Note: Descriptions are shown in the official language in which they were submitted.
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TAMPER EVIDENT PLASTIC FOOD CONTAINER
CROSS REFERENCE TO RELATED APPLICATION
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED
RESEARCH OR DEVELOPMENT
[0002] Not applicable.
SEQUENCE LISTING, TABLE OR COMPUTER
PROGRAM ON COMPACT DISC
[0003] Not applicable.
FIELD OF INVENTION
[0004] This invention relates generally to plastic food containers. The
invention is more
specifically related to resealable plastic food containers having tamper
evident sealing
mechanisms.
BACKGROUND OF THE INVENTION
[0005] It is known to use plastic containers in the food preparation and
restaurant
industry to package prepared foods. The typical food container of the prior
art consists of a clear
or solid colored base and a clear lid. In order to maintain the quality of
food contents and
prevent tampering with the contents of a sealed container, it is desirable
that the food container,
once initially sealed, flot be capable of being initially opened without
visible indication of the
container having been opened. To achieve this feature, container manufacturers
have designed
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containers having integral tamper evident features. Typically, these
containers consist of a lid
that is hingedly attached to a base. The lid seals to the base by superposing
the rim of the lid
upon the rim of the base. These types of plastic containers are sold as one-
piece containers and
are often referred to as "clamshell" containers or packages.
[0006] In one type of hinged tamper evident container the lid and base
each have
interlocking elements respectively located on or near the lid rim and base rim
where the two rims
meet when the container is sealed (i.e., at a non-hinged side or portion of
the container). The
interlocking element of the lid or base is conventionally located on a tab or
flange extending
from the rim of the lid or base. Either or both of the tabs are attached to
their respective rims by a
frangible section of plastic. When the lid and base are placed in initial
sealing arrangement, the
interlocking elements on or near the lid rim and base rim engage and lock
together. In order to
open the initially sealed container, the frangible section of one or both tabs
must be ruptured so
as to release the tab or tabs from the container. Because the interlocking
sealing elements are
located on the tabs, rupturing one or more tabs from the container disables
the locking
mechanism. The ruptured tab provides evidence of the container having been
opened.
[0007] One shortcoming with the prior art food container described above
is that the
interlocked tabs can be cut from the container in clean fashion using scissors
or another cutting
implement so as to remove any indicia of the container having had a tamper
evident mechanism.
[0008] In view of the issues presented by incorporating a tamper evident
mechanism in
the meeting rims of the hinged container, some manufacturers have incorporated
tamper evident
features as part of the structure that forms or includes the hinge. In these
containers, the
container is designed to require a severanee near the hinge in order to unseal
(initially open) the
container. This construct make the hinge a single use hinge. These containers
typically employ
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a square-shaped hinge arrangement (as seen from the side when the container is
closed) in which
the flange of the lid rim extends beyond the lid rim and then near-
perpendicularly connects to a
vertical segment that descends down from the lid flange. The vertical segment
meets an
extended portion of the base flange in similar near-perpendicular arrangement.
The two flanges
generally run parallel to each other and by their connection to the vertical
segment form three
sides of a square.
[0009] One example of a container with a square-shaped tamper evident
hinge structure
is shown in U.S. Patent No. 7,073,680 (Boback, et al.). As can be seen in this
patent, at the
containers hinge area, the flange of the lid rim is vertically spaced above
the flange of the base
rim. A span of material (equal to the vertical spacing) adjoins to and
descends from one end to
the flange of the lid rim. The other end of the span of material adjoins to
and ascends from the
flange of the base rim. The span of material thus forms a strip of material
connecting the lid rim
flange and the base rim flange and operates to form hinge structure for the
container. The unes
of connection between the strip and the flanges are scored or include serial
perforations such that
the strip is a frangible section that can be tom away from the container after
it is first sealed.
With this type of tamper evident arrangement, one is left with a separate tear
strip that must be
disposed of and likely will not be recycled with the bulk of the container.
