U.S. patent application number 10/498528 was filed with the patent office on 2005-06-09 for two piece screw cap closure.
Invention is credited to Luburic, Frano, Sturk, Ron.
Application Number | 20050124057 10/498528 |
Document ID | / |
Family ID | 23329073 |
Filed Date | 2005-06-09 |
United States Patent
Application |
20050124057 |
Kind Code |
A1 |
Sturk, Ron ; et al. |
June 9, 2005 |
Two piece screw cap closure
Abstract
A closure for attachment to a cover having an opening presenting
an upstanding rim, comprising a body having an annular top wall,
said top wall merging with spaced inner and outer walls defining a
depending body recess for capturing said rim, said outer wall
having threads extending generally outwardly therefrom and the top
wall presenting a notch; a cap having a top, said top presenting a
projection disposed for alignment with said notch, an outer wall
depending from said top, said outer wall having threads for
engagement with the threads of said body outer wall.
Inventors: |
Sturk, Ron; (Brampton,
CA) ; Luburic, Frano; (Anaheim Hills, CA) |
Correspondence
Address: |
KEYSER MASON BALL, LLP
FOUR ROBERT SPECK PARKWAY
SUITE 1600
MISSISSAUGA,
ON
L4Z 1S1
CA
|
Family ID: |
23329073 |
Appl. No.: |
10/498528 |
Filed: |
January 18, 2005 |
PCT Filed: |
December 12, 2002 |
PCT NO: |
PCT/CA02/01905 |
Current U.S.
Class: |
435/287.1 ;
215/335 |
Current CPC
Class: |
B65D 2251/0015 20130101;
B65D 51/20 20130101; B65D 2251/0087 20130101; B65D 47/103
20130101 |
Class at
Publication: |
435/287.1 ;
215/335 |
International
Class: |
B65D 041/34 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 14, 2001 |
US |
60339457 |
Claims
1. A closure (4) for attachment to a cover (1) having an opening
presenting an upstanding rim (3) comprising: (a) a body (5) having
an annular recess (14, 15) formed between a spaced inner (18) and
outer (11) annular wall, said recess (14, 15) adapted to capture
said rim (3), said annular outer wall (11) having threads (12)
extending generally outwardly therefrom; (b) a cap (16) having a
top wall (17), said top wall (17) presenting an outer wall (20)
depending from said top wall (17), said cap outer wall (20) having
threads (21) for engagement with said threads (12) of said body
outer wall (11); (c) said rim (3), body (5) and cap (16) co-axially
disposed about an axis (27); characterized in that: (d) said
threads (12) of said body outer wall (11) and said threads (21) of
said cap outer wall (20) are both disposed at and below a
horizontal plane defined by said rim (3).
2. A closure (4) as claimed in claim 1 wherein said body (5)
presents only two annular walls comprising: (a) said inner annular
wall (8); (b) said outer annular wall (11).
3. A closure (4) as claimed in claim 1 wherein said body (5) is
voidless.
4. A closure (4) as claimed in claim 1 wherein: (a) said body (5)
has a top wall (10) presenting a notch (22); (b) said cap presents
a projection (18) disposed for alignment with said notch (22); and
wherein said rim (3), notch (22) and projection (18) are radially
aligned.
5. A closure as claimed in claim 4 wherein said body top wall (10)
contacts said rim (3) and said cap top (7) wall contacts said body
top wall (10).
6. A closure (4) as claimed in claim 5 wherein said body threads
(12) have a relatively wide lower face (25a), and said cap threads
(21) have a relatively wide upper face (25b) for secure engagement
between said cap (16) and body (25).
7. A closure (4) as claimed in claim 6 wherein said body outer wall
threads (12) move radially annularly outwardly relative said cap
threads (21) when said beaded rim (3) is pressed through said
annular recess (14, 15).
8. A closure (4) as claimed in claim 7 wherein said notch (22)
comprises an annular tapered notch adapted for sealing engagement
with said cap projection (18) for maintaining sealing
engagement.
9. A closure (4) as claimed in claim 8 wherein said body (5)
comprises low density polyethylene and said cap comprises high
density polyethylene.
10. A closure (4) as claimed in claim 8 wherein said lower face
(25a) and said upper face (25b) are radially disposed and said body
threads (12) are spaced from said cap outer wall (20).
11. A closure (4) as claimed in claim 10 wherein said threads 12
and 21 are not disposed above the horizontal plane defined by said
rim (3).
Description
FIELD OF THE INVENTION
[0001] This invention relates in general to two piece plastic
threaded closures with removable body diaphragm for press fit
installation on container openings with beaded rim. The invention
relates to an improved low profile closure, which overlies a
relatively tall container annular beaded rim. The invention relates
to the position of the threads below the level of the container
beaded rim for a lower closure profile on the container. The
position of the cap threaded wall overlying the threaded body outer
wall, braces the attachment of the closure to the container beaded
rim for a strong mechanical attachment.
