U.S. patent application number 14/242972 was filed with the patent office on 2014-07-31 for lid featuring ease of use and improved release from a tray or container.
This patent application is currently assigned to Waddington North America, Inc.. The applicant listed for this patent is Waddington North America, Inc.. Invention is credited to William A. Gallop, Ashish K. Mithal, Matthew J. Wichmann.
Application Number | 20140208698 14/242972 |
Document ID | / |
Family ID | 42311049 |
Filed Date | 2014-07-31 |
United States Patent
Application |
20140208698 |
Kind Code |
A1 |
Mithal; Ashish K. ; et
al. |
July 31, 2014 |
LID FEATURING EASE OF USE AND IMPROVED RELEASE FROM A TRAY OR
CONTAINER
Abstract
A method for releasing a lid from a base without disturbing
contents and without undue lid stress includes flexing two
graspable members at separated locations about the lid periphery,
thereby providing two distinct initial disengagement locations and
overcoming any tendency of the lid to reactively grip the tray when
disengagement is initiated. The separated locations are not
directly opposite to each other, and can be separations of between
20 and 60 degrees or between 25 and 50 degrees. The lid is then
easily removed by lifting the lid upward. The method can include
simultaneous and/or sequential flexing of the graspable members by
one or both of a user's hands. The graspable members can include
lift tabs and/or indentations. In embodiments where the lid further
includes press locations, the method includes pressing on the press
locations while flexing the graspable members.
Inventors: |
Mithal; Ashish K.;
(Chelmsford, MA) ; Wichmann; Matthew J.; (Cresent
Springs, KY) ; Gallop; William A.; (Westminster,
MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Waddington North America, Inc. |
Chelmsford |
MA |
US |
|
|
Assignee: |
Waddington North America,
Inc.
Chelmsford
MA
|
Family ID: |
42311049 |
Appl. No.: |
14/242972 |
Filed: |
April 2, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12652483 |
Jan 5, 2010 |
8701930 |
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14242972 |
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61142423 |
Jan 5, 2009 |
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Current U.S.
Class: |
53/492 |
Current CPC
Class: |
B65D 2543/00731
20130101; B65D 2543/00416 20130101; B65D 2543/00796 20130101; B65D
2543/00407 20130101; B65D 2543/00092 20130101; B65D 2543/00685
20130101; B65D 85/07 20180101; B65B 69/00 20130101; B65D 43/0212
20130101; B65D 2543/00537 20130101; B65D 2543/00842 20130101; B65D
2543/00361 20130101; B65D 2543/00296 20130101; B65D 2543/00648
20130101; B65D 2543/00527 20130101 |
Class at
Publication: |
53/492 |
International
Class: |
B65B 69/00 20060101
B65B069/00 |
Claims
1. A method for using and opening a container assembly, said method
comprising the steps of: engaging a lid with a container base by
cooperatively locking a lid engagement feature provided in the lid
proximal to a peripheral boundary of the lid, with a base
engagement feature provided in the container base proximal to a
peripheral boundary of the container base, said lid including a
first graspable member and a second graspable member proximal to
the peripheral boundary of the lid in locations that are not
directly opposite to each other, each of said graspable members
extending beyond the peripheral boundary of the container base;
flexing the first graspable member manually via a user's first
hand, thereby rotating the first graspable member upward and
disengaging a first portion of the lid engagement feature from a
corresponding first portion of the base engagement feature,
creating a first region of disengagement therebetween; flexing the
second graspable member manually via the user's second hand,
thereby rotating the second graspable member upward and disengaging
a second portion of the lid engagement feature from a corresponding
second portion of the base engagement feature, creating a second
region of disengagement therebetween; and removing the lid from the
container base by lifting said lid away from said container
base.
2. The method of claim 1, wherein the first and second regions of
disengagement extend peripherally in both directions from the
corresponding graspable members.
3. The method of claim 1, wherein the first and second regions of
disengagement merge to form a single region of disengagement that
extends at least from the first graspable member to the second
graspable member.
4. The method of claim 1, wherein said lid and container base
engagement features are substantially round.
5. The method of claim 1, wherein the lid further includes a first
press location cooperative with the first graspable member and a
second press location cooperative with the second graspable
member.
6. The method of claim 5, wherein the lid includes visible
indications associated with the first and second press locations
suggesting that pressure be applied to the first and second press
locations, and visible indications associated with the first and
second graspable members suggesting that the first and second
graspable members be lifted.