[0010] Another example of a clamshell container utilizing a square-shaped
tamper
evident hinge formation is shown in U.S. Published Patent Application No.
20120181280
(Barbier, et al). This reference discloses a hinge structure that is adapted
to break by application
of a squeeze force that causes the relative movement of two-adjacent sides
(the top flange and
the vertical span of material) that form the hinge arrangement.
4
[0011] Square-shaped hinge containers suffer from a variety of deficits. One
is a tendency of the
container not to remain fully open for purposes of filling the container. The
memory of the square
hinge mechanism is such that the lid tends to flop over and cover ail or part
of the base. Another
deficit, at least as far as the Barbier container is concerned, is that the
squeezing action required
must move two adjacent, near perpendicular sides of the hinge structure and
therefore the entire
hinge structure must be effectively crushed in order to break the frangible
line located at the bottom
outside corner of the hinge structure. Thus, as is seen from the drawings in
that published
application, in order to rupture the frangible line, a squeezing force is
applied to the entire box
structure of the hinge area. This extended crushing motion may require the
container to be stabilized
with one's other hand in order to entirely rupture the frangible section.
There is thus a need in the
art for a re-closable plastic food container that is easy for end consumers to
operate; combines
reliable tamper evidence and defense against prying intrusion; and that uses a
minimum of material
to manufacture.
[0011a]
Also disclosed is a tamper evident container capable of assuming an open
arrangement and an initially sealed arrangement, the container comprising:
a lid and a base;
the lid including a lid rim circumferentially extending about the periphery of
the lid and the
base including a base rim circumferentially extending about the periphery of
the base, the lid rim
and the base rim frictionally engaging each other when the container is in the
sealed arrangement;
a frangible hinge, the hinge being a vertex formed by the convergence of a top
pinch segment
connecting to a lid rim flange extending from the lid rim and a bottom pinch
segment connecting to
a base rim flange extending from the base rim;
the top pinch segment peripherally projecting from the lid rim and the bottom
pinch segment
peripherally projecting from the base rim such that when the container is in
the initially sealed
arrangement: the vertex is vertically situated at a position interposed
between the height of the lid
rim flange and the height of the base rim flange; and the top pinch segment
and the bottom pinch
segment have a vertical separation distance between them that extends between
a first point on the
top pinch segment and a second point on the bottom pinch segment; and
the frangible hinge rupturing when the vertical separation distance is
reduced.
SUMMARY OF THE INVENTION
[0012] The present invention satisfies the needs in the art and provides an
aesthetically appealing
food container that is tamper resistant, tamper evident and easy to use. In
this respect the present
invention food container comprises a plastic food container that, when viewed
from the left or right
side, hinges about a frangible vertex instead of hinging about a square-shaped
structure. Unlike in
the case of containers with square-shaped hinge structures, the frangible
vertex projects
peripherally out from the container in horizontal alignment with the flanges
of the lid rim and base
rim. Hence, rather than crushing upon itself, the hinge-forming structure
moves through empty
space when pinched. VVhen viewing the closed container from the rear side
Date Reçue/Date Received 2020-07-23
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aspect (facing the hinge), the hinge is a scored, thirmed or perforated une
that represents the
point where structure projecting from the lid and base flanges meet to form
the hinge. Thus, as
opposed to the prior art containers with square-shaped hinge structures, the
container of the
instant invention eliminates the vertical span at the hinge end by having the
structures that extend
from the flanges converge to form a hinge vertex.
[00131 There are several embodiments to the invention, which are broadly
described in
this summary section and more specifically described in the detailed
description of the invention.
