Note: Descriptions are shown in the official language in which they were submitted.
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f
CUP LID HAVING COMBINED ST~~AW SLOT DEPRESSION
AND TEAR BACK LIlit~ RETAINER
CROSS REFERENCE i O RELA7.'ED APPLICATIONS
This application is a Continuation-in-Part of Application Serial No.
09/281,267 filed
March 30, 1999; which itself is a Division of Serial No. 08/703,771 filed
August 27, 1996,
now U.S. Patent 5,947,323.
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates generally to lids for beverage containers
and more
specifically to lids having a tear-back drink-thru opening flap which is
securably held in an
open position within a straw depression formed in the lids.
BACKGROUND OF THE INVENTION
[0002] It is well-known to provide covers for drinking containers to prevent
the spillage of
the contents of the container. Many prior art covers incorporate an opening in
the top of the
cover in order to allow drinking of the contents either in the normal drinking
fashion or by
the insertion of a straw. Some coven have an opening which is sealed by a
depressible tab
such that when the tab is depressed by the insertion of a straw, the opening
is unsealed for
drinking the contents of the container. U.S. Patent No. 3,048,317 issued to
Cochrane et al.
discloses one such lid having an opening for a straw disposed in a depression
formed in the
lid with an integrally formed hinged flap in the bottom of the depression. The
hinged flap is
severed from the lid about the majority of the periphery of the flap to pivot
open when a
pressure is exerted on the flap by the end of a straw. However, unless the
hinged opening is
exactly the same diameter as the straw, the fluid within the cup may spill out
the opening
between the straw and the sides of the opening once the hinged flap has been
pivoted open.
(0003] Other coven utilize a releasable drinking flap in order to prevent the
sloshing of the
contents out of the containers. An example of this type of cover is disclosed
in U.S. Patent
4,738,373 issued to DeParales, which shows a cover having a hinged tab which
is defined by
score lines formed in the cover leading from the rim of the cover to a hinge
positioned, in the
medial portion of the cover. A recess is formed in the cover on the opposite
of the hinge
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r
from the tab, wherein the recess receives the rim portion of the tab once the
tab is torn opened
and pivoted about the hinge in order to retain the hinged tab in an open
position. However, if
the user desired to use a straw with a cover of this type, the straw would
have to be inserted
into the opening created by the tearing open of the hinged tab. This would
create an
exceptionally large opening for a straw, allowing the straw to float about and
allowing the
contents of the cup to be spilled.
[0004] In an effort to overcome the aforementioned shortcomings, other covers
have been
proposed utilizing both a straw slot and a releasable flap, depending upon the
desired use by
the consumer. An example of this type of cover is disclosed in U.S. Patent No.
4,090,660 to
Schram et al., which discloses a cup lid having a liftable tab which snap fits
on the rim of a
cup with a straw slot formed in the portion of the lid constituting the
liftable tab. This design,
however, does not include a feature incorporated into the lid which will
retain the liftable tab
in an open position for convenient repeated drinking from the opening created
by the liftable
tab.
[0005] Another example of a prior art drinking lid utilizing both a straw slot
and a releasable
flap is disclosed in U.S. Patent No. 5,335,812 issued to Boiler, which shows a
lid having a
straw puncturable area formed in a rupturable depression in the lid. The lid
further includes a
flap defined by lines of weakness that may be torn and pivoted to overlie a
central portion of
the lid to retain the flap in an open position. Of course, designs of this
general type forming a
retaining portion in the center of the lid to hold the flap open as well as
forming a separate
rupturable depression for a straw are difficult to mold due to the number of
depressions and
features which must be formed in the cup Iid.
[0006] Yet another type of prior art drinking lid utilizing both a straw slot
and a releasable
flap is disclosed in U.S. Patent No. 3,994,41 1 issued to Elfelt et al., which
shows a lid having
a foldback drink opening. A pull tab formed on the edge of the rim of the
foldback portion is
insertable in a straw slit formed in the lid in order to hold the foldback
portion in an open
position. This foldback drink opening requires a great amount of attention by
the user to
insert the pull tab into the narrow straw slot in order to hold the foldback
portion of the lid
open. Furthermore, since the straw slot must be forced open to receive the
pull tab, the straw
slot will be slightly ajar when retaining the pull tab which can allow the
contents of the cup to
spill therethrough.
