U.S. patent application number 10/234441 was filed with the patent office on 2003-04-17 for closure for a container.
This patent application is currently assigned to Gateway plastics incorporated. Invention is credited to Vogel, William C..
Application Number | 20030071041 10/234441 |
Document ID | / |
Family ID | 46203923 |
Filed Date | 2003-04-17 |
United States Patent
Application |
20030071041 |
Kind Code |
A1 |
Vogel, William C. |
April 17, 2003 |
Closure for a container
Abstract
A plastic cap has one or more hinged flaps that cover openings
in the cap, as well as a stepped sealing ring against which the top
of a plastic bottle seals. The sealing ring is stepped, much like
the rows of seats in a circular stadium. This stepped arrangement
permits the cap to be used with many different bottle rim diameters
and automatically corrects any ovality of the bottle rim by forcing
it to flex into a more circular shape as it engages the steps of
the stepped ring.
Inventors: |
Vogel, William C.;
(Milwaukee, WI) |
Correspondence
Address: |
FOLEY & LARDNER
777 EAST WISCONSIN AVENUE
MILWAUKEE
WI
53202
US
|
Assignee: |
Gateway plastics
incorporated
|
Family ID: |
46203923 |
Appl. No.: |
10/234441 |
Filed: |
September 3, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10234441 |
Sep 3, 2002 |
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09663874 |
Sep 15, 2000 |
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6460718 |
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09663874 |
Sep 15, 2000 |
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09374976 |
Aug 16, 1999 |
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6250517 |
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09374976 |
Aug 16, 1999 |
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08959399 |
Oct 28, 1997 |
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5971231 |
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Current U.S.
Class: |
220/254.2 ;
220/254.3; 220/287 |
Current CPC
Class: |
Y10S 215/01 20130101;
B65D 21/0219 20130101; B65D 2251/1041 20130101; B65D 47/0847
20130101 |
Class at
Publication: |
220/254.2 ;
220/254.3; 220/287 |
International
Class: |
B65D 047/08 |
Claims
I claim:
1. A circular plastic cap having a longitudinal axis, the cap
comprising: a. an end cover; b. at least one flap integrally formed
with the end cover; c. a cylindrical skirt integrally coupled to
the end cover at one end and having a second open end configured to
receive the mouth of a receptacle; and d. a circular sealing ring
disposed inside the skirt and adjacent to the end cover, the
sealing ring having a plurality of planar sealing surfaces, axially
spaced apart, such that each sealing surface has a greater diameter
the closer that sealing ring is to the open end of the skirt.
2. The cap of claim 1, wherein each sealing surface has an axial
width substantially equal to or less than an average thickness of
the cap.
3. The cap of claim 2, wherein the sealing ring includes a
plurality of substantially right cylindrical surfaces coaxial with
the cap disposed between adjacent sealing surfaces.
4. The cap of claim 3, wherein each right cylindrical surface has a
greater diameter the preceding right cylindrical surface as one
approaches the open end of the skirt.
5. The cap of claim 4, wherein the sealing ring is fixed to the end
cover.
6. The cap of claim 5, wherein the sealing ring is not fixed to the
skirt.
7. A container comprising: a. a receptacle including a right
cylindrical sidewall having an externally threaded upper end and a
lower end, a bottom integrally formed with the sidewall and
enclosing the lower end of the sidewall, wherein the upper end of
the receptacle defines a mouth having a mouth sealing surface; and
b. a circular plastic cap having a longitudinal axis, wherein the
cap further comprises, i. an end cover; ii. at least one flap
integrally formed with the end cover; iii. a cylindrical skirt
integrally coupled to the end cover at one end and having a second
open end configured to receive the mouth of a receptacle, and iv. a
circular sealing ring disposed inside the skirt and adjacent to the
end cover, the sealing ring having a plurality of planar sealing
surfaces, axially spaced apart, such that each sealing surface has
a greater diameter the closer that sealing ring is to the open end
of the skirt, wherein one of the plurality of sealing surfaces is
engaged with the mouth sealing surface and at least one of the
plurality of sealing surfaces is not engaged with the mouth sealing
surface.
8. The container of claim 7, wherein the end cover and the at least
one flap are configured to provide the cap with a substantially
flat planar end surface.
9. The container of claim 8, wherein the at least one flap is
recessed into and flush with the end cover.
10. The container of claim 9, wherein the cap further comprises: a.
at least a second flap, wherein the second flap is integrally
formed with the end cover.
