Note: Descriptions are shown in the official language in which they were submitted.
~002:940
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TAMPER EVIDENT CLOSURE
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FIELD OF THE INVENTION - -
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This invention~ relates to a tamper evident cloqure
and especially to a tamper evident screw cap for a
container, a package including quch a screw cap, and a
container adapted for use with such a ~crew cap.
It i~ desirable to provide a clear indication to a
purchaser that a package ha~ not been tampered with
especially where the package is a food package eg. a
coffee or jam jar. It i~ a current practise to provide
vessels, for example glass jars, with a closure cap
removably attached to the jar by means of screw threadq,
the cap comprising a closure portion (generally planar~
with a skirt depending from a periphery thereof, the skirt
having internal screw threads adapted to cooperate with
external threads on a neck portion defining an openin~ in
the jar through which access may be gained to the interior
of the jar. Such screw cap~ are commonly moulded of a
suitable plastics material, for example polypropylene.
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Such jars when used for certain products, for example
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coffee, are commonly supplied with a qheet material, for
example a ~etal foil, covering the opening and sealed to
the rim of the jar bounding the opening:
intactness of the foil when the screw cap is first removed
can provide some visual reassurance that the contents have
not been tampered with, aq well a~ the foil maintaining
the contents of the jar in good condition. However, the
foil may ~ometimes be damaged when first removing the
closure qo that this visual reaqqurance is not very
reliable and in any event a hypodermic syringe may be used
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to inject noxious material through the foil in a position
which is not readily noticeable at a casual inspection.
Furthermore, jars are not sealed when used for other
products, for example jam, with a separate foil qeal of
thiY type.
In GB-A-2203416 is described a tamper evident package
having a seal member secured over the mouth of a
receptacle and indicating mean~ joined to the seal member
proiecting through an opening in a cover member (in the
~ form of a screw cap) which is ripped off when the cover
member is moved from a closed condition towards an open
condition. However, with a such a package there i9 a risk
that the indicating means will merely be deformed should
unauthorised removal of the cover member occur and,
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following replacement of the cover member over the mouth
of the receptacle, returned to its apparently "~afe"
condition, or that the indicating means may accidentally
be detached (as it projects to some extent through the
opening). Furthermore, the indicating means provides a
substantially visual indication which is of little or no
benefit to a blind or partially-sighted person. In
addition, as the opening in the cover member i~ in
register with the seal member there is a substantial ri~k
that noxious substances may be introduced into the
receptacle without disturbing the indicating means,
through the opening itself, for example by a hypodermic
needle introduced between the sealing member and the
receptacle. Thus the packa~e deYcribed in thi~
specification has a number of disadvantages and does not
provide a package which is reliably tamper evident nor
convenient. -
`~ It has alYo been proposed, for example, in GB-A-
2149765 and GB-A-2163413 to provide a tamper evident cap
for a container comprising a closure portion with a skirt
depending therefrom, inter-engagin8 meanY on the interior
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of the cap and on the exterior of a neck portion defining
an opening in a container whereby to removably retain the
cap on the neck portion to close the opening, the cap
2002C~40
being removable form the container by an action including
rotation of the cap relative to the neck portion, the cap
further comprising at least one portion which is connected
to the remainder of the cap by fran8ible means and means
which is adapted to be engaged by a projection provided on
the neck portion of a container to which the cap has been
applied a~ the cap is rotated relative to the neck portion
to remove it therefrom and to thereby fracture the
frangible means but which is not fractured during initial
application of the cap to the neck portion wherein said
one portion of the cap comprise-q an indicator provided by
a frangible portion of the skirt which when fractured
becomes separated from the remainder of the skirt and
leaves an opening in the skirt, thus to provide an
indication that the cap has previously been removed from
the neck portion.
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In both of theqe patents said one portion of the cap
is provided by a band connected to the skirt of the cap by
the frangible means. On rotation of the cap to remove it
from a container the band is prevented from rotation by
engagement of the projection on the neck portion of the
container with the means on the cap and the band is thus
separated from the skirt portion. While thii may provide
an indication that a container has previou_ly been opened
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in some circum~tance~, the band may remain around the neck
portion and mi~ht only be ~een to have been separated by
very close examination. Even if the band become~
completely detached, for ~ighted people this may provide
an indication of tampering ~though only if an intact cap
is close by for compari~on) but blind or partially sighted
people would meet with difficulty in assessing the
condition of the cap.