7. The method of claim 5, wherein the step of flexing the first
graspable member manually via a user's first hand is accompanied by
pressing on the first press location to facilitate disengagement at
said first region; and the step of flexing the second graspable
member manually via user's second hand is accompanied by pressing
on the second press location to facilitate disengagement at said
second region.
8. The method of claim 1, wherein the lid includes visible
indications associated with the first and second graspable members
suggesting that the first and second graspable members be
lifted.
9. The method of claim 1, wherein the graspable members are lift
tabs.
10. The method of claim 1, wherein said lid is dome shaped.
11. The method of claim 1, wherein said graspable members are
sequentially flexed by at least one of a user's hands.
12. The method of claim 1, wherein the first graspable member is
flexed by a first hand of the user and the second graspable member
is concurrently flexed by a second hand of the user.
13. The method of claim 1, wherein the graspable members are
located at an angular separation of between 20 degrees and 60
degrees.
14. The method of claim 1, wherein the graspable members are
located at an angular separation of between 25 degrees and 50
degrees.
15. The method of claim 1, wherein at least one of the graspable
members is located at a vertex of the peripheral boundary of the
lid.
16. The method of claim 1, wherein the first and second graspable
members are located adjacent to either side of a vertex of the
peripheral boundary of the lid.
17. The method 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.
18. A method for releasing a lid from engagement with a container
base comprising the steps of: providing a container assembly that
includes said lid engaged with said container base, the lid
including a lid engagement feature proximal to a peripheral
boundary of the lid, said lid engagement feature being engaged in
mutual cooperation with a base engagement feature provided in the
container base, a first graspable member and a second graspable
member being attached to the lid proximal to the peripheral
boundary of the lid in locations that are not directly opposite to
each other, each of said graspable members extending beyond the
peripheral boundary of the container base, a first press location
being cooperative with the first graspable member and a second
press location being cooperative with the second graspable member;
flexing the first graspable member while pressing on the first
press location, said flexing and pressing being performed manually
via a user's first hand, thereby rotating the first graspable
member upward and disengaging a first portion of the lid engagement
feature from a corresponding first portion of the base engagement
feature, creating a first region of disengagement therebetween;
flexing the second graspable member while pressing on the second
press location, said flexing and pressing being performed manually
via the user's second hand, thereby rotating the second graspable
member upward and disengaging a second portion of the lid
engagement feature from a corresponding second portion of the base
engagement feature, creating a second region of disengagement
therebetween; and removing the lid from the container base by
lifting said lid away from said container base.
19. The method of claim 18, wherein the lid further includes: a
visible indication associated with the first press location
suggesting that pressure be applied to the first press location; a
visible indication associated with the first graspable member
suggesting that the first graspable member be lifted; a visible
indication associated with the second press location suggesting
that pressure be applied to the second press location; and a
visible indication associated with the second graspable member
suggesting that the second graspable member be lifted.
20. The method of claim 18, wherein the steps of flexing the first
graspable member and flexing the second graspable member are
conducted concurrently.
21. A method for using and opening a container assembly, said
method comprising the steps of: engaging a lid with a container
base by cooperatively locking a lid engagement feature provided in
the lid proximal to a peripheral boundary of the lid, with a base
engagement feature provided in the container base proximal to a
peripheral boundary of the container base, a first graspable member
and a second graspable member being attached to the lid proximal to
the peripheral boundary of the lid in locations that are not
directly opposite to each other, each of said graspable members
extending beyond the peripheral boundary of the container base;
flexing the first graspable member manually via a user's first
hand, thereby rotating the first graspable member upward and
disengaging a first portion of the lid engagement feature from a
corresponding first portion of the base engagement feature,
creating a first region of disengagement therebetween; flexing the
second graspable member manually via the user's second hand,
thereby rotating the second graspable member upward and disengaging
a second portion of the lid engagement feature from a corresponding
second portion of the base engagement feature, creating a second
region of initial disengagement therebetween; the step of flexing
the second graspable member being performed concurrently with the
step of flexing first graspable member; and removing the lid from
the container base by lifting the lid away from said container
base.
22. The method of claim 21, further comprising the steps of:
pressing on a first press area of the lid with said first hand
while concurrently flexing said first graspable member; and
pressing on a second press area of the lid with said second hand
while concurrently flexing said second graspable member.