11. The container of claim 10, wherein the second flap is recessed
into and flush with the end cover.
12. The cap of claim 11, wherein each sealing surface has an axial
width substantially equal to or less than an average thickness of
the cap.
13. The cap of claim 12, wherein the sealing ring includes a
plurality of substantially right cylindrical surfaces coaxial with
the cap disposed between adjacent sealing surfaces.
14. The cap of claim 13, wherein each right cylindrical surface has
a greater diameter the preceding right cylindrical surface as one
approaches the open end of the skirt.
15. The cap of claim 14, wherein the sealing ring is fixed to the
end cover.
16. The cap of claim 15, wherein the sealing ring is not fixed to
the skirt.
17. A method of attaching an sealing a cap to a bottle, wherein the
cap comprises an end cover; a cylindrical skirt integrally coupled
to the end cover at one end and having a second open end configured
to receive the mouth of a receptacle, and a circular sealing ring
disposed inside the skirt and adjacent to the end cover, the
sealing ring having a plurality of planar sealing surfaces, axially
spaced apart, such that each sealing surface has a greater diameter
the closer that sealing ring is to the open end of the skirt, and
wherein the bottle comprises a right cylindrical sidewall having an
externally threaded upper end and a lower end, a bottom integrally
formed with the sidewall and enclosing the lower end of the
sidewall, wherein the upper end of the receptacle defines a mouth
having a mouth sealing surface, the method comprising: a. gripping
the bottle in an automatic capping machine; b. gripping the cap in
an automatic capping machine; c. rotating the cap clockwise with
respect to the bottle while advancing the cap toward the bottle; d.
engaging the external threads on the bottle to the internal threads
on the cap; e. rotating the cap until the mouth sealing surface
engages a first of the plurality of sealing surfaces; f. further
rotating the cap until the mouth sealing surface engages a second
of the plurality of sealing surfaces, wherein the second of the
plurality of sealing surfaces has a smaller diameter than the first
of the plurality of sealing surfaces; and g. sealing the container
against the second of the plurality of sealing surfaces.
18. The method of claim 17, wherein the step of further rotating
the cap includes the step of guiding at least a portion of the
mouth sealing surface inwardly toward the axis of the cap.
19. The method of claim 18, wherein the step of further rotating
the cap includes the step of deforming the mouth sealing surface
into a more circular shape.
Description
FIELD OF THE INVENTION
[0001] This invention generally relates to hand-held plastic
containers for storing and dispensing particulate matter. More
particularly, it relates to such containers with a cover having a
plurality of flaps for enclosing, respectively, a plurality of
openings in the cover. More particularly, it relates to containers
for foodstuffs having a shaker opening with a plurality of holes
and/or a spooning opening with a large opening adapted to receive a
common household spoon.
BACKGROUND OF THE INVENTION
[0002] Plastic caps and receptacles for the disposable container
industry suffer from certain incompatibilities. Generally speaking,
they are considered interchangeable, since they have standard
threads and standard major diameters. For this reason, one can
expect a nominal "63 mm" cap to handily screw onto a "63 mm"
receptacle. Beyond this, however, one cannot be assured of
compatibility. Commercial receptacles or bottles typically have
recessed shoulders adjacent to their open threaded ends to receive
the threaded skirt of the cap. The goal is to screw a cap with an
outer circular diameter onto a bottle with the same unrecessed
outer diameter, thereby providing a cylindrical container with a
constant outer diameter over its entire height. As a result, when
one screws a random cap onto a random bottle, the skirt of the cap
may interfere with the unrecessed portion of the bottle before the
cap is screwed down. This will prevent the cap from being screwed
completely down, thereby preventing the sealing surfaces of the cap
from completely engaging the sealing surfaces of the bottle.
[0003] In addition to this incompatibility, the diameter and width
of the sealing surfaces of the bottle and cap are often different,
even when they have the same nominal thread pitch and major
diameter. If a manufacturer wishes to make a cap (or bottle) that
can be used with the greatest range of bottles (or caps) by other
manufacturers, he is compelled to make as wide a sealing surface as
possible. Unfortunately, this requires additional plastic.
