U.S. patent application number 10/579343 was filed with the patent office on 2007-09-20 for container neck closure device and container equipped with one such device.
Invention is credited to Hanno Kaess, Michel Luzzato, Claude Pradinas, Rachel Prioul.
Application Number | 20070215570 10/579343 |
Document ID | / |
Family ID | 34943400 |
Filed Date | 2007-09-20 |
United States Patent
Application |
20070215570 |
Kind Code |
A1 |
Prioul; Rachel ; et
al. |
September 20, 2007 |
Container Neck Closure Device and Container Equipped With One Such
Device
Abstract
The device comprises a removable cap (20) for closing the neck
of a receptacle (3), and a peelable membrane for hermetically
covering the lip of the neck. In order to guarantee good sealing of
the receptacle when it is reclosed with the cap, the peelable layer
of the membrane is adapted to cover only an inner zone (61) of the
lip (6) of the neck (3), the cap being provided internally with a
skirt (24) for bearing in leaktight manner against an outer zone
(62) of the lip that is distinct from the inner zone (61), and said
skirt is plastically deformable between a generally cylindrical
configuration and a flared configuration, the inside face of said
skirt presenting a transmission surface (244) for transmitting a
bearing force (F.sub.2) associated essentially with co-operation
between the skirt in its flared configuration and the lip of the
neck.
Inventors: |
Prioul; Rachel; (Greize,
FR) ; Luzzato; Michel; (Lyon, FR) ; Kaess;
Hanno; (Limonest, FR) ; Pradinas; Claude;
(Couzon au Mont d'Or, FR) |
Correspondence
Address: |
Ralph A. Dowell of DOWELL & DOWELL P.C.
2111 Eisenhower Ave
Suite 406
Alexandria
VA
22314
US
|
Family ID: |
34943400 |
Appl. No.: |
10/579343 |
Filed: |
November 16, 2004 |
PCT Filed: |
November 16, 2004 |
PCT NO: |
PCT/FR04/02922 |
371 Date: |
December 20, 2006 |
Current U.S.
Class: |
215/43 ;
215/343 |
Current CPC
Class: |
B65D 2251/0093 20130101;
B65D 2251/20 20130101; B65D 51/20 20130101; B65D 2251/0015
20130101; B65D 41/023 20130101 |
Class at
Publication: |
215/043 ;
215/343 |
International
Class: |
B65D 41/02 20060101
B65D041/02 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 17, 2003 |
FR |
031341.3 |
Claims
1. A closure device for closing a tubular neck (3) of a receptacle
(2), in particular a substantially cylindrical neck of a bottle,
the closure device comprising firstly a tubular cap (20) for
closing the neck, provided internally with a skirt (24) for bearing
in leaktight manner against an outer zone (62) of the lip (6) of
the neck and provided with means (23) enabling it to be releasably
connected to the neck, and secondly a membrane (10) for covering
the lip of the neck in hermetic manner and provided with peelable
means (12) for securing it to the lip of the neck, and adapted to
cover only an inner zone (61) of the lip of the neck that is
distinct from said outer zone (62), the device being characterized
in that the skirt (24) for bearing against the outer zone (62) of
the lip (6) is plastically deformable between a first configuration
in which it presents a generally cylindrical shape on the same axis
as the cap (20), and a second configuration in which it flares
towards the open end of the cap, and in that the inside face of
said skirt (24) presents a first surface (244) for transmitting a
bearing force (F.sub.2) associated essentially with said skirt in
said second configuration co-operating with the lip (6) of the neck
(3).
2. A device according to claim 1, characterized in that the cap is
provided internally with retaining means (246) for retaining the
membrane (10) inside the cap (20) before the membrane is secured to
the lip (6) of the neck (3).
3. A device according to claim 2, characterized in that the
retaining means (246) for retaining the membrane (10) are carried
by the inside face of the skirt (24) for bearing against the outer
zone (62) of the lip (6).
4. A device according to claim 1, characterized in that the maximum
radial dimension of the membrane (10) is adapted to be less than
the outside diameter (D.sub.6) of the lip (6) of the neck (3).