OBJECTS OF THE INVENTION
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One of the various objects of the present invention
is to provide an improved tamper-evident cap for use in
closing an opening in a container.
Another of the objects of the invention is to provide
an improved tamper-evident package.
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SUMMARY OF THE INVENTION
In one a~pect the invention may be considered to
: provide a tamper evident cap for a container, comprising a
closure portion with a skirt dependin8 therefrom, -;~
interengaging means on the interior of the cap and on the
exterior of a neck portion defining an opening in a -~
2002940
container whereby to removably retain the cap on the neck
portion to cloqe the opening, the cap being removable from
the container by an action including rotation of the cap .: ~-
relative to the neck portion, the cap further compriqing
at leaqt one portion which i~ connected to the remainder ,~ ~
of the cap by frangible mean~ and meanq which is adapted ~ ~,
to be engaged by a projection provided on the neck portion :~
of a container to which the cap has been applied a~ the cap :.
iY rotated relative to the neck portion to remove it ;:
therefrom and to thereby fracture the frangible meanq
which i.q not fractured durin~ initial application of the .;i:;.;.. '~
cap to the neck portion wherein qaid one portion of the '~
cap compriseq an indicator provided by a frangible portion ~ ',;,;:',;
of the ~kirt which when fractured becomeq qeparated from
the remainder of the skirt and leaves an opening in the .
qkirt, thu~ to provide an indication that the cap ha~
previou~ly been removed from the neck portion.
Preferably the interengaging meanq of a cap in accordance
wit~ ,the invention haq internal ~crew threads adapted to
cooperate with external threadq on the neck portion. ':, ~
Preferably the indicator comprise~ an inwardly projecting .
engagement portion compriqing a firqt qurface adapted to :'
be engaged by the external projection from the neck :~:.. .:~.
portion of a container to which the cap ha~ been applied ` "-` -
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Z002940
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as the cap is rotated to remove it from the neck portion
thereby to apply a force to the franKible portion cau~in~
it to fracture. Conveniently the engagement portion
further comprising a second surface adapted to engage said
external projection of a container as the cap i~ first
applied thereto and to permit the indicator to pa~s the
projection a~ the cap iq fir3t applied to the neck portion
without fracture of the frangible portion.
The frangible portion is preferably attached to the
remainder of the skirt by frangible supports which extend
between a body of the frangible portion and portions of
the ~kirt at either side, axially, of the body. Suitably
the ~upports have a relatively ~mall circumferential width
(by comparison with the circumferential width of the
body).
In a preferred screw cap in accordance with the ~
invention the body has a weakened portion at a ~ -
circumferentially central region of the body which extends
generally axially acros~ the body thuY to divide it into
two psrts. The weakened portion suitably ha~ a
circumferèntial width which is between about 5% and 10% of
the circumferential width of the frangible portion.
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Preferably the opening within which the frangible portion
is supported extends between about 30 and 50 of arc
around the skirt, suitably about 40. .~ :
The preferred screw cap compriYes two pairq of
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frangible supports each pair associated with one of the
two parts of the frangible portion. The ~upports of each . ~:;:
pair are axially opposed at oppo~ite side~ of the body and
are conveniently situated at a central region of the ...
as~ociated part. Conveniently each of the fran~ible :
~upports extend~ acro~s between about 10 and 15% of the
circumferential width of the as~ociated part of the
frangible portion, suitably about 12.5X and is dispo3ed
with its centre ~ub~tantially at the centre of the - r~
a~sociated part, considered circumferentially. .:-~.d
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Preferably a screw cap according to the invention .~
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comprises two inwardly projecting portions on the .~- '".'.~1!'
frangible portion, po.~itioned at circumferentially
opposite end portions thereof. The first, engagement
portion is adapted to be engaged by a projection from the .
neck of the container as afore~aid, whilst the second
projecting portion i~ adapted to engage the neck portion .~
when the frangible portion is fractured to militate . .;
again~t the frangible portion becoming forced between the .~
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~ 200Z940
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neck portion and the remainder of the skirt as the cap i~
rotated to remove it. Preferably, in addition, in the
preferred screw cap, the second end portion is configured
so that when the supports are fractured during removal of
the cap, the second end portion is urged into en~agement
with part of the skirt boundin8 the frangible portion
whereby to urge the franeible portion away from the skirt
and, in some cases, to cause the weakened portion to
fracture.
