Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF THE INVENTION
The invention relates to a twist-off closure
cap for containers such as beverage or liquor bottles and
more particularly to an improved molded unitary plastie
closure cap. More particularly, the application relates to
a molded closure bottle cap having a flowed-in sealing gasket.
It may also have a tamper indicating band which is applied
with the cap during the normal bottle sealing operation
and which prevents the removal of the cap without being ~orn
off or partly torn and broken providing an indication of any
attempt to remove the cap.
A number of well-known caps are now being
used for sealing beverage bottles. One particularly well-
known cap of this general type is an aluminum cap having a
sealing portion and a generally non-detachable or tamper
indicating ring. The application of the tamper indicating
ring to the container requires a separate shaping operation
during cap application to shape the tamper indicating ring
around a bead on the bottle finish.
The closure cap of the present invention
provides an inexpensive unitary molded plastic cap which
provides a high pressure seal. It includes a flowed-in
sealing liner and may include a tamper indicating band or
ring. The caps are applied by high speed bo~tle sealin~
machinery in a sealing operation which both seals the bo~les
with the sealing caps and which simultaneously applies the
tamper indicating bands without band reshaping operations.
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63285-827
Specifically, the present invention provides a unitary
molded plastic closure cap for sealing a container having a
threaded neck comprising the combination of: a cover; a depend-
ing skirt having container engaging threads on its inner surface;
a radially inwardly extending bead positioned on said skirt
between said cover and said skirt threads and forming a liner
retaining groove between said cover and said threads and facili-
tating stripping the threads from the thread forming portions of
the molding die; a flowed-in plastic sealing liner positioned on
the underside of said cover with its outer edge occupying said
groove; and said liner having its greatest width at its outer
edge and occupying substantially the entire groove and having a
progressively lesser width radially inwardly of the closure cap
cover.
A unique advantage of the cap is the improved flowed-
in liner and the shaping of the plastic cap for retaining the
liner in place and for forming a pressure resistant seal. The
improved unitary molded plastic closure cap is capable of sealing
at high pressures. The cap may include tamper indicating means,
and can be applied using existing high speed bottle sealing
machinery.
Other features of the present invention will become
apparent upon an understanding of the illustrative embodiments
about to be described or will be indicated in the appended claims,
and various advantages not referred to herein will occur to one
skilled in the art upon employment of the invention in practice.
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BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a bottle
sealed with a closure cap in accordance with the present
invention .
FIG. 2 is a sectional view taken along line
2-2 on FIG. 1 of the closure cap of the invention and a bottle
sealed with it.
FIG. 3 is a vertical sectional view illustrating
a closure cap in accordance with the present invention being
applied to a bottle.
FIG. 4 is a vertical sectional view of ~he
closure cap.
FIG. 5 is a vertical sectional view of the liner
being flowed into the closure cap.
FIGS. 6 and 7 are sectional and bottom plan
views of another embodiment.
DESCRIPTION OF THE P~EFERRED
EMBODIMENT __
This invention relates to a ~mitary molded
plastic closure cap which is applied to filled bottles or
similar containers on high speed ~utomatic sealing ma~hines
and which provides a satisfactory seal even at high pressures.
Prior tamperproof closures of this general-
type include metal closure caps wuch as aluminum caps where
there is a cup-like sealing portion of the cap and usually
an attached tamper indicating ring. These prior caps
are applied to the filled bottles with complicated
automatic machinery which applies the caps and which then
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must also crimp or otherwise deform the metal cap shells to
interlock the tamper indicating band.
The present invention subs~itutes a unitary
molded plastic cap for the metal closure and provides for both
the sealing cup like cap portion and when desired a unitary
tamperproof or tamper indicating band.
A characteristic of the presently used metal
caps is their ability to be applied to filled containers on
high speed automatic sealing machinery. The closure cap of
the present invention also has this advantage and provides for
a high speed and low cost sealing machine application while at
the same time providing a simple low cost plastic closure cap
useful for high pressure sealing.
The closure cap 1 as illustrated includes a
sealing means or liner 2 on the underside of the cap cover 3
for forming a tight seal between the cap 1 and the upper surface
4 of the bottle 5 finish 6.
A tamperproofing band 7 is attached to the
lower edge of the cap skirt lOby a number of relatively thin
and rupturable bridges 9. The bridges 9 hold the tamper
indicating band 7 onto the sealing portion of the closure 1
during cap application and sealing until the bottle is
opened for use and while remaining unruptured indicate that
the cap seal has not been tampered with. The closure cap
may also be used without a tamper indicator in which case
the band is elimin~ted fromthe cap and the cap forming die.
