Note: Descriptions are shown in the official language in which they were submitted.
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BOTTLE CAP
FIELD OF INVENTION
This invention relates to improved tamper resistant
push on assemblies for containers. It is particularly
useful in connection with re-usable glass bottles such as
milk bottles, but not necessarily limited to such use.
BACKGROUND OF INVENTION
Bottles in the nature of milk bottles were
conventionally closed by means of friction fitted
cardboard disks, crimped on aluminum foil caps and
crimped on paper caps, none of which are tamper
resistant.
Although there had been described a number of tamper
resistant closures for screw bottles, as for example
shown in U.S. Patent No. 4,394,918, we did not regard it
as practical to convert re-usable glass bottles such as
milk bottles to screw type bottles simply to allow
existing tamper resistant closures to be used, given the
major capital cost involved in such conversion.
Moreover, as a result of the relatively large diameter of
the necks of bottles of this type and the relatively wide
tolerances to which such bottles are manufactured, it was
also viewed as impractical to construct tamper resistant
closures on the basis of expedience such as ratcheting
teeth.
With a view to providing a one piece molded tamper
resistant push-on closure particularly suited for closing
glass bottles which would be readily adaptable for use
with existing closure machinery, we earlier devised the
closure described and claimed in our U.S. Patent No.
5,875,908. That one piece molded tamper resistant push-
on closure comprises a latch ring portion and a cap
portion, the latch portion including a plurality of
integral, upwardly inwardly angled teeth for snap
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retaining the latch ring portion beneath a shoulder
associated with the bottle when the closure in pushed
onto the bottle, while restricting detachment of the
closure therefrom. The latch ring portion and the cap
portion of the closure are connected by a plurality of
frangible tabs, some of which serve to retain the latch
ring portion in the form of a closed annulus. The cap
portion includes a pull tab disposed on a peripheral
portion thereof. By exerting a moderate force on the
pull tab the aforementioned frangible tabs are ruptured,
opening the annulus to permit the latch ring portion to
be moved transversely from engagement above the neck of
the bottle.
We have since discovered that, with certain types of
bottles having particular contours and dimensions of the
upper rim of the bottle and the shoulder below the upper
rim it is occasionally possible, with some effort, to
prise a closure according to the '908 patent from the
bottle, without rupturing the frangible tabs so as to
provide clear visual evidence of tampering.
In order to provide a one piece molded tamper
resistant push-on closure that is suited for closing
glass bottles such as milk bottles, even where the rim
and shoulder shape associated with the bottle opening are
unusual or irregular, we found it advantageous to design
more aggressive means for locking the closure in place,
but without diminishing the ease of legitimate removal of
the closure by tearing away the latch ring.
It is an object of the present invention to provide
such an improved one piece molded tamper resistant push-
on closure for glass bottles which need not be assembled
on the neck of the bottle and which is readily adapted
for use with existing closure machinery.
It is another object of this invention to provide
such closures with frangible members that can be ruptured
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without the necessity of using excessive force.
It is still a further object of this invention to
provide such closures that are easily removable to permit
the re-use of the bottle.
SUN~1ARY OF THE INVENTION
In accordance with a broad aspect of the invention,
a one piece molded tamper resistant push-on closure
suitable for closing glass bottles comprises a latch ring
portion having an upper and lower peripheral margin, an
inwardly directed surface extending therebetween, and a
plurality of circumferentially spaced slots therethrough.
A plurality of resiliently deformable teeth depends from
the latch ring in an upwardly inwardly direction relative
to the interior surface thereof, each said tooth
presenting on its surface an integral bead of a shape and
disposition adapted to project through a corresponding
one of said slots through the latch ring portion as the
latch ring is engaged onto the neck of a bottle.
The closure of the invention further comprises a cap
portion having a lower peripheral margin and an inwardly
directed surface extending upwardly from the lower
peripheral margin thereof. A plurality of frangible tabs
connect between the latch ring portion and the cap
portion. A manually engagable tab integral with.the
latch ring portion projects outwardly from the latch ring
portion. Application of a suitable manual force to the
tab with progressively rupture the frangible tabs and
permit the cap to be removed from the bottle to which the
closure has been applied.
In this arrangement, force exerted on the projecting
tab is applied at one radial point rather than about the
whole of the periphery of the cap and results in the more
or less serial rupture of the frangible tabs, rather than
their being ruptured simultaneously. Accordingly, it is
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found that the force necessary to disengage the cap from
the latch ring using the manually engagable tab is well
within the capability of the average person, while the
cumulative force is sufficiently high as to reduce the
likelihood of an inadvertent detachment.
In a preferred embodiment, the manually engagable
tab is in the form of a part-parabolic convex projection
having a rearward truncated wall surface acutely angled
to a diameter of the closure therethrough for comfortable
accommodation of the tip a user's thumb or finger,
affording the grip and leverage needed to break the first
frangible tabs and so permit tearing away of the latch
ring portion.
Generally speaking, the upper end of the cap portion
will be in the form of a flat dome, and suitably a
stopper will depend downwardly from the dome to provide a
liquid tight seal with the interior surface of the
bottle. Desirably, the stopper will have a tubular
cross-section so as to be resiliently deformable and
accommodate normal variations found in glass milk
bottles, for example. Also preferably, the stopper will
have a maximum external diameter intermediate the axial
ends thereof so as to facilitate the initial engagement
of the stopper in the neck of the bottle and to localize
sealing forces.
