U.S. patent application number 14/877001 was filed with the patent office on 2016-04-14 for container or platter assembly having locking and release features.
The applicant listed for this patent is Waddington North America, Inc.. Invention is credited to William A. Gallop, Malcolm Harris, Ashish K. Mithal, Matthew J. Wichmann.
Application Number | 20160101892 14/877001 |
Document ID | / |
Family ID | 55654941 |
Filed Date | 2016-04-14 |
United States Patent
Application |
20160101892 |
Kind Code |
A1 |
Wichmann; Matthew J. ; et
al. |
April 14, 2016 |
CONTAINER OR PLATTER ASSEMBLY HAVING LOCKING AND RELEASE
FEATURES
Abstract
A polygonal lid and container base provide secure and reliable
engagement therebetween, while also facilitating removal of the lid
without disturbing contents and without applying undue stress to
the lid. The lid includes at least one graspable member near or at
a designated "release" vertex that facilitates disengagement of the
lid from the container base at the release vertex. The lid further
includes regions of enhanced engagement that enhance the attachment
of the lid to the container base at least along the two sides of
the lid that adjoin the release vertex, causing the overall
attachment to be less dependent on attachment at the release
vertex. As a result, the strength of attachment at the release
vertex can be made weaker than at the other vertices, for easy
release of the release vertex, without undue weakening of the
overall attachment of the lid to the container base.
Inventors: |
Wichmann; Matthew J.;
(Crescent Springs, KY) ; Mithal; Ashish K.;
(Chelmsford, MA) ; Harris; Malcolm; (LaFayette,
GA) ; Gallop; William A.; (Westminster, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Waddington North America, Inc. |
Chelmsford |
MA |
US |
|
|
Family ID: |
55654941 |
Appl. No.: |
14/877001 |
Filed: |
October 7, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62061800 |
Oct 9, 2014 |
|
|
|
Current U.S.
Class: |
220/270 |
Current CPC
Class: |
B65D 2543/00361
20130101; B65D 2543/00527 20130101; B65D 2543/00731 20130101; B65D
2543/00694 20130101; B65D 2543/00203 20130101; B65D 2543/00805
20130101; B65D 43/0212 20130101; B65D 2543/00842 20130101; B65D
2543/00296 20130101; B65D 2543/0062 20130101; B65D 2543/00537
20130101 |
International
Class: |
B65D 17/00 20060101
B65D017/00; B65D 43/06 20060101 B65D043/06 |
Claims
1. A container assembly including a polygonal lid and a polygonal
container base, the lid being adapted for engagement with and easy
release from the container base, the container assembly comprising:
a container base having a container bottom wall, a container
sidewall that extends upwardly and outwardly from said container
bottom wall, and a peripheral container rim that is substantially
polygonal in shape; a lid having a lid top and a lid engagement
feature proximal to a peripheral lid rim, said peripheral lid rim
being substantially polygonal in shape, said lid engagement feature
being configured for mutual cooperation and attachment with the
peripheral container rim of the container base, thereby forming a
container assembly, the peripheral lid rim including a vertex that
is designated as a release vertex; at least one graspable member
provided in said lid proximal to the release vertex of the
peripheral rim, said graspable member being configured for
disengaging the release vertex from the peripheral container rim;
and at least one region of enhanced engagement included in each
side of the peripheral lid rim and at least one cooperating region
of enhanced engagement included in each side of the peripheral
container rim, said regions of enhanced engagement in the
peripheral lid rim along with said cooperating regions of enhanced
engagement in the peripheral container rim collectively ensuring a
secure attachment between the container base and the lid, thereby
avoiding or impeding unintentional disengagement between the tray
and the lid during at least one of handling, transporting, and
carrying said container assembly.
2. The container assembly of claim 1, wherein said lid engagement
feature provides weaker engagement with the container base in a
region encompassing the release vertex of the peripheral rim, as
compared to regions of the engagement feature that encompass other
vertices of the peripheral rim.
3. The container assembly of claim 1, wherein said lid engagement
feature comprises a peripheral groove extending substantially
continuously about the peripheral rim, said peripheral groove being
configured for mutual cooperation and attachment with the container
base by receiving said peripheral container lip of the container
base therein.
4. The container assembly of claim 3, wherein the peripheral groove
is deeper in the enhanced engagement regions of the peripheral rim
as compared to other regions of the peripheral rim.
5. The container assembly of claim 1, further comprising regions of
modified shaping of the lip of the container base that cooperate
with the regions of enhanced engagement of the peripheral rim of
the lid to strengthen the engagement of the lid with the container
base in the regions of enhanced engagement.
6. The container assembly of claim 1, wherein the graspable member
is provided in a peripheral skirt of the lid.
7. The container assembly of claim 6, wherein said peripheral skirt
is configured for guiding said base peripheral container lip into
cooperation with said lid engagement feature and facilitating
formation of said container assembly; and the peripheral skirt is
sufficiently short to enable a user to lift the container base from
below when the lid is engaged with the container base.
8. The container assembly of claim 6, wherein said peripheral skirt
extends between 0.1'' and 0.3'' below said peripheral container lip
of said container base.
