Note: Descriptions are shown in the official language in which they were submitted.
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SEALING MEANS FOR A CLOSURE, CLOSURE AND PROCESS
FIELD OF THE INVENTION
The invention relates to a sealing means for closures, especially sealing
means for closures
for packages for liquids such as beverages. In particular the invention
relates to a sealing
means for containers for carbonated liquids such as soft drinks but is well
adapted to seal
other containers such as glass or PET containers with contents at above or
below atmos-
pheric pressure or having gaseous components or requiring a hermetic seal. The
invention
further relates to a closure and a process for making and applying of a
sealing means, re-
spectively a closure.
BACKGROUND OF THE INVENTION
Seals of closures are generally manufactured from several types of plastic,
such as Polyethyl-
ene (from now on PE) or Polypropylene (from now on PP) or EVA-based materials
such as
DarexTm liner material. The latter is mainly used for the manufacture of liner
closures; the
material is less hard and less durable than PE. Softer material such as Low
density PE (LDPE),
ethylene vinyl acetate (EVA) or compounds based on polyolefine raw materials
are often
used as sealing material. More rigid materials such as Polypropylene are often
used as a
shell material of closures.
From prior art a vast amount of documents is available which are directed to
closures and
caps for sealing of containers. A selected range is explained subsequent.
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EP0076778 of Albert Obrist AG was filed in 1982 and is directed to a closure
cap made of
plastics material which has a circular outer sealing lip having a thickness
which continuously
decreases versus its free end. The outer sealing lip is arranged in the region
of the joint be-
tween an outer vertical skirt and a disc like top portion and points obliquely
inwards. At its
smallest diameter, the sealing lip has a rounded sealing portion. Below the
sealing portion
the sealing lip is widened outwards in the manner of a funnel to receive a
container opening.
However, due to the obliged arrangement of the sealing lip the sealing lip
often tends to be
distorted during application, especially crooked application onto a neck of a
container. A
further disadvantage consists in that due to the inclined arrangement this
seal is relatively
rigid and therefore not very good in adjusting in lateral direction.
US4489845 was filed in 1984 and assigned to Albeit Obrist AG. US4489845 is
directed to
a screw-cap for closing a container opening. The cap has a sealing lip which
is affixed to the
cap top. The inner side-wall of the outer sealing lip has a diameter which is
greater than the
outer diameter of the container outer wall. A clamping device, which can be
designed as an
inner seal, creates a contraction of the cap top when the screw-cap is screwed
onto the con-
tainer due to deformation of the outer shell of the closure, by which means
the sealing lip
shall be pressed against the container mouth. In this manner the sealing lip
is only pressed
radially against the container mouth during the course of the screwing-on
process. Thereby
over-stretching and damage to the material of the sealing lip shall be
prevented. In an en-
gaged position the sealing lip engages around the upper outer rim of the neck
of a con-
tainer opening. One disadvantage is that the described deformation of the
closure is related
to extensive operating forces. A further disadvantage consists in that the
outer shell tends to
break due to extensive stress and deformation (stress cracking) which results
in complete
failure of the closure and loss of the product.
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EP0114127, filed in 1984, of Continental Whitecap and EP0176205, filed in
1985, of Sun
Cost Plastic both disclose a seal having two sealing flaps arranged in general
V-shape, When
the closure is drawn down onto a container, the flaps will deform in
accordance with the
cross section of the sealing surface area of the container including down
inside of the mouth
of the container and down along-side the exterior surface of the neck finish
to provide effec-
tive sealing contact with the container sealing area. The sealing flaps are in
engaged posi-
tion laterally supported and pressed against the neck of the closure.
EP0529383, filed in 1992 by Jacob Berg GmbH, is directed to a plastic screw
cap for con-
tainers, in particular pressurised beverage containers. The closure comprises
an annular seal-
ing strip which is integrally moulded with the shell of the closure. Adjacent
to the sealing
strip a bead is arranged pressing the sealing strip against an upper outer
edge of the neck
of a container. One disadvantage consists in the reduced lateral
adjustability.