5. A device according to claim 1, characterized in that a portion
(26) of the end wall (21) of the cap (20) is covered in an adhesive
substance (261) adapted to hold the membrane (10) to the end wall
of the cap prior to the membrane being secured to the lip (6) of
the neck (3).
6. A device according to claim 1, characterized in that the bottom
face of the skirt (24) for bearing against the outer zone (62) of
the lip (6) presents a second surface (243; 243') for transmitting
a bearing force (F.sub.1) associated essentially with the
co-operation between the releasable connection means (23) of the
cap (20) and the corresponding means (5) of the neck (3).
7. A device according to claim 6, characterized in that the second
transmission surface (243') is carried by a deformable annular bead
(249) projecting radially from the inside face of the skirt (24)
for bearing against the outer zone (62) of the lip (6).
8. A device according to claim 6, characterized in that the first
and second transmission surfaces (244 and 243; 243') are distinct
from each other.
9. A device according to claim 8, characterized in that the first
and second transmission surfaces (244 and 243; 243') are separated
by a concave surface (245).
10. A device according to claim 1, characterized in that the cap
(20) is also provided internally with a skirt (25) for bearing
against the membrane (10) when securing the membrane to the inner
zone (61) of the lip (6), said skirt being disposed radially inside
the skirt (24) for bearing against the outer zone (62) of the lip
and being situated, when the cap is connected to the neck (3),
substantially in register with the inner zone of the lip.
11. A device according to claim 10, characterized in that the skirt
(25) for bearing against the membrane (10) is flexible so that once
the membrane (10) has been separated, the skirt bears against the
inner zone (61) of the lip (6) of the neck (3) when the cap (20) is
connected to the neck.
12. A leaktight receptacle (2) having a neck (3) for pouring out
the content from the receptacle, together with a closure device (1)
for closing the neck, the closure device being in accordance with
claim 1.
Description
[0001] The present invention relates to a device for closing a
tubular neck of a receptacle, and to a leaktight receptacle
provided with such a device.
[0002] More particularly, the invention relates to closure devices
comprising both a cap for closing the neck, and a peelable membrane
for hermetically covering the lip of said neck in order to
guarantee that the receptacle is not put into contact with ambient
air between the receptacle being closed, e.g. at the end of a
bottling line, and the first occasion on which the receptacle is
opened by a consumer of the content of the receptacle, in
particular a beverage.
[0003] To this end, the membrane generally comprises a layer of
aluminum covered on its side adjacent to the neck that is to be
closed in a peelable synthetic covering for heat-sealing onto the
lip of the neck. To put such a membrane into place, the present
practice is to use the cap, by covering the underside of its end
wall with the membrane that is to be put into place, and then
fitting the cap onto the neck of a receptacle that has just been
filled. In order to prevent the membrane from escaping, and in
particular in order to prevent it from dropping out of the cap
before the cap is placed in register with the neck of a receptacle,
the membrane is dimensioned in such a manner that its diameter is
slightly greater than the inside diameter of the cap, which means
that its diameter is equal to or slightly greater than the outside
diameter of the lip of the neck. Once the cap has been fitted onto
the neck of the receptacle, e.g. screwed onto the neck, the
membrane is interposed between the end wall of the cap and the lip
of the neck. The receptacle is then placed close to an induction
plate which causes induced currents to appear in the aluminum layer
of the membrane, thereby heating it. The synthetic covering melts
and is thus heat-sealed to the lip of the neck. On first use of the
receptacle, the consumer unscrews the cap and then removes the
membrane by peeling it off.
[0004] Although such a device guarantees that the receptacle is
sealed on leaving the bottling line, it presents a certain number
of drawbacks. Firstly, when the user peels off the membrane,
residue of the peelable synthetic material, and possibly also of
aluminum, remains on the lip of the neck, which the consumer often
sees as lacking in cleanliness or even constituting a health risk.
In addition, the sealing of the device when it is reclosed is
generally mediocre because of the presence of the residue of
peelable synthetic material on the lip of the neck. When the cap is
screwed back onto the neck, the residue leaves gaps between the cap
and the neck which are harmful to good conservation of the content
of the receptacle.