23. The method of claim 22, wherein said first and second press
areas are located inwardly from said lid engagement feature
proximal to said peripheral boundary of the lid.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of co-pending application
Ser. No. 12/652,483, filed on Jan. 5, 2010, which claims the
benefit of U.S. Provisional Application No. 61/142,423 filed Jan.
5, 2009. Both of these applications are incorporated herein by
reference in their entirety for all purposes.
FIELD OF THE INVENTION
[0002] This invention relates generally to lids adapted for use
with trays and containers, and more particularly to lids featuring
ease of use and improved release from trays and containers.
BACKGROUND OF THE INVENTION
[0003] 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 engagable therewith for
presenting, handling, transporting, and/or protecting a variety of
food items. The tray or base usually has an upwardly projecting
sidewall terminating 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 which are 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, 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" or a
"base".
[0005] Most disposable lids for use with food containers and
platters are usually 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 will preserve the shape,
form, decorative appearance and/or the general presentation of
items such as certain food preparations, including desserts, cakes,
sandwiches, or other foods. Or the lid may be substantially flat,
and may be attachable to a container which has sufficient depth to
surround food items or other contents to be contained therein. In
some approaches, 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.
[0006] In the case of food containment, 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 from which the lid is constructed, the
lid may even tear or rip during removal, thereby rendering
subsequent reengagement of the lid with tray or container
ineffective or futile.
[0007] 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
or plate.
[0008] 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 is typically 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, a user typically has 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 thus
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 removal the lid from the
tray.
[0009] 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 even more tightly onto the
tray at those locations, and thereby rendering removal of the dome
from the tray base extremely difficult, or at least cumbersome.
[0010] Thus, there is a need for a lid that is securely engageable
with a tray or a container and yet can be conveniently removed from
the tray or container with relative ease and without disturbing the
contents of the tray or container. These and other needs are met by
the lid of the present invention.
BRIEF SUMMARY OF THE INVENTION
[0011] A lid is claimed for a tray that enables secure and reliable
engagement between the lid and the tray while enabling easy removal
of the lid from the tray without disturbing contents supported by
the tray 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.
[0012] 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, 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 compatible
with a "tray," 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.
[0013] Note also that while the following discussion is presented
in the context of describing feature(s) of a lid, whereby the
feature(s) enable removal of the lid from a tray, the roles of the
lid and the tray can be reversed without departing from the scope
of the invention. In other words, a specific feature or 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
containing assembly comprising a first half and a second half,
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
containing assembly, such as "tray," "container," and "support
base," without departing from the meaning or scope of the
invention.
[0014] The claimed lid facilitates separation of the lid from the
tray-lid assembly by providing at least two tabs or indentations at
two separate locations on the outer periphery of the lid, 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,
without subjecting the lid to undue stress, and without unduly
disturbing the contents of the tray-lid assembly.
[0015] An additional feature of the present invention is to
facilitate lifting of a tray-lid assembly securely from a flat
surface by utilizing a lid construction with a peripheral skirt
that is short enough to allow a user's fingers to reach underneath
the skirt and support the sidewalls of the tray when lifting and/or
carrying the tray-lid assembly, so that the entire weight of the
tray-lid assembly, including any contents supported thereby, is not
exclusively borne by the cooperative engagement features.
[0016] Still another feature of the present invention is to provide
a lid having a peripheral flange and a peripheral skirt, wherein
the peripheral flange has at least a first pressing area and a
second pressing area, and wherein the peripheral skirt has a first
lifting tab and a second lifting tab. The first pressing area works
cooperatively with the first lifting tab and the second pressing
area works cooperatively with the second lifting tab. During the
process of removing the lid from the tray, a user presses the first
pressing area and lifts the first lifting tab with one hand, and
concurrently presses the second pressing area and lifts the second
lifting tab with the second hand. Once at least a partial
separation has been created at the first and second lifting tab
locations, the entire lid can be readily removed from the tray.