9. The lid according to claim 6, wherein said peripheral skirt
extends about 0.2'' below said peripheral container lip of said
container base.
10. The container assembly of claim 1, wherein the graspable member
is a lift tab.
11. The container assembly of claim 1, further comprising a visible
indication cooperative with the graspable member, said visible
indication being an indication that suggests lifting of the
graspable member.
12. The container assembly of claim 1, further comprising a press
area proximate to said graspable member and located relatively
inwardly from said lid engagement feature, said press area being
downwardly pressable by a hand of a user while said hand is lifting
said graspable member, thereby disengaging the release vertex from
the lip of the container base.
13. The container assembly of claim 12, further comprising a
visible indication cooperative with the press area, said visible
indication being an indication that suggests pressing on the press
area while lifting the graspable member.
14. The container assembly of claim 1, wherein said lid is dome
shaped.
15. The container assembly of claim 1, wherein the graspable member
is located at the release vertex of the lid.
16. The container assembly of claim 1, wherein a pair of graspable
members are located adjacent to either side of the release
vertex.
17. The container assembly of claim 16, wherein said graspable
members are simultaneously operable with a user's left and right
hands respectively.
18. The container assembly of claim 16, wherein said graspable
members are sequentially operable with at least one of a user's
hands.
19. The container assembly of claim 1, wherein said container base
is a substantially flat tray.
20. The container assembly of claim 1, wherein the material of
construction of the lid is one of: polypropylene (PP), oriented
polystyrene (OPS), polyethylene terephthalate (PET), styrene
butadiene copolymer, and rubber modified styrene.
21. The container assembly according to claim 1, wherein said lid
is made by a thermoforming process.
22. The container assembly according to claim 1, wherein said lid
is thermoformed from an oriented polystyrene sheet.
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application No. 62/061,800, filed Oct. 9, 2014, which is herein
incorporated by reference in its entirety for all purposes.
FIELD OF THE INVENTION
[0002] This invention relates generally to container assemblies,
such as tray or platter assemblies comprising a base and a lid, and
more particularly to container assemblies having locking and
release features for ensuring a secure assembly between the base
and the lid, while offering improved release of the lid from the
base.
BACKGROUND OF THE INVENTION
[0003] Container assemblies are sometimes referred to simply as
"containers." Containers with detachable and re-attachable lids,
including disposable food containers, trays, and platters with
compatible lids, are well known and are commonly employed in many
industries, including food related industries such as restaurants,
caterers, institutional food service establishments, cafeterias,
and households.
[0004] A tray, serving platter, or container base for use in
catering and other food service applications frequently features a
lid or cover that is cooperatively engageable therewith for
presenting, handling, transporting, and/or protecting a variety of
food items. The tray or base usually has an upwardly projecting
sidewall that terminates in a rim. The base or tray rim may simply
feature a lip area, or may include sealing ridges, channels, or
other locking mechanisms that are adapted for cooperative
engagement with corresponding grooves, inverted channels, or other
cooperative features integrated with the lid. Note that the terms
"tray" and "base" are used generically herein to refer to any type
of tray, serving platter, container base, or other support base
which is attachable to a lid or cover. Note also that the term
"lid" is used generically herein to refer to any type of lid or
cover that is compatible with and attachable to a "tray", a
"platter", or a "base".
[0005] Most disposable lids for use with food containers and
platters are thermoformed from a sheet of Polyethylene
Terephthalate (PET) or Oriented Polystyrene (OPS), although other
plastic materials may be employed. The lid is configured to fit the
base, and may include an elevated and/or dome-shaped central
portion to allow for comfortably accommodating a certain quantity
or height of foods or other contents, and to preserve the shape,
form, decorative appearance and/or the general presentation of
items such as certain food preparations, including desserts, cakes,
sandwiches, and other foods. Or the lid may be substantially flat,
and may be attachable to a container which has sufficient depth to
fully surround food items or other contents to be contained
therein.
[0006] In some designs, once a lid has been engaged with a tray to
form a first tray-lid assembly, a second tray-lid assembly can be
stacked on top of the first tray-lid assembly, and thus a plurality
of tray-lid assemblies can be stacked on top of each other for
compact storage and for ease of transportation and handling.
[0007] For the purposes of food containment in a commercial
setting, it is paramount that food preparations be protected, and
that inadvertent disengagement or removal of the lid from the tray
be avoided. Therefore, in many cases one or more locking features
and/or undercuts are provided at the periphery of the tray and/or
the lid, resulting in a relatively tight interference fit between
the lid and the tray. However, this tight interference fit can make
it difficult for a user to disengage and/or remove the lid at the
time of use, resulting in an inconvenience to the user at best, and
spilling of the food at worst, as the user struggles to remove the
lid from the tray. Depending on the material of construction of the
lid, the lid may even tear or rip during removal, thereby rendering
subsequent reengagement of the lid with tray or container
ineffective or futile.
[0008] A typical method for disengaging a generic container-lid
assembly is by holding the container with one hand and pulling the
lid off with the other hand. Sometimes a tab or an indent is
provided in either the lid or the container so as to facilitate
creating an initial separation or opening between the lid and the
container at the location of the tab or indent, and then separating
the lid from the container around the entire periphery of the
container-lid assembly. However, this method of disengaging or
separating a lid from a container can be difficult if the container
is shallow, for example if the container is in the form of a tray,
a platter, or a plate.
