Title: Cup lid having combined straw slot depression and tear back lid retainer
Abstract: 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 tear-back section extending from the annular skirt to a hinge portion located in a medial portion of the lid. The tear-back section includes a raised protrusion extending outwardly from an upper surface of the lid. A recess is further formed in a medial portion of the lid on the opposite side of the hinge portion from the raised protrusion, wherein the tear-back section 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 frictionally engaged by the 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 different angles to form a frangible juncture in the deepest portion of the recess.
Patent Number: 6,948,633 Issued on 09/27/2005 to Freek, et al.
| Inventors:
|
Freek; Michael (Bradford, CA);
Thomas; Michael (Toronto, CA)
|
| Assignee:
|
Fort James Corporation (Atlanta, GA)
|
| Appl. No.:
|
341604 |
| Filed:
|
January 14, 2003 |
| Current U.S. Class: |
220/711; 220/254.1; 220/254.3; 220/712; 220/831 |
| Intern'l Class: |
A47G 019/22 |
| Field of Search: |
220/711-713,831,254.1,254.3,254.7
229/404,606.1
|
References Cited [Referenced By]
U.S. Patent Documents
| 2304214 | Dec., 1942 | Straub.
| |
| 3048317 | Aug., 1962 | Cochrane et al.
| |
| 3171580 | Mar., 1965 | Davis et al.
| |
| 3524566 | Aug., 1970 | Kenneth.
| |
| 3822030 | Jul., 1974 | Tanzer.
| |
| 3945528 | Mar., 1976 | Mowrey, Jr.
| |
| 3994411 | Nov., 1976 | Elfelt et al.
| |
| 4026459 | May., 1977 | Blanchard.
| |
| 4056210 | Nov., 1977 | Boyle.
| |
| 4090660 | May., 1978 | Schram et al.
| |
| 4184604 | Jan., 1980 | Amberg et al.
| |
| 4202459 | May., 1980 | DeParales et al.
| |
| 4253582 | Mar., 1981 | Shields.
| |
| 4438865 | Mar., 1984 | Scattaregia.
| |
| 4460103 | Jul., 1984 | Rama et al.
| |
| 4502608 | Mar., 1985 | Mills.
| |
| 4619372 | Oct., 1986 | McFarland.
| |
| 4629088 | Dec., 1986 | Durgin.
| |
| 4721210 | Jan., 1988 | Lawrence et al.
| |
| 4738373 | Apr., 1988 | DeParales.
| |
| 4753365 | Jun., 1988 | Seppala.
| |
| 4760934 | Aug., 1988 | Netsch.
| |
| 5025947 | Jun., 1991 | Leone.
| |
| 5090584 | Feb., 1992 | Roberts et al.
| |
| 5111961 | May., 1992 | Van Melle.
| |
| 5183172 | Feb., 1993 | Boller.
| |
| 5197624 | Mar., 1993 | Dodaro.
| |
| 5335812 | Aug., 1994 | Boller.
| |
| 5392949 | Feb., 1995 | McKenna.
| |
| 5397023 | Mar., 1995 | Toczek et al.
| |
| 5460286 | Oct., 1995 | Rush et al.
| |
| 5490609 | Feb., 1996 | Lane et al.
| |
| 5503289 | Apr., 1996 | Fox.
| |
| 5613619 | Mar., 1997 | Van Melle.
| |
| 5839601 | Nov., 1998 | Van Melle.
| |
| 5947323 | Sep., 1999 | Freek et al.
| |
| 6505753 | Jan., 2003 | Freek et al.
| |
Primary Examiner: Hylton; Robin A
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a Continuation-in-Part of application Ser. No. 09/281,267
filed Mar. 30, 1999, now U.S. Pat. No. 6,505,753; which itself is a Division of
Ser. No. 08/703,771 filed Aug. 27, 1996, now U.S. Pat. No. 5,947,323.
Claims
1. A disposable lid for a drinking cup comprising:
an annular mounting portion for sealingly engaging the drinking cup, said annular
mounting portion including a downwardly extending annular skirt;
a tear-back section of the lid extending from said annular skirt to a hinge portion
located in a medial portion of the lid;
a raised protrusion extending outwardly from an upper surface of the lid; said
protrusion being positioned on said tear-back section of the lid between said hinge
portion and said annular mounting portion;
a recess formed in a medial portion of the lid on the opposite side of said hinge
portion from said raised protrusion for receiving said raised protrusion, said
recess including at least two end walls and at least two sidewalls, said sidewalls
extending from the upper surface of the lid and conversing together forming an
apex adjacent the deepest point in said recess;
wherein said at least two side walls extend towards said apex at different angles
with respect to a vertical plane of said recess including said apex.
2. The lid as defined in claim 1, wherein said apex includes a frangible force
concentration region rupturable by a force applied to said recess.
3. The lid as defined in claim 2, wherein said side walls separate from one another
to form an opening in the lid as said frangible portion is ruptured, said side
walls further bending to conform to the shape of an object inserted into said opening.
4. The lid as defined in claim 2, wherein said protrusion frictionally engages
said end walls of said recess and is spaced from said side walls of said recess
to retain said tear-back section of the lid in an open position.