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63285-827
The closure cap 1 has the molded cup-like sealing and
bottle engaging portion comprising the cover 3 and a depending
skirt 10. The skirt 10 includes container engaging threads 11 on
its inner surface and preferably has knurls 12 on its outer sur-
face to facilita-te cap removal. The cap 1 is formed of suitable
plastic such as polypropylene, polyethylene, polystyrene or
similar plastics.
The sealing liner 2 is preferably flowed in so that
it covers the underside of the cap cover 3 and has a thickened
outer edge 14 in inter-locking engagement with a channel 15 formed
at the corner between the cap cover 3 and the cap skirt 10. The
lower side 16 of the channel 15 is the upper surface 17 of a
circular bead 18. The bead 18 preferably has a generally tri-
angular cross-section with its inner-most edge or apex being
rounded in the form of a radius and with its upper liner engaging
surface 17 forming an angle in the range 25 to 60 and preferably
about 30 with the horizontal. The properties of the preferred
sealing liner 2 plastic, which is polyvinylchloride or PVC, as it
is flowed into a rotating closure 1 by a nozzle 21 (FIGURE 5)
cause it to have a thickened outer edge at the Channel 15 forming
both an adhesive and a physical interlock between the liner 2 and
the Channel 15. The above described taper of about 30 degrees for
the upper surface 17 of the bead 18 assists to retain the liner 2
and also facilitates the stripping of the molded closure cap 1
shell from the molding tools during the shell molding portion.
The taper of bead 18 tends to slightly flare the molded cap skirt
10 during the stripping to facilitate the withdrawal of the
groove forming portion of a die as well as the thread forming
portions.
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63285-827
FIGURE 2 illustrates the sealing liner 2 of the
closure cap 1 ln engagement with the rim 4 of a sealed bottle 5.
The bottle rim 4 has penetrated into the liner 2 causing an
extrusion or build-up of the liner sealing portion around both
the outer and inner edges 19 and 20 of the bottle rim 4. This
inter-action between the liner 2 and the bottle 5 at the channel
15 perfects the seal between the liner 2 and the bottle rim 4
and forms tight seals which are effective even for relatively
high pressures within the sealed bottles such as is the case
with beers and sodas.
As already indicated, the closure cap may be used
with a tamper indicating band or without such a band.
FIGURES 1-3 illustrate one form of band which includes
the container engaging band 7 and which has a number oE bridges
or gates 9 which attach the band 7 to the cap skirt 10. When
the cap is removed from -the bottle 5 this band tears loose and
remains on the bottle 5 indicating that the cap has been turned
upwardly.
Another Eorm of band may be used such as is described
in United States Patent No. 4,299,328, dated November 10, 1981.
That form of band 22 (FIGURE 4) on a cap 23 has a strapping
action which insures the retention oE the tamper indicating band
22 on a bottle. Two diametrically spaced lugs 24 on the band 22
hold the band on the bottle and provide a strapping action on
removal in combination with a pair of bridge groups 25 each
about 90 displaced from the lugs 24. Thus the frangible bridge
groups 25 provide reduced attaching force to the band directly
, above the lugs 24.
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FIGS. 6 and 7 illustrate an lmproved
embodiment of a strapping type of tamper indicating band 26
on a cap 27. The band 26 includes approximately diametrically
spaced lugs 2~ to provide the strapping forces. In addition,
the band 26 has several bridges 29 positioned about 90
away from the lugs 28 and a stronger bridge or hinge 30
positioned approximately diametrically opposite to the bridge
29~ Additionally a notch 31 is provided in the band 26
adjacent to the hinge 30. In this embodiment of the closure
cap, a removal of the cap 27 first snaps the band 26 at the
notch 31 and then tears the bridges 29. This gives an
immediate indication of closure tampering. During the final
removal of the cap 27, the hinge 30 does not tear but remains
intact lifting the tamper band 26 off of the bottle with
the closure cap 27. Such a removable band is desired for
certain sealing applications.
It will be seen that an improved molded
unitary closure cap has been described which is readily
manufactured and which is applied using existing high speed
bottle sealing machinery to form excellent seals useful at
high and low pressures.
As various changes may be made in the form,
construction and arrangement of the parts herein without
sacrificing any of its advantages, it is to be understood
that all matter herein is to be interpreted as illustrative
and not in a limiting sense.