[0004] There is another problem when manufacturing caps with wide
sealing flanges: the propensity of the bottle top to buckle when
screwed down too tightly. A wide flange permits force to be applied
evenly to the top of bottles with warped sealing surfaces. These
bottles have sealing surfaces at their mouths that are not truly
circular, but are oval. By screwing a cap down firmly onto the
bottle, such as with an automatic capping machine, the oval top
begins to buckle, with some portions of the bottle bending inward,
and some portions of the bottle bending outward. U.S. Pat. No.
4,693,399, which issued to Hickman (Sep. 15, 1987) purported to
solve the ovality problem by providing the cap with a wide, flat
sealing surface that was wide enough to accommodate a warped,
oval-topped bottle. By providing a wide, flat surface against which
the bottle could seal, the top of the bottle could be quite oval,
yet there would still be sufficiently wide, flat surface against
which it could seal. Unfortunately, this arrangement merely
accommodated the out-of-roundness of a warped bottle. The tops of
the bottles remained warped. This was an effective solution for
hand-tightened caps, but was of quite limited value for
machine-attached and tightened caps. Machines for attaching caps to
bottles operate at high speeds. It is quite difficult to adjust
them to provide a constant tightening torque. As a result the
torque applied to seal a cap on bottle will vary significantly in a
single production run. Given this wide range of tightening torques,
the wide flange of the '399 patent can actual cause bottles to
buckle during capping.
[0005] As the cap is tightened, the oval rim of the bottle slides
against the wide, flat sealing flange, reducing friction between
the rim and the wide sealing flange, making it easier to move
axially inward or outward, toward or away from the central axis of
the bottle. As a result of this reduced friction, the oval rim of
the bottle tends to increase in ovality as the bottle is
over-tightened until it either disengages from the threads or the
bottle collapses.
[0006] What is needed is an improved cap that can accommodate a
wide range of bottle mouth diameters. What is also needed is a cap
that can correct (and not accommodate) bottles with warped oval
mouths and sealing surfaces. It is an object of this invention to
provide such a cap.
SUMMARY OF THE INVENTION
[0007] In accordance with a first embodiment of the invention, a
circular plastic cap having a longitudinal axis is disclosed, the
cap including an end cover, at least one flap integrally formed
with the end cover, a cylindrical skirt integrally coupled to the
end cover at one end and having a second open end configured to
receive the mouth of a receptacle, and a circular sealing ring
disposed inside the skirt and adjacent to the end cover, the
sealing ring having a plurality of planar sealing surfaces, axially
spaced apart, such that each sealing surface has a greater diameter
the closer that sealing ring is to the open end of the skirt. Each
sealing surface may have an axial width substantially equal to or
less than an average thickness of the cap. The sealing ring may
include a plurality of substantially right cylindrical surfaces
coaxial with the cap disposed between adjacent sealing
surfaces.
[0008] Each right cylindrical surface may have a greater diameter
the preceding right cylindrical surface as one approaches the open
end of the skirt. The sealing ring may be fixed to the end cover.
The sealing ring may or may not be fixed to the skirt.
[0009] In accordance with a second embodiment of the invention, a
container is disclosed, the container including a receptacle
including a right cylindrical sidewall having an externally
threaded upper end and a lower end, a bottom integrally formed with
the sidewall and enclosing the lower end of the sidewall, wherein
the upper end of the receptacle defines a mouth having a mouth
sealing surface, and a circular plastic cap having a longitudinal
axis, wherein the cap further comprises an end cover, at least one
flap integrally formed with the end cover, a cylindrical skirt
integrally coupled to the end cover at one end and having a second
open end configured to receive the mouth of a receptacle, and a
circular sealing ring disposed inside the skirt and adjacent to the
end cover, the sealing ring having a plurality of planar sealing
surfaces, axially spaced apart, such that each sealing surface has
a greater diameter the closer that sealing ring is to the open end
of the skirt, wherein one of the plurality of sealing surfaces is
engaged with the mouth sealing surface and at least one of the
plurality of sealing surfaces is not engaged with the mouth sealing
surface. The end cover and the at least one flap may be configured
to provide the cap with a substantially flat planar end surface.
The at least one flap may be recessed into and flush with the end
cover. The cap may further comprise a second flap, wherein the
second flap is integrally formed with the end cover. The second
flap may be recessed into and flush with the end cover. Each
sealing surface may have an axial width substantially equal to or
less than an average thickness of the cap. The sealing ring may
include a plurality of substantially right cylindrical surfaces
coaxial with the cap disposed between adjacent sealing surfaces.