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There now follow detailed descriptions to be read
with reference to the accompanying drawings of two ~crew
caps embodying the invention. It will be reali~ed that
theqe qcrew caps have been selected for description to ~;
illuqtrate the invention by way of example and not of
limitation of the invention. ~ ;
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BRIEF DESCRIPTION OF THE DRAWINGS ~ -
In the accompanying drawings; ;~ ~
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Fieure 1 is a perspective view of a first cap
embodyln~ the invention;
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Figure 2 i~ a perspective view showing part of a
first container embodying the invention;
Figure 3 is a fragmentary perspective view showing
part of the fir~t illustrative cap;
Fi~ure 4 is a view in section of part of the first :~-
illustrative cap showing an indicator and ~howing in chain :~
dot line a frangible portion of the indicator as it is ...
fractured during the initial opening of the container;
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Figure 5 is a view in section showing an indicator ;
and screw threads of the first illustrative cap; . -~
Figure 6 is a perQpectiVe view showing part of a ~, :
second container embodying the invention;
Figure 7 is a view in section of part of a second
illu~trative oap showing an indicator;
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Figure 8 i~ a plan view of part of the second
illustrative cap showing the indicator viewed from within . ~.
the cap; and ,`, .`.
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Figure 9 is a view of the second illustrative cap
generally correqponding to Figure 7 but showing the
indicator as it is fractured during initial opening of the
second illustrative container.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The firqt illustrative screw cap 10 iY intended for
use with a container, namely a glass jar 11 which is
especially suitable for use in storing granulated coffee
or the like. The first illustrative tamper evident screw
cap 10 comprises a substantially flat closure portion 12
from which a ~kirt 14 dependq. The skirt 14 has internal
screw threadq 16 (qee figure 5) adapted to cooperate with
external threadq 18 on A neck portion 20 which defines an
opening in the jar 11, whereby to retain the cap on the
neck portion 20 to close the opening. The first
illustrative cap 10 and jar 11 are provided with four-
start thread~; however, any convenient number of start~
may_ ~e used, e.g. a six-~tart thread which may simplify
manufacture.
The qkirt 14 comprises two indicators 22 (positioned
at oppoqite qides of the skirt 14) which are frangible.
Each indicator 22 compriseq a frangible portion including
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a body 24 and frangible support~ 26. The frangible
supports 26 extend between the body 24 and portion~ of the
skirt 14 at either ~ide, axially, of the body 24 (that is
the portion~ nearer to the closure portion 12 and to the
rim of the skirt 14 remote from the clo~ure portion 12,
respectively). The frangible supports 26 have a
relatively small circumferential width by compari~on with
the circumferential width of the body 24, suitably bein8
about 6% of the circumferential width of the whole of the
body 24. The body 24 ha~ a weakened portion 29 at a
circu~ferentially central region of the body. The
weakened portion is in the form of a groove 28 (po~itioned
internally of the skirt 14) which extends generally
axially across the body to divide it into two parts (see
figure 4). The width of the groove 28 is about 7.5% of the
circumferential width of the body 24. The body 24 further
comprises two inwardly projecting portions 30, 32
positioned at circumferentially opposite end portions of
the body 24 one on each of the two parts of the body. The
first portion 30 comprises a first ~urface 34 and a ~econd
surface 36 the purpo~e of which will be described
hereinafter. The end portion of the body 24 adjacent the
second projecting portion 32 comprise~ a surface 38, the
purpose of which will be described hereinafter.
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2002940
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The first illustrative cap lO can readily be moulded
from plastics material by the techniques commonly used in
moulding caps and can be applied to the neck of an
appropriate jar or other container including the necessary
projection~ 40 by the techniques commonly u~ed without
there being any need to modify the operation of existing
equipment. It iq, of course, neceQsary to select an
appropriate plastics material which will fracture when
suitable pressure is applied in opening the container and
to select the dimension~ of the frangible supports 26, the
weakened portion 29 and the width of the groove 28 so that
the indicator 22 functions correctly. A suitable plastics
material from which to manufacture the illustrative cap lO
is polypropylene. Although other sufficiently brittle
polymers, for example, polyQtyrene or styrene
acrylonitrile copolymer may be used.