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[0007] Clearly, there is a need for a drink-thru cup lid which provides both a
straw slot and a
tear-back flap which is simple to form and which does not require multiple
separate
components to be formed in the lid for each drink-thru feature. Moreover,
there is a need for
a drink-thru cup lid which securably retains the tear-back flap in place
within the straw slot
depression without rupturing the cup lid in the straw slot area.
SUMMARY OF THE INVENTION
[0008] A primary object of the present invention is to provide a drink-thru
cup lid design
which overcomes the aforementioned shortcomings associated with prior art
designs.
[0009] A further object of the present invention is to provide a drink-thru
cup lid having a
straw slot and a tear-back flap which is simple to manufacture and which does
not require
multiple separate components to be formed in the lid for each drink-thru
feature.
[0010] Yet another object of the present invention is to provide a drink-thru
cup lid wherein
the tear-back flap is securably retained in place within the straw slot
depression.
[0011] A still further object of the present invention is to provide a drink-
thru cup lid wherein
the tear-back flap is securably retained in place within the straw slot
depression without
rupturing the cup lid in the straw slot area.
[0012] Yet another object of the present invention is to provide a drink-thru
20 cup lid
wherein the skirt of the cup lid includes a plurality of interrupted beads
formed therein for
securing the cup lid to the brim of a cup.
(0013] It is yet another object of the present invention is to provide a drink-
thru cup lid,
wherein the walls of the straw slot bend without fracturing to conform to the
shape of the
straw as the straw is inserted into the straw slot in order to seal the cup
lid around the straw to
prevent the contents of the cup from spilling out of the straw slot.
[0014] These, as well as additional objects of the present invention, are
achieved by
providing a drink-thru lid for a drinking cup including an annular mounting
portion for
sealingly engaging the drinking cup, wherein the annular mounting portion
includes a
downwardly extending annular skirt. The lid further includes a pivotal flap
extending from
the annular skirt to a hinge portion located in a medial portion of the lid. A
raised protrusion
extends outwardly from an upper surface of the lid where the protrusion is
positioned on the
pivotal flap between the hinge portion and the annular mounting portion. A
recess is further
formed in a medial portion of the lid on the opposite side of the hinge
portion from the raised
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protrusion, wherein the pivotal flap may be torn away from the lid on its
sides and pivoted
about the hinge portion until the raised protrusion is received within the
recess for holding
said pivotal flap open. The raised protrusion and the recess are shaped such
that the raised
protrusion is matingly received within the recess with end surfaces of the
raised protrusion
frictionally engaging end walls of the recess. The recess further includes a
straw slot formed
therein, wherein the straw slot is defined by two sloping side walls extending
from an upper
surface of the lid and converging together at a frangible line of weakness
formed in the
deepest portion of the recess. The slope of the side walls may be identical or
may vary
between 0° and 60° with respect to a vertical plane of the lid.
The sloping side walls also
bend to conform to the shape of the straw as a straw inserted in to the straw
slot in order to
seal the lid around the straw.
[0015] In one embodiment of the cup lid of the present invention, a plurality
of interrupted
beads are formed about the annular skirt to secure the lid to a brim of a cup.
The beads are
spaced apart from one another with beads of a first length being formed in the
skirt outside of
the section in the skirt included in the pivotal flap and two beads of a
second shorter length
than the first length being formed in the section of the skirt included in the
pivotal flap. The
configuration allows the pivotal flap to securably be reattached to the brim
of the cup after
the pivotal flap has already been torn open.
[0016] These, as well as additional objects of the present invention will
become apparent
from the following detailed description when read in light of the several
figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Fig. 1 is a perspective view of a lid in accordance with the present
invention.
[0018] Fig. 2 is a perspective view of the Iid illustrated in Fig. 1 with an
opening formed by
tearing back a portion of the lid.
[0019) Fig. 3 is a top plan view of the lid illustrated in Figure 1.
[0020] Fig. 4 is a cross-sectional side view of the lid of Fig. 1 taken along
line 1V-N of
Figure 3.
[0021] Fig. 5 is a cross-sectional side view of the lid of Fig. 4 in a stacked
relationship with
another lid.