Each right cylindrical surface may have a greater diameter than a
preceding right cylindrical surface as one approaches the open end
of the skirt. The sealing ring may be fixed to the end cover. The
sealing ring may not be fixed to the skirt.
[0010] In accordance with a third embodiment of the invention, a
method of attaching an sealing a cap to a bottle is disclosed,
wherein the cap comprises an end cover; a cylindrical skirt
integrally coupled to the end cover at one end and having a second
open end configured to receive the mouth of a receptacle, and a
circular sealing ring disposed inside the skirt and adjacent to the
end cover, the sealing ring having a plurality of planar sealing
surfaces, axially spaced apart, such that each sealing surface has
a greater diameter the closer that sealing ring is to the open end
of the skirt, and wherein the bottle comprises a right cylindrical
sidewall having an externally threaded upper end and a lower end, a
bottom integrally formed with the sidewall and enclosing the lower
end of the sidewall, wherein the upper end of the receptacle
defines a mouth having a mouth sealing surface, wherein the method
includes gripping the bottle in an automatic capping machine,
gripping the cap in an automatic capping machine, rotating the cap
clockwise with respect to the bottle while advancing the cap toward
the bottle, engaging the external threads on the bottle to the
internal threads on the cap, rotating the cap until the mouth
sealing surface engages a first of the plurality of sealing
surfaces, further rotating the cap until the mouth sealing surface
engages a second of the plurality of sealing surfaces, wherein the
second of the plurality of sealing surfaces has a smaller diameter
than the first of the plurality of sealing surfaces, and sealing
the container against the second of the plurality of sealing
surfaces. The step of further rotating the cap may include the step
of guiding at least a portion of the mouth sealing surface inwardly
toward the axis of the cap. The step of further rotating the cap
may include the step of deforming the mouth sealing surface into a
more circular shape.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a cross-sectional side view of a container
including a cover and receptacle in accordance with the current
invention showing the flaps in an open position and as dashed lines
in a closed position;
[0012] FIG. 2 is an orthogonal view of the cover of FIG. 1, showing
the flaps in an open position;
[0013] FIG. 3 is a cross-sectional view of the container of FIG. 1
showing the angled orientation of the flap skirts;
[0014] FIG. 4 is a top view of the cover of FIG. 1 with the flaps
in an open position;
[0015] FIG. 5 is a bottom view of the cover showing the circular
sealing surfaces;
[0016] FIG. 6 is a partial plan view of the sealing ring of the cap
(not to scale) showing each of the sealing surfaces enlarged in
exaggerated form together with the rim of the receptacle, wherein
the rim of the receptacle is oval and the rim has just contacted
the sealing ring during tightening;
[0017] FIG. 7 is a partial cross-sectional side view of the sealing
ring and receptacle rim of FIG. 6 in cross-section wherein the
cutting plane for the cross section is coplanar with the
longitudinal axis of the receptacle and sealing ring;
[0018] FIG. 8 is a partial plan view of the sealing ring of the cap
(not to scale) showing each of the sealing surfaces enlarged in
exaggerated form together with the rim of the receptacle as in
FIGS. 6 and 7, but after the cap has been tightened and the rim has
been drawn down into the sealing ring and the ovality of the rim
corrected;
[0019] FIG. 9 is a partial cross-sectional side view of the sealing
ring and receptacle rim of FIG. 8 wherein the cutting plane of the
cross-section is coplanar with the longitudinal axis of the sealing
ring and the receptacle; and+
[0020] FIGS. 10-12 are fragmentary cross sections of the cover and
receptacle along a section line that is planar with the major
elliptical axis of the warped receptacle shown in FIGS. 6-9 as the
cap is tightened on the receptacle.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Before explaining at least one embodiment of the invention
in detail it is to be understood that the invention is not limited
in its application to the details of construction in the
arrangement of the components set forth in the following
description or illustrated in the drawings. The invention is
capable of other embodiments or of being practiced or carried out
in various ways. Also, it is to be understood that the phraseology
and terminology employed herein is for the purpose of description
and should not be regarded as limiting.
[0022] FIG. 1 illustrates a container 10 having a receptacle 12 and
a cap or cover 14. Cover 14 includes a shaker flap 16, called a
shaker flap because it covers (when closed) shaker openings 18
disposed in planar top portion 20 of the cover. Cover 14 also
includes a spooning flap 22 that similarly covers a larger spooning
opening 24 also disposed in top portion 20.
