Note: Descriptions are shown in the official language in which they were submitted.
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"Device for closing a threaded neck of a container providing tamper-evidence"
The invention relates to a device for closing a threaded neck of a container
providing
tamper-evidence, a container with a threaded neck comprising such a device,
and the
use of such a device.
A large variety of closures for containers is known which attempt to give
evidence that
the container has been opened or at least has been placed in a condition for
opening
once it has been filled.
A separate induction heat seal (IHS) component is known which is used to seal
a
container in transit and up until first use, provides tamper evidence.
However, the
component which is formed as an induction heat seal foil requires a step of
heating
during the closure of the container. A tamper indicating closure with adhesive-
attached
gasket is known from US 4 747 499 A.
In other closure applications, design features such as bore seals and tamper
evidence
bands are used to overcome the requirement of a separate IHS component.
However,
in some of the known designs it is hard to identify whether the container
already has
been opened or not.
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Known from US 8 596 477 B2 is a retortable package with plastic closure cap
which
includes a tamper-evidencing band attached to the terminal end of a skirt of
the cap.
The band is an extension of the skirt and/or otherwise attached to the skirt
by a plurality
of bridges. This design requires a certain extent of the neck of the container
and the
breakage of skirt and band is not necessarily evident and in that case it has
to be
manually verified whether the band is broken from the skirt.
It is an object of the present invention to provide a device for closing a
threaded neck of
a container which is improved with regard to at least one of the
aforementioned issues
and/or disadvantages. Further, it is an object of the present invention to
improve a
container comprising such a device.
The object is solved according to the independent claims. Advantageous
embodiments
are the subject-matter of the dependent patent claims and/or can be gathered
from the
following description.
The gist of the invention is to provide a two-part device having a plug and a
cap,
wherein the cap comprises a piece of the front surface which is in mechanical
engagement with the cap and the mechanical engagement allows a rotational
force to
be transmitted from the piece to the plug. The piece of the front surface is
connected to
the remainder of the front surface by a material weakening. Preferably, the
piece can
be rotatably supported in the rotational direction in case the cap is rotated
in the closing
direction (usually clockwise rotation) and when the cap is rotated in the
opening
direction (usually anti-clockwise rotation) the piece can be broken from the
remainder
of the front surface by breaking along the material weakening. The material
weakening
can transfer a rotational force to the piece and further to the plug during
the capping
process, whilst in the reverse direction the material weakening can be
unsupported and
thus breaks on opening due to a friction of the plug on the inner neck of the
container.
This provides a tamper evident solution to a consumer, both visual and with an
audible/physical break. The invention does not require any modification to the
neck of
the container. Instead, existing outer geometry of containers, especially the
neck, can
be maintained and most importantly no modifications are required to existing
filling
equipment. Further, a linerless cap can be provided. The plug can provide a
leak-proof
seal to the neck of the container. The plug can have a diameter which is wider
than a
seal usually used to ensure firm and consistent contact is maintained. Once
the cap is
fully applied, the thread and the front surface of the cap can provide
additional pressure
to maintain the seal. The container does not have to be manufactured by
injection blow
moulding (IBM) which is proven to achieve a container having great accuracy
and
consistency. Further, sealing of an extrusion blow moulded (EBM) container,
especially
a bottle made of HDPE or a similar material, becomes possible, which
especially allows
an existing dairy application to remain light-weight. However, the material is
not limited
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to the application of HDPE but the container can also be manufactured from
PET, R-
PET, PP, PLA, PS or LDPE. The device can be applied to a wide range of closure
applications which require sealing of products and tamper evidence without
requiring
additional features on the external neck to provide a locating feature for a
tamper
evidence band to snap over, like existing forms of closures.