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[0022] Fig. 6 is a cross-sectional side view of the mold used to form beads in
the skirt of the
lid of Figure I .
[0023] Fig. 7 is an enlarged, cross-sectional side view of the area A of the
mold of Fig. 6.
[0024] Fig. 8 is a cross-sectional side view of the mold used to form the lid
of Figure 1.
[0025] Figs. 9-11 illustrate a process of inserting a straw through the lid in
accordance with
the present invention.
[0026] Fig. 12 is a perspective view of a lid in accordance with a preferred
embodiment of
the present invention.
(0027] Fig. 13 is a top view of the lid illustrated in Fig. 12.
[0028] Fig. 14 is a cross sectional view taken along line XIV of Fig. 13.
[0029] Fig. 15 is a cross sectional view taken along line XV of Fig. 13.
(0030] Figs. I6-18 illustrate a process of inserting a straw through the lid
illustrated in Fig.
1z.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
(0031] The present invention is generally embodied in a Iid 10 for a drinking
cup I2. The lid
may be used with cups of various types, and is particularly suitable for use
with disposable
cups of the type commonly used as carry-out containers for beverages such as
coffee and the
like. Such cups are commonly made of Styrofoam or paper. The drinking cup 12
has a
generally circular upper lip or rim 14 with a bead formed on it for receiving
and securing the
lid 10 thereon.
[0032] Refernng now to Figures 1, 2, and 3, the lid 10 of the present
invention is illustrated.
The lid 10 provides a cover for the cup 12 which inhibits spillage and reduces
heat transfer
between the beverage and the surrounding atmosphere. The lid 10 is secured in
place on the
cup 12 by an annular mounting portion 16 which engages the rim or lip 14 of
the cup 12,
wherein the annular mounting portion 16 includes a downwardly extending skirt
I7 which
forms the outer peripheral circumference of the lid 10. A portion 18 of the
lid 10 may be torn
back to provide an opening 20 in the lid 10 to enable drinking from the cup 12
without
removal of the lid 10. The Iid also includes a straw slot opening 22 which
functions as a
means for facilitating the insertion of a drinking straw (not shown) into the
cup 12 for
withdrawing liquid by suction.
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[0033] A central raised portion 24 is formed about a substantial portion of a
medial area
within the circumference of the lid 10 with an upstanding annular wall 26
forming the side
surfaces of the central raised portion 24. Bridging the space between the
mounting portion 26
and the upstanding annular wall 26 is an annular channel 28 which readily
receives any fluid
which may flow out of the opening 20 when the container is jarred or which may
spill during
consumption of the container. As can be seen from Figs. 1 and 2, the annular
channel 28 is
signif cant in size to accommodate more than just a few droplets of fluid.
[0034] In the embodiment of the present invention illustrated in Figs 1-11,
the tear-back
portion 18 of the lid 10 and the straw slot opening 22 are formed in a medial
portion of the lid
which is not raised, wherein the non-raised medial portion is surrounded on
three of its sides
by central raised portion 24. The straw slot opening 22 is formed radially
inward of the tear-
back portion 18 of the lid 10, wherein the tear-back portion 18 of the lid 10
includes a
protrusion 30 which extends from the upper surface of the lid 10. The tear-
back portion 18 of
the lid 10 extends from the annular mounting portion 16 to a trough 32 formed
radially
inward of the annular mounting portion 16 between the protrusion 30 and straw
slot opening
22. The trough 32 serves as the pivotal hinge axis for the tear-back portion
18 of the lid 10,
so that, as the tear-back portion 18 is torn away from the remaining portion
of the lid 10, the
tear-back portion 18 will rotate away from the brim 14 of the cup 12 while
pivoting about
trough 32.
[0035] A flange 34 extends from the edge of the skirt 17 away from the cup 12
on the tear-
back portion 18 of the lid 10 to provide a gripping surface for a consumer to
grasp and pull in
order to tear open tear-back portion 18. In order to facilitate tearing, a
pair of cuts 36 may be
formed through the skirt 17 adjacent to flange 34 to provide a starting point
for tearing open
tear-back portion 18. In an alternative embodiment of the present invention, a
plurality of
corrugations 36 may be formed on both sides of protrusion 30, as shown in Fig.