[0017] One general aspect of the present invention is a method for
using and opening a container assembly. The method includes
engaging a lid with a container base by cooperatively locking a lid
engagement feature provided in the lid proximal to a peripheral
boundary of the lid, with a base engagement feature provided in the
container base proximal to a peripheral boundary of the container
base, said lid including a first graspable member and a second
graspable member proximal to the peripheral boundary of the lid in
locations that are not directly opposite to each other, each of
said graspable members extending beyond the peripheral boundary of
the container base, flexing the first graspable member manually via
a user's first hand, thereby rotating the first graspable member
upward and disengaging a first portion of the lid engagement
feature from a corresponding first portion of the base engagement
feature, creating a first region of disengagement therebetween,
flexing the second graspable member manually via the user's second
hand, thereby rotating the second graspable member upward and
disengaging a second portion of the lid engagement feature from a
corresponding second portion of the base engagement feature,
creating a second region of disengagement therebetween, and
removing the lid from the container base by lifting said lid away
from said container base.
[0018] In embodiments, the first and second regions of
disengagement extend peripherally in both directions from the
corresponding graspable members. In some embodiments, the first and
second regions of disengagement merge to form a single region of
disengagement that extends at least from the first graspable member
to the second graspable member.
[0019] In other embodiments, said lid and container base engagement
features are substantially round. In various embodiments, the lid
further includes a first press location cooperative with the first
graspable member and a second press location cooperative with the
second graspable member.
[0020] In further embodiments, the lid includes visible indications
associated with the first and second press locations suggesting
that pressure be applied to the first and second press locations,
and visible indications associated with the first and second
graspable members suggesting that the first and second graspable
members be lifted. And in some of these embodiments, the step of
flexing the first graspable member manually via a user's first hand
is accompanied by pressing on the first press location to
facilitate disengagement at said first region, and the step of
flexing the second graspable member manually via user's second hand
is accompanied by pressing on the second press location to
facilitate disengagement at said second region.
[0021] In certain embodiments, the lid includes visible indications
associated with the first and second graspable members suggesting
that the first and second graspable members be lifted.
[0022] In embodiments, the graspable members are lift tabs. In some
embodiments, said lid is dome shaped. In other embodiments, said
graspable members are sequentially flexed by at least one of a
user's hands.
[0023] In certain embodiments, the first graspable member is flexed
by a first hand of the user and the second graspable member is
concurrently flexed by a second hand of the user. In further
embodiments, the graspable members are located at an angular
separation of between 20 degrees and 60 degrees.
[0024] In exemplary embodiments, the graspable members are located
at an angular separation of between 25 degrees and 50 degrees. In
various embodiments, at least one of the graspable members is
located at a vertex of the peripheral boundary of the lid.
[0025] In embodiments, the first and second graspable members are
located adjacent to either side of a vertex of the peripheral
boundary of the lid. And 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.
[0026] Another general aspect of the present invention is a method
for releasing a lid from engagement with a container base. The
method includes providing a container assembly that includes said
lid engaged with said container base, the lid including a lid
engagement feature proximal to a peripheral boundary of the lid,
said lid engagement feature being engaged in mutual cooperation
with a base engagement feature provided in the container base, a
first graspable member and a second graspable member being attached
to the lid proximal to the peripheral boundary of the lid in
locations that are not directly opposite to each other, each of
said graspable members extending beyond the peripheral boundary of
the container base, a first press location being cooperative with
the first graspable member and a second press location being
cooperative with the second graspable member, flexing the first
graspable member while pressing on the first press location, said
flexing and pressing being performed manually via a user's first
hand, thereby rotating the first graspable member upward and
disengaging a first portion of the lid engagement feature from a
corresponding first portion of the base engagement feature,
creating a first region of disengagement therebetween, flexing the
second graspable member while pressing on the second press
location, said flexing and pressing being performed manually via
the user's second hand, thereby rotating the second graspable
member upward and disengaging a second portion of the lid
engagement feature from a corresponding second portion of the base
engagement feature, creating a second region of disengagement
therebetween, and removing the lid from the container base by
lifting said lid away from said container base.
[0027] In embodiments, the lid further includes a visible
indication associated with the first press location suggesting that
pressure be applied to the first press location, a visible
indication associated with the first graspable member suggesting
that the first graspable member be lifted a visible indication
associated with the second press location suggesting that pressure
be applied to the second press location, and a visible indication
associated with the second graspable member suggesting that the
second graspable member be lifted.
[0028] In some of these embodiments, the steps of flexing the first
graspable member and flexing the second graspable member are
conducted concurrently.