[0023] The cover as best seen in FIG. 2, is in the form of a
substantially cylindrical portion 26, and top portion 20 which is
coupled to an upper end of cylindrical portion 26 to enclose
cylindrical portion 26. Referring to FIG. 1, which shows a portion
of the cover in cross-section with the receptacle attached, threads
28 are provided on the inner surface of cylindrical portion 26 for
coupling cylindrical portion 26 to the outside of the top of
receptacle 12. As seen in FIG. 1, mating threads are disposed on an
outer indented top portion of receptacle 12 to engage threads 28.
Alternatively, cylindrical portion 26 may be equipped with an inner
detent or a raised ring to allow it to be snap connected to the top
portion of receptacle 12. Referring to FIG. 2, an elongate recess
19 is provided in which shaker flap 16 will fit when flap 16 is in
a closed position, to provide a substantially flat upper surface of
top portion 20 on which a similar container can be stacked.
[0024] Referring back to FIG. 1, receptacle 12 includes a
substantially planar bottom portion 30 that is adapted to engage a
lip 32 of cover 14. There is a significant advantage to this
feature: since the bottom portion 30 is adapted to engage lip 32,
then a plurality of containers identical to the one pictured in
FIGS. 1 and 2 can be stacked one atop the other, lip 32 serving
to-orient the bottom of the next higher container and so keep the
containers in proper alignment when stacked. In FIG. 1, two
identical containers are shown in this stacked arrangement, the
bottom of the upper container being shown as dashed line 34
engaging rim 32 when the flaps of the lower container are in a
closed position (shown in FIG. 1 as dashed lines when in their
closed positions). It can be seen that bottom portion 30 (and hence
identical bottom portion 34) and top portion 20 with lip 32 are
adapted to engage one another. Lip 32 is disposed at an outer edge
of cover 14 to engage a recess 36 at the junction of bottom 30 and
wall 38 of receptacle 12. By disposing both lip 32 and recess 36 to
engage each other near the outer periphery of the container, study
has shown that the containers are more easily stacked, and when
stacked tend to self-center. A portion of lip 32 is preferably
disposed on shaker flap 16, spooning flap 22 as well as on the
non-hinged sides of top portion 20 as can be best seen in FIG. 4.
Each of these portions is preferably disposed at an outer edge of
cover 14 and have substantially the same diameter. Other designs,
provide orienting means disposed more closely to the center of the
container, such as by providing an indentation at or near the
center of the receptacle bottom that engages with an upwardly
extending protrusion located near the center of the cover on which
it is stacked, are more difficult to stack accurately and also tend
to tip more easily. In addition, it is harder to hold tolerances on
an inner indentation than an outer indentation as shown in FIG. 1.
These designs have the added disadvantage of requiring an internal
recess to be formed in the center of the receptacle bottom,
requiring additional machining to manufacture.
[0025] Referring to FIGS. 1 and 2, a plurality of oval shaker
openings 18, preferably substantially circular as shown here, are
provided to allow foodstuffs within the container to be shaken out
when shaker flap 16 is opened. These openings are preferably
arranged not along a straight line, but along an arc. On the
underside of shaker flap 16 is an arcuate flange 40 adapted to
engage and seal central shaker opening 18. This flange extends for
about 30 degrees around the periphery of its mating opening 18 when
in a closed position. Flange 40 engages the inner surface of
opening 18 and holds the shaker flap closed.
[0026] FIG. 3 shows cover 14 in cross-section along a diametral
line of the cover. The cross section is perpendicular to both the
shaker flap hinge 50 and the spooning flap hinge 58. Flange 40 does
not extend perpendicularly from the underside of shaker flap 16,
but downward and outward at an angle of between 9 and 25 degrees,
and more preferably of between 5 and 20 degrees with respect to the
longitudinal axis of container 10. This angular relationship is
particularly beneficial in that it allows the cover, including the
flaps, to be readily and integrally molded as a single monolithic
piece. In addition, this angle allows flange 40 to releasably lock
into central opening 18 when shaker flap 16 is closed.
[0027] Shaker flap 16 also includes a skirt 46 that extends
downwardly from shaker flap 16. Skirt 46 is disposed an outer edge
of shaker flap 16. Skirt 46 is indented into the cap to provide,
together with the outer surface of cylindrical portion 26 a
substantially right circular cylindrical wall.
[0028] Skirt 46 has an indentation 48 disposed at a central outer
portion of skirt 46 and is configured to receive a finger or finger
nail of the user. This allows the user to grasp shaker flap 16 and
readily open container 10 by lifting upward on the indentation.