[0009] Typically, a lid having a raised portion, herein referred to
generically as a "dome lid" regardless of whether the lid is round,
rectangular, or some other shape, features a downwardly projecting
peripheral skirt that overhangs beyond the perimeter of the tray or
container base. As will be appreciate by those skilled in the art,
for a relatively shallow tray the overhang of the peripheral skirt
of the lid can typically be almost as tall as the tray, making it
difficult for a user to slide his or her fingers underneath the
peripheral skirt of the lid for lifting the tray-lid assembly.
Instead, it is typically necessary for a user to lift the tray-lid
assembly by the peripheral edge of the lid without touching the
tray. In this situation, the entire weight of the tray and its
contents is borne by the locking or engagement mechanism between
the tray and the lid, further necessitating that the tray and lid
have a tight fit, and making it even more difficult to remove the
lid from the tray.
[0010] A particular difficulty for removing lids from tray-lid
assemblies of the type described above is encountered due to the
fact that in many cases the lid is flexible, and the periphery of
the tray-lid assembly is relatively large compared to the size of
the tab or indent that is provided with the lid or the tray for
initiating separation of the lid from the tray. Consequently, when
a user exerts an upward or downward force on the tab or indent
provided in the lid or tray for pulling the tray-lid assembly
apart, the rim of the lid tends to press opposingly inwardly at
other locations, causing the lid to grip onto the tray even more
tightly at those locations, and thereby rendering removal of the
dome from the tray base extremely difficult, or at least
cumbersome.
[0011] One approach to making lid removal from a container base
easier is described in U.S. Pat. No. 8,701,930, also by the present
applicant. In this approach, separation of the lid from the
tray-lid assembly is facilitated by providing at least two tabs or
indentations at two separate locations on the outer periphery of
the lid that are not opposite to each other, thereby providing at
least two distinct locations for initial disengagement of the lid
from the tray. By disengaging the lid from the tray at two or more
separated locations about the rim, the tendency of the elastic lid
to responsively grip the tray is overcome, and the lid is released
from the tray without the user applying undue effort. In some
implementations, the initial disengagements at the two tabs
propagate toward each other and merge, thereby creating a large
area of disengagement that greatly facilitates removal of the lid
from the tray.
[0012] This approach works very well for substantially round trays
and lids, but can be problematic when applied to square,
rectangular, or otherwise polygonal lids and trays having three or
more vertices. It has been observed that a container assembly with
a polygonal periphery exhibits engagement between the base and the
lid mostly in the corners, while the sides of the base and the lid
which make up the majority of the periphery show relatively weaker
engagement, due at least in part to the flexible nature of the lid.
In a typical polygonal container assembly, the lid corners have to
be stretched over the corresponding corners in the base so as to
engage the base and the lid in a reasonably secure manner, with the
lid being held in tension in the assembled state. Thus, in contrast
to a round container assembly, only a relatively small portion of
the periphery of a typical polygonal container assembly is
available for actual engagement, leading to concerns regarding
inadvertent disengagement between the base and the lid.
[0013] As a result, it is challenging and difficult to fully
utilize the food-holding capacity of a polygonal container
assembly. It will be realized that a large polygonal container
assembly is particularly susceptible to disengagement when it is
lifted and carried, in comparison to a round container assembly of
similar construction.
[0014] In addition, each vertex of a square or rectangular
container assembly, holding a certain weight of food, contributes
significantly (25% on average) to the overall engagement strength
between the base and the lid. In contrast, a round peripheral
section on a round container assembly comparable in size to the
vertex of a typical square or rectangular container contributes a
much smaller percentage of the total engagement. Consequently,
release of a square or rectangular polygonal lid from a tray will
typically require greater force so as to overcome at least 25% of
the overall engagement force at a selected vertex, referred to
herein as the "release" vertex. If one or more tabs or indentations
are provided, they will typically be located at or near the release
vertex, for example on either side of a corner of a square or
rectangular lid. Accordingly, to facilitate the initial release of
the lid from the tray, it may be beneficial to weaken the
attachment of at least one release vertex as compared to the other
vertices. However, weakening of the release vertex or vertices can
create yet another undesirable side effect, in that a weak release
vertex could also make the container assembly more susceptible to
unintentional disengagement.
[0015] To address the problems relating to engagement of container
assemblies with polygonal peripheries, a few approaches have been
used in the prior art. One of the approaches is to make the fit
extremely tight at the corners or vertices of a polygonal container
base to overcome the tendency of the base to detach from the lid.
However, this approach can lead to a container assembly that is
very difficult to open.
[0016] Another approach that has been utilized in the prior art is
to construct quasi-square trays with rounded sides; such container
shapes are frequently described by the blend word squround (or
scround).
[0017] Still another approach that has been used in the prior art
is to incorporate a protruding button in proximity to the corners
of one of the lid and the base, and equipping the opposing member
of the container assembly with a corresponding mating recess. Such
a button-recess locking feature included at or near the corners of
the container can provide a more aggressive engagement, but can
also pose a shortcoming in that substantial effort may be required
to open the container assembly and separate the lid from the
base.