3, to direct
the tearing of tear-back portion 18 in a predetermined manner and prevent
accidental and
random tear directions to be assumed. The corrugations 36 preclude random
tearing by the
fact that the lid structure is extremely rigid across the corrugated sections
36 and weak only
on the precise line at which the corrugations 36 stop. Therefore, a sharp and
accurate tear
line is provided along the edge 38 of the corrugations 36 without the
disadvantages of a score
line which is the most frequently used tear inducing means. The formation of
corrugations 36
in the lid 10 provides a simple and efficient method of producing an accurate
tear Line since
the corrugations 36 can be formed along with the rest of the lid 10 and
delicate tool adjusting
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is not required as is required with a score line to avoid cutting through the
lid material if the
score is too deep or forming an inadequate score line if too shallow.
[0036] The straw slot opening 22 is formed in a depression 40 within the lid
10, wherein the
depression 40 facilitates the receipt of the end of a straw in the straw slot
opening 22 as the
opening to the depression 40 in the top surface of the lid 10 is larger than
the diameter of the
straw. The depression 40 includes a pair of sloping side walls 42 and 44 which
extend from
the top surface of the lid 10 toward a frangible junction 46 at the bottom of
the depression 40,
so that the depression 40 has a V-shaped or triangular cross-sectional shape,
as can be seen
from Fig. 4. The thickness of the lid material at frangible portion 46 is
thinner than the lid
material in the other portions of the lid 10 to allow frangible portion 46 to
be ruptured by the
force exerted by the end of a straw as it is inserted into straw slot opening
22. As a straw is
inserted into straw slot opening 22, the tapered shape of the depression 40
causes the circular
shape of the end of the straw to flatten until the end of the straw deforms
into a V-shaped
cross-sectional shape similar to that of the depression 40, as shown in Figs.
9-11. Therefore,
the end of the straw is deformed into a point as it progresses into depression
40 which acts to
assist in piercing frangible portion 46 in addition to the force applied by
the straw pushing
side walls 42 and 44 away from one another. The side walls 42 and 46 further
extend
between end walls 48 and SO in depression 40, wherein end walls 48 and 50
prevent against
extended fracture, cracking or tearing of the frangible junction 46 which may
be caused by
the insertion of the drinking straw into the straw slot opening 22. Due to the
V-shaped
configuration of the depression 40, a momentary countering force is created to
center the
straw over the frangible portion 46 by side walls 42 and 44. If the force used
to insert the
straw is excessive, the end walls 48 and SO provide a structure which
redirects and absorbs.
the tearing forces to prevent extended tears across the lid 10. The momentary
excessive force
will be absorbed by the end walls 48 and 50 such that the radial propagation
of the tear will
reach the end walls 48 and 50 which causes the radial force to be redirected
upwardly which
prevents continued tearing of the frangible juncture 46.
[0037] The frangible portion 46 is formed at substantially the same time as
the 10 remaining
structural portions of the lid configuration. That is, a sheet of thermo-
deformable material,
such as thermoplastic, is placed in a predetermined position with respect to a
die element in a
known manner for forming lids of this nature. The thermo-deformable material
is either
previously heated or subsequently heated to a deformable temperature and then
vacuum
formed over the die element. A suction device draws the thermo-deformable
material into a
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depression in the die element to form depression 40, wherein the thermo-
deformable material
is drawn into the depression until the desired thickness of the material
forming frangible
portion 46 at the bottom of the depression is achieved. Therefore, frangible
portion 46 is
formed at the same time as the rest of the lid configuration without the need
for delicate tool
adjusting to provide the proper scoring in the lid material as is usually done
when forming
straw slots. Furthermore, since frangible portion 46 is integrally formed with
the rest of the
lid 10, the lid 10 has no openings where the contents of the cup 12 can spill
out if the cup 12
is advertently knocked over. While the depression 40 is described above as
having a V-
shaped cross-sectional shape, it is understood that the depression 40 may
comprise any shape
which allows the straw slot opening 22 to function with the goals and
objectives of the
present lid configuration as described herein.