In ail embodiments the invention is directed to a tamper evident container
having a lid and base
hingedly attached to each other and capable of assuming an open arrangement,
an initially sealed
arrangement and an unsealed (open) arrangement. The lid includes a cover
surface and a lid
rim. The inventive container includes a frangible hinge. The hinge is formed
between a top
pinch segment that peripherally projects from the lid rim flange and a bottom
pinch segment that
peripherally projects from the base rim flange. The frangible hinge is
configured to rupture
when the container is in the initially sealed arrangement by the application
of a pinching force to
the top pinch segment and bottom pinch segment that results in the relative
vertical movement of
the segments toward each other. In an altemate embodiment, the lid rim also
includes a lid rim
bead that includes an outer wall. The base of the alternate embodiment
container includes a base
rim that includes a base rim bead. The base rim bead includes an undercut
inner wall that is
configured to receive and frictionally engage the outer wall of the lid rim
bead when the
container is closed, whether in the initially sealed arrangement or when re-
closed after opening.
100141 In another embodiment the frangible hinge of the inventive
container is connected
to a top pinch segment that peripherally projects from the lid rim flange and
a bottom pinch
segment that peripherally projects from the base rim flange. When the
container is in the
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initially sealed arrangement the top pinch segment and the bottom pinch
segment have a vertical
separation distance between them that extends between a first point on the top
pinch segment and
a second point on the bottom pinch segment. The frangible hinge is configured
to rupture when
the vertical separation distance is reduced which can occur by virtue of a
pinching force applied
to both pinch segments.
[0015] In another embodiment the frangible hinge of the inventive
container is
connected to a top pinch segment that peripherally projects from the lid rim
flange and a bottom
pinch segment that peripherally projects from the base rim flange. The top
pinch segment
includes a top vertex-forming segment and the bottom pinch segment includes a
bottom vertex-
forming segment. In the initially sealed configuration, the top vertex-forming
segment and the
bottom vertex-forming segment converge to form a vertex at their meeting
point. The vertex is
the containers hinge. As is further described herein, the top pinch segment
may include a top
pinch bead and the bottom pinch segment may include a bottom pinch bead. The
pinch beads
provide added rigidity to the pinch segments, which enhances the frangibility
of the vertex hinge.
Additionally, the pinch beads allow for more vertical movement during
application of a pinching
force, thus serving to ensure rupture of the frangible fine. Also, the pinch
beads designate a
location at which a user can position his or her fingers to apply pinch force.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a front perspective view of a preferred embodiment of the
present
invention plastic container in the open arrangement, ready to be filled.
[0017] FIG. 2 is a left elevation view of the preferred embodiment
container in the open
arrangement.
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[0018] FIG. 3 is a top plan view of the preferred embodiment container in
the open
arrangement.
[0019] FIG. 4 is a rear perspective view of a preferred embodiment of the
present
invention plastic container in the initially sealed arrangement.
[0020] FIG. 5 is a left elevation view of the preferred embodiment
container in the
initially sealed arrangement.
[0021] FIG. 6 is a detail view of the hinge area structure of the
container in the initially
sealed arrangement.
[0022] FIG. 7 is a top plan view of the preferred embodiment container in
the initially
sealed arrangement.
[0023] FIG. 8 is a rear elevation view of the preferred embodiment
container in the
initially sealed arrangement.
[0024] FIG. 9 is a detail view of the hinge area structure shown in FIG.
6, showing the
rupture of the hinge as a result of pinching the top and bottom pinch
segments.
[0025] FIG. 10 is a rear perspective view of a preferred embodiment
container showing
the increased vertical separation between the top and bottom pinch segments
atter rupturing of
the hinge, the increased vertical separation being due to the memory of the
plastic in the
container flanges and pinch segments.
[0026] FIG. 11 is a front perspective view of the base of the preferred
embodiment
plastic container after the initially sealed container has been opened.
[0027] FIG. 12 is a front perspective view of an embodiment of the present
invention
plastic container in the initially sealed state.
[0028] FIG. 13 is a view of a cross-section of the engaged rims of the
container.
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100291 FIG. 14 is a top plan detail view of the hinge of a preferred
embodiment container
in the open arrangement.
100301 FIG. 15 is a top plan detail view of the hinge of a preferred
embodiment container
in the initially sealed arrangement.