[0029] Skirt 46 preferably extends around cover 14 for an arcuate
length of between 60 and 120 degrees (see FIG. 4). From an outward
appearance, therefore, skirt 46 would appear to form between 60 and
120 degrees of the circumference of the upper part of cover 14.
This provides a significant advantage in the design of cover
14.
[0030] Since skirt 46 is arcuate, rather than straight, it is less
likely to be bent over when the cover is grasped and opened, and
further distributes the grasping load more evenly around the outer
edge of shaker flap 16. This allows shaker flap 16 to be made
thinner and therefore to require less plastic when
manufactured.
[0031] Referring to FIG. 3, when the shaker flap 16 is closed,
flange 40 engages an outer portion of shaker opening 18 to thereby
releasably lock shaker flap 16 to top portion 20 in a closed
position. While only a single flange 40 is shown in cross section
in FIG. 4, each of the other openings 18 may also have a flange
(not shown) to provide additional engagement surfaces and thereby
hold the shaker flap closed even better.
[0032] Shaker flap 16 is coupled to top portion 20 by a flexible
and integrally formed hinge 50 preferably extending the entire
length of shaker flap 16.
[0033] Spooning flap 22 is coupled to top portion 20 by a flexible
and integrally formed hinge 58 preferably extending the entire
length of spooning flap 22. Note that, unlike certain prior art
covers with hingeable flaps, hinges 50 and 58 are disposed adjacent
to a diametral line of cover 14 to allow the flaps to hinge upward
and toward the middle of cover 14. In prior art covers, the hinges
were formed along an outer edge of the cover, which allowed the
flaps to be opened upward and outward. This caused the flap to
dangle in its open position. As a result, the flap was often in the
way of the material being shaken out of the container, causing the
flap to be covered with the foodstuffs or other materials
inside.
[0034] Spooning flap 22 covers spooning opening 24. Spooning flap
22 has a flange 52 depending from a lower surface of spooning flap
22 that engages and locks against the inside of opening 24. As with
flange 40 on the shaker flap, Flange 52 does not extend
perpendicularly from the underside of spooning flap 22, but extends
at an angle, preferably between 9 and 25 degrees outward and
downward away from the underside of the spooning flap.
[0035] As with flange 40 of the shaker flap, by disposing flange 52
at this angle, cover 14 can be manufactured in a single piece with
spooning flap 22 formed integrally with cover 14. Flange 52
preferably has an arcuate length of between 20 and 180 degrees
(shown as 20 degrees here). Over this length, flange 52 engages the
inside edge of spooning opening 24 to releasably lock spooning flap
22 to top portion 20 when spooning flap 22 is in a closed
position.
[0036] Spooning flap 22 also includes a skirt 60 like skirt 46 of
the shaker flap. Like skirt 46, skirt 60 extends downwardly from
spooning flap 22 near an outer edge of spooning flap 22 and has an
arcuate shape to define an outer substantially vertical surface of
cover 14 when spooning flap 22 is in a closed position. Skirt 60
has an indentation 61 disposed at a central outer portion of skirt
60 and is configured to receive a finger or fingernail of the user.
This allows the user to grasp spooning flap 22 and readily open
container 10. Skirt 60 preferably extends around the circumference
of cover 14 when in the closed position for an angle pi of between
100 and 150 degrees (see FIG. 4). From an outward appearance,
therefore, skirt 60 would appear to form between 100 and 150
degrees of the circumference of the upper part of cover 14. As with
skirt 46 of shaker flap 16, since skirt 60 is arcuate, rather than
straight, it has greater structural strength and it is less likely
to be bent over when its flap is grasped and opened, and further
distributes the grasping load more evenly around the outer edge of
spooning flap 22. This allows spooning flap 22 to be made thinner
and therefore to require less plastic when manufactured. Note that
the arcuate length of skirt 60 is preferably greater than the
arcuate length of skirt 46. This additional arcuate length of skirt
60 therefore provides additional strength to spooning flap 22 when
the user attempts to open spooning flap 22.