[0005] To avoid this drawback, the user of the device is tempted to
clamp the cap back on tightly when reclosing the receptacle.
However such handling is awkward for the user, and indeed
impossible for certain users such as children or old people, and it
becomes ineffective in the long run because of the deformation
applied to the cap and/or to the neck.
[0006] French patent No. 2 828 173 proposes solving that problem by
providing for an inner sealing skirt of the cap to bear against an
outer zone of the lip of the neck when the receptacle is closed and
reclosed, which outer zone is distinct from the inner zone on which
a peelable membrane has previously been heat-sealed. Any deposit of
adhesive on said inner zone of the lip, and any other damage that
stems from heat-sealing the membrane, then does not interfere with
the quality of the sealing provided by the inner skirt. However,
that sealing is ensured only by the fact that the skirt is designed
to be flexible, so that its bears elastically against the outer
zone of the lip of the neck. On reclosure, it is therefore
necessary for the user to clamp the cap back on tightly around the
neck in order to good sealing, with the drawback mentioned above.
In addition, because of its elasticity, the skirt returns to its
initial configuration when the cap is removed and thus runs the
risk during reclosure of impeding the user by forming an abutment
for the neck.
[0007] The object of the present invention is to propose a cap and
membrane device of the above-described type that guarantees
reliable sealing of the receptacle when it is reclosed, while
remaining easy both to assemble on the receptacle during initial
packaging, and for use by any consumer.
[0008] The invention provides a device for closing a tubular neck
of a receptacle, in particular a substantially cylindrical neck of
a bottle, as defined in claim 1.
[0009] In the invention, a distinction is made between firstly the
inner zone of the lip that is to enable the peelable membrane to be
secured thereto, and secondly the outer zone of the lip against
which the skirt of the cap comes to bear, in particular when the
receptacle is reclosed. Since no residue of peelable material is
present on said outer zone, the skirt can bear thereagainst in
perfectly leaktight manner, and since the strength of this bearing
force is essentially a function of the co-operation between the
skirt in its plastically-deformed configuration and the outer zone
of the lip, the user does not need to clamp the cap back on
tightly, while reclosing, in order to obtain satisfactory sealing.
In addition, in its flared deformed configuration, the sealing
skirt does not interfere with putting the cap into place around the
neck.
[0010] Initial closure of the receptacle, e.g. at the end of a
bottling line, is performed in a manner analogous to that used in
the prior art, i.e. by placing on the neck of the receptacle the
cap that has been provided internally with the membrane for
securing to the neck.
[0011] Advantageous characteristics of the device of the invention
taken in isolation or in any technically feasible combination are
set out in dependent claims 2 to 11.
[0012] The invention also provides a leaktight receptacle having a
neck for pouring out the content from the receptacle, together with
a device for closing the neck, which device is as defined
above.
[0013] The invention can be better understood on reading the
following description given by way of example and made with
reference to the drawings, in which:
[0014] FIG. 1 is an exploded longitudinal section view of a closure
device of the invention, prior to being assembled on a neck of a
bottle;
[0015] FIGS. 2A, 2B, and 2C are views on a larger scale of a detail
in circle II in FIG. 1, respectively showing three successive steps
in assembling the device on the neck of bottle;
[0016] FIGS. 3A and 3B are views analogous to FIGS. 2A and 2B
relating to a first variant embodiment of the device of the
invention; and
[0017] FIG. 4 is a fragmentary longitudinal section view of a
second variant of the device of the invention.
[0018] FIG. 1 shows a closure device 1 for closing a leaktight
receptacle 2, e.g. for containing a liquid beverage. In FIG. 1,
only the neck 3 of the receptacle 2 is visible, the receptacle
being constituted for example by a bottle of plastics material such
as polyethylene terephthalate (PET), of glass, or of any other
material that is compatible with storing the liquid under
consideration, or more generally that is of food grade. The neck 3
is essentially cylindrical in shape about an axis X-X and is
provided on its outside face 4 with a helical thread 5. The free
end of the neck 3 forms a rim or lip 6 of rounded shape or at least
that is not sharp.