DETAILED DESCRIPTION
[00311 FIGS. 1-15 depict a preferred embodiment present invention tamper
evident
plastic container 1 along with its preferred features. As is seen in the
figures, the inventive
container 1 includes a lid 2 and a base 3 that are attached to each other
through a hinge 6 located
on one side of the container. In practical use, the outer surface of fioor 26
of base 3 will
norrnally rest upon a surface (such as a table top) considered horizontal in
reference to the user.
Thus, the directional terms "vertical" and "horizontal" and the like are used
to describe the
container 1 and its components with respect to the orientation illustrated in
FIGS. 1-15 and are
employed merely for the purposes of clarity and illustration. For example,
FIG. 6 shows the
hinge area of container 1 when container 1 is in an initially sealed state. In
the orientation shown
in FIG. 6, at the point where top pinch segment 7 connects to lid rim flange
9, top pinch segment
7 is spaced "vertically" above bottom pinch segment 8. The directional terms
"inner" and
"inwardly" and the like are used herein with respect to the described
container to refer to
directions along the directional component toward the geometric center of the
container. The
directional terms "outer," "peripherally" and the like are used herein with
respect to the described
container to refer to directions along the directional component away from the
geometric center
of the container. Additionally, the terms "upward," "downward" and the like
are used to describe
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spatial relationships among structure when lid 2 of container 1 is sealed or
closed upon the base
3.
[0032] As shown in the figures, lid 2 and base 3 respectively include lid
rim 4 and a base
rim 5. Lid rim 4 includes peripherally projecting lid rim flange 9. Base rim 5
similarly includes
base rim flange 10. Unlike other tamper evident containers that use a square-
shaped, multi-
segmented hinge structure, hinge 6 of the present invention container is
confined to a vertex 30
that is vertically situated at a position interposed between the height of the
lid rim flange and the
height of the base rim flange. (In the case of the Boback container, the
frangible unes are at the
same height as the flange structures emanating from the rims. In the Barbier
container, the
frangible une is actually below the height of the flange structure emanating
from the base rim.)
Further, as can be particularly seen in FIG. 6, the interposed frangible
vertex projects
horizontally and peripherally out from the container in alignment with the
fianges of the lid rim
and base rim.
[0033] As shown in the figures, preferred embodiment container 1 is
capable of assuming
an open arrangement (FIGS. 1-3, 14), an initially sealed arrangement (FIGS. 4-
8, 12, 15) and an
opened arrangement (FIGS. 9-11). Additionally, container 1, after being opened
from the
initially sealed state can be closed (re-sealed). The first embodiment
container comprises lid 2
and base 3. Lid 2 includes cover portion 33 and lid rim 4. Lid rim 4
circumferentially extends
about the periphery of lid 2. FIG. 13 depicts preferred embodiment rim
structural features that
make the embodiment container flot just tamper evident, but also tamper
resistant. In the
preferred embodiment, lid rim 4 includes lid rim bead 17 that comprises a
downwardly
descending lid rim inner vertical wall 18, an upwardly extending lid rim outer
wall 19 and a bead
bottom segment 20. Bead bottom segment 20 extends from the bottom 21 of lid
rim inner wall
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18 and curves into the bottom 22 of the lid rim outer wall 19. Base 3 includes
base rim 5
circumferentially extending about the periphery of base 3. Base rim 5 includes
base rim bead 11
that comprises upwardly extending inner vertical wall 12, downwardly extending
outer wall 13
and bead top segment 14. Bead top segment 14 extends from top 15 of upwardly
extending inner
vertical wall 12 to top 16 of the downwardly extending outer wall 13.
Downwardly extending
inner wall 12 includes undercut surface 24 configured to receive and
frictionally engage outer
wall 19 of lid rim 4 when container 1 is in the sealed or closed arrangement.
[0034] As is best shown in FIGS. 6-9, at the hinge area of container 1,
lid rim flange 9
extends out and connects to top pinch segment 7. In the same area, base rim
flange 10 extends
out and connects to bottom pinch segment 8. As can be readily seen, when
container 1 is in the
initially sealed arrangement, top and bottom pinch segments 7, 8 project out
respectively from
flanges 9, 10 and converge to form vertex 30. Frangible vertex 30 projects
peripherally out from
the container in horizontal alignment with the flanges of the lid rim and base
rim. Hinge 6 is
defined by vertex 30 and is the point about which lid 2 and base 3 articulate
for initially sealing
and closing of the container.