[0038] Once frangible junction 46 is broken by the end of a straw, the side
walls 42 and 44 of
depression 40 are separated from one another and allow the straw to travel
into the cup 12
between the side walls 42 and 44. As the straw passes between side walls 42
and 44, the side
walls 42 and 44 bend around the straw to conform to the shape of the straw.
Therefore, the
side walls 42 and 44 provide a close engagement around the inserted straw,
which acts to seal
the cup lid 10 around the straw to prevent the contents of the cup 12 from
spilling out of the
straw slot opening 22 between the straw and side walls 42 and 44.
Additionally; each of side
walls 42 and 44 included guides 43 and 45, respectively which aid the consumer
in inserting
the straw into the depression 40.
[0039] The protrusion 30 is shaped such that when the tear-back portion 18 of
the lid 10 is
opened and pivoted about hinge 32, the protrusion 30 is received within
depression 40 to
retain the protrusion in an open position, as shown in Fig. 2. The width of
protrusion 30 is
slightly larger than the width of depression 40, resulting in the end walls 48
and 50
fi-ictionally engaging the end surfaces 52 and 54 of protrusion 30 to hold the
protrusion
within depression 40. In order to be received within depression 40, protrusion
30 includes
sloping side surfaces 56 and 58 of a substantially similar slope to that of
sloping side walls 42
and 44 of depression 40, wherein sloping side surfaces 56 and 58 rest adjacent
to sloping side
walls 42 and 44, respectively, when protrusion 30 is inserted into depression
40. In
accordance with the present invention, protrusion 30 has a substantially
trapezoidal cross-
sectional shape, as illustrated best in Fig. 4. However, protrusion 30 may be
triangular or any
other shape which allows the protrusion to be positioned within depression 40
without
rupturing frangible juncture 46.
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[0040] By forming protrusion 30 having a substantially similar shape as
depression 40, the
protrusion 30 will not engage the sloping side walls 42 and 44 of depression
40 and cause
frangible juncture 46 to be broken. Therefore, the straw slot opening 22
remains unaffected
and frangible juncture 46 remains intact when the straw slot depression 40 is
used to retain
the tear-back portion 18 of the lid 10 in an open position. Even if frangible
juncture 46 is
broken by inserting a straw into depression 40, end walls 48 and 50 of
depression 40 will still
function equivalently by frictionally engaging protrusion 30 to retain the
tear-back portion 18
in the open position. Accordingly, the prior use of one of the drink-thru
features of the lid 10
will not affect later use of the other drink-thru feature by a consumer.
[0041] A recess 60 is also formed in the lid configuration radially inward of
the depression
40 for receiving the mounting portion 16 of the lid 10 when the tear-back
portion 18 is
retained in its open position. The lid configuration is further designed such
that a plurality of
lids 10 may be positioned together in a stacked relationship, as shown in Fig.
5.
[0042] In one embodiment of the lid configuration of the present invention, a
plurality of
inwardly projecting interrupted beads 62 are formed about the periphery of the
skirt 17 to
assist in retaining the lid 10 on the rim 14 of the cup 12. The beads 62
extend radially inward
further than the remaining portions of skirt 17, causing the mounting portion
16 of the lid 10
to engage the rim 14 of the cup 12 more tightly in the portions of the skirt
17 where the beads
62 are formed. This causes a greater frictional engagement between the lid 10
and the rim 14
of the cup 12 at beaded portions 62 which assists in retaining the lid 10 on
the rim 14 of the
cup 12. Greater frictional engagement between the lid 10 and cup 12 is
especially useful in
retaining the lid 10 in place when an upward force is applied on flange 34 to
tear open tear
back portion 18. For this reason, beads 62 of a first predetermined length are
formed in the
skirt 17 at least on both sides of tear-back portion 18 to retain the lid 10
on the rim 14 of the
cup 12 as a force trying to remove the lid 10 will be exerted on that area of
the lid 10 when
tear-back portion 18 is opened. Furthermore, two spaced-apart beads 64 of a
second
predetermined length, shorter than the beads 62 of the first predetermined
length, are formed
in the skirt 17 connected to tear-back portion 18. The beads 64 assist in
retaining the tear-
back portion 18 of the lid 10 on the rim 14 of the cup 12, especially when
closing tear-back
portion 18 after it has already been opened.