[0019] The device 1 essentially comprises a membrane 10 and a cap
20.
[0020] For convenience, the description below assumes that the
elements of the device 1 that are facing towards the receptacle 2
are facing downwards, i.e. they are directed towards the bottom
portions of FIGS. 1 and 2A to 2C, whereas the elements facing in
the opposite direction are considered as being outwardly-directed,
i.e. towards the top portions of the same figures.
[0021] The membrane 10 comprises an aluminum disk 11 shown in FIG.
1 as having the same axis as the neck 3. The bottom face of the
disk 11 is entirely covered in a layer 12 of a synthetic material,
e.g. of polyethylene, suitable for uniting the membrane 10
hermetically with the lip 6 of the neck 3. More precisely, the
layer 12 is suitable for being heat-sealed to the lip 6 when the
membrane 10 is subjected to a rise in temperature, in particular by
generating induced current in the aluminum disk, while being
suitable for being peeled off subsequently by hand. For this
purpose, the membrane 10 is advantageously provided on its top face
with a layer 13 of plastics material for ensuring that the aluminum
disk does not tear while the membrane is being peeled off, and a
pull-tab 14 to be taken hold of by the user in order to remove the
membrane 10.
[0022] In a variant that is not shown, only the outline of the
bottom face of the aluminum disk 11 is covered in the peel-off
material 12.
[0023] In any event, the diameter d.sub.12 of the peel-off covering
12 is less than the outside diameter D.sub.6 of the lip 6 of the
neck 3, while naturally also being greater than the inside diameter
d.sub.6 of the lip. In other words, only an inner peripheral zone
61 of the lip 6 is covered by the heat-sealed material 12 of the
membrane 10, as is explained in greater detail below. The remainder
of the lip, i.e. the outer peripheral zone distinct from the zone
61 is given reference 62.
[0024] The cap 20 is generally cylindrical in shape and is shown in
FIG. 1 as having the same axis as the neck 3. It is adapted to
close the neck in leaktight manner and for this purpose it has an
end wall 21 in the form of a solid disk having a main cylindrical
skirt 22 projecting downwards from its periphery, the inside
diameter of the skirt being substantially equal to the outside
diameter of the thread 5 on the neck 3.
[0025] The inside face of the main skirt 22 is provided with a
projecting thread 23 complementary to the outside thread 5 on the
neck 3, the cap 20 thus being suitable for being screwed onto the
neck 3 and for being unscrewed therefrom by turning it
correspondingly about its longitudinal axis X-X.
[0026] Two coaxial inner skirts 24 and 25 centered on the axis X-X
are provided inside the cap 20, projecting downwards from the end
wall 21. When the cap 20 is not in place on the neck 3, as shown in
FIG. 1, these inner skirts 24 and 25 extend generally parallel to
the main skirt 22.
[0027] As shown in greater detail in FIG. 2A, the first inner skirt
24 that is radially farther from the axis X-X than the second inner
skirt 25 is constituted by a tubular body 241 connected to the end
wall 21 of the cap 20 by a root 242 that is a little thicker than
the remainder of the body 241. The root 242 presents an essentially
cylindrical inside face of diameter referenced d.sub.242 in FIG. 1
that is very slightly smaller than the diameter of the aluminum
disk 11 of the membrane 10, i.e., for the membrane shown, the
diameter d.sub.12. The inside face of the root 242 forms a kind of
wedging surface for the membrane 10 while it is being assembled in
the cap, as explained in greater detail below. A difference between
the diameters of about one-tenth of a millimeter enables such
wedging to occur in practice.
[0028] The inner skirt 25 is likewise constituted by a tubular body
251 of axial size that is considerably smaller than that of the
body 241 of the skirt 24, and corresponds for example to
approximately the axial height of the root 242 minus the thickness
of the membrane. Its outside face 252, in particular in the bottom
portion thereof, flares upwardly towards the end wall 21.
