Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to a tamper resistant
closure for use on a container and, in particular, to a
tamper resistant closure containing a tear strip in
combination with a tamper evident band containing a flange
that is hinged to said band.
For safety and security reasons, tamper resistant
closures are known. One such previous closure is described
in European Patent Application Number 90310078.2 published
on April 10th, 1991. The closure in that Application has a
tamper evident band having a movable flange thereon with the
band being connected to the closure along a weakened line.
The weakened line can be formed by scoring or by
circumferentially-spaced bridges. When the closure is
installed on the container, the flange and tamper evident
band override a ring on the container. When the closure is
desired to be removed, sufficient force must be exerted on
the closure to sever the tamper evident band and flange from
the rest of the closure along the weakened line. A
disadvantage of this closure is that the weakened line must
; 20 be designed within a very fine tolerance, one that is not
always satisfactorily achieved during manufacture. If the
weakened line is not made sufficiently strong, the band and
flange will sever from the rest of the closure during the
initial installation of the closure on the filled container
or during shipping and handling. When this occurs, the
packaging process of the manufacturer is greatly disrupted,
; often resulting in the product located within the container
being discarded. If the weakened line is strong enough so
that it is not severed during the initial installation or
during subsequent shipping and handling, the weakened line
is often too strong to be readily opened by the ultimate
consumer without the use of tools or other aids. Also, when
the tamper evident portion is separated from the remainder
of a closure along a weakened line, it is possible to remove
the closure, tamper with the contents of the container and
replace the closure. A consumer who does not subject the
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closure and container to close inspection, may not notice
that the weakened line has been severed until after the
purchase has been completed and an attempt is made to open
the container for the first time. Further, as closures are
often tightly turned onto the containers, a consumer may not
even notice that the weakened line has been severed when
they open the container for the first time.
It is an object of the present invention to
provide a tamper resistant closure having a tear strip in
combination with a flange hinged onto a tamper evident band,
said closure providing clear visual evidence of tampering
and providing relatively wide tolerances for manufacture.
A tamper resistant closure is used on a container
having a neck surrounding an opening said neck having
external threads thereon, said neck having a ring located
beneath said threads when the container is in an upright
position. The closure has a central portion having a
periphery with a skirt extending from said periphery, a tear
strip extending from said skirt, a tamper evident band
extending from said tear strip and a movable flange
extending from said band, The tear strip is affixed between
said skirt and said band by a plurality of severable
attachment means. The skirt has an interior surface with
threads thereon corresponding to the threads on said
container. The flange is connected to said band by hinging
means so that said flange extends inwardly relative to said
band and a free edge of said flange is movable between an
upper position and a lower position. The central portion,
skirt, strip, band and flange are sized to fit snugly on
said neck so that when the threads of the neck are engaged
with the threads of the closure, the closure is in a closed
position relative to said container. The free edge of said
flange is located above said hinging means and beneath said
ring. The flange overrides said ring as the closure is
installed on said container. The flange engages said ring
when the closure is attempted to be removed from said
:, . ` - . ..
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container to prevent said flange from overriding said ring,
said band and flange being detachable from said skirt by
severing said attachment means to rernove said tear strip.
A method of installing and removing a tamper
resistant closure relative to a container is used where the
container has a neck surrounding an opening with the neck
having external threads thereon and a ring located beneath
said threads when the container is in an upright position.
The closure has a central portion with a periphery and a
skirt extending from said periphery, a tear strip extending
from said skirt, a tamper evident band extending from said
tear strip and a movable flange extending from said band.
The tear strip is affixed between said skirt and said band
by severable attachment means. The skirt has an interior
surface with threads thereon corresponding to threads on the
container. The flange is connected to said band by hinging
means so that the flange extends inwardly relative to said
band and a free edge of said flange is movable between an
upper position and a lower position. The method comprises
installing said closure on said container so that said
flange overrides said ring and is located beneath said ring
when the closure is in a closed position relative to said
container. The free edge of said flange is located above
said hinging means and beneath said ring. Subsequently,
when it is desired to remove said closure from said
container, grasping one end of said tear strip and manually
pulling it to sever the attachment means and to remove the
tear strip from said closure. Then, removing said closure
from said container, the band and flange remaining on said
container.
In the drawings:
Figure 1 is a somewhat expanded perspective view
of a closure located above a partial container;
Figure 2 is a partial sectional side view of a
closure partly installed on a container;
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Figure 3 is a partial sectional top view of a
tamper evident band and flange;
Figure 4 is a partial sectional side view of a
closure and container in a closed position relative to one
another; and
Figure 5 is a partial sectional side view and a
partial side view of a closure and container in a closed
position with a tear strip removed.
In Figure 1, a closure 2 is located above a
container 4. The container 4 has a neck 6 with external
threads 8 thereon. The neck has a ring 10 located beneath
the threads 8 when the container is in an upright position
as shown in said Figure. The closure 2 has a central
portion 12 with a periphery 14 and a skirt 16 extending from
said periphery. A tear strip 18 extends from the skirt 16
and a tamper evident band 20 extends from the tear strip 18.
A movable flange 22 extends from the band 20. The tear
strip 18 is affixed between the skirt 16 and the band 20 by
severable attachment means, being a plurality of severable
tabs 24. Alternatively, the tear strip could be affixed
between the skirt and the band by a scored line of contact.