BACKGROUND OF THE INVENTION
[0002] One and two piece screw cap closures are commonly used to
contain and dispense liquids from containers. Two piece closures
commonly combine a body piece incorporating a threaded neck with an
overlying threaded cap. The body piece typically has an annular
recess or rim for attachment to the container, and may incorporate
tamper evidence means such as a pull out diaphragm. The container
or container cover is typically manufactured with an annular
opening modified for subsequent attaching of the closure. Often the
liquid contents are filled through the container opening, and the
two piece closure is installed as part of the filling operation.
Metal cans with a beaded rim for press fit of a two piece plastic
closure is a common example. Cardboard dairy product containers
with a thermally bonded plastic threaded closure is another recent
example.
[0003] One piece threaded plastic and metal screw caps remain the
most common closures due to low cost. One piece threaded caps may
be applied directly to the container wherever the container opening
is manufactured with suitable mating threads. Plastic and glass
bottles with either plastic or metal threaded caps are common
examples. Cap liners and gaskets are often required to close the
voids between the cap and container to achieve a satisfactory
liquid tight seal. The success of the one piece screw cap closure
to retain the product without leaking depends upon the correct
dimensional tolerance of both the cap and container threads, proper
installation torque, and the elimination of voids in the joint.
[0004] Two piece closures are often preferred where the container
opening thread dimensions vary due to manufacturing process
variables, or where fabricating a threaded opening in the container
is difficult. For example forming a threaded neck in metal
containers is difficult due to the mechanical limitations of metal
drawing. Plastic injection molded containers such as open head
pails have molded threads which are subject to uneven post molding
shrinkage leading to ovality of the threaded opening which can
result in binding when threading the cap to the body. Plastic
container manufacturing may be simplified by switching from a
threaded opening to a simpler beaded rim, which results in savings
in tooling and process scrap. Two piece threaded closures which
combine ease of installation to the container with high performance
and low cost are desirable.
[0005] One limitation of two piece threaded closures resides in the
available height of the closure above the container surface where
the cap must be sufficiently exposed to allow for easy gripping by
hand for unthreading. If the cap is too high, it may be struck and
dislodged during shipping and handling. A cap and body combination
which has a low profile and strong attachment, but still allows for
easy removal is desirable. Furthermore a two piece closure which
incorporates a removable diaphragm in the body is a desirable
tamper evident feature.
[0006] Threaded cap closures often incorporate a gasket or liner to
close voids in the mechanical joint, and create a liquid tight seal
between the container opening and the closure. Gaskets and liners
add cost to the manufacture of closures, but allow for looser
manufacturing tolerances by both the closure and container
manufactured and assembled as a set generally allows for tighter
tolerances and improved mechanical seal design. A body piece molded
of relatively soft plastic aids in the establishing of a good seal
between the relatively hard plastic of both the container and the
closure cap, due to the spreading force of the relatively soft
plastic between the hard plastic to fill in any voids.
[0007] It is an objective of this invention to provide an improved
two piece threaded closure design for press fit installation on
plastic containers with beaded rims. The improvements include the
strong mechanical attachment and low profile of the closure which
closely overlies a relatively tall container beaded rim.
[0008] It is a further objective of this invention to provide an
improved two piece threaded closure utilizing a tapered or "V"
shaped mechanical seal which substantially eliminates the need for
cap gaskets or liners.
[0009] It is a further objective of this invention to provide an
improved two piece threaded closure utilizing a mechanical seal
between the closure cap and body which eliminates the need for cap
gaskets or liners.
DESCRIPTION OF THE PRIOR ART
[0010] Prior art two piece threaded closures are common and
typically comprise of a body portion incorporating a threaded neck
for engagement with a removable threaded cap. The shape of the
closures varies according to end use, the materials used and the
method of attachment of the body piece to containers. Methods of
attachment of the closure to the container include mechanical press
fit, thermal bonding, adhesives and by other means. The closure cap
is removable from the body at a later date for dispensing the
product. Tamper evident features such as pull out diaphragms may be
incorporated. Secure attachment is important for the performance of
the container.
[0011] U.S. Pat. No. 5,267,675 illustrates a two piece closure that
has a body which is designed for press fit into the container. An
overlying threaded cap is shown removed for the attachment of the
paint dispenser. The closure body is a mechanical press fit inside
an annular container opening. The body threads are above the plane
where the closure attaches to the container. This design has the
disadvantage of being exposed to side impact, with the closure
being easily dislodged.