EP0770559, filed in 1996 by Sacmi Cooperativa Meccanici, is directed to a
plastic screw
cap with a liner made by compression moulding. The closure comprises an
annular lip that is
designed to support a liner and protrudes from the disk-like portion
concentrically with re-
spect to the cylindrical outer wall. The annular lip is acting as a shoulder
for a sealing liner,
so that the liner, when the cap has been applied to the container, engages to
the rim of the
mouth of the container.
US4489844 was filed in 1982 and assigned to Charles A. Breskin Assoc. Inc. is
directed to a
reusable cap for closing carbonated beverage containers or the like. The
closure consists of
an internally threaded shell having a fitment therein which sealingly engages
the neck of
the beverage container at the free edge thereof. The shell and the fitment are
constructed of
different plastic materials and are injection moulded in different portions of
the same
moulding cavity. First, the fitment is formed and then, without moving the
fitment from the
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position in which it was formed, the shell is formed, to produce a unitary
structure in which
substantial portions of the fitment are imbedded in the shell.
US5447674 filed in 1993 by Frank Schellenbach is directed to a method and a
mould core
for the production of two-component injection moulded plastic closure. A mould
core for use
in a two-component injection moulding method is presented for two-component
injection
moulding of plastic closures for containers. The mould core consists of first
and second sub-
core. After injecting the first substance, one sub-core or tool element is
displaced by a prede-
termined amount relative to the first moulding. One disadvantage of the
described proce-
dure is that displacement of the core can only take place when the material of
the first stage
has sufficiently congealed which results in a significant delay. A further
disadvantage con-
sists in that the geometry of the closure and the seal is significantly
restricted due to the
mould function. A still further disadvantage is that the seal may not comprise
a radial pro-
trusion which would result in an undercut the mould because displacement of
the mould
core would not be possible anymore.
W003011699 filed in 2002 by Bericap is directed to a closure cap comprising an
internal
sealing skirt which is substantially truncated and converges from the sealing
skirt base to-
wards the free end of the sealing skirt. The inside of the sealing skirt is
designed to co-
operate with the outside of the neck. The internal diameter of the sealing
skirt towards its
free end portion is designed smaller than the external diameter of the neck.
As described the
closure can comprise an annular v-notch designed to improve attachment of a
liner to the
rim of the neck or contact between the liner and the rim.
From the inventor of the herein disclosed invention a series of closures for
carbonated bev-
erage containers is known and described among others in W099/03746 (1998),
W099/03747 (1999), W089/12584 (1989), W003/022701, W000/56616,
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W0/56615. The seals of these closures are all having in common that an annular
sealing
rib, which initially is projecting downwardly and inwardly with respect to the
top portion of
the closure, is turned inside-out during application onto a neck of a
container.
A problem of closures known from prior art is that the seal of these closures
often fails at
high internal pressure and content leaks due to doming or lift-off of the top
portion of the
cap. Especially with caps which seal primarily on the inner peripheral surface
or on the an-
nular top surface of the neck of the container this problem may occur. A
further problem
often occurring with closures known from prior art is leakage of the seal due
to high internal
pressure in the container and additional top load applied to the top of the
closure, e.g. due
to stacking of several containers. The reason for this can be found in
deformation of the
closure and therewith related displacement of the seal. A further problem of
the closures
known from prior art is that the seal fails due to crooked application of the
closure onto a
neck of a container.
It is an object of the present invention to provide a sealing means for
closures, especially
closures for containers for carbonated beverages and other hot or cold
liquids, which has an
improved capability to adapt to necks of containers, especially necks of
containers having a
certain imperfection or damage.
It is a further object of the present invention to provide a sealing device
and closure suitable
for carbonated beverages and other hot or cold liquids, to offer advantages in
production
such as low cycle time and less material consumption and to be still pressure
tight at high
internal pressures and top load.