[0029] The inside face of the body 241 of the skirt 24 presents two
inwardly-bulging, i.e. convex surfaces 243 and 244 in the
transition zone between the root 242 and the remainder of the body
241, these two surfaces being disposed one after another along the
axis X-X. These bulging surfaces 243 and 244 are separated from
each other along the axis X-X by a concave surface 245.
[0030] The bottom end portion of the first inner skirt 24 is also
provided with a series of projections 246 distributed around the
periphery of said skirt and extending radially inwards from the
inside face of the skirt. By way of example, this series comprises
six projections 246 that are diametrically opposite in pairs. The
radial distance referenced d.sub.246 in FIG. 1 between two
diametrically-opposite projections is less than the diameter of the
aluminum disk 11 of the membrane 10, i.e., for the membrane 10,
less than the diameter d.sub.12. In this way, the top faces 247 of
the projections 246 constitute safety retaining surfaces for
preventing the membrane 10 from dropping out downwards before the
membrane is secured to the lip 6 of the neck 3.
[0031] Advantageously, the bottom faces 248 of the projections 246
flare downwards for reasons that are explained below.
[0032] The way in which the closure device 1 is assembled on the
neck 3 of the receptacle 2 is described below with reference to
FIGS. 2A to 2C.
[0033] Initially, the neck 3, the membrane 10, and the cap 20 are
fabricated independently of one another and they are obtained in
the state shown in FIG. 1, for example.
[0034] In a first step, the membrane 10 is assembled with the cap
20 by inserting the membrane inside the cap. More precisely, as
shown in FIG. 2A, the membrane 10 is placed inside the first inner
skirt 24, e.g. by deforming the membrane elastically, so that its
edge becomes wedged against the root 242 of the skirt 24. In this
configuration, the cap can be handled in any direction without
running the risk of the membrane 10 escaping from the inside of the
cap since even if it becomes separated from the root 242, it is
retained reliably in a downward direction by the projections 246,
in an upward direction by the end wall 21, and in a sideways
direction by the body 241 of the skirt 24.
[0035] In a variant that is not shown, the membrane 10 is placed
inside the skirt 24 without being brought into wedging contact with
the root 242. The membrane 10 then rests directly on the
projections 246, with the peel-off layer 12 pressing against the
top faces 247 of the projections.
[0036] In order to close the neck 3 of the receptacle 2
hermetically, e.g. immediately after it has been filled with a
perishable liquid, or more generally a foodstuff, the cap 20
carrying the membrane 10 is brought to a position immediately above
the neck 3 and on the same axis as the neck. By way of example,
this operation can be performed at the end of a bottling line.
[0037] Thereafter, the cap 20 is moved towards the neck 3 so as to
cause the threads 5 and 23 to engage, with the cap either being
forced onto the neck 3 or else being screwed around the neck.
[0038] When the end wall 21 of the cap 20 comes close to the lip 6
of the neck 3, the neck splays the skirt 24 radially outwards, with
the flared bottom surfaces 248 of the projections 246 then forming
ramp surfaces for the lip 6. The body 241 of the skirt 24 then
changes from a generally cylindrical configuration as shown in FIG.
2A to a generally frustoconical configuration that flares
downwards, as shown in FIG. 2B, with the root 242 being deformed,
preferably essentially plastically.
[0039] As the cap 20 continues to move towards the neck 3, the
membrane 10 becomes pinched axially between the inner zone 61 of
the lip 6 and the outer face 252 of the skirt 25, as shown in FIG.
2B. If the membrane is initially resting on the top faces 247 of
the projections 246, then it is brought into contact with the inner
skirt 25 by being lifted upwards by the lip 6.
[0040] Advantageously, the body 251 of the skirt 25 is provided to
be sufficiently flexible to be deformed inwardly, with its flared
outside face 252 forming a corresponding ramp surface.
[0041] Simultaneously, the bottom face of the skirt 24 comes into
contact with the outer zone 62 of the lip 6 which, more precisely,
bears against the bulging surfaces 243 and 244.
[0042] The receptacle 2 fitted with the cap 20 and the membrane 10
is then