The neck portion 20 of the jar 12 as well as having
screw thread~ 18 is provided with four projections 40
~paced equisngularly around the neck portion 20 but at the
same po~ition axially of the neck portion. There may,
however, be provided more, or fewer, projections, e.g.
six~ likewise equiangularly disposed. Each of the
projections comprises a stop face 42 which is
~ubstantia11y rmdia1 of the necù portion anù meet- a
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200XC~40 '
14
sloping cam face 44 at an apex, the cam face 44 smoothly ~- -
merging at the end opposite the stop face 42 with the ,-
remainder of the neck portion 20.
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When the cap 10 is applied to the neck portion 20 the
threads 16 on the cap engage with the threads 18 of the
neck portion 20 and the cap 10 is rotated to tighten the
closure portion 12 into sealing engagement with the rim of
the neck portion 20. It will be understood that the mouth
of the neck portion may, if desired, be also closed by a
sealing member in known manner e.g. a foil which may be
iecured to the rim of the neck portion by adhe~ive as is
common practice. The ~ealing member may be applied
carried within the cap and pressed into adherent
en~agement with the rim by pres~ure applied by the cap as
it iY applied in known manner. After the closure portion
12 has been tightened against the rim, the indicators 22
are then positioned relative to the projection~ 40 in the
relationship 3hown in figure 4 in full line, namely with
the fir~t surface 34 of the fir~t projecting portion 30 of
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the body 24 adjacent the stop face 42. As the cap 10 is
applied to the neck portion 20 it will be rotated in the
direction indicated by the arrow A relative to the neck
portion. As the indicator 22 approaches the position in
- which it is ~hown in full line in figure 4, the second
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surface 36 of the projecting portion 30 will engage the
cam face ~4 of the projection 40 from the jar and permit ;
the frangible portion to pass the projection 40 a~ the cap
is first applied to the neck portion 20, without fracture
of the frangible portion, the surface 36 riding over the
cam surface 44 and easing the projecting portion 30 past
the projection 40. Likewise if the second projection 32
from the body 24 ~hould engage the projection 40 during
application, the projecting portion 32 is so ~haped a~ to
likewise engage the cam surface 44 and ride over the
projection 40 without fracturing the frangible body 24 or
the frangible supports 26. :
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When the first illustrative cap 10 is first to be
removed from the neck portion 20, it is rotated in the
direction indicated by the arrow B (fi~ures 3 and 4). As '~
can be seen viewing figure 4, the second surface 34 of the
:-
projecting portion 30 is moved firmly into engagement with
: the -qtop face 42. Continuing attempts to rotate the cap
10 t~ unscrew it from the neck portion 20 force the body 24
toward~ the po~ition in which it is shown in line in
figure 4 (and in which it i~ shown in figure 3). The body
24 pivots about the frangible support~ 26 and the weakened
portion 29 of the body at the bottom of the groove 28 act~
as a hinge ~o that the body 24 begins to bend at the
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weakened portion 29. Continued rotation of the cap 10
breaks the frangible supports 26 and forces the surface 38
of the body 24 into engagement with a part 39 of the skirt
defining the opening within which the frangible body 24 is
po~itioned. When the qurfaces 38, 39 come into
engagement, the stop face 42 still continues to push
against the first surface 34 of the projection 30 and
continues to cause the body to bend at the weakened
portion 29 until the force exerted on the weakened portion
29 may be sufficient to cause it to fracture (as shown in
chain dot line in figure 4). The groove 28 is made as
narrow as conveniently possible so that, when pressure is
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exerted as aforesaid during opening, the innermo~t edge
portions contact each other as soon as possible.
Continued pressure then causes these edge portion~ to act
a~ a pivot and thus applies increasine tension to the ;~
weakened portion 29, finally cau~ing it to break. A~ can
be seen from figure 4, the second projecting portion 32
from the body 24 engages the surface of the neck portion
20 wh,en the body 24 is fractured and is confi~ured to
prevent the body 24 becoming forced between the neck
portion 20 and the remainder of the skirt 14 as the cap is
rotated to remove it. ~-
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The broken parts of the indicator 22 have thus become
completely separated from the remainder of the skirt 1
and fall away leaving an opening in the ~kirt.