[0018] Accordingly, these approaches do not simultaneously address
the need for firm, reliable attachment and the need for ease of
opening or separating the lid from the container base without
disturbing the contents of the container.
[0019] Thus, there is a need for a square, rectangular, or
otherwise polygonal lid that is securely engageable with a
corresponding square, rectangular, or otherwise polygonal tray or
container base, and yet can be conveniently removed from the tray
or container base with relative ease, and without disturbing the
contents of the tray or container base. These and other needs are
met by the lid and container base of the present invention.
BRIEF SUMMARY OF THE INVENTION
[0020] At the heart of the present invention is the observation
that a polygonal container assembly holding food is most
susceptible to disengagement when it is being lifted and carried by
a user, and that disengagement is not a single event but rather an
event that propagates through a series of steps. When a food-filled
container assembly is lifted, the entire weight of the food is
supported by the container base, which causes the container base to
flex. It will be realized that the tray or container base is
usually made quite thin to conserve material and to provide an
economical article, and that this thinness can further exacerbate
the flexing.
[0021] During handling and carrying of a square or rectangular
container assembly, two sides of the container assembly are
typically held or supported by the user's hands, while the other
two sides remain unsupported. The unsupported portions of the
container base are thereby naturally subject to sagging under the
weight of food contained in the tray. This flexing of the container
base due to content weight first initiates moderate amounts of
disengagement between the lid and the container base, usually along
a region of the unsupported sides. As the container assembly is
transported or carried, the flexing may be intensified, and the
container base may progressively flex enough to create significant
disengagement, initially at the unsupported sides, and then at one
or more of the corners. Once one of the corners is compromised, the
flexing typically extends to the other corners, and the entire
container assembly may be compromised, causing food to spill from
the container assembly.
[0022] In accordance with the present invention, a polygonal
container assembly comprising a container base and a lid is
provided with at least a supplemental, auxiliary, or secondary
locking feature in addition to the primary lid-base engagement
features. The secondary locking feature inhibits initial flexing of
the container base, thereby impeding or averting unintentional
disengagement between the container base and the lid. A polygonal
lid and container base (where the base is also referred to
generically herein as a "tray," unless the context requires
otherwise), according to the invention, thereby enables secure and
reliable engagement between the lid and the container base, while
also enabling easy removal of the lid from the container base
without disturbing contents supported by the container base, and
without applying undue stress to the lid. In particular, the
present invention enables removal of the lid from a tray-lid
assembly in a reversible manner, i.e. without damaging the lid
during removal.
[0023] The container base and lid according to the present
invention are configured to facilitate separation of the lid from
the base-lid assembly by providing at least one graspable member,
such as a tab or an indentation, at or adjacent to at least one
designated "release" vertex of the polygonal lid, thereby providing
for initial disengagement of the lid from the container base at the
release vertex. The container base and the lid further include
mutually-cooperating regions of enhanced or secondary engagement
that provide strengthened engagement therebetween along at least
the two sides of the lid that extend from the release vertex.
[0024] Preferably, the enhanced-engagement features are provided
along all sides of the polygonal lid. It will be realized that
these secondary or enhanced engagement features provided in the
sides do not necessarily extend along the entire lengths of the
sides, and may be localized to small segments of the sides. The
regions of enhanced engagement strengthen the attachment of the lid
to the container base along the sides of the lid, so that the
overall attachment of the lid to the container base is not as
strongly dependent on the attachment at the vertices. As a result,
the attachment at the release vertex can be made weaker than at the
other vertices, without reducing the overall lid-tray attachment to
an unacceptable degree. Thus by employing a secondary locking
feature and a release vertex, inadvertent detachment of the lid is
rendered unlikely, while the lid can be intentionally released from
the container base without requiring the user to apply undue
effort, without subjecting the lid to undue stress, and without
unduly disturbing the contents of the tray-lid assembly.
[0025] Note that except where the context requires a more specific
definition, the terms "tray" and "base" are used herein to refer
generically to a tray, platter, dish, container, plate, or any
other container base that is compatible with a lid or cover; and
that the term "lid" is used generically herein to refer to any sort
of lid or cover that is compatible with a "tray," or "base,"
including flat lids and "dome" lids that include raised portions so
as to have cross sectional profiles that are rectangular, rounded,
or any other raised shape.
[0026] Note also that while the following discussion is presented
in the context of describing enhanced engagement feature(s) of a
polygonal container assembly comprising a container base and a lid,
whereby the feature(s) enable enhanced engagement between the
container base and the lid to prevent inadvertent removal of the
lid from the container base, the roles of the lid and the container
base can be reversed without departing from the scope of the
invention. In other words, a specific engagement feature or
features ascribed herein as pertaining to the "lid" (or upper
element or cover component) can be incorporated instead into the
"tray" (or lower element or food holding receptacle or container
base) of the tray-lid combination, and vice versa. Therefore, the
invention applies generally to separable halves of a container
assembly comprising a first half and a second half, whereby terms
used for convenience to describe one half of the container
assembly, such as "lid" and "cover," can generally be exchanged
herein with terms used to describe the other half of the container
assembly, such as "tray," "container base," and "support base,"
without departing from the meaning or scope of the invention.