Also preferably, the latch ring is in the form of an
open annulus which permits is ready removal from the neck
of a bottle once the frangible tabs have been ruptured.
The foregoing objects and aspects of the invention,
together with other objects, aspects and advantages
thereof will be more apparent from a consideration of the
following description of the preferred embodiment thereof
taken in conjunction with the drawings annexed hereto.
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BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a bottle cap in accordance with the
invention in perspective view, together with a portion of
a milk bottle;
S FIG. 2 shows the bottle cap of FIG. 1 in elevation,
facing toward the latch ring removal tab;
FIG. 3 is a plan view from above of the bottle cap
of FIG. l:
FIG. 4 is a section along line A-A of FIG. 3 in the
direction of the arrows;
FIG. 5 is a further plan view from above of the
bottle cap of FIG. 1, but rotationally displaced from the
view of FIG. 3 to put the region of the closure including
the latch ring removal tab in the upper half the drawing;
FIG. 6 is a section along line B-B of FIG. 5,
including that portion of the closure including the latch
ring removal tab; and
FIG. 7 is a plan view from below from the bottle cap
of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in detail, a bottle
closure in accordance with the invention is denoted
generally by the numeral 10. Bottle closure 10 comprises
a cap portion 20 defined in part by a lower peripheral
margin 22, a cover 24 and inwardly directed surface 26
extending therebetween.
Closure 10 further comprises a latch ring 30 defined
in part by a lower peripheral margin 32, an upper
peripheral margin 34, and inwardly directed surface 36
therebetween. A plurality of elongate rectangular slots
37 through latch ring 30 are regularly disposed around an
upper portion 30a of the latch ring. A corresponding
plurality of resiliently deformable teeth 38 depend
upwardly inwardly from the lower peripheral margin 32 of
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the latch ring. Each of these teeth includes an
outwardly directed integral locking bead 39, the slots 37
and beads 39 being dimensioned such that the deformation
of teeth 38 when the closure 10 is push fitted onto a .
bottle neck N results in the fitting of the beads through
- slots, therebylocking the latch ring against vertical
displacement, as will be further described.
A plurality of frangible tabs 40 interconnect the
upper peripheral margin 34 of the latch ring 30 to, the
lower peripheral margin 22 of the cap portion 20, to
integrate the two portions. Latch ring portion 30 is in
the form of an open annulus.
The cover 24 of cap portion 20 is generally in the
form of a flat dome, and a stopper 42 is downwardly
dependent therefrom. Stopper 42 has a tubular cross-
section with a portion 46 of maximum diameter
intermediate the axial ends of the stopper.
The structure of closure 10 as described is such
that the closure is moldable in one piece, with teeth 38
angled inwardly upwardly as illustrated, which avoids the
necessity of a separate operation to re-form the teeth
following the initial molding step. This unitary
operation permits the diameter of the inwardly directed
surface 36 of latch ring portion 30 to be closely
controlled so as to provide a_close friction fit for the
latch ring portion over the neck of a bottle with the
greatest design diameter, while permitting its use. with
bottles with smaller necks within the normally
anticipated tolerance range.
In use, closure l0 is applied to bottle B using
,standard bottle capping machinery by merely pushing the
cover about the opening into the bottle. This will cause
teeth 38 to be deformed so that their associated locking
beads 39 project through corresponding slots 37 and
engage lockingly with the walls thereof.
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Unlike the bottle cap described and claimed in our
U.S. Patent No. 5,875,908, the locking of the intact-.
closure 10 is not only effected -by the latching of
locking teeth of the latch ring under the shoulder S of a
bottle rim (which can depart from size tolerance), but
- also by the locking of the teeth 38 in place on the
tamper-evident band itself, i.e., on the latch ring
portion 30, by the engagement of locking beads 39 with
slots 37. In the result, it is practically impossible to
remove closure 10 manually without destroying the
integrity of the latch ring portion and producing obvious
signs of tampering. The fitting of closure 10 in this
manner will cause stopper 92 to enter into the neck N of
bottle B and be compressed to form a tight liquid seal.
l5 To remove closure 10 from the bottle initially, a
levering force -is applied by the thumb or fingers to
latch ring removal tab 44 to rupture frangible tabs 40.
Tab 44 may advantageously be molded integrally to the
upper portion of the latch ring 30a, in the form of a
convex paraboloidal dome having an oblique rear wall 49a
to receive finger or thumbnail pressure. The rupturing
force applied to tab 44 will serve to progressively break
the frangible tabs, thereby permitting cap portion 20 to
be removed from the bottle. This, in turn, permits the
latch ring portion to be removed from the neck of the
bottle in a transverse manner under a negligible force,
and this removal is likely to arise at the time when a
user first removes the cap portion 20 from bottle B.
Although a particular embodiment of the invention.
has been illustrated and described herein, one of
ordinary skill in the art will appreciate that changes or
additions may be made to the design of the closure
without departing from the spirit and scope of the
invention, which is defined in the claims attached
hereto .