The invention provides (a) a cap and (b) a plug, wherein the cap comprises a
front
surface and a skirt surrounding the front surface, wherein the skirt comprises
an inner
thread for engaging with a thread of the threaded neck of the container,
wherein the
plug is at least partially arranged inside the skirt, wherein the front
surface has an inner
piece and an outer piece that surrounds the inner piece, wherein the inner
piece is
connected to the outer piece by a connection, wherein the connection between
the
inner piece and the outer piece has a material weakening, wherein the inner
piece is in
mechanical engagement with the plug, the mechanical engagement allowing a
rotational force to be transmitted from the inner piece to the plug.
The term "cap" according to the description encompasses a screw cap or closure
made
of plastic or metal which is screwed on and off a thread on a neck of a
container. The
cap can comprise continuous inner threads or lugs. The cap can be adapted to
be
reclosable together with the plug. The cap can further be adapted to at least
partially
cover the neck of a container. The cap can be adapted to be an over cap which
in use
can be positioned over the plug.
The term "plug" according to the description encompasses a plug which can have
a top
surface and a circumferential projection or plug extending at least partially
in a direction
transverse to the radial direction of the top surface. The top surface can be
adapted to
cover an opening at the neck of the container. The circumferential projection
which is in
use facing the opening of the neck is adapted to be in engagement of the inner
and/or
outer edge of the opening at the neck of the container. The plug or
circumferential
projection is adapted to protrude into the neck of the container. The plug can
comprise
two circumferential projections extending at least partially in a direction
transverse to
the radial direction of the top surface, one of the two circumferential
projections can be
adapted to engage at least partially with the inner edge or outer edge of the
neck of the
container. In case two projections are provided, the other one of the two
circumferential
projections can be adapted to engage at least partially with the other edge of
the neck
of the container which is not in engagement with the first of the two
projections. The
plug can be adapted to be inside the cap. The plug and the cap can be
manufactured
separately from each other. The plug can have a maximum diameter which is
greater
than the inner diameter defined by the thread inside the cap. Being
manufactured
separately from each other, the cap and the plug can be assembled by pushing
the
outside rim or outer circumference of the plug behind the inner thread of the
cap so that
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the cap and the plug remain together ¨ the plug remains in the cap ¨ to
provide a
consumer with a single unit once the device is removed from the container. In
a
preferred embodiment the plug can be designed as a plug seal which is adapted
to
seal the container, i.e. the opening at the neck of the container.
The term "front surface" of the cap according to the description encompasses a
surface
which is adapted to at least partially cover the opening at the neck of the
container. The
front surface can be bigger than the area surrounded by the edge of the
opening. The
front surface can have a closed surface, but it does not necessarily have to
be a closed
surface. Holes, gaps and/or windows in the front surface are possible.
The term "skirt" according to the description is a part of the cap which
surrounds the
front surface and extends in a direction transverse the plane of the front
surface.
Especially, the skirt and the front surface can confine an angle between 50
and 130 ,
preferably between 60 and 120 , more preferably between 70 and 110 , most
preferably between 80 and 100 . In a preferred embodiment the skirt and the
front
surface confine an angle of substantially 90 . The skirt can be structured to
increase
the contact grip for manual engagement to rotate the cap in closing direction
or
opening direction. The skirt can have ribs extending in radial direction
extending away
from the center of the cap. The skirt can have a circular shape. The circular
shape of
the skirt can be coaxial with the front surface.
The terms "inner piece" and "outer piece" according to the description
encompass
pieces of the cap which have a different distance with regard to the center of
the cap
which can be determined as a point in the plane of the front surface having
the same
distance to a circular shape defined by the skirt. The inner piece is arranged
closer to
the center of the cap. The distance between the outer piece and the center of
the cap
is greater than the distance between the inner piece and the center of the
cap.
The outer piece can be integrally formed or connected with the skirt. To
increase easy
handling and in order to reduce sharp edges, the connection between the outer
piece
and the skirt can be rounded.
The term "material weakening" according to the description is a structural
design or
configuration which leads to a weakening of the material so that the inner
piece can be
broken from or off the outer piece. This can be done in a way that the inner
piece can
be rotatably supported in the rotational direction in case the cap is rotated
in the closing
direction and when the cap is rotated in the opening direction the inner piece
is
unsupported and can be broken from the remainder of the front surface breaking
the
material weakening.