[0043] Fig. 6 shows a cross-sectional view of a die element 70 which may be
used to form
the interrupted beads 62 and 64 of the lid illustrated in Fig. 1. This die 70
is used along with
otherwise conventional thermoforming equipment in a lid thermoforming process
such as is
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conventionally performed to create the remaining features molded into the
plastic disposable
cup lids 10. Further, the die 70 may be readily added to the present
thermoforming cup dies
for the formation of disposable cup lids. The die 70 includes an outer
circumferential
projection 72 which is used to form the mounting portion 16 and skirt 17 of
the lid 10. Fig. 7
shows an enlarged view of area A on the circumferential projection 72 of Fig.
7. The
projection 72 includes a plurality of indentations 74 which are used to form
interrupted beads
62 and 64, wherein vacuum passageways 76 are formed in the die 70 extending
from
indentations 74 to a suction device (not shown) to draw the thermo-deformable
material in
the indentations 74.
[0044] Fig. 8 shows a die element 80 which may be used to form the remaining
portions of
the lid configuration of the present invention, wherein die element 80 may be
used in
conjunction with die element 70 to form lid 10. The die 80 includes recess 82
designed to
form straw slot depression 40, wherein a groove 84 is formed at the bottom of
recess 82 to
form frangible portion 46. A vacuum passageway, similar to that of vacuum
passageway 76,
is formed at the nadir of groove 84 to draw the thermo-deformable material
into recess 82.
The die 80 also includes recesses 86 and 88 to form trough 32 and recess 60 in
the lid 10,
respectively: Additionally, die 80 includes an aperture 90 for receiving an
alignment
projection 78 from die 70 in order to ensure the interrupted beads 62 and 64
are formed in the
proper locations with respect to the remaining features of the lid formed by
die 80.
[0045] As can be seen from the foregoing, a cup lid formed in accordance with
the present
invention provides a simpler structure to manufacture due the straw slot
depression 40
serving dual functions of providing a straw slot opening as well as retaining
the tear-back
portion 18 of the lid in an open position. Therefore, only one depression
needs to be formed
in the cup lid to accomplish both functions. Furthermore, forming a cup lid in
accordance
with the present invention provides a straw slot and tear-open flap which can
be molded at
substantially the same time as the remaining features of the 1'id without the
need for precise
tooling to perform scoring in the lid.
[0046] With reference now to Figs. 12-18 an alternative and preferred
embodiment of the
present invention will be discussed in detail hereinbelow.
[0047] Similar to the previous embodiment, the lid 100 maybe used with lids of
various types
and is particularly suitable for use with disposable cups of the type commonly
used as carry
out containers for beverages such as coffee and the like. Additionally, it
should be noted that
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the lid may take on various sizes so as to accommodate brims of varying
diameters. Like the
previous embodiment, the lid 100 provides a cover for cups which inhibits
spillage and
reduces heat transfer between the beverage and the surrounding atmosphere. The
lid 100 is
secured in place on the cup by an annular mounting portion 116 which engages
the rim of a
cup. The annular mounting portion 116 includes a downwardly extending skirt
117 which
forms the outer peripheral circumference of the lid 100. A portion 118 of the
lid 100 may be
torn back to provide an opening in the lid 100 to enable drinking from a cup
without
removing the lid 100. The lid also includes a straw slot 122 which functions
as a means for
facilitating the insertion of a drinking straw into the cup for withdrawing
liquid by suction.
[0048] A central raised portion 124 is formed by a substantial portion of a
medial area within
the circumference of the lid 100 with an upstanding annular wall 126 forming
the side
surfaces of the central raised portion 124. Bridging the space between the
mounting portion
116 and the upstanding annular wall 126 is an annular channel 128 which
readily receives
any fluid which may overflow out of the opening when the container is jarred
or which may
be spilled during consumption of the contents of the container. In accordance
with the
embodiment of the invention set forth in Figs. 12-18, the tear-back portion
118 of the lid 110
and the straw slot opening 122 are formed in a medial portion of the lid which
is not raised
wherein the non raised medial portion is surrounded on three sides by the
central raised
portion 124. The straw slot opening 122 is formed radially inward of the tear-
back portion
118 with the tear-back portion 118 including a protrusion 130 which extends
from an upper
surface of the lid 100. The tear-back portion 118 of the lid extends from the
annular
mounting portion 116 to a trough 132. The trough 132 serves as a pivotal hinge
axis for the
tear-back portion 118, so that, as the tear-back portion 118 is torn away from
the remaining
portion of the lid 100, the tear-back portion 1 l8 will rotate away from the
annular mounting
portion 116 while pivoting about trough 132.