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SUMMARY OF THE INVENTION
The closure having a sealing device according to the present invention is
suitable to be en-
gaged with containers comprising a standardized neck of a container. The
standardized neck
comprises an outer peripheral surface with an external thread. The outer
peripheral surface
blends by an edge surface into an annular top surface which forms the upper
end of the
container when it is standing upright. Between the annular top surface and the
external
thread an outer free surface extends over a length of approximately 1 mm to 3
mm of the
neck which is not covered by the thread and suitable for sealing purposes.
Furthermore the
neck of the container comprises a cylindrical, inner peripheral surface
adjacent to the annu-
lar top surface.
Beside a sealing means according to the present invention the closure
comprises in general
a base with a disc like top portion and a therewith adjacent outer skirt with
retaining means,
such as an internal thread, suitable to be engaged with corresponding
retaining means such
as an external thread of the standardized neck of a container as described
above. If appro-
priate the closure may have a hinged lid which is interconnected to the base
of the closure
and suitable to sealingly close an orifice.
Preferably the plastics material of the closure is high density polyethylene,
low density poly-
ethylene, polypropylene or a combination thereof. Where the container is to be
used for
gaseous liquids, the plastics material preferably has a very low porosity to
the gas.
The herein described sealing means comprises in a first embodiment an
essentially P-shaped
cross-section. The sealing means comprises a cylindrical skirt extending in
general perpen-
dicular from the disk like top portion of the closure into the closure inside
radially distanced
to the outer skirt of the closure by a gap having a defined width and depth.
The inner skirt,
which in general has with respect to its cross section the form of a free
standing lateral ad-
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justable downward leg, is at its base preferably interconnected directly to
the top portion of
the closure. In the area of its opposite lower free end the inner skirt turns
into at least one
toroidal sealing ring which protrudes above the side surface of the
cylindrical skirt. The tor-
oidal sealing ring interacts in closed position radially from the outside with
the outer free
surface of the neck of the container via a designated contact surface, whereby
this contact
surface is arranged preferably as far down onto the free surface of the neck
of the bottle as
possible to reduce influence of known problems, e.g. doming, bottle finish
damage at the
upper outside rim, lifting of closure, which might occur. The cylindrical
skirt acts as a base
for the toroidal sealing ring and has a length which avoids negative
interaction of the tor-
oidal sealing ring with the thread of the neck of the container. The at least
one toroidal
sealing ring is preferably shaped such that it seals primarily due to annular
tension. There-
fore the sealing means is preferably freestanding even in radially deformed
position when
applied onto the neck of a container. In a preferred embodiment the gap
between the inner
and the outer skirt is designed such that no contact occurs between the
sealing means and
the outer skirt at any time.
The toroidal sealing ring comprises a protrusion which is arranged in engaged
position to-
wards the neck of the container and defines a contact zone. In difference to
seals known
form prior art which are mainly subject to annular pressure or bending forces
in the root, the
in general perpendicularly freestanding sealing means according to the present
invention
mainly seals due to annular tension forces occurring in the toroidal sealing
ring when ap-
plied onto the neck of a container. The sealing means is designed such that it
is capable to
adjust/compensate a certain amount of lateral and/or radial offset or
distortion of the neck
of the container. The cylindrical skirt, which acts as the base, provides a
certain flexibility in
lateral/radial direction. Good results are achieved in that the proportion
ratio vertical length
to radial thickness of the base of the sealing means, which is arranged
between the top
portion of the closure and the toroidal sealing ring, is at least 1:1
preferably 4:1. Depending
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on the field of application further aspect ratios are relevant such as the
radial thickness and
shape of the base of the sealing means and the radial thickness of the annular
sealing ring
and the aspect ratio of the vertical length to the radial thickness of the
annular sealing ring
and the gap between the inner and the outer skirt.
In a further embodiment the seal has an in general R-shaped cross-section
whereby the P-
shaped cross-section blends at the inside into an inner top surface of the
closure. Said blend
is shaped such that it forms a second sealing region with the edge surface of
the neck of the
container which causes, when the edge surface presses onto the blend, the
annular sealing
ring to be pulled, due to controlled deformation of the base, inwardly onto
the outer free
surface of the neck of the container. Depending on the field of application
the blend inter-
connects the base and the top surface smoothly by a concave shape having a
radius or by a
ramp like shape or by a convex shape protruding locally outwardly.