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When it is mentioned that the inner piece is connected to the outer piece by a
connection, more than one connection, i.e. 2, 3, 4, 5, 6, 7 or more
connections can be
possible. The connections can be arranged symmetrical around the inner piece
between the inner and outer piece. The connections can be provided around the
inner
piece, wherein all neighboring connections with regard to the circumference
can have
substantially the same distance. However, an unsymmetrical arrangement of the
connections can also be possible.
The term "mechanical engagement" according to the description encompasses a
contact of the inner piece with the plug that reduces a relative movement of
the inner
piece with regard to the plug when the cap is moved, for example rotated. In a
preferred embodiment, the plug can be forced by the mechanical engagement to
move
together with the inner piece when rotated in the closing direction. However,
the inner
piece can be held static by the plug by the resistance of the plug against
rotating, due
to the friction against the inner neck of the container when the cap is
rotated in the
opening direction in this preferred embodiment. As the cap continues to rotate
in the
opening direction, the resistance force of the plug can be specified to be
greater than
the breaking strength of the material weakening at the connection between
inner piece
and outer piece, resulting in the connection to be broken as the cap is
rotated further.
With regard to first closure of the container, the insertion of the plug can
be assisted by
an existing rotational application during the filling process which can reduce
the top
load required to push the seal plug within the neck preventing the requirement
for neck
support or additional material to strengthen this area.
Although the description refers to a detachable screw cap as a cap, the
invention can
also be used if the neck of the container has no thread. The cap can, for
example, be
lifted from the neck with a linear movement. In this respect, the cap can also
be
designed as a push-on cap. Alternatively or additionally, it is possible for
the cap to be
designed as a cap which can be lifted from the neck of the container by means
of a
pivoting or tilting movement. Each of the relative movements described (purely
linear
movement, mixed movement with a linear component, in particular tilting or
pivoting
movement) between the cap and the container can ¨ in addition to or as
alternative to
the relative rotary movement between the cap and the container - lead to a
break
between the inner part and the outer part which provides a tamper evidence.
For
designs that work with a linear movement or a pivoting/tilting movement, it is
not strictly
necessary that the inner piece is in a mechanical engagement with the plug,
which
allows a rotational force to be transmitted from the inner piece to the plug.
In these
designs it can be sufficient, if a mechanical engagement between the inner
piece and
the plug is provided that allows for a linear force to be transmitted from the
plug to the
inner piece / from the inner piece to the plug.
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According to a preferred embodiment, the inner piece is a center piece and the
outer
piece is a rim piece. This embodiment provides an inner piece which can be in
mechanical engagement with the plug at a point or an area which is arranged at
a
position in which the rotational force acting on the cap and the plug is
reduced. Thus,
the rotational force when rotating in the opening direction as well as when
rotating in
the closing direction can be decreased. Further, a symmetric arrangement can
be
provided which can be used to stabilize the inner piece and/or decrease the
effort in
construction and/or manufacture.
According to a preferred embodiment, the top surface of the inner piece and
the top
surface of the outer piece are arranged in the same plane. This allows for a
usual
appearance and a simple design. In addition, the tamper evidence can be
observed
when looking down from above the container.
According to a preferred embodiment, the inner piece or the plug comprises a
protrusion having a circumference which is correspondingly structured to a
recess in
the plug or the inner piece, respectively. The protrusion extends in a
direction which is
transverse to the plane of the front surface. Especially, the protrusion and
the front
surface can confine an angle between 50 and 130 , preferably between 60 and
120 ,
more preferably between 70 and 110 , most preferably between 80 and 100 . In
a
preferred embodiment the protrusion and the front surface confine an angle of
substantially 90 . A mechanical engagement of the inner piece and the plug can
be
insured and maintained. The mechanical engagement can be established by an
interference fit, a press fit, friction fit or form fit. In a most preferred
embodiment the
protrusion is structured as having a non-circular outer circumference and the
recess
having a corresponding non-circular inner circumference to establish a form
fit. The
shape of the circumference of the recess can comprise abutment surfaces of the
protrusion for a rotation in the opening as well as closing direction. The
protrusion and
the recess can be mechanically joined to obtain the mechanical engagement by
means
of a drive gear. The pitch of the teeth on the drive gear can be specified to
aid the
assembly process to maintain high levels of output by keeping alignment to a
minimal.