5. The lid as defined in claim 1, wherein said protrusion and said recess have
substantially similar cross-sectional shapes.
6. The lid as defined in claim 1, further including a depression formed in a
medial portion of the lid located radially inward of said recess for receiving
a section of said annular mounting portion on said tear-back section of the lid
when said tear-back section of the lid is in an open position and said protrusion
is received by said recess.
7. The lid as defined in claim 1, wherein the lid is of a thermoplastic material.
8. The lid as defined in claim 1, further including a pull tab extending from
a portion of said annular skirt connected to said tear-back section of the lid,
said annular skirt containing scored cuts through said skirt on both sides of said
pull tab to facilitate the tearing back of said tear-back section of the lid from
the lid.
9. The lid as defined in claim 1, further including a plurality of corrugations
formed in the lid on both sides of said raised protrusion to direct the tearing
of said tear-back section of the lid.
10. The lid as defined in claim 1, wherein the side wall of said recess closest
in proximity to said protrusion slopes at an angle in the range of 30° to
60° with respect to said vertical plane.
11. The lid as defined in claim 1, wherein the side wall of said recess closest
in proximity to said protrusion slopes at an angle in the range of 45° to
50° with respect to said vertical plane.
12. The lid as defined in claim 1, wherein the side wall of said recess closest
in proximity to said protrusion slopes at an angle of 47° with respect to
said vertical plane.
13. The lid as defined in claim 1, wherein the side wall of said recess furthest
from said protrusion slopes at an angle in the range of 0° to 10° with
respect to said vertical plane.
14. The lid as defined in claim 1, wherein the side wall of said recess furthest
from said protrusion slopes at an angle in the range of 2° to 5° with
respect to said vertical plane.
15. The lid as defined in claim 1, wherein the side wall of said recess furthest
from said protrusion slopes at an angle of 4° with respect to said vertical plane.
16. The lid as defined in claim 1, wherein the end walls of said recess slope
toward one another in a direction from said medial portion of the lid to said apex.
17. The lid as defined in claim 16, wherein said end walls slope toward one another
at an angle in the range of 0° to 10° with respect to a second vertical
plane perpendicular to said vertical plane.
18. The lid as defined in claim 16, wherein said end walls slope toward one another
at an angle in the range of 2° to 5° with respect to a second vertical
plane perpendicular to said vertical plane.
19. The lid as defined in claim 16, wherein said end walls slope toward one another
at an angle of 4° with respect to a second vertical plane perpendicular to
said vertical plane.
Description
TECHNICAL FIELD OF THE INVENTION
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
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. Pat. 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.
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. Pat. No. 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 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.
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.
Pat. 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.
Another example of a prior art drinking lid utilizing both a straw slot and
a releasable flap is disclosed in U.S. Pat. No. 5,335,812 issued to Boller, 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 lid.
Yet another type of prior art drinking lid utilizing both a straw slot and a
releasable flap is disclosed in U.S. Pat. No. 3,994,411 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.
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
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.
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.
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.
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.
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.
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.
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 protrusion,
wherein the pivotal flap may be tom 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.
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.
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
FIG. 1 is a perspective view of a lid in accordance with the present invention.
FIG. 2 is a perspective view of the lid illustrated in FIG. 1 with an opening
formed by tearing back a portion of the lid.
FIG. 3 is a top plan view of the lid illustrated in FIG. 1.
FIG. 4 is a cross-sectional side view of the lid of FIG. 1 taken along line
IV—IV of FIG. 3.
FIG. 5 is a cross-sectional side view of the lid of FIG. 4 in a stacked relationship
with another lid.
FIG. 6 is a cross-sectional side view of the mold used to form beads in the
skirt of the lid of FIG. 1.
FIG. 7 is an enlarged, cross-sectional side view of the area A of the mold of
FIG. 6.
FIG. 8 is a cross-sectional side view of the mold used to form the lid of FIG. 1.
FIGS. 9-11 illustrate a process of inserting a straw through the lid in accordance
with the present invention.
FIG. 12 is a perspective view of a lid in accordance with a preferred embodiment
of the present invention.
FIG. 13 is a top view of the lid illustrated in FIG. 12.
FIG. 14 is a cross sectional view taken along line XIV of FIG. 13.
FIG. 15 is a cross sectional view taken along line XV of FIG. 13.
FIGS. 16-18 illustrate a process of inserting a straw through the lid illustrated
in FIG. 12.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is generally embodied in a lid
10 for a drinking
cup
12. The lid
10 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.
Referring now to FIGS. 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
17 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 lid 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.
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
16 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 significant in size to accommodate more than just
a few droplets of fluid.
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.
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
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.
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
50
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
50 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.
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 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.
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.
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 frictionally 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.
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.
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.
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.
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 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.
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.
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 lid without the need for precise tooling to perform
scoring in the lid.
With reference now to FIGS. 12-18 an alternative and preferred embodiment of
the present invention will be discussed in detail hereinbelow.
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 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.
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
118
will rotate away from the annular mounting portion
116 while pivoting about
trough
132.
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. 13 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 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.
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.
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.
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 50°. 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.
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.
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.
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 contents of a cup from spilling out of the straw
slot opening
122 between the straw
170 and the side walls
142
and
144.
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.
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.
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.
*