In a preferred embodiment the aspect ratio between the radial thickness of the
annular seal-
ing ring and the base is in the range of 2:1 and 3:1 (depending on the field
of application
other aspect ratios may be appropriate). The aspect ratio between the vertical
free length of
the annular sealing ring and its radial thickness is preferably in the range
of 1:1 and 4:1.
Depending on the field of application other aspect ratios are appropriate. The
shape of the
cross section of the annular sealing ring and the eccentricity of the contact
surface with
respect to the base of the sealing means is of further relevance for the field
of application
because these parameters influence the distribution of annular tension forces.
The shape and the alignment of the base of the sealing means is relevant for
the perform-
ance and the physical behavior of the sealing means. E.g. if the base of the
sealing means is
inclined (conically) at an angle with respect to the top of the closure, the
pop on of the clo-
sure onto the orifice (opening) of the container becomes more difficult and
failures due to
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mismatch are more likely. One reason for this is that the distribution of
forces and the initial
widening of the seal become more difficult.
A preferred embodiment of the sealing means and the closure are made by an
injection
moulding process, respectively two-component injection moulding process, in a
multi-
component mould whereby a sealing liner is made in that a first plastic
material is injected
in liquid form into a first cavity onto a core of a mould cavity where the
first material form-
ing the liner congeals. Afterwards the liner is displaced with the first core
into a second cav-
ity position wherein a second material for an outer shell of the closure is
injected into the
second cavity. The material of the sealing liner and the material of the outer
shell are
thereby integrally joined to each other.
To optimize the production process the area in the cavity of the sealing-liner
which is not in
contact with the first core is preferably shaped such that the sealing-liner
can be taken out
of the first cavity without retaining forces. Therefore hindering undercuts
mainly extending
perpendicularly with respect to the displacing direction or the core are
avoided. By the de-
scribed injection moulding process a firm bonding is obtained between the
liner and the
shell material. In difference to the two-component closures as known from
prior art made by
a compression moulding process, the herein disclosed invention results in more
reliable seal.
Problems which typically occur when demoulding of closures made by compression
mould-
ing, where the shell of the closure is made first and the sealing liner
second, do not occur
with the herein described invention. The outer shell is preferably made out of
Polypropylene
(PP) or High Density Polyethylene (HDPE) whereby the liner is formed out of a
softer mate-
rial such as EVA, LDPE or a compounded material based on polyolefinic raw
materials. The
embodiment of the closure further comprises a sealing means which interacts
with an outer
thread-free peripheral cylindrical surface arranged between the thread and the
annular top
surface of the neck of the container.
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A preferred embodiment of the sealing means for sealing of a neck of a
container comprises
a radially deformable outer sealing means suitable to be engaged with an outer
free surface
of the neck, whereby the outer sealing means has an in general P-shaped cross-
section with
an annular base and an annular sealing ring arranged at a free end of the
annular base,
protruding radially inwardly above the inner surface of the base and forming
in engaged
position with the neck a first sealing area with the outer free surface.
In a further preferred embodiment the sealing means has an outer sealing means
with an in
general R-shaped cross-section. A blend is arranged at the base and
interconnects the base
with a vertical top surface of the closure. The blend may form in engaged
position of the
sealing means and the neck a second sealing area between an edge surface of
the neck and
the outer sealing means. The outer sealing may be shaped such that by
interaction between
the edge surface and the blend the outer sealing means controllably deforms
such that the
annular sealing ring is pressed more firmly against the outer free surface of
the neck. The
blend can have, depending on the field of application, different shapes: e.g.
a ramp-like
cross-section, a convex cross-section or concave cross-section. When the blend
is designed a
smooth interconnection the, it preferably has a radius R which is larger than
the radius of
the edge surface of the neck of the container.