[0027] In certain embodiments, secondary locking or enhanced
engagement is provided by incorporating one or more protruding
elements or cleats near the periphery of the lid or cover which
cooperate with the regions of enhanced engagement that are provided
in the rim of the container base, or at least in a location
proximate thereto.
[0028] In certain embodiments, the lid is provided with at least
two graspable members located on either side of a release vertex at
the outer periphery of the lid.
[0029] In some of these embodiments, a pressing area is provided
adjacent to each of the graspable members, which can be pressed
while the graspable member is lifted. In certain embodiments, the
graspable members are in the form of first and second lifting tabs
that are cooperative with first and second pressing areas
respectively. During the process of removing the lid from the
container base, a user can press the first pressing area and lift
the first lifting tab with one hand, while concurrently pressing
the second pressing area and lifting the second lifting tab with
the second hand. Once a release vertex of the lid has been released
from the container base, the entire lid can be readily removed from
the container base.
[0030] In embodiments, at least one region of enhanced or secondary
engagement is provided on each side of the polygonal periphery of
the container assembly. In various embodiments, the regions of
enhanced engagement are located midway between adjacent vertices.
And in some embodiments, each of the regions of enhanced engagement
extends over between 5% and 50% of the length of the corresponding
side of the polygonal lid.
[0031] The present invention is a container assembly including a
polygonal lid and a polygonal container base, the lid being adapted
for engagement with and easy release from the container base. The
container assembly includes a container base having a container
bottom wall, a container sidewall that extends upwardly and
outwardly from said container bottom wall, and a peripheral
container rim that is substantially polygonal in shape; a lid
having a lid top and a lid engagement feature proximal to a
peripheral lid rim, said peripheral lid rim being substantially
polygonal in shape, said lid engagement feature being configured
for mutual cooperation and attachment with the peripheral container
rim of the container base, thereby forming a container assembly,
the peripheral lid rim including a vertex that is designated as a
release vertex; at least one graspable member provided in said lid
proximal to the release vertex of the peripheral rim, said
graspable member being configured for disengaging the release
vertex from the peripheral container rim; and at least one region
of enhanced engagement included in each side of the peripheral lid
rim and at least one cooperating region of enhanced engagement
included in each side of the peripheral container rim, said regions
of enhanced engagement in the peripheral lid rim along with said
cooperating regions of enhanced engagement in the peripheral
container rim collectively ensuring a secure attachment between the
container base and the lid, thereby avoiding or impeding
unintentional disengagement between the tray and the lid during at
least one of handling, transporting, and carrying said container
assembly.
[0032] In embodiments, the lid engagement feature provides weaker
engagement with the container base in a region encompassing the
release vertex of the peripheral rim, as compared to regions of the
engagement feature that encompass other vertices of the peripheral
rim.
[0033] In some embodiments, said lid engagement feature comprises a
peripheral groove extending substantially continuously about the
peripheral rim, said peripheral groove being configured for mutual
cooperation and attachment with the container base by receiving
said peripheral container lip of the container base therein. And in
some of these embodiments the peripheral groove is deeper in the
enhanced engagement regions of the peripheral rim as compared to
other regions of the peripheral rim.
[0034] Other embodiments further include regions of modified
shaping of the lip of the container base that cooperate with the
regions of enhanced engagement of the peripheral rim of the lid to
strengthen the engagement of the lid with the container base in the
regions of enhanced engagement.
[0035] In various embodiments, the graspable member is provided in
a peripheral skirt of the lid. In some of these embodiments, the
peripheral skirt is configured for guiding said base peripheral
container lip into cooperation with said lid engagement feature and
facilitating formation of said container assembly, and the
peripheral skirt is sufficiently short to enable a user to lift the
container base from below when the lid is engaged with the
container base. In certain of these embodiments the peripheral
skirt extends between 0.1'' and 0.3'' below said peripheral
container lip of said container base. And in other of these
embodiments the peripheral skirt extends about 0.2'' below said
peripheral container lip of said container base.
[0036] In embodiments, the graspable member is a lift tab. And some
embodiments further include a visible indication cooperative with
the graspable member, said visible indication being an indication
that suggests lifting of the graspable member.
[0037] Various embodiments further include a press area proximate
to said graspable member and located relatively inwardly from said
lid engagement feature, said press area being downwardly pressable
by a hand of a user while said hand is lifting said graspable
member, thereby disengaging the release vertex from the lip of the
container base. And some of these embodiments further include a
visible indication cooperative with the press area, said visible
indication being an indication that suggests pressing on the press
area while lifting the graspable member.
[0038] In certain embodiments, said lid is dome shaped. In some
embodiments, the graspable member is located at the release vertex
of the lid.
[0039] In various embodiments, a pair of graspable members are
located adjacent to either side of the release vertex. In some of
these embodiments, the graspable members are simultaneously
operable with a user's left and right hands respectively. In other
of these embodiments, the graspable members are sequentially
operable with at least one of a user's hands.
