
mold cavities have a different design, and the third mold cavity
has a design that is generally identical to the design of the first
mold cavity, but the third mold cavity is rotated within the mold
base relative to the first mold cavity.
[0055] The amount of stack height reduction achieved will vary
based on the geometry of the container that is being stacked.
According to one embodiment, the stack height was reduced by about
sixty percent (60%). In an embodiment of the present invention
where only partial stack height reduction may be achieved based on
the number of mold cavities and the mold base cavity geometry the
stack may only be reduced by about twenty percent (20%).
[0056] The reduction in stack height reduces the cube size of the
transportation packaging for a stack of containers. A reduced cube
size for the transportation packaging reduces the transportation
costs for transporting a stack of containers, as smaller containers
are generally more cost effective to ship than larger containers. A
reduction in the cube size for the transportation packaging also
lowers the cost of storing the containers before the are used,
because the smaller transportation packaging occupies less storage
space.
[0057] The containers of the present invention are typically formed
from polymeric materials, but may be formed from materials such as
paper or metal. The polymeric containers are typically formed from
orientated polystyrene (OPS), polyethylene terephthalate (PET),
polyvinyl chloride (PVC), polyolefins (e.g., polypropylene), and
combinations thereof. It is contemplated that other materials may
be used to form the polymeric containers. The containers may be
made from a mineral-filled polymeric material such as, for example,
talc or calcium carbonate-filled polyolefin. An example of paper
that may be used in forming the containers is paperboard or molded
fiber. Paperboard and molded fiber typically have a sufficient
coefficient of friction to maintain the first and second containers
in a lockable position.
[0058] The materials used in forming the containers may assist in
releasably locking the containers. For example, the material(s)
forming the containers may have a fairly tacky laminate on one side
that corresponds with a fairly tacky laminate on the opposing side,
resulting in a desirable releasably lockable container. It is
contemplated that additives may be added to the containers.
[0059] The containers of the present invention are typically made
from a thermoforming process. However, it is also contemplated that
the containers may be made using other processes known in the art
such as, but not limited to, an injection molding process, a
rotomolding process, a rotational molding on a planar surface
process, a stamping process, or a molded fiber process.
[0060] The containers of the present invention are typically
disposable, but it is contemplated that they may be reused at a
future time.
[0061] As discussed above, the containers may be used with food
items. A method of using such containers includes placing the food
and locking the container to form a container with food therein.
The container is then placed in a heating apparatus and heated.
Typical heating apparatuses include microwaves and conventional
ovens. The containers may contain solid food products. The
containers may be used for storage in the refrigerator and/or the
freezer.
[0062] The thickness of the container generally ranges from about
0.002 to about 0.25 inch, but is typically from about 0.005 to
about 0.04 inch. The containers may be opaque or a variety of
colors or color combinations. The containers may be transparent if
it is desired for the customer to ascertain the nature of the
accommodated product and the condition thereof without having to
open the container.
[0063] While particular embodiments and applications of the present
invention have been illustrated and described, it is to be
understood that the invention is not limited to the precise
construction and compositions disclosed herein and that various
modifications, changes, and variations may be apparent from the
foregoing descriptions without departing from the spirit and scope
of the invention as defined in the appended claims.
* * * * *