In a further embodiment the sealing means, respectively the closure may
comprises a liner
made out of a liner material. Thereby the liner may comprise an inner skirt
which extends
vertically along an outer downward leg. An annular sealing ring, made out of
liner material,
may be arranged a the end of the inner skirt.
In addition the sealing means may comprises a bore seal whereby the bore seal
may be
made out of liner material and may have a core made out of shell material.
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BRIEF DESCRIPTION OF THE DRAWINGS
The sealing means and the closure according to the present invention are
explained in more
detail according to preferred embodiments.
Fig. 1 shows a closure with a sealing means in a perspective view from
below;
Fig. 2 shows the closure according to Figure 1 in a perspective view from
above;
Fig. 3 shows a closure with a first embodiment of a sealing means in a
side view;
Fig. 4 shows a cross cut through the closure according to Figure 3 along
line AA;
Fig. 5 shows detail B of Figure 4;
Fig. 6 shows a closure with a second embodiment of a sealing means in a
side view;
Fig. 7 shows a cross cut through the closure according to Figure 6 along
line CC;
Fig. 8 shows detail D of Figure 7;
Fig. 9 shows a closure with a third embodiment of a sealing means in a
side view;
Fig. 10 shows a cross cut through the closure according to Figure 9 along
line EE;
Fig. 11 shows detail F of Figure 10.
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DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Figure 1 is showing a closure 1 comprising a sealing means 2 according to the
present in-
vention in an isometric side view from below and Figure 2 the same closure 1
from a per-
spective side view from above. The closure 1 comprises an outer skirt 3
extending in general
perpendicular from a disc-like top portion 4. The outer skirt 3 has on its
outside vertically
arranged knurls 5 which provide a better grip while operating the closure. On
the inside the
outer skirt 3 comprises a thread 6 consisting of thread segments 7. At its
lower end the
outer skirt is interconnected to a tamper band 8. The tamper band 8 of the
displayed em-
bodiment has in general the same outer diameter as the outer skirt 3 of the
closure. On its
inside the tamper band 8 comprises undercut segments 9 protruding radially
inwardly and
having a in general spherical lower part 10. During application of the closure
onto the neck
of a container (not visible) the spherical undercut segments support centering
and align-
ment of the sealing means with respect to the neck of the container. Thereby
failure due to
tilt application can be significantly reduced. Above the undercut segments 9
centering ele-
ments 11, which protrude radially above the inner surface 15 of the tamper
band 8, are
arranged which are aligned to the closure axis z and which help to centre the
closure 1 with
respect to a locking bead of the neck of a container. Thereby tilting of the
tamper band dur-
ing opening of the closure 1 is reduced.
The tamper band 8 is interconnected to the outer skirt 3 of the closure 1 by
frangible
bridges 12 which are destroyed while initial opening of the closure 1. The
tamper band 8 is
distanced from the closure skirt 3 by a gap 13. The bridges 12 are arranged in
the shown
embodiment in recesses 14 which extend the length of the bridges 12 and
thereby help to
avoid unwanted disrupting of the bridges 12 during application of the closure
1.
Figure 3 is showing a further embodiment of a closure 1 in a side view. The
closure 1 com-
prises a tamper band 8 with an in general smaller outside diameter than the
skirt 3 of the
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closure 1. The tamper band 8 comprises a shoulder 16 which suits as a contact
point during
ejection of the closure 1. The bridges 12 are similar to the closure according
to Figures 1
and 2 arranged in recesses 14. The crosscut along line AA is shown in figure
4.