[0040] In embodiments, the container base is a substantially flat
tray. In some embodiments, the material of construction of the lid
is one of: polypropylene (PP), oriented polystyrene (OPS),
polyethylene terephthalate (PET), styrene butadiene copolymer, and
rubber modified styrene.
[0041] In various embodiments, the lid is made by a thermoforming
process. And in certain embodiments the lid is thermoformed from an
oriented polystyrene sheet.
[0042] The features and advantages described herein are not
all-inclusive and, in particular, many additional features and
advantages will be apparent to one of ordinary skill in the art in
view of the drawings, specification, and examples of claims.
Moreover, it should be noted that the language used in the
specification has been principally selected for readability and
instructional purposes, and not to limit the scope of the inventive
subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] The invention will be better understood upon reading the
following Detailed Description in conjunction with the drawings, in
which:
[0044] FIG. 1 is a perspective view from above, drawn to scale, of
a lid and corresponding tray according to an embodiment of the
present invention;
[0045] FIG. 2A is a view from above, drawn to scale, of the lid of
FIG. 1;
[0046] FIG. 2B is a cross-sectional view of the lid of FIG. 2A,
drawn to scale, taken along a line that intersects regions of
enhanced engagement on the rim;
[0047] FIG. 2C is an enlarged cross-sectional view, drawn to scale,
of the shaping in the region of enhanced engagement of the lid of
FIG. 2B;
[0048] FIG. 2D is an enlarged view from above, drawn to scale, of a
release vertex region of a lid similar to the lid of FIG. 2A, which
includes press areas associated with each of the graspable members,
and further includes visible indications of the press areas;
[0049] FIG. 3A is a view from above, drawn to scale, of the tray of
FIG. 1;
[0050] FIG. 3B is a cross-sectional view of the tray of FIG. 3A,
drawn to scale, taken along a line that intersects regions of
modified shaping of the lip of the tray that cooperate with the
regions of enhanced engagement in the rim of the lid;
[0051] FIG. 3C is an enlarged view, drawn to scale, of the modified
shaping of the lip of FIG. 3B that cooperates with the regions of
enhanced engagement of the lid of FIG. 2C;
[0052] FIG. 3D is an enlarged view from above, drawn to scale, of
the region of the tray of FIG. 3A that includes the region of
modified shaping;
[0053] FIG. 4A is an enlarged cross-sectional view, drawn to scale,
of the shaping of the lid rim and tray lip of the embodiment of
FIG. 3A in a region that lies outside of the region of enhanced
engagement; and
[0054] FIG. 4B is an enlarged cross-sectional view drawn to scale
of the regions of enhanced engagement and modified shaping of FIG.
2C and FIG. 3D shown in engagement with each other.
DETAILED DESCRIPTION OF THE INVENTION
[0055] The present invention is generally directed to a container
assembly comprising a container base and a cooperating lid that
enables secure and reliable engagement between the lid and the
container base, while also enabling easy removal of the lid from
the container base without disturbing contents supported by the
container base, and without applying undue stress to the lid. The
container base can be sized and shaped according to the application
for which it is used, including the type of food and the amount of
food to be placed thereon. For example, the container base can be
in the form of a tray or a platter. In particular, the present
invention enables removal of the lid from a polygonal tray-lid
assembly in a reversible manner, i.e. without damaging the lid
during removal.
[0056] The tray and lid components of the polygonal tray-lid
assembly are configured to facilitate separation of the polygonal
lid from the tray-lid assembly by providing at least one graspable
member on the outer periphery of the lid near or at a designated
"release" vertex, thereby facilitating initial disengagement of the
lid from the container base at the release vertex. The lid and tray
further include regions of enhanced or secondary engagement that
enhance the attachment of the lid to the tray or container base, so
that the overall attachment of the lid to the container base is
less dependent on the attachment at the vertices. As a result, the
strength of attachment of the lid to the container base at the
release vertex can be made weaker than at the other vertices, for
easy release of the release vertex, without undue weakening of the
overall attachment of the lid to the container base.
[0057] Note that, except where the context requires a more specific
definition, the term "tray" is used herein to refer generically to
a tray, platter, dish, container base, plate, or any other support
base compatible with a lid or cover, and the term "lid" is used
generically herein to refer to any sort of lid or cover that is
compatible with a container base, including flat lids and "dome"
lids that are round, rectangular, or any other shape.
[0058] Note also that while the discussion that follows is
presented in the context of describing features of a lid that
enable removal of the lid from a tray or container base, the roles
of the lid and the container base can be reversed without departing
from the scope of the invention, so that the features ascribed
herein to the "lid" (or upper element) can be incorporated into the
"tray" (or lower element) of the tray-lid combination. Therefore,
the invention applies generally to separable halves of a container
assembly, whereby terms used for convenience to describe one half
of the containing assembly, such as "lid" and "cover," can
generally be exchanged herein with terms used to describe the other
half of the container assembly, such as "tray," "container base,"
and "support base," without departing from the meaning or scope of
the invention.