[0037] A recess 62 is provided in the cylindrical portion of cover
14 to receive skirt 46 of shaker flap 16. By providing recess 62,
skirt 46 can be set into an outer surface of cover 14 when shaker
flap is closed, thereby reducing the risk that skirt 46 will be
accidentally jostled and caught, shaker flap 16 opened and the
contents of container 10 spilled. Similarly, a recess 64 is
provided in cover 14 on the opposite side of cover 14 from recess
62 to similarly receive skirt 60 of spooning flap 22 for the same
reason. The effect of skirts 46 and 60 being recessed is that the
skirts form a smooth and contiguous part of the outer surface of
the cylindrical portion of cover 14.
[0038] The rim 70 of receptacle 12 has an upper sealing surface 72
that abuts sealing ring 74 of the cover when the cover is screwed
onto the receptacle. Sealing ring 74 has several separate and
distinct sealing surfaces 76. These surfaces are flat and extend
normal to the longitudinal axis of the cap. Each sealing surface is
separated from adjacent sealing surfaces by cylindrical walls 78
that are circular and parallel to the longitudinal axis of the cap.
Each sealing surface defines a plane that is substantially
perpendicular to the longitudinal axis of the receptacle and cover.
Each of these planes intersects the longitudinal axis at a
different point along its length.
[0039] The wide sealing surface of the '399 patent discussed
briefly in the Background of the Invention is intended to
accommodate rather than correct the ovality of the bottle openings.
By providing a wide sealing surface, the bottle opening can be
quite oval, yet will engage around its entire periphery with the
sealing surface, thus providing a good, although oval seal. As we
noted above, this may be effective for hand-tightened caps but not
for machine-tightened caps. As torque is applied to a cap with an
oval bottle opening and bottle sealing surface, the walls of the
bottle at its mouth that are distorted inward toward the central
axis of the bottle will collapse and be forced inward. In a similar
fashion, the walls of the bottle at its mouth that are distorted
outward away from the central axis of the bottle, will collapse and
be forced outward. Thus, when the cap is over tightened on the
bottle, the mouth of an oval bottle becomes even more oval until it
finally collapses. In contrast to this, the sealing surfaces of the
present invention are designed to prevent the collapse of the
bottle's mouth by forcing the mouth of the bottle into a circular
shape. Alternatively, the mouth of the bottle becomes ever more
oval as the cap is over-torqued onto the bottle. This causes the
threads adjacent to the minor axis of the oval bottle mouth to pull
away from the mating threads on the caps. This disengagement, in
turn, causes the cap to pop off.
[0040] The stepped sealing surfaces are preferable to that of the
prior art since they force warped, non-circular container mouths
into a circular shape as the cap is screwed down, unlike the wide
sealing surface of the '399 patent.
[0041] In FIGS. 6 and 7, a warped bottle with an oval rim 70 and
sealing surface 72 of FIGS. 6-7 has just been screwed into cover 14
of FIGS. 6 and 7 by an automatic capping machine. Rim 70 just
contacts the outermost sealing surface 76 of cover 14 having the
largest inner and outer diameter (a slight gap is shown for
convenience). In a typically manufacturing line, the automatic
capping machine would rotate the cover until it reached this
position, at which a certain (minimal) initial resistance to
rotation would exist due to contact at points 78 and 80.
[0042] The top of the bottle is in the form of an ellipse or oval
and therefore rim 70 has a major axis and a minor axis. The first
parts of the bottle sealing surface to contact ring 74 are the
portions of the sealing surface at the opposing ends of the major
axis. The endpoints 82, 84 of the minor axis of the sealing surface
do not even contact the cover, but are suspended in space.
[0043] The tightening process does not stop with this initial
contact at points 78, 80, however. The torque applied by automatic
capping machines has not reached its preset torque limit, and hence
continues rotating, tightening the cover even more firmly to the
receptacle.
[0044] Since there are several independent sealing surfaces 76 on
the cap, arranged in a stair step fashion, the bottle contacts the
cap initially at only two small points on the rim as shown in FIGS.
6 and 7. As a result of this relatively high load on two small
points of rim 70, the capping machine's additional torque causes
rim 70 to deflect and bend slightly.
[0045] As the cover is further screwed down, endpoints 78, 80 of
the major axis of sealing surface 72 are deflected inward under the
increasing pressure between the cover and receptacle. Eventually,
rim 70 and its sealing surface 72 assume a more circular shape. As
the cover is screwed down further, the endpoints 78, 80 of the
major axis are pushed inward toward the central axis of the cover
and receptacle, and the endpoints 82, 84 of the minor axis are
deflected outward, away from the central axis. Eventually, the rim
itself is circular enough (i.e. the major axis is small enough)
that the rim collapses into the next smaller diameter sealing ring
76.