[0012] U.S. Pat. No. 3,770,156 discloses the cross section of a
container using a mechanical seal to replace traditional tubular
rubber gaskets in plastic pails. The seal incorporates two flexible
annular rings that are tapered to a flexible point. This design
utilizes a seal between a semi-rigid plastic pail cover and similar
plastic in the container body. This invention relates to two piece
closures with a removable diaphragm, which are installed by
mechanical press fit over a beaded rim.
[0013] Two piece plastic threaded closures, which are assembled to
metal cans, are well known. Metal containers typically have a
circular opening punched in the cover area. The edge of the opening
may be reinforced by forming an annular lip or bead in the metal.
The metal bead may be used as an attachment for a mating recess in
the plastic closure body.
[0014] Prior art arrangements of two piece closures teach a closure
body that is molded from a softer plastic relative to a harder
plastic cup, due to the sealing ability of the softer plastic. The
body-threaded neck is generally located in alignment with a body
mating recess. The relatively harder plastic cap overlies the body
threaded neck portion. The closure cap and body are typically
pre-assembled by being threaded together. During installation the
closure is positioned so the body recess aligns with the container
opening rim. The closure and container are forced together with the
body recess and typically sized to expand over and securely grip
the container rim. In this arrangement the container is now sealed
for shipment. The threaded cap can later be easily removed and
resealed by the end user. Limitations on this design are the
relatively high profile of the closure above the container, which
may be struck and dislodged during shipment. It is desirable to
have a closure which has a low profile.
[0015] A closure from Reike (trade name) on the other hand has a
relatively low profile but the securing means does not extend much
beyond the beaded rim.
[0016] Other prior art devices are shown in De 42 40 485 C.
[0017] Generally speaking the body recess in such prior art
arrangements are limited by the size of the beaded rim that can be
formed in the metal. This limits the mechanical engagement and seal
performance that can be achieved between the container and closure.
It is desirable to increase the relative height of the opening rim
and deepen the body recess for better attachment and seal
performance. The taller opening rim can easily be achieved in the
manufacture of plastic injection molded and blow molded
containers.
[0018] This invention relates to a two piece closure with a
removable diaphragm, which is installed by mechanical press fit
over a beaded rim.
[0019] In this invention, injection molded and blow plastic
containers with relatively tall opening with beaded rims have been
identified as suitable candidates forte improved two piece threaded
closures.
SUMMARY OF THE INVENTION
[0020] This invention relates in general to two piece plastic
threaded closures with removable diaphragm for press fit
installation on container openings with beaded rim. More
specifically the invention relates to the attachment of the closure
to the container beaded rim using both a relatively tall inner wall
and outer skirt, the outer skirt incorporating the body thread. The
invention also relates to the position of the threads below the
level of the container beaded rim for a lower closure profile on
the container. The position of the cap threaded wall overlying the
threaded body skirt, braces the attachment of the closure to the
container beaded rim for improved seal performance.
DRAWINGS
[0021] FIG. 1 is a side and cross-sectional view of the two piece
threaded closure before installation on a container cover.
[0022] FIG. 2 is a side and cross-sectional view of the two piece
threaded closure after installation on a container cover.
[0023] FIG. 3 is a side and cross-sectional view of the closure
body
[0024] FIG. 4 is a top view of the closure body
[0025] FIG. 5 is a side and cross-sectional view of the closure
cap
[0026] FIG. 6 is a top view of the closure cap
[0027] FIG. 7 is a sectional view of a typical container cover
opening
[0028] FIG. 8 is a sectional view of an optional container opening
with neck ring
[0029] FIG. 9 is a partial enlarged cross-sectional view of the two
piece threaded closure after installation on a container cover.
LIST OF DRAWING NUMBERS
[0030] Number Description
[0031] 1 container cover
[0032] 2 cover opening rim
[0033] 3 rim bead
[0034] 4 two piece threaded closure
[0035] 5 closure body
[0036] 6 body pull out diaphragm
[0037] 7 diaphragm pull ring
[0038] 8 body inner wall
[0039] 9 body inner rim
[0040] 10 body top wall
[0041] 11 body outer wall
[0042] 12 body thread
[0043] 13 frangible web
[0044] 14 annular body recess
[0045] 15 annular rim recess
[0046] 16 closure cap
[0047] 17 cap top
[0048] 18 cap seal projection
[0049] 19 cap lugs
[0050] 20 cap outer wall
[0051] 21 cap thread
[0052] 22 sealing recess
[0053] 23 container
[0054] 24 container neck ring
[0055] 25 thread face
[0056] 25(a) lower face
[0057] 25(b) upper face
[0058] 26 body outer rim
[0059] 27 central axis
DESCRIPTION OF THE INVENTION
[0060] Like parts shall be given like numbers throughout the
figures.