[0059] FIG. 1 illustrates a polygonal lid 100 and tray 102 in an
embodiment of the present invention. The lid 100 is surrounded by a
lid rim 104, and the tray 102 is surrounded by a tray rim 106 that
engages with the lid rim 104 of the lid 100. In the embodiment of
FIG. 1, two release tabs 108, 110 are located on either side of a
designated "release" vertex 112 of the lid. In similar embodiments,
a single release tab or other graspable member is located at or
near the release vertex. Although not readily visible in the
figure, the attachment of the release vertex to the tray 102 is
weaker than at the other three vertices, so as to facilitate
initial release of the release vertex of the lid 100 from the tray
102. Note that each of the release tabs 108, 110 includes a visual
indication in the form of the word "LIFT" imposed on the release
tab, indicating that the release tabs 108, 110 should be lifted to
initiate release of the release vertex of the lid 100 from the tray
102.
[0060] With reference to FIG. 2A, each of the sides of the lid 100
includes an inwardly protruding region of enhanced engagement,
denoted by cleats 114A, 114B, 114C and 114D, which increase the
engagement between the lid 100 and the tray 102 when assembled to
form a tray-lid assembly, as is discussed in more detail below.
Similarly, each of the sides of the tray 102 includes a receiving
region of enhanced engagement, denoted by recessions 116A, 116B,
116C, and 116D, which cooperate with cleats 114A, 114B, 114C and
114D of the lid 100, respectively. It will be noted that only
cleats 114A and 114B, and recessions 116A and 116B are visible in
FIG. 1.
[0061] FIG. 2A is a view from above of the lid 100 of FIG. 1. It
can be seen in FIG. 2A that all four sides of the lid 100 include
inwardly protruding regions of enhanced engagement or cleats 114A,
114B, 114C and 114D that strengthen the attachment of the sides of
the lid 100 to the tray 102. A dotted line in FIG. 2A indicates the
location of the cross-sectional illustration of FIG. 2B.
[0062] FIG. 2B is a cross-sectional view of the lid 100 of FIG. 2A,
where the cross-section intersects two opposing cleats 114A and
114C of the lid 100. The cross-sectional profile which includes
cleat 114A is shown in a dotted circle 119 on the right side of
FIG. 2B.
[0063] FIG. 2C is an enlarged view of the circled region 119 of
FIG. 2B. It can be seen that the shaping of the rim in this region
includes lid sidewall 120 and the primary engagement peripheral
groove 121 that terminates in cleat 114A. FIG. 2C clearly shows
that cleat 114A protrudes inwardly towards the interior of the lid,
and is configured for engagement with recession 116A in the tray
102, as is described in more detail below.
[0064] FIG. 2D is an enlarged view from above of the release vertex
112 of an embodiment similar to FIG. 2A. It can be seen from the
figure that in this embodiment press areas 200, 202 are provided
with visual indications suggesting that a user should press on the
press areas 200, 202 while lifting the lift tabs 108, 110, where
the visual indications in this embodiment are the word "PRESS"
appearing on the press areas 200, 202.
[0065] FIG. 3A is a top view of the tray 102 of FIG. 1. It can be
seen in FIG. 3A that all four sides of the tray 102 include
receiving regions of enhanced engagement or recessions 116A, 116B,
116C and 116D that cooperate with the protruding regions of
enhanced engagement or cleats 114A, 114B, 114C and 114D in the lid
100 respectively, and thereby strengthen the attachment of the
sides of the tray 102 to the sides of the lid 100. It can also be
seen in the figure, which is drawn to scale, that the receiving
regions of enhanced engagement or recessions 116A, 116B, 116C and
116D extend along about 10% of each side of the tray 102. In
similar embodiments, the recessions 116A, 116B, 116C and 116D
extend along up to 50% of the respective lengths of each of the
sides of the tray 102. A dotted section line in FIG. 3A indicates
the location of the cross-sectional illustration of FIG. 3B.
[0066] FIG. 3B is a cross-sectional view of the tray 102 of FIG.
3A, where the cross section intersects the two opposing sides that
include recessions 116A and 116C respectively. The tray rim region
that includes recession 116A is shown in a dotted circle on the
right side of the figure.
[0067] FIG. 3C is an enlarged view of the circled region of FIG.
3B, and FIG. 3D is an enlargement of the region of modified shaping
of FIG. 3C. FIG. 3C shows tray sidewall 130, while both FIGS. 3C
and 3D show the tray rim, which includes a primary engagement lip
131 that is adapted to engage with primary engagement channel 121
of the lid 100. Recession 116A is provided below primary engagement
lip 131, and is adapted for engagement with cleat 114A.
[0068] FIG. 4A is a cross-sectional enlarged view of the rim of the
lid 100 engaged with the lip of the tray 102, where the
cross-section does not intersect any of the regions of enhanced
engagement. It can be seen that the primary engagement groove 121
of lid 100 is engaged with the primary engagement lip 131 of tray
102.
[0069] FIG. 4B is a cross-sectional enlarged view of the rim of the
lid 100 engaged with the lip of the tray 102, where the
cross-section intersects the regions of enhanced engagement
provided by cleat 114A and recession 116A. In the figure, a
relatively large indentation or cleat 114A in the rim of the lid
100 engages with a relatively large recession 116A in the lip of
the tray 102.