Once the seal plug is inserted into the cap being in mechanical engagement
with the
same, the seal plug is locked and maintained within the front surface of the
cap.
According to a preferred embodiment, the inner piece is formed as a disc-
shaped
element. The disc-shape of the inner piece, especially as a center piece,
provides the
possibility to obtain an inner piece being substantially symmetrical. The
inner piece can
be arranged inside the front surface with a small effort of construction
and/or
manufacture.
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According to a preferred embodiment, the cap comprises an inwardly extending
projection that supports an outer circumference of the plug allowing an axial
force to be
transmitted from the cap onto the plug. The axial force can be in the same
direction as
the longitudinal direction of the neck and/or container. By this, the cap can
be
unscrewed on the neck of the container and becomes in contact with the outer
circumference or rim of the plug to provide a "lifting" action away from the
neck. The
plug can remain in the cap.
According to a preferred embodiment, the projection is at least partially
provided by the
inner thread of the cap. Providing the projection as at least partially by the
inner thread
of the cap, it becomes possible that the contact with the outer circumference
or rim of
the plug is at least partially angled with regard to the longitudinal axis of
the neck or
cap which can obtain a "peeling" action of the plug away from the neck.
According to a preferred embodiment, the material weakening of the connection
between the inner piece and the outer piece is provided by the thickness of
the cap at
the connection being thinner than the thickness of the inner piece and the
outer piece.
This form of material weakening is easy to construct and to design so that the
breaking
strength of the material weakening can be controlled in a simple manner.
According to a preferred embodiment, the material weakening of the connection
between the inner piece and the outer piece is provided by the connection
having a
circumferential gap between the inner piece and the outer piece that surrounds
the
inner piece, whereby the gap is bridged by a least one bridge that connects
the inner
piece to the outer piece. This form of material weakening is easy to construct
and to
design, too. Thus, the breaking strength of the material weakening can be
controlled in
a simple manner. Further, the visual appearance with regard to the purpose as
a
tamper evidence is simple to recognize.
According to a preferred embodiment, the bridge extends at an angle to the
radial
direction. An angle to the radial direction, which can be between 50 and 130
,
preferably between 60 and 120 , more preferably between 70 and 110 , most
preferably between 80 and 100 , and can be in a preferred embodiment
substantially
90 , offers the possibility that the material weakening can even support
rotation of the
inner piece in the closing direction via the outer piece when rotated, whilst
in the
reverse direction can be unsupported and thus break.
When it is mentioned that the gap is bridged by at least one bridge, more than
one
bridge, i.e. 2, 3, 4, 5, 6, 7 or more bridges can be possible. The bridges can
be
arranged symmetrically at the inner piece. The bridges can be provided around
the
inner piece, wherein all neighboring bridges with regard to the circumference
can have
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the same distance. However, an unsymmetrical arrangement of the bridges can
also
be possible.
The invention also provides a container with a threaded neck and a device as
described above which is attached to the threaded neck.
The term "container" according to the description encompasses any receptacle
or
vessel, which can be especially a bottle-like, a jar-like or a tube-like
container. In a
preferred embodiment the container can have an extrusion blow moulded (EBM) or
an
injection stretch blow moulded (ISBM) neck or most preferably the container is
made
by extrusion blow moulding. .
According to a preferred embodiment of the container, the plug has a plug that
protrudes into the neck of the container, wherein an interference fit is
provided between
the outer circumferential surface of the plug and the inner circumferential
surface of the
neck.