[0029] Yet another general aspect of the present invention is a
method for using and opening a container assembly. The method
includes engaging a lid with a container base by cooperatively
locking a lid engagement feature provided in the lid proximal to a
peripheral boundary of the lid, with a base engagement feature
provided in the container base proximal to a peripheral boundary of
the container base, a first graspable member and a second graspable
member being attached to the lid proximal to the peripheral
boundary of the lid in locations that are not directly opposite to
each other, each of said graspable members extending beyond the
peripheral boundary of the container base, flexing the first
graspable member manually via a user's first hand, thereby rotating
the first graspable member upward and disengaging a first portion
of the lid engagement feature from a corresponding first portion of
the base engagement feature, creating a first region of
disengagement therebetween, flexing the second graspable member
manually via the user's second hand, thereby rotating the second
graspable member upward and disengaging a second portion of the lid
engagement feature from a corresponding second portion of the base
engagement feature, creating a second region of initial
disengagement therebetween; the step of flexing the second
graspable member being performed concurrently with the step of
flexing first graspable member, and removing the lid from the
container base by lifting the lid away from said container
base.
[0030] Some embodiments further include the steps of pressing on a
first press area of the lid with said first hand while concurrently
flexing said first graspable member, and pressing on a second press
area of the lid with said second hand while concurrently flexing
said second graspable member. And in some of these embodiments,
said first and second press areas are located inwardly from said
lid engagement feature proximal to said peripheral boundary of the
lid.
[0031] 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
[0032] The invention will be better understood upon reading the
following Detailed Description in conjunction with the drawings in
which:
[0033] FIG. 1A is a perspective view of a simple lid of the prior
art having a single lift tab;
[0034] FIG. 1B is a perspective view of the simple lid of FIG. 1A,
illustrating lifting of a single lift tab and consequent opposing
inward distortion of the lid that grips the tray and hinders
release of the tray from the lid;
[0035] FIG. 2 is a perspective view of a dome lid according to an
embodiment of the present invention;
[0036] FIG. 3 is a top view of the lid of FIG. 2;
[0037] FIG. 4 is a side view of the lid of FIG. 2;
[0038] FIG. 5 is an enlarged view of a press area and lift tab of
the lid of FIG. 2;
[0039] FIG. 6 is a partial cutaway view of a tray-lid assembly
according to an embodiment of the invention wherein the lid
displays a short peripheral skirt;
[0040] FIG. 7 is a partial cutaway view of a tray-lid assembly
wherein the lid displays a relatively tall peripheral skirt as
typically utilized in dome lids of the prior art;
[0041] FIG. 8 is a perspective view of a user removing a dome lid
from a tray with both hands according to an embodiment of the
present invention;
[0042] FIG. 9A is a perspective view of the dome lid of FIG. 8
having its lift tabs engaged with the tray and prepared for full
engagement of the dome lid with the tray;
[0043] FIG. 9B is a perspective view of the dome lid and tray of
FIG. 9A showing pressure being applied to the dome lid so as to
attach the dome lid to the tray;
[0044] FIG. 10 is a perspective view of a square dome lid with lift
tabs at two corners according to an embodiment of the present
invention;
[0045] FIG. 11 is a perspective view of a square lid having two
lift tabs located on either side of a corner and one additional
lift tab located at an adjacent corner, according to an embodiment
of the present invention;
DETAILED DESCRIPTION OF THE INVENTION
[0046] The present invention is generally directed towards a lid
that can be securely engaged with a tray or container base and yet
is readily removable without unduly disturbing the contents of the
tray-lid assembly and without applying undue stress to the lid. The
following description of one or more embodiments, in conjunction
with the accompanying drawings, are offered by way of illustration
only, and should not be regarded as restricting the scope of the
invention.
[0047] 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, 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 compatible
with a tray, including flat lids and "dome" lids that are round,
rectangular, or any other shape.
[0048] 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, the roles of the lid and the
tray 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 containing 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
containing assembly, such as "tray," "container," and "support
base," without departing from the meaning or scope of the
invention.
[0049] As will become readily apparent from the foregoing
description, a lid that is easy to use and can be readily removed
without damaging the lid according to the present invention
provides several advantages over prior art lids and tray-lid
assemblies. In the case of a food-containing tray-lid assembly, the
present invention enables a user to comfortably remove the lid from
a tray or other container base with relative ease and without
unduly disturbing any of the food items contained within the
tray-lid assembly. In particular, the release features or mechanism
of the present invention enables lid removal without use of
excessive force, which could otherwise result in tearing or
damaging of the lid during removal. Being undamaged, the lid can be
reattached to the tray and reused as needed.