[0070] It will be understood by persons skilled in the art that the
embodiments illustrated by FIGS. 4A and 4B assume that tray 102 is
resting on a generally horizontal table surface with the lid 100
engaged therewith.
[0071] Based on the views shown in various figures herein, it
should be readily apparent that relative terms such as "horizontal"
are used only for illustrative purposes in describing embodiments
of the invention, and that more general terms such as "planar" can
be substituted without departing from the scope of the invention.
Furthermore, modifiers such as `generally` and `substantially` are
intended to be construed liberally. Thus, for example, `generally
planar` and `substantially planar` are intended to allow for
irregular deviations from perfectly flat surface and to reasonably
broaden terms such as "planar" so as to encompass curved and other
non-planar surfaces.
[0072] A typical method of removing the lid 100 of the embodiment
of FIG. 1 from the tray 102 will now be described. With reference
to FIG. 2D, during removal of the lid 100 from the tray 102, a user
presses on press area 200 and lifts lift tab 108 with one hand, and
concurrently presses on press area 202 and lifts lift tab 110 with
the second hand. This lifting action with both hands serves to
rotate the tabs 108, 110 upward, thereby disengaging the rim at the
release vertex 112 of lid 100 from the peripheral tray lip of the
cooperatively engaged tray 102 or container base 102. Once the lid
100 is released from the tray 102 at the release vertex 112, the
lid 100 is easily pulled away from the tray 102, at least as far as
the protruding and receiving regions of enhanced engagement denoted
by cleats 114A-114D and recessions 116A-116D, which are centered in
the sides of the lid 100 and tray 102 respectively. But since the
cooperating cleat and recessions along each of the sides are
separated by some distance from the release vertex, further lifting
of the corner of the lid 100 applies leverage that easily separates
these regions of enhanced engagement from each other. This allows
removal of the entire lid 100 from the tray 102.
[0073] Note that press areas 200, 202 may be indicated by
integrally forming or molding the word "PRESS" therein, and lift
tabs 108, 110 may be indicated by integrally forming or molding the
word "LIFT" therein for the purposes of providing simple lid
removal instructions to a user.
[0074] For various embodiments that include more than two lift
tabs, for example on larger trays and lids, or on polygonal trays
and lids that include more than four vertices, sequentially applied
lifting actions may be required, by which more than one vertex of
the lid is disengaged from the tray. Similarly, embodiments may
include more than one release vertex.
[0075] According to embodiments of the invention, the tray and lid
are constructed of suitable materials that allow engagement and
subsequent reengagement therebetween if desired by the user.
[0076] It will be apparent to those skilled in the art that the
lids and trays of the present invention can be made of a suitable
thermoplastic material, which can be processed by common polymer
processing methods known in the art, such as thermoforming or
injection molding. The choice of a thermoplastic resin is typically
governed by a variety of factors, including cost, resin
processability, and other functional requirements of the tray and
lid. Accordingly, lids and trays of the present invention can be
manufactured by thermoforming and/or injection molding. In some
embodiments of the present invention, the lid and tray are
thermoformed from a polyethylene terephthalate (PET) sheet
material. According to other embodiments of the present invention,
the lid and tray are injection molded from a suitable grade of
polypropylene resin.
[0077] It will be realized that the lid and tray can be constructed
from different materials. In addition, the lid and tray can be
produced by different processes.
[0078] The exemplary embodiments discussed above all include lids
that incorporate lift tab features of the present invention for
facilitating separation of a lid from a tray. However, it will be
understood by anyone skilled in the art that the same purpose can
be accomplished by providing any appropriate graspable member, such
as indentation features or recessed locations in the tray for
allowing access to a user's hands for grasping and manipulating the
lid periphery. Therefore, the graspable members can be created for
example by indentations provided in either the tray or the lid.
Furthermore, graspable members for manipulating separation of a
tray-lid assembly may be configured in the form of lift tabs, push
tabs, indentations, or combinations thereof. In addition, it will
be understood by those skilled in the art that the features of the
present invention can be included in the lower, or "tray" portion
of a tray-lid assembly, rather than in the lid.
[0079] The foregoing description of the embodiments of the
invention has been presented for the purposes of illustration and
description. It is not intended to be exhaustive or to limit the
invention to the precise form disclosed. Accordingly, the drawing
and description are to be regarded as illustrative in nature, and
not as restrictive. Many modifications and variations are possible
in light of this disclosure. The advantages of the invention may be
further realized and attained by means of the instrumentalities and
combinations particularly pointed out in the appended example of
claims.
[0080] Although the present application is shown in a limited
number of forms, the scope of the invention is not limited to just
these forms, but is amenable to various changes and modifications
without departing from the spirit thereof. The disclosure presented
herein does not explicitly disclose all possible combinations of
features that fall within the scope of the invention. The features
disclosed herein for the various embodiments can generally be
interchanged and combined into any combinations that are not
self-contradictory without departing from the scope of the
invention. In particular, the limitations presented in dependent
claims below can be combined with their corresponding independent
claims in any number and in any order without departing from the
scope of this disclosure, unless the dependent claims are logically
incompatible with each other.
* * * * *