[0049] A flange 134 extends from the edge of the skirt 117 away from the
annular mounting
portion 116 to provide a gripping surface for a consumer to grasp and pull in
order to tear
open the tear-back portion 118. In order to facilitate this tearing, a pair of
cut outs 136 may
be formed in the skirt 117 adjacent to the flange 134 to provide a starting
point for tearing
opening the tear-back portion 118. The annular mounting portion may also
include a
plurality of corrugations 136 formed on both sides of the protrusion 130 as
illustrated in Fig.
l3 to direct the tear-back portion 118 in a predetermined manner to prevent
accidental and
random tear directions which do not terminate at the trough 132. The
corrugations 136
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preclude random tearing in that the structure is extremely rigid across the
corrugated section
which includes a line-of weakness 138 at which the corrugations 136 stop.
Therefore, a
sharp and accurate tear line is provided along the edge of the corrugations
136 without the
need of a score line as noted hereinabove.
[0050] The straw slot opening 122 is formed in a depression 140 within the lid
100, wherein
the depression 140 facilitates the receipt of the end of the straw within the
straw slot 122 as
the opening to the depression 140 in the top surface of the lid is larger than
the diameter of a
straw. The depression 140 includes a pair of sloping side walls 142 and 144
which extend
from a top surface of the lid 100 toward a frangible junction 146 at the
bottom of the
depression 140. As can be seen from Fig. 14, the depression 140 takes on a
somewhat funnel
like shape with the side wall 142 being sloped and angled much greater than
that of the side
wall 144.
[0051] The thickness of the lid material at the frangible portion 146 is
thinner than the lid
material of the other portions of the lid 100 so as to allow the frangible
portion 146 to be
ruptured by the force exerted by the end of a straw as it is inserted into the
straw slot opening
122. This feature is discussed in greater detail hereinbelow.
[0052] The angle of inclination of the side wall 142 is in the range of
30° to 60° and
preferably in the range of 45° to SO°. More preferably, in
accordance with a preferred
embodiment of the present invention, the angle of inclination of the side wall
142 is 47°.
Additionally, the angle of inclination of the side wall 144 is in the range of
0° to 10° and
preferably in the range of 2° to 5°. In accordance with a
preferred embodiment of the present
invention, the angle of inclination of the side wall 144 would be 4°.
The particular angles of
inclination are configured so that the straw when inserted into the straw slot
opening 122
exerts a significant outward force to the side walls 142 and 144 so as to
readily rupture the
thinned frangible portion 146 of the depression 140. With reference to Fig. 15
it is noted that
the depression 140 also includes end walls 148 and 150 which extend from a
surface of the
lid 100 to the frangible portion 146. As can be particularly noted from Fig.
15, each of the
end walls 148 and 150 are inclined with respect to the surface of the lid 100.
Such inclination
is in a range of 0° to 10° and preferably within a range of
2° to 5° with the preferred
embodiment being inclined at 4°. This aids in exerting a force against
and frictionally
engaging the surfaces 152 and 154 of the protrusion 130. While specific angles
of inclination
are set forth hereinabove, various may be used to achieve similar results;
however, those set
forth hereinabove have been determined to be optimal.
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[0053] With reference now to Figs. 16-18, as a straw 170 is inserted into the
straw slot 122,
the tapered shape of the depression 140 causes the cylindrical shape end of
the straw 170 to
flatten until the end of the straw forms into a funnel-like or off set V
shaped cross section
taking on the shape of the depression 140 as illustrated in Fig. 17. In doing
so, the end of the
straw 170 is deformed into a point as it progresses into the depression 140
which acts to assist
in piercing the frangible portion 146 in addition to the force applied by the
straw pushing the
side walls 142 and 144 away from one another.