Figure 4 is showing a cross cut through the closure 1 and the sealing means 2
along line
AA of Figure 3 and Figure 5 is showing detail B of the sealing means 2 of
Figure 3 in a
magnified manner. In figure 5 a neck 25 (dashed line) of a container is
schematically dis-
played. The sealing means 2 of the shown embodiment is displayed in an
undeformed man-
ner and comprises an outer side seal 20 and an in general V-shaped top seal 21
protruding
from the inner surface of the disk like top portion 4 of the closure 1 in a
generally perpen-
dicular way inside the closure 1 and arranged such that it interacts in a
closed position with
the annular end surface 27 of the neck 25. The side seal 20 has an in general
P-shaped
cross-section and comprises a base 22 and an annular sealing ring 23 laterally
protruding
radially inwardly above the base 22 suitable to seal on an outer peripheral
surface 17 of the
neck 25 in a thread free area above thread 26. The side seal 20 is arranged
radially dis-
tanced to the outer skirt 3. In the shown embodiment an annular gap 24 with in
unde-
formed stage in general parallel side walls extends vertically between the
side seal 20 and
the outer skirt 3 of the closure 1 defining the outer free length L of the
side seal 20. The
thickness t of the annular gap 24 is chosen such that the annular sealing ring
23 and the
base 22 may extend freely in radial direction r+ while the closure is applied
onto the neck
25. The vertical length L of the base 22 of the side seal 20 is here chosen
such that the an-
nular sealing ring 23 is arranged as far as possible down along the free
length of the outer
vertical surface 17 of the neck 25 in the shown embodiment just above the
start of the out-
side thread 26 container. The contact zone is on a PET-container, depending
from the thread
start, typically positioned about 0.5 mm to 2 mm below the annular end surface
of the neck.
By this arrangement the influence of doming or other deformation of the
closure 1 may be
minimised such that the seal 2 becomes over all more reliable. The laterally
flexibly adjust-
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able and vertically stiff base 22 of the side seal 20 guarantees that the
annular sealing ring
23 may sideways adjust even while pop-on of the side seal 20 onto a neck of a
container
which is eccentric, especially in radial direction. The radial protrusion p of
the annular seal-
ing ring 23 over its base 22 is relevant for the interference with the neck
25. To obtain a
radial sealing force the inner diameter D of the annular sealing ring 23 is
smaller than the
outer diameter Da of a neck of the container. If appropriate the vertical
position of the seal-
ing means 2 with respect the neck 25 is defined by an additional stop element
Figure 6 is showing a further embodiment of a closure 1 in a side view, Figure
7 is showing
a cross cut through the closure according to Figure 6 along line CC and Figure
8 is showing
detail D of Figure 7 in a magnified manner. The general setup of the closure 1
corresponds
to the closure as described according to the Figures 1 to 5. The explanation
of similar details
such as outer skirt, tamper band and thread are therefore not repeated again
and reference
is made to these drawings.
As it can be seen in Figure 8 the side seal 20 which has in the here shown
embodiment of
the sealing means 2 an in general R-shaped cross-section and is arranged
radially distanced
to the outer skirt 3. An annular gap 24 with in undeformed stage in general
parallel side
walls extends vertically between the side seal 20 and the outer skirt 3 of the
closure 1. The
annular gap 24 is chosen such that the annular sealing ring 23 and the base 22
may de-
form at least initially free in radial direction r while the seal is applied
onto a neck 25
(schematically indicated by dashed line). The vertical length L of the base 22
of the side seal
20 is adjusted such that the annular sealing ring 23 is arranged as far as
possible down
along the free length 17 of the outer vertical surface of the neck 25 in the
shown embodi-
ment just above the start of the thread 26. In applied position a first
sealing zone 30 is de-
veloped between the sealing means 2 and the neck 25 in that the annular
sealing ring 23 is
pressing against the outer free surface 17 of the neck 25 due to lateral
stretching. As it can
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be seen base 22 blends on the inside by a blend 34 having here a radius R into
a vertical
top surface 35 of the closure 1. The blend 34 is shaped such that it is
forming a second
sealing area/contact region 31 in that it is in closed position in tight
contact with an edge
surface 28 interconnecting the outer free surface 17 and the annular top
surface 27 of the
neck 25. The radius R is in general larger than the radius of the edge surface
28 such that a
precise interaction zone is determined. During the application process of the
sealing means
2 onto the neck 25, the annular sealing ring 23 of the outside seal 20 is
first in contact with
the annular top surface 27 and/or the edge surface 28 of the neck 25. During
further ap-
plication the annular sealing ring 23 is circumferentially stretched until it
slips onto the
outer free surface 17 of the neck 25 establishing a first contact zone 30.