According to a preferred embodiment of the container, the container is an
extrusion
blow moulded container.
According to a preferred embodiment of the container, the cap comprises an
inwardly
extending projection that supports an outer circumference of the plug allowing
an axial
force to be transmitted from the cap onto the plug, wherein in a first state
of the
container, the extending projection is spaced apart from the outer
circumference and in
a second state of the container, the extending part supports the outer
circumference of
the plug, whereby the cap is screwed further down onto the thread of the
threaded
neck in the first state of the container than in the second state of the
container. The
distance between the projection, which can be the inner thread of the cap, and
the
outer circumference of the plug insures that the plug can be pushed into the
neck of the
container without any mechanical interaction of the cap and the plug. However,
the
projection still allows for a lifting or peeling action of the plug away from
the neck. The
projection can be at least partially formed along the inner circumference of
the cap. The
projection can be formed in a plane which is substantially parallel to the
front surface.
An inclination of the projection with regard to the front surface is preferred
as the force
for lifting or peeling can be initiated at a portion of the outer
circumference of the plug
and by further rotation of the cap the portion of the outer circumference of
the plug
which acts with the projection is changed and/or increased. The projection can
be
formed as a continuous projection or as a projection having breaks so that the
projection is only formed along portions of the inner circumference of the
cap.
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The invention further provides a use of a device described above to close a
threaded
neck of a container that contains a product, especially a dairy food product.
The
container with the device can establish an airtight or nearly airtight storage
for the
product contained therein. The airtight or nearly airtight storage can even be
established after the container has been opened and closed again. The product
can be
sealed in the container. The device can also provide the user a tamper
evidence
feature to check before first opening. Applications can include chemical
packaging,
pharmaceutical, confectionary or any other product that may require sealing
and
tamper evidence within a container with a threaded neck. The product to be
stored in
the container can be a liquid and/or solid.
According to the description, the term "at least partially" encompasses that
the
respective component can be formed completely or in part or parts along a
respective
indicated section.
According to the description, the naming of a numerical value includes not
only the
actual numerical value, but also - in order to take into account in particular
manufacturing tolerances - a range around the concrete numerical value, which
can be
+/- 15%, preferably +/- 10%, of the indicated numerical value.
The description with regard to the device, especially the description with
regard to
similar terms used, holds for the container and the device being attached to
the
threaded neck of the container as well as for the described use.
Exemplary embodiments of the invention will now be described in greater detail
with
reference to the drawings.
It is shown in the drawings:
Fig. 1 an isometric view of a device for closing a threaded neck of a
container
providing tamper-evidence and a container;
Fig. 2 the device and the container of Fig. 1 in partially cut view;
Fig. 3 a detail of the device of Fig. 1;
Fig. 4 a sequence of steps when the container of Fig. 1 is opened for the
first time;
Fig. 5 the device and the container of Fig. 1 in partially cut view when the
container
has been opened for the first time;
Fig. 6 the device shown in Fig.1 seen from below and before being assembled;
Fig. 7 the device shown in Fig. 1 in partially cut view and being assembled;
and
Fig. 8 a further embodiment of a device for closing a threaded neck of a
container
providing tamper-evidence in partially cut view.
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Fig. 1 shows in a schematic view a device 1 for closing a threaded neck 2 of a
container 3 (see Fig. 2). The device 1 provides tamper-evidence. The device 1
comprises a cap 4 and a plug 5, which is formed as a plug seal. The cap 4
comprises a
front surface 6 and a skirt 7 surrounding the front surface 6. The skirt 7
comprises an
inner thread 8 for engaging with a thread 9 of the threaded neck 2 of the
container 3.
The plug 5 is arranged inside the skirt 7 and the plug 5 is pressed within the
neck 2 of
the container 3 by the front surface 4 when the cap 4 is screwed on the
threaded neck
2. The plug 5 comprises a top surface 16 for covering the neck 2 of the
container 3.