[0035] Hinge 6 is formed between top pinch segment 7 that peripherally
projects from lid
rim flange 9 and bottom pinch segment 8 that peripherally projects from base
rim flange 10.
Frangible hinge 6 is configured to rupture when container 1 is in the first
sealed arrangement by
the application of a pinching force to top pinch segment 7 and bottom pinch
segment 8 that
results in the relative vertical movement of segments 7, 8 toward each other.
The action of the
hinge and container-opening technique is best seen in FIGS. 6-10.
[0036] Hinge 6 is frangible and its length can be seen best in FIGS. 1, 3,
and 8.
Container lis preferably thermoformed from a single sheet of plastic. Hinge 6
is manufactured
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by thinning, scoring or making perforations in a une 31 across the segment of
material that joins
lid 2 to base 3. Frangible une 31 can be best seen in FIG. 14, but also can be
seen in FIGS 1, 3
and 8. The remnant frangible une 31 can be seen in FIG. 11. The process of
thinning, scoring or
perforating serves to concentrate the point of articulation during closing of
the container at the
vertex and flot on other sections of the container. Also, the process of
thinning, scoring and
perforating operates to make hinge 6 frangible and determines the amount of
pinch force needed
to rupture hinge 6. The material connecting hinge 6 to lid rim flange 9 forms
top pinch segment
7. The material connecting hinge 6 to base rim flange 10 forms bottom pinch
segment 8.
[0037] The
geometric relationship of the hinge area structures and the action of opening
the container can be described in more particular fashion. As shown best in
FIG. 6, when
container 1 is in the initially sealed state pinch segments 7, 8 are
vertically separated from each
other at ail points along their length except at vertex 30. Hinge 6, and thus,
vertex 30 are
therefore vertically located between pinch segments 7, 8 when the container is
in the initially
sealed arrangement. Point 60 represents a first point on top pinch segment 7.
Point 61
represents a second point on bottom pinch segment 8. When a pinching force
(shown by arrows
A, B) is applied to pinch segments 7, 8 as shown in FIG. 6, the vertical
distance D between
points 60 and 61 on segments 7, 8 is reduced and top pinch segment 7 is pulled
away from
bottom pinch segment 8 at vertex 30. This pulling action causes hinge 6
located at vertex 30 to
rupture and end point 58 of top pinch segment 7 to slide upon and down bottom
pinch segment 8
toward container 1. As shown in FIG. 9, once the pinching force is released,
pinching segments
7, 8 spring apart vertically due to the action of the memory in the plastic
material forming
pinching segments 7, 8 and flanges 9, 10. It can be seen in FIG. 10 that
separated pinching
segments 7, 8 can be pulled apart and used to peel open lid 2 from base 3.
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100381 In the preferred embodiment, top pinch segment 7 includes a top
vertex-forming
segment 40 and bottom pinch segment 8 includes bottom vertex-forming segment
41. Hinge 6 is
thus a vertex formed by the convergence of top hinge point-forming segment 40
and bottom
hinge point-forming segment 41. In an altemate embodiment, either or both of
lid rim 3 and
base rim 4 could lack their respective flanges 9, 10 around the sides and
front of container 1, in
which case pinch segments 7, 8 would respectively connect to lid rim 3 and
base rim 4 at the rear
(hinge area) of the container.
[0039] As best shown in FIGS. 4, 6, 7 and 8-10, top pinch segment 7 may
include a top
pinch bead 42. Similarly, bottom pinch segment 8 may include a bottom pinch
bead 46. Pinch
beads 42, 46 are desirably formed as follows. As displayed in FIG. 9, top
pinch bead 42 may
comprise a first sidewall 43, a second sidewall 44 and a top finger rest
segment 45 extending
between a top 52 of first sidewall 43 and a top 53 of second sidewall 44. It
is preferable that
bottom pinch bead 46 also comprise a first sidewall 47, a second sidewall 48
and a bottom finger
rest segment 49 extending between a bottom 54 of first sidewall 47 and a
bottom 55 of second
sidewall 48.