[0050] FIG. 1A illustrates a simple lid 100 of the prior art. Lid
100 includes a groove 102 into which a lip of a tray (not shown)
can be inserted for secure engagement therewith. Lid 100 also
includes a skirt 104 that extends downwardly from the groove 102. A
tab 106 is provided in an attempt to facilitate removal of lid 100
from a tray. As illustrated in FIG. 1B, lifting of the tab 106
causes an initial separation between the groove 102 and the rim of
the tray in a region 108 immediately proximal to the tab 106.
However, lifting the tab 106 also necessarily leads to an outwardly
radial elongation 110 of the groove 102 toward the tab 106, and
consequently orthogonal, inwardly radial forces 112 on opposing
sides of the groove 102. These opposing, inwardly radial forces 112
cause the groove 102 to be tightly pressed toward the rim of the
tray as the tab 106 is lifted, thereby causing removal of the lid
100 to be very difficult. In the resulting struggle to overcome
this gripping force 112, food or other contents of the tray-lid
assembly can be disturbed, and in extreme cases the lid material
can fail and the lid 100 can be damaged.
[0051] A lid designated by reference numeral 10, according to an
embodiment of the present invention, is shown in FIGS. 2 through 6,
wherein like reference numerals represent like parts. Lid 10 is
adapted for engaging with a tray or container base, and as
particularly shown in FIG. 6, lid 10 is shown in a superjacent
relationship with tray 30 and is engaged therewith.
[0052] In FIGS. 2 through 6, lid 10 is shown with a plurality of
ornamental design features, however, it will be apparent to those
skilled in the art that the utilitarian structural features of the
present invention can be readily utilized with or without a variety
of aesthetic and/or ornamental lid designs, and that the features
of the present invention are not limited to a particular lid style
or design. Thus, variations in the lid sidewall and top wall are
within the scope of the present invention, and do not affect the
ease of use and release functionality described herein.
Additionally, the height of the lid 10 is shorter or taller in
certain embodiments, and/or the lid sidewall in some embodiments
includes upright ribs and/or the lid top wall includes a
combination of structural features, including a shape other than a
flat top, such as a rounded shape.
[0053] As shown in FIG. 2, the container lid 10 of the illustrated
embodiment integrally comprises a generally planar central top wall
11; a raised shoulder portion 12 circumscribing or encircling top
wall 11; a peripheral top portion 13 circumscribing raised shoulder
portion 12; a sidewall 20 extending circumferentially downward from
said peripheral top portion 13; a peripheral flange 23 extending
outwardly from the bottom end of sidewall 20; a peripheral groove
portion 24; and a downwardly projecting peripheral skirt 25.
[0054] In the embodiment shown in FIGS. 2-6, central top wall 11 is
generally planar and substantially horizontal as shown, and is
adapted to allow a user to view the contents of the tray-lid
assembly. In other embodiments, the lid is opaque or translucent,
and/or has a rounded or other non-planar shape or appearance.
[0055] In the embodiment shown in FIGS. 2-6, the raised shoulder
portion 12 of lid 10 is adapted for facilitating stacking of
another tray-lid assembly on top of lid 10, whereby nesting of the
raised shoulder 12 into a recess provided in the bottom of a second
tray stacked above the lid 10 serves to stabilize the stacked
assembly (or assemblies) and prevent sliding thereof during
transportation or while handling and carrying a plurality of
stacked assemblies.
[0056] As shown, peripheral top portion 13 may include a variety of
ornamental features which also serve as structural stiffening
members that strengthen the lid, so that the peripheral top portion
13 can retain its dimensional stability against a downward force
typically applied thereto during assembly of lid 10 with a tray or
container (see FIG. 9), and when supporting the weight of another
tray-lid assembly. In the exemplary embodiment illustrated herein
in FIGS. 2-6, peripheral top portion 13 features a plurality of
flutes 14 and a plurality of ribs 15. In the illustrated
embodiment, the flutes 14 and ribs 15 are organized in sections
that form an alternately repeating pattern circumferentially
arranged around raised shoulder portion 12. As is best shown in
FIGS. 2 and 4, the flutes 14 have an upwardly raised or convex
geometry. However it will be appreciated by those skilled in the
art that a variety of designs, geometries, patterns and/or other
structural elements may be readily imparted to or included in
embodiments of the lid of the present invention so as to provide
aesthetic appeal and/or structural reinforcement.