[0046] This new position is shown in FIGS. 8 and 9. Note that the
rim is more circular, and is completely supported on the next
smaller sealing surface 76. Since the diameter of the sealing
surface 72 on rim 70 is substantially the same as the diameter of
the sealing surface 76 on the cover, the cover cannot be screwed
any further onto the receptacle without collapsing or bending the
entire rim of the receptacle. As additional torque is applied by
the capping machine to rotate the cover onto the receptacle, there
is no further collapse of the rim, and the torque rises quite
rapidly to the torque limit of the automatic capping machine.
[0047] During this final period of rotation, the two abutting
sealing surfaces rotate with respect to each other. It is this
relative rotation and slippage that applies the additional torque.
As a result, the friction between the surfaces is reduced to
sliding friction and the rim slides with respect to sealing
surface. In the device of the '399 patent, there is nothing to stop
the deflection from causing rim 70 to warp into an extremely oval
shape. As a result, the threads often pull apart and the cover pops
off.
[0048] In the present invention, however, there is a mechanism to
prevent the additional torque from causing more ovality. The
cylindrical wall 79 between sealing surfaces 76a and 76b of the
cover prevents rim 70 from deflecting outward as the final torque
is applied. Rim 70 is nested inside this cylindrical surface, and
therefore cannot move outward into a more out-of-round condition.
If it starts to move outward, it abuts cylindrical surface 79 and
stops while it is still substantially circular, and before the
threads of the cover and the receptacle pull away from each other
and disengage.
[0049] FIGS. 10-12 show how a receptacle rim collapses to a smaller
diameter along the major axis of the receptacle's rim. FIG. 10
shows rim 70 as it approaches sealing surface 76 of cover 14. Point
78 is one of the end points on the major diameter of the
oval-topped warped receptacle. Threads 28a on the receptacle engage
threads 28b on the cover. As the cover and receptacle are rotated
with respect to each other receptacle 12 moves until it is in the
position shown in FIG. 11, the second of the three FIGURES. In this
position, the rim just contacts the sealing surface 76 (a slight
gap is shown to make the drawing easier to understand). As
additional torque is applied to the cap, it rotates further until
it is in the position of FIG. 12 and point 78 of rim 70 collapses
to the next smaller diameter sealing surface 76. Note that the
threads 28a and 28b move slightly apart. At this stage, the entire
sealing surface 72 of the rim contacts sealing surface 76 of cover
14 (a slight gap is shown to make the drawing easier to
understand). The rim cannot collapse inward any further when
additional torque is applied, since the minor axis has increased
(as shown in FIG. 8-9) so that it abuts cylindrical surface 79
between two adjacent sealing surfaces 7b.
[0050] The FIGURES show how a single receptacle with a single rim
diameter is sealed against the cover. The cover is not limited to a
single rim diameter, however. Since there are several sealing
surfaces on the cover (four of them in the embodiments illustrated
herein), each having a slightly smaller diameter, the cover can be
screwed onto four different receptacles with four different rim
diameters. For each of these receptacles, the operation would be
the same as described above: initial contact with a first sealing
surface at two points on the major diameter, collapse to the next
smaller sealing surface on the cover's sealing ring, and the
application of a final tightening torque while the cylindrical
surface prevents the rim from deflecting outward. With four
different sealing surfaces and three different cylindrical surfaces
between them, this cover can accommodate at least three different
receptacle rim diameters--three different receptacles. The only
difference in operation is that receptacles with smaller rim
diameters will rest on sealing surfaces 76 that also have smaller
diameters. Receptacles with larger diameter will nest on sealing
surfaces 76 with larger diameters.
[0051] The system therefore accommodates a variety of receptacle
mouth sizes by providing several sealing surfaces against which
they can seal. It also corrects the shape of warped bottles used
with automatic capping machines by forcing the bottles to collapse
inward until the entire sealing surface at the rim of the bottle
assumes a circular shape.
[0052] Thus, it should be apparent that there has been provided in
accordance with the present invention an improved container that
fully satisfies the objectives and advantages set forth above.
Although the invention has been described in conjunction with
specific embodiments thereof, it is evident that many alternatives,
modifications, and variations will be apparent to those skilled in
the art. Accordingly, it is intended to embrace all such
alternatives, modifications and variations that fall within the
spirit and broad scope of the appended claims.
* * * * *