The front surface 6 has an inner piece 10 and an outer piece 11 that surrounds
the
inner piece 10. The inner piece 10 is connected to the outer piece 11 by four
connections 12. The four connections between the inner piece 10 and the outer
piece
11 each have a material weakening.
In the embodiment shown in Figs. 1 to 7, the material weakening of the
connections 12
between the inner piece 10 and the outer piece 11 is provided by the
connection 12
having circumferential gaps between the inner piece 10 and the outer piece 11
that
surround the inner piece 10 (see Fig. 3). The gaps are bridged by the four
connections
forming four bridges that connect the inner piece 10 to the outer piece 11.
The bridges extend at an angle to the radial direction of the cap 4 which is
substantially
90 .
Shown in Fig. 2 is that the inner piece 10 is in mechanical engagement with
the plug 5.
The mechanical engagement allows a rotational force to be transmitted from the
inner
piece 10 to the plug 5.
The inner piece 10 comprises a protrusion 13 having a circumference which is
correspondingly structured to a recess 14 in the plug 5 (see Fig. 6).
In the embodiment shown in Figs. 1 to 7, the inner piece 10 is a center piece
and the
outer piece 11 is a rim piece being connected to the skirt 7. Further, the top
surface of
the inner piece 10 and the top surface of the outer piece 11 are arranged in
the same
plane.
As can be seen from Fig. 3 the inner piece 10 is formed as a disc-shaped
element.
Fig. 2 shows that the plug 5 is in interference fit within the neck 2 of the
container 3.
The plug 5 comprises a projection 15 which extends substantially transverse to
the top
surface 16 and along a direction transverse to the radial direction of the
plug 5. The
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projection 15 is adapted to extend into the neck 2 of the container 3 from the
inside
forming a plug which protrudes into the neck 2 of the container 3. The
projection 15 is
pressed against the inside of the neck 2 of the container 3. The plug forms an
interference fit between the outer circumferential surface of the plug and the
inner
circumferential surface of the neck 2.
The plug 5 comprises a further projection 17 as a sealing lip that extends
substantially
transverse to the top surface 16 and along a direction transverse to the
radial direction
of the plug 5. The projection 15 and the further projection 17 are
substantially parallel
to each other. The projection 17 surrounds the outer edge of the neck 2 of the
container 3.
Fig. 4 shows the steps when the container 3 with device 1 is opened for the
first time.
Fig. 4a shows the condition in which the container 3 is closed by the device
1. Fig. 4b
shows that the cap 4 is rotated anti-clockwise and when the cap 4 is rotated
anti-
clockwise due to the mechanical engagement of the inner piece 10 with the plug
5
which is in interference fit within the neck 2 of the container 3, the
material weakening
of the connections 12 is strained and the connection 12 breaks (see Fig. 4c).
Formed by a section of the inner thread 8 of the cap 4 is an inwardly
extending
projection 18 that supports an outer circumference 19 of the plug 5 allowing
an axial
force to be transmitted from the cap 4 onto the plug 5 to lift or peel the
seal plug 5 from
the neck 2 of the container 3. In the closed state (first state) of the
container 3, the
inwardly extending projection 18, which can support the outer circumference 19
of the
plug 5 for allowing an axial force to be transmitted from the cap 4 onto the
plug 5, is
spaced apart from the outer circumference 19 and in a state between closed
state and
opened state (second state), the extending projection 18 is in contact with
the outer
circumference 19. Vice versa, when the cap 4 is screwed down onto the thread
of the
threaded neck 2 (Fig. 5), the contact between the projection 18 and the outer
circumference 19 becomes lost and the projection 18 and the outer
circumference 19
become spaced apart (Fig. 2).
Fig. 8 shows in a schematic view a further embodiment of a device 1 for
closing a
threaded neck 2 of a container 3 providing tamper-evidence in a partially cut
view. The
inner piece 10 is arranged off-center with regard to the cap 4 and the seal
plug 5. The
mechanical engagement of the inner piece 10 and the plug 5 is established by
the
projection 13 of the inner piece 10 extending into a recess of the plug 5.