[0061] FIG. 1 illustrates a two piece threaded closure 4 before
installation on container cover 1. The closure 4 generally
comprises a closure body 5 made of soft flexible plastic (i.e. low
density polyethylene (LDPE)) or the like, and a closure cap 16,
made of semi-rigid plastic (for example high density polyethylene
(HDPE)) or the like. The body 5 and cap 16 are co-axially disposed
about central axis 27 and secured in threaded assembly by body
thread 12 and cap thread 21.
[0062] A variety of thread types can be used in this invention. In
one embodiment buttress threads nave been favorably used as shown
providing a strong fit. Furthermore there is a small gap which in
one example can be in the order of up to 0.100 of an inch between
the outer lip of the buttress threads and the body outer wall 11
and top outer wall 20 respectively, which accommodates any ovality
of the annular shape of the body outer wall 11 and cap outer wall
20 so as to facilitate the treading and unthreading of the closure
cap 16 to closure body 5, and minimize binding of the parts.
[0063] Furthermore the buttress threads each present a relatively
wide thread face 25 for strong threaded engagement therebetween.
More specifically the body outer wall 11 presents buttress threads
having a relatively wide lower face 25(a) while the cap outer wall
20 prevents buttress threads having a relatively wide upper face
25(b).
[0064] As is shown in greater detail in FIG. 9, closure body 5 is
comprised of a body pull out diaphragm 6 attached to a diaphragm
pull ring 7. The diaphragm 6 is attached by an annular frangible
web 13 to the annular body inner wall 8. The inner wall 8 is
generally cylindrical in shape and terminates in body inner rim 9.
A body top wall 10 beginning near body inner rim 9 extends
generally radially outward from the body inner wall 8, and leads to
body outer wall 11. Outer wall 11 is cylindrical in shape, and lies
racially outside of body inner wall 8. The inner wall 8, top wall
10, and body outer wall 11, together form an annular body recess 14
on one side of the body top wall 10 and an annular rim recess 15 so
as to facilitate the treading and unthreading of the closure cap 16
to closure body 5, and minimize binding of the pasts, sized to
attach to the container cover 1.
[0065] FIG. 2 is a side and cross-sectional view of the two piece
threaded closure after installation on container cover 1. The
container 1 presents a cover opening rim 2 having a generally
upstanding peripheral edge with a rim bead 3 adapted to be received
or captured by the annular rim recess 15 in a manner to be more
fully described herein. As shown in FIG. 2 the rim bead 3 is
outwardly bulbous in one embodiment of the invention.
[0066] As shown in greater detail in FIG. 9 the generally
cylindrical inner wall 8 braces against cover opening rim 2 and
body top wall 10 overlies rim bead 3. During installation, the body
outer wall 11 expands generally radially outwardly (i.e. the
diameter expands) as rim bead 3 passes along body annular recess 14
and into the annual rim recess to be captured therein. After
installation, the body outer wall 11 relaxes to a smaller diameter
and underlies rim bead 3. The cap outer wall 20 overlies and braces
the body outer wall 11 against rim bead 3 to further resist removal
of closure 4 from container cover 1.
[0067] FIG. 3 specifically shows the body inner rim 9, body top
wall 10 and body outer rim defining a notch or sealing recess 22
which is adapted to receive cap seal projection 18 when the cap 16
is threaded to the closure body 5. As the cap 17 is threaded to the
body 6 the relatively soft plastic of body 5 "gives" and creates a
substantially tight seal, which seals quickly, rather than
gradually, and acts as a gasket.
[0068] FIG. 4 is a top view of the closure body 5. Pull ring 7 is
used to remove pull out diaphragm 6.
[0069] FIG. 5 is a side and cross-sectional view of the closure cap
16 having top 17.
[0070] FIG. 6 is a top view of the closure cap 16. A plurality of
cap lugs 19 are used as finger grips to assist the installation and
removal of cap 16. Cap seal projection 18 is designed to engage
with body inner rim 9 and body outer rim 26 to create a seal.
[0071] FIG. 7 is a side and cross-sectional view of the opening in
a typical container cover 1. A cover opening rim 2 which is
generally cylindrical in shape terminates in a rim bead 3.
[0072] FIG. 8 is a side and cross-sectional view of an optional
container 3 with neck ring 2 and rim bead 3. An annular container
neck ring 24 may be used to support the container 23 during the
installation of closure 4.
[0073] FIG. 9 is a detail side and cross-sectional view of the two
piece threaded closure after installation on container cover 1.
[0074] The assembly shown creates a low profile closure, resisting
dislodgment when accidentally struck. Moreover the seal and closure
is stronger and more robust.
[0075] Various embodiments of the invention have now been described
in detail.
[0076] Since changes in and/or additions to the above-described
best mode may be made without departing from the nature, or scope
of the invention, the invention is not to be limited to said
details.
* * * * *