A second illu~trative cap and second illustrative
container are described hereinafter.
The iecond illustrative cap and ~econd illustrative
container are generally similar to the fir~t illu~trative
cap and container, except a~ hereinafter de~cribed and
like numbers are used to indicate like part~ in the
drawing~
The second illu~trative container namely a glass jar
11_ (see Figure 6~ i~ identical with the first
illustrative container, ~hown in Figure 2, except that it
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is provided with a cylindrical collar 50. The collar 50
extends around the neck portion 20 remote from itY rim.
The collar 50 is intended to be Ylidingly received, as a
cap lO is applied to the neck portion 20, in the skirt 14
~o that the rim portion of the ~kirt 14 remote from the
clo~ure portion 12 cannot be squeezed inwardly. Thus
distortion of the skirt in ~uch a manner that the
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indicators 22 might be eased, without fracturing, passed
the projections ~0 when the cap 10 is rotated to remove
it, is prevented.
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The ~econd illustrative cap is ~enerally similar to
the first except in the region of the indicator 20, as
described hereinafter with reference to and ai shown in
Figure 7 to 9 of the drawings. The body 24 of the
indicator i8 connected to the ~kirt 14 not merely by
axially extendin8 fran8ible support~ 26 but also by a
circumferentisl frangible support 56 extending between an
end portion of the indicator adjacent the projecting
portion 30 and the skirt 14. At the circumferentially
opposite end of the indicator there is no corresponding
support. However, the skirt 14, adjacent the second
projecting portion 32, i8 formed with a guide pas~age 52 ~ -
terminating, remote from the indicator, with a stop face
part 39 of the skirt 14. A web 54 overlies the passage 52,
spaced from the neck portion 20.
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As the ~econd illustrative cap lOa iq rotated to ;~
remove it from the neck portion and the portion 30 engages
the projection 40, the frangible support 56 first
; stretches and finally snaps: however the support 56 acts ~ ; ~
to assist in retaining the portion 30 firmly in contact ~
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with the projection 40 (preventing the indicator being
lifted and eased passed the projection 40) and to prevent
the body 24 twisting, thus facilitating effective
operation of the indicator. Additionally, as the body 24
iY forced by the projections towards the part 39 it is
guided by the thin, relatively flim~y, web 54 into the
passage 52 in which the body is slidingly received. When
the Yurface 38 of the body engages the part 39 of the
qkirt, the qecond illustrative cap 10_ functions in a
similar manner to the first, the portion 32 preventing the
body 24 becoming jammed between the skirt 14 and neck
portion 20. However, the paqsa~e 52 guideq the body 24
aqsisting in holding the portions 30, 32 in contact with
the neck portion 20 and preventing the body 24 twi~ting
and thuY ensuring that the indicator operates as intended.
The indicator of the second illuqtrative cap functions
Yatiqfactorily the body 24 being reliably ejected from the
opening in the skirt 14 as the cap 10_ iq removed.
The weakened portion of the Yecond illustrative cap
10_ primarily actq as a hinge and does not normally break
when the cap is removed from a container.
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2002C~40
Any rotation of the caps 10 of the illustrative
package~, sufficient to permit acce~s to the contents of
the jar 12 causeY the frangible supports 26,56 to fracture
and the body 2~ of the indicator to become ~eparated from
the remainder of the skirt. Thi~ provideY a clear visual
indication that the cap 10 ha~ previouYly been removed
from the jar 20 and the ab~ence of the indicator iY also
readily detectable by touch so that it alqo provide~ a
warning to a blind per~on.
Becau~e the openin8 in the ~kirt 14 formed when the
part~ of the indicator 22 fall away ~after fracturing the
frangible supportq) i~ dispo~ed below the rim of the neck
portion 20 there ix little or no po~sibility of any
contaminant being introduced into the jar through the
opening in the Ykirt and the neck portion, e~pecially
where a separate Yealing member e.8. a foil is secured
over the mouth of the neok portion.
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