[0057] As is best shown in FIG. 4, sidewall 20 extends downwardly
from peripheral top portion 13 and tapers radially outwardly so as
to provide a gradual draft angle for ease of processing and so as
to facilitate mold release during the thermoforming process or
during any other processing method used for manufacturing lid 10.
Sidewall 20 includes a plurality of panels 21 and flutes 22 that
are circumferentially arranged in an alternately repeating pattern
therein. The bottom end of sidewall 20 is connected to peripheral
flange 23 which is generally horizontal in the embodiment of FIGS.
2-6.
[0058] 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.
[0059] As is best shown in FIGS. 4 and 6, peripheral flange 23
rolls downwardly to define a peripheral groove portion 24.
Peripheral groove portion 24 has a C-shaped or U-shaped cross
section which is adapted for engaging with a tray by receiving a
tray lip therein. Referring to FIG. 6, there is shown a
cross-sectional view of a tray 30 attached to lid 10. Tray 30
comprises a tray bottom wall 31 resting on a generally horizontal
table surface 60, a tray sidewall 32 which extends upwardly and
outwardly from the tray bottom wall 31, and a peripheral tray lip
33. In the embodiment of FIG. 6, the peripheral tray lip 33 has a
bead-like configuration. In other embodiments, the tray lip
includes other features, such as a turned-down configuration (not
shown). As shown in FIG. 6, peripheral tray lip 33 nests within the
peripheral groove portion 24 of lid 10, and the slight undercut in
the groove portion 24 provides a reasonably secure interference fit
between the lid 10 and the tray 30.
[0060] Lid 10 also features a peripheral skirt 25 which extends
downwardly from the underside of the peripheral groove portion 24
and flares radially outwardly. Peripheral skirt 25 facilitates a
good lid-fit by guiding the tray lip 33 within the peripheral
groove portion 24.
[0061] As mentioned above, the present invention provides ease of
use and release functionality. The release functionality is
accomplished by means of at least two lift tabs provided in the
peripheral skirt. Accordingly, in the embodiment of FIGS. 2-6, lift
tabs 27 and 29 are provided in the tray skirt 25. Lift tab 27 is
adapted to work cooperatively with press area 26. Lift tab 29 is
adapted to work cooperatively with press area 28. Press areas 27
and 28 lie in the peripheral flange 23 proximate to panels 21.
[0062] A typical method of removing the lid 10 of the embodiment of
FIG. 6 from the tray 30 will now be described. With reference to
FIG. 8, during removal of the lid from the tray, a user presses on
press area 26 and lifts lift tab 27 with one hand, and concurrently
presses on press area 28 and lifts lift tab 29 with the second
hand. The lifting action with both hands serves to rotate the tabs
upwardly thereby disengaging a sufficient peripheral portion of lid
10 from the peripheral tray lip of the cooperatively engaged tray
or container base to allow removal of the entire lid from the tray.
The region of initial disengagement extends peripherally away from
each point of lifting action in both directions, and may or may not
extend continuously between the two points of lifting action. The
removal of the lid of the present invention from a tray by a user
is graphically shown in FIG. 9. As is best shown in FIGS. 1, 2, 4,
and 7, press areas may be indicated by integrally forming or
molding the word "PRESS" therein, and lift tabs may be indicated by
integrally forming or molding the word "LIFT" therein for the
purposes of providing simple lid removal instructions to a
user.
[0063] Since lift tabs 27 and 29 lie along the peripheral skirt 25,
the arcuate distance between lift tab 27 and 29 can be optimized
for allowing a user to comfortably grip the respective tabs with
both hands and for providing a convenient release from the tray.
According to some embodiments of the invention, the arc angle
between lift tabs 27 and 29 varies from 20 to 60 degrees, and
according to some embodiments of the invention the arc angle
between the lift tabs is between 25 to 50 degrees. Polygon-shaped
trays and lids can have lift tabs located at two or more adjacent
corners, as illustrated in FIG. 10. In other embodiments, two lift
tabs are located on either side of one corner, as shown in FIG. 11.
Various embodiments that include more than two lift tabs, for
example on larger trays and lids, may require sequentially applied
lifting actions by which suitable peripheral portions of the lid
are disengaged from the tray. It is will be appreciated by those of
ordinary skill that removing the lid of the present invention with
one hand by using a single lift tab is significantly more
cumbersome compared to utilizing two of the lift tabs concurrently,
or more than two sequentially, for removing the lid from the
tray.