[0040] In a preferred embodiment top finger rest segment 45 is
substantially
perpendicular (80-100 degrees) to first sidewall 43 of top pinch bead 42. It
is also preferable that
bottom finger rest segment 49 be substantially perpendicular to first sidewall
47 of the bottom
pinch bead 46. As shown in the figures, second sidewall 44 and top finger rest
segment 45
include a textured surface or Icnurling 67 so as to enhance purchase on top
pinch segment 7
during pinching action. Additionally, as best seen in FIGS. 10, 14 and 15 the
rim and pinch
segment structures may include formed or impressed pinch segment lugs 66 and
rim lugs 68 to
add rigidity in the hinge area so that the hinge more readily breaks when
pinched.
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[0041] Top pinch segment 7 further preferably includes transition segment
50 that
extends between top pinch bead 42 and lid rim flange 9. More optimally, top
pinch segment 7
includes a transition segment 50 that extends between second sidewall 44 of
the shown
embodiment top pinch bead 42 and lid rim flange 9. For optimal operation of
the hinge breaking
mechanism, bottom pinch segment 8 may also include a transition segment 51
that extends
between bottom pinch bead 46 and base rim flange 10. In the particular
embodiment shown,
bottom pinch segment 8 includes a transition segment 51 that extends between
second sidewall
48 of bottom pinch bead 46 and base rim flange 10. Top segment finger rest 45
is preferably
longer than either first sidewall 43 or second sidewall 44 of top pinch bead
42.
[0042] To thwart prying into the container without rupturing hinge 6, base
rim 5 may
include rim bead 11 described above and shown in FIG. 13. When container 1 is
in the sealed
arrangement lid rim flange 9 assumes a position above or on top of the top
surface 25 of top
segment 14 of base rim bead 11. As the figures also show, lid rim 4 is
structured such that it
includes lid rim flange 9 connected to lid rim outer wall 19. Lid rim outer
wall 19 is of such
height that lid rim flange 9 is positioned higher than cover portion 33 of lid
2. As an added
tamper resistance feature against prying or grasping of the lid rim, cover
portion 33 includes one
or more elongate caver beads 34 protruding upward from the outer surface 35 of
cover portion
33. Bead 34 is optimally positioned 5 millimeters or less from lid rim outer
wall 19 to prevent
grasping of lid rim flange 9.
[0043] As shown by the figures, the container can be polygonal with
beveled corners at
its floor. The inclusion of beveled corners also enhances the security of the
container by
reducing the chance of the container cracking open or developing holes should
it be dropped. In
this particular version container 1 has a base 3 that comprises floor 26 and a
plurality of
14
sidewalls 27. Each sidewall 27 has a top 28 and bottom 29. The bottom 29 of
each sidewall 27 is
connected to floor 26. The plurality of sidewalls 27 form a polygon in which
each sidewall 27 extends
between and connects to two other sidewalls 27. Each connection between
sidewalls 27 forms a
corner 32. Each corner 32 includes a bevel 64 that is connected to floor 26
and the sidewalls 27
that form that corner 32. In the shown embodiment, container 1 can include
flutes 65 on sidewall 27
that add strength to the container and define the width of bevel 64.
[0044] A container constructed in accordance with the present invention can be
manufactured in a
variety of shapes and sizes, and is preferably formed of resins or plastic
materials including, but not
limited to, polyethylene, polypropylene, polyvinyl chloride or polyethylene
terephthalate ("PET"). The
container is preferably thermoformed, but can be blow-molded or injection
molded. The container
lid and base can be transparent or translucent, and may be colored in either
instance. Further, the
container is preferably polygonal so as to include the described bevels 64,
but can be of any shape.
Date Reçue/Date Received 2020-07-23