` The tabs 24 are preferred to a scored line. The skirt 16
has an interior surface 26 with threads 28 thereon
corresponding to the threads 8 on the container. The
threads 28 can be one continuous thread or several partial
threads or any suitable combination in between. The flange
22 is connected to the band 20 by hinging means which is
simply a scored line of contact between the flange 22 and
the band 20. The flange 22 extends inwardly relative to the
band 20 and a free edge 30 of the flange 20 is movable
between an upper position and a lower position. The upper
position is shown in Figure 2. A tear strip 18 has two ends
with one end having a handle 32. Preferably, there are no
tabs 24 located to affix the handle 32 to either the skirt
16 or the band 20. It can be seen that there are two sets
of tabs 24, one set interconnecting the tear strip 18 and
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the skirt 16 and the other set interconnecting the tear
strip 18 and the band 20. Preferably, the tabs of each set
are offset vertically from one another and, still more
preferably, the tabs of one set are located to alternate
vertically along said tear strip with the tabs of the other
set. The spacing between the tear strip and the skirt and
the tear strip and the band as well as the length of the
tabs has been exaggerated for ease of illustration to expose
the tabs.
In Figure 2, a partial sectional side view is
shown through one side of the closure and container. The
other side would be a mirror image of the side shown. It
can be seen that the closure 2 is partly installed on the
neck 6 of the container 4. The threads 28 of the closure 2
are interlocking with the thread 8 of the container 4. The
closure has been turned onto the container to a point where
the flange 22 has partially overridden the ring 10. The
flange 22 is forced into the upper position by said ring.
Two concentric circular ridges 34 are located on an interior
surface 36 of the central portion 12. The ridges 34 provide
a double seal with the container 4 when the closure is in a
closed position relative to said container. The ridges 34
have been omitted from the closure shown in Figure 1 to
~ avoid confusion. The tear strip in Figure 2 is located very
- 25 close to the skirt and to the band, the tabs being much
shorter than the tabs of Figure 1. Figure 2 is more
accurate than Figure 1 in relation to the length of the tabs
of an actual closure.
In Figure 3, a sectional top view through the band
20 shows the movable flange 22. The flange 22 has a
plurality of lateral ribs 38 to add strength to the flange
22 so that it will not buckle and override the ring 10 when
the closure is being removed from the container unless the
tabs 24 are severed.
Figure 4 is similar to Figure 2 except that the
closure 2 is in a closed position on the container 4. In
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this position, the flange 22 has overridden the ridge 10 and
the free edge 30 of the flange 22 rests against the neck 6
beneath the ring 10. In Figure 4, a gap between the free
edge 30 and the ring 10 is exaggerated for ease of
illustrationO However, the closure should be designed to
have a gap between the edge 30 and the ring 10 when the
closure is in a closed position on the container to allow
for manufacturing tolerances. If the closure is designed
without such a gap and a particular closure is somewhat
smaller than the design, the flange 22 will not be located
beneath the ring 10 when the closure is in a closed position
and the tamper resistant feature will be inoperable.
Further, it can be seen that the ridges 34 are in contact
with an upper surface 40 of the neck 6.
In Figure 5, there is shown a side view of the
closure 2 in a closed position on the container 4 with part
of the view shown in cross-section. The tear strip 18 is
not shown in Figure 5 as it has been removed. It can be
seen that when the tear strip is removed, a readily apparent
gap 42 exists between the skirt 16 and the band 20 exposing
part of an outer surface of the neck 6 and part of the ring
10. Once the tear strip 18 has been removed, the closure 2
can be removed from and replaced on the container in a
normal fashion and will function as a conventional closure.
Thus, when the tear strip is removed, it is immediately
visually apparent to any potential purchaser or user of the
product within the container that the product may have been
tampered with. The spacing of the tear strip in Figures 4
and 5 is the same as that shown in Figure 2.
From Figure 1, it can be seen that the tabs are
all of equal size and shape and are located between the
skirt and tear strip and between the band and tear strip so
that the tabs are flush with the interior surface of the
skirt but set back from an exterior surface of the skirt.
When the tabs are formed in the mold, the cavities to allow
for the tabs are located in the core of the mold. The knife
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that advances into the space between the skirt and the strip
and between the band and the strip is formed in two parts,
each having a segment that abuts the core. The two segments
together form a circle when the knife is fully inserted.
When the two parts of the knife are withdrawn from the core,
they are withdrawn in opposite directions. If the tabs were
not set back from the outer surface, the removal of the
knives would distort those tabs that were located near the
side edges of each part of the knife. Each tab that was
further removed from the side edges of the knife would be
distorted to a lesser degree and the tabs closest to a
centre of each part of the knife would not be distorted at
all. The tabs would therefore have to be designed to be of
different sizes and shapes. This might cause some of the
tabs to sever prematurely during installation, shipping or
handling. By setting the tabs back from the outer surface
in accordance with the present invention, the tabs can all
have equal size and shape and all of the tabs therefore have
the same strength.
The present invention has a significant advantage
over previous tamper resistant closures in that the use of
the hinged flange 20 allows variations in the relative size
of the closure and container within acceptable tolerances.
Also, the tabs 24 can be made with a great deal of strength.
This strength can be increased by increasing the number or
size of the tabs 24. Since the tabs 24 are severed by
manually pulling the tear strip 18, the tabs 24 are severed
one at a time, if the two sets of tabs are alternated or, if
the two sets of tabs are vertically aligned with one another
at the rate of two at a time. With previous tamper
resistant closures using the hinged flange 22 and tabs or a
scored line, the removal of the closure requires that all of
the tabs or the entire scored line be severed virtually
simultaneously. Sometimes, a great deal of strength is
required to sever the tabs or the scored line. With the
present invention, the tabs can be severed easily, singly or
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in pairs, while always providing more than sufficient
strength to ensure that the tabs do not sever prematurely
during the initial installation of the closure on the
container or during shipping and handling. The present
invention permits a broad range of design relating to the
strength of the tabs.
.