[0064] FIG. 5 shows an enlarged view of one of the lift tabs,
particularly lift tab 27. Lift tab 27 features a front wall 27a, an
arcuate front end 27b, and a pair of wedge-shaped side ends 27c and
27d. Front wall 27a may be curved outwardly to allow lifting or
flexibly turning or rotating of the tab 27 upward, and thereby
locally disengaging the peripheral groove portion 24 from tray 30.
Local disengagement of peripheral groove portion 24 from tray 30 at
both tab locations 27 and 29 sufficiently disturbs the lid
engagement to allow an easy removal of the lid from the tray or
container base. It will be realized that tabs 27 and 29 can feature
a variety of shape configurations which are all deemed within the
scope of the invention, including rectangular, button-shaped, or
other structural shapes and appearances.
[0065] According to an embodiment of the invention, the peripheral
groove portion 24 and lift tabs 27 and 29 are adapted for
detachably engaging and fitting lid 10 with a tray or container
base 30. Accordingly lid 10 is constructed of suitable materials to
allow engagement and subsequent reengagement if desired by the
user.
[0066] It will be apparent to those skilled in the art that the
lids 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 lid.
Accordingly, lids of the present invention can be manufactured by
thermoforming and/or injection molding. In some embodiments of the
present invention, the lid is thermoformed from a polyethylene
terephthalate (PET) sheet material. According to other embodiments
of the present invention, the lid is injection molded from a
suitable grade of polypropylene resin.
[0067] Certain embodiments of the present invention also include a
low profile or short peripheral skirt. As shown in FIG. 6, arrow
segment 40 indicates the vertical spacing between the bottom of
peripheral skirt 25 and the table surface 60, and arrow segment 50
indicates the horizontal spacing between the outer edge of
peripheral skirt 25 and tray sidewall 32. The advantages will be
better understood by contrasting the peripheral skirt 25 according
to the embodiment of FIG. 5 with the construction of a prior art
lid. FIG. 7 illustrates a lid 210 according to the prior art fitted
onto tray 230. The peripheral skirt 225 of lid 210 is appreciably
longer than peripheral skirt 25 of lid 10. The longer length of
peripheral skirt 225 results in a much reduced spacing, indicated
by arrow segment 240, between the table surface 260 and peripheral
skirt 225. This poses an inconvenience to the user when lifting the
tray-lid assembly represented by tray 230 and lid 210. Furthermore,
the horizontal distance between the outer edge of peripheral skirt
225 and the tray sidewall 232 represented by arrow segment 250 is
also too large for a user to conveniently reach the tray with his
or her fingers when lifting the tray-lid assembly, thus requiring
the fit between the tray and lid to be sufficiently tight for the
tray-lid engagement feature to support the entire weight of the
assembly and of any items contained therein. However, in some
embodiments of the present invention, the distance between the tray
sidewall 32 and the outer peripheral skirt 25 represented by arrow
segment 50 is sufficiently short to conveniently allow a user to
lift the tray-lid assembly while touching and supporting the tray,
thereby reducing the stress or weight felt by the tray-lid
engagement features. In addition, allowing a user to hold the
tray-lid assembly more securely without relying on just the
tray-lid engagement and/or interlocking features also provides ease
of use and safety.
[0068] The dual tab feature described above is not limited to round
lids, but can be implemented on lids of any shape, including
rectangular and square lids. A square lid 10 with two corner tabs
27, 29 according to an embodiment of the present invention is shown
in FIG. 10. It will be realized that the positions of the two or
more tabs can be optimized to provide ease of release on square and
rectangular lids. According to another exemplary embodiment of the
invention illustrated in FIG. 11, the two tabs 27A, 27B are located
in a proximate relationship about a bottom corner of a square or
rectangular lid 10 and are disposed in a slightly offset position
from that corner on both sides thereof. In addition, FIG. 11 shows
a third lift tab 29 at an adjacent corner. Dual or multiple tabs
can thus also be implemented on lids having a general shape such as
a polygonal shape. Thus, the exemplary embodiments shown in FIG. 10
and FIG. 11 are illustrative of embodiments of the invention for
non-round containers and do not limit the scope of the invention
with regards to lid shape and locations of tabs.
[0069] The 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 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 tabs can be created 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.
[0070] 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.
* * * * *