[0054] As noted hereinabove, adjacent each of the side walls 142 and 146 are
end walls 148
and 150 which extend between the edges of the side walls 142 and 146. These
end walls
prevent against extended fracture or cracking or tearing of the frangible
portion 146 which
may be caused by the insertion of the drinking straw into the straw slot
opening 122. As can
be seen from Fig. 18, once the straw has broken the frangible portion 146, the
straw returns to
its substantially cylindrical shape and extends through the straw slot opening
122. Unlike the
previous embodiment wherein substantially equal forces are directed against
both the side
walls 142 and 144, in accordance with the preferred embodiment of the present
invention, a
greater force is exerted against the side wall 142 as compared to that of the
side wall 144
which aids significantly in the rupturing of the frangible portion 146. It has
been found that
the breaking of the frangible portion 146 is eased in accordance with the
configuration
illustrated in this embodiment. Further, similar to the previous embodiment,
due to the off
set V shaped configuration of the depression 140, a counter force greater than
that of the
previous embodiment is exerted on the side wall 142. However, as with the
previous
embodiment if the force used to insert the straw is excessive, the end walls
148 and 150
provide a structure which redirects and absorbs the tearing force to prevent
extended tears
across the lid 100. The momentary excessive force will be absorbed by the end
walls 148 and
150 such that the radial propagation of the tear will reach the end walls 148
and 150 which
causes the radial force to be redirected upwardly which prevents continued
tearing of the
frangible structure 146.
[0055] As noted hereinabove, once the frangible portion 146 is broken by the
end of the
straw 170, the side walls 142 and 144 of the depression 140 are separated from
one another to
allow the straw to travel into the cup for access to the contents therein. As
the straw passes
between the side walls 142 and 144, the side walls bend around the straw and
conform to the
shape of the straw. In doing so, the side walls 142 and 144 provide a close
engagement
around the inserted straw which acts to seal the cup lid 100 around the straw
to prevent the
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contents of a cup from spilling out of the straw slot opening 122 between the
straw 170 and
the side walls 142 and 144.
[0056] With respect to the protrusion 130, this protrusion is substantially
identical to that set
forth in the previous embodiment. That is, the protrusion 130 is shaped such
that when the
tear back portion 118 of the lid 100 is opened and pivoted about trough 132,
the protrusion
130 is received within the depression 140 to retain the protrusion in an open
position similar
to that shown in Fig. 2. The width of the protrusion 130 is slightly larger
than the width of
the depression 140 resulting in the end walls 148 and 150 frictionally
engaging the end
surfaces 152 and 154 of the protrusion 130 to hold the protrusion within the
depression 140.
As noted hereinabove, the end walls 148 and 150 are slightly inclined so as to
aid in the
frictional engagement with the end surfaces 152 and 154 of the protrusion 130.
In order to
readily receive the protrusion 130 within a depression 140, the protrusion 130
includes
sloping end surfaces 156 and 158 similar to that of the previous embodiment.
In doing so,
the protrusion will not engage the sloping side walls 142 and 144 of the
depression 140 when
inserted therein which could otherwise cause inadvertent rupturing of the
frangible portion
146. Therefore, the straw slot opening 122 remains unaffected and the
frangible portion 146
remains in tact when the straw slot depression 140 is used to retain the tear-
back portion 118
of the lid 100 in an open position.
[0057] Additionally, as with the previous embodiment, the lid 100 includes a
recess 160
formed in the lid configuration radially inwardly of the depression 140 for
receiving a
mounting portion 116 of the lid 100 when the tear-back portion 118 is retained
in its opening
position. The lid configuration is further designed such that a plurality of
lids 100 maybe
positioned together in a stacked relationship similar to that illustrated in
Fig. 5 of the previous
embodiment. Also, as with the previous embodiment, the lid 100 may include
beads 162 and
164 formed about the periphery of the skirt 117 in order to assist in
retaining the lid 100 on a
rim of a container. The beads 162 and 164 function substantially identically
to the beads 62
and 64 referred to in the previous embodiment.
[0058] While the present invention has been described with reference to a
preferred
embodiment, it should be appreciated by those skilled in the art that the
invention may be
practiced otherwise than as specifically described herein without departing
from the spirit and
scope of the invention. It is, therefore, to be understood that the spirit and
scope of the
invention be limited only by the appended claims.
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