During the further
procedure the annular sealing ring 23 and the first contact zone 30 slips down
along the
outer free surface 17 of the neck 25 until the blend 34 is getting in contact
with the outer
edge surface 28 of the neck 25 establishing the second contact zone 31. In
that the edge
surface presses against the inner root (blend 34) of the outside seal 20,
schematically indi-
cated by arrow F, it is achieved that because of the geometry the annular
sealing ring 23 is
due to controlled deformation of the closure pulled inwardly (schematically
indicated by
arrow rp) and thereby pressed more firmly against the outer free surface 17
such that the
sealing performance is improved. This functional interconnection between the
first and the
second contact zone is schematically indicated by arrow a. Before the second
contact zone
31 is established the base 22 of the outside seal 20 is laterally adjustable
and is locked in
its final position due to the functional interconnection, when the second
contact zone 31 is
established. Thereby it is achieved that during application of the sealing
device 2, before the
second contact zone 31 is established, all advantages of the embodiment as
described ac-
cording to figures 3 to 5 are maintained and in the final position, when the
second contact
zone is established and the outer seal 20 thereby locked 31, a further
improved overall seal-
ing performance results.
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As it can be seen the annular sealing ring 23 protrudes locally above the
inner side surface
of the base 22. The protrusion 33 has in the shown embodiment an in general
circular cross
section which forms an appropriate first contact zone between the annular
sealing ring 23
and the outer free surface 17 and still allows demoulding of the undercut. The
annular seal-
ing ring 23 further comprises a funnel shaped first lead in surface 29
suitable to establish a
first contact between the outside seal 20 and the neck 25 and acting as a ramp
for the an-
nular sealing ring 23 such that it slides easily onto the outer free surface
17.
The shown sealing means 2 is further equipped with a bore seal 36 which
reaches in a clos-
ing position down into the orifice of the neck 25. The bore seal 36 has an in
general conical
shape extending from it's root, where it is interconnected to the disk like
top portion 4 of the
closure 1, versus it's free end radially outwardly at an angle a. The cross
section of the base
37 of the bore seal 36 is in general V-shaped at an angle p having it's apex
in the region of
the free end. The bore seal 36 further has a funnel shaped second lead in
surface 38 which
guarantees easy plug in of the bore seal 36 into the orifice of the neck 25.
Adjacent to the
second lead in surface 38 the bore seal is equipped with a here toroidal
contact surface 39
forming in closed position a third contact zone 32 between the sealing means 2
and the
inner side surface 41 of the neck 25. As it can be seen the sealing means 2 is
shown in an
undeformed stage and is due to that overlapping with the geometry of the neck
25. How-
ever, it is clear that the closure 1 adjusts during operation to the neck 25
due to elastic de-
formation of the closure material. The root diameter Dr of the bore seal 36 is
chosen such
that the bore seal 36 does not interact with the neck of the closure in the
area of it's base.
During application of the toroidal sealing means 20 onto the neck 25 the bore
seal 36 is
bent inwardly in the direction r- such it adjusts to the inner diameter Di of
the orifice of the
neck 25. In the herein described embodiment of the invention the in the closed
position
established third contact zone 32 is arranged approximately at the same
vertical level (z-
direction) as the first contact zone 30 of the outside seal 20. By this
opposite arrangement
CA 02580467 2012-05-24
17
at the same level the neck 25 is firmly hold which results in an increased
tightness and seal-
ing performance. The vent angle of the closure can be adjusted by the active
length Lb
which corresponds to the distance between third contact zone 32 and root of
bore seal 36.
To obtain a longer vent angle the active length Lb of the bore seal 36 is
increased and to
reduce a lower vent angle reduced (the vent angle corresponds to the angle the
closure has
to be turned until venting occurs). Depending on the field of application the
bore seal can
be avoided.
If the sealing means comprises in the area or adjacent to the intermediate top
surface 35 an
in general v-shaped protrusion (not shown in detail) which forms a top seal
(fourth contact
zone/sealing region) and interacts in the closing position with an annular top
surface 27 of
neck 25.
Figure 9 shows a further embodiment of a closure 1 comprising a sealing device
according
to the present invention in a side view made by two-component injection
moulding. Figure
is showing a cross cut through the closure according to Figure 9 along line EE
and Fig-
ure 11 is showing detail F of Figure 10 in a magnified manner.
A detailed explanation of how a sealing means as shown in the Figure 9 to 11
can be best
made is explained in full detail in the international patent application
PCT/EP2005/051559 of the same inventor as the herein disclosed invention.
The attention is now directed to Figure 11. The cross section and the
functionality of the
sealing means 2 as shown in Figure 11 corresponds to the sealing means shown
in Figure 8
with the only difference that the sealing means 2 is made here out of two
materials (shell
material and liner material). With respect to the functionality it is
therefore referred to Fig-
ure 8 and the explanation belonging to it.
CA 02580467 2007-03-15
WO 2006/117024 PCT/EP2005/053777
18
In difference to the closures described according to the previous Figures 1 to
8 the sealing
means 2 of the closure according to the Figures 9 to 11 is made out of two
materials pref-
erably by two-component injection moulding having an outer shell 45 (disk like
top portion
4 and outer skirt 3) made out of a shell material and a sealing liner 46 made
out of liner
material which covers here all surfaces exposed to the good stored in the
container to be
sealed. The outer shell 2 of the closure 1 is preferably made out of
Polypropylene (PP) or
High Density Polyethylene (HDPE) whereby the sealing liner 46 is preferably
formed out of
a softer liner material such as DarexTM. The outer shell 45 and the sealing
liner 46 are, as
shown here, firmly bonded to each other along their boundary surfaces 49, 50
such that a
save application and positioning of the sealing means 2 becomes possible.
The base 22 of the sealing means 20 comprises an outer downward leg 47 made
out of
shell material which supports an inner skirt 48 made out of liner material.
The downward
leg 47 supports and stabilizes the inner skirt 48 and the toroidal sealing
ring 23 made par-
tially out of liner material and arranged at the end of the base 22 in lateral
and vertical
direction. As it can be seen the liner 46 is formed such that it extends in xy-
direction along
the inner top surface 35 of the closure 1 and down along the outer downward
leg 47 (-z-
direction). The inner skirt 48 blends by blend 34 into the vertical top
surface 35. Both the
inner skirt 48 and the inner base 22 are shown in an undeformed manner but
will be ex-
tended radially outwardly during application onto a neck of a closure. The
vertical boundary
surface 49 between the outer downward leg 47 of the sealing liner 46 and the
inner skirt
48 of the shown embodiment is in general straight and slightly tapered such
that the liner
46 can easily be taken out of the mould after moulding in the first stage.
Depending on the
field of application the boundary surface can have a different shape such as
indicated by
line s such that the lower end of the outer seal 20 is made completely out of
shell material
and supported only in it's lower end by the outer downward leg 47.
CA 02580467 2007-03-15
WO 2006/117024 PCT/EP2005/053777
19
As explained in connection with Figure 8 the sealing means may comprise in the
area or
adjacent to the intermediate top surface 35 an in general v-shaped protrusion
(not shown in
detail) which forms a top seal (fourth contact zone) and interacts in the
closing position with
an annular top surface 27 of neck 25 (see Figure 8).
The sealing means 2 further comprises in the shown embodiment a bore seal 36
which has,
in difference to the embodiment shown in Figures 6 to 8, an in general olive
shaped cross
section. As it can be seen the bore seal 36 is integrated into liner disc 46.
If appropriate the
bore seal 36 may comprise a section made out of shell material to obtain
increased lateral
support. Alternatively or in addition the bore seal may be supported by
lateral ribs (not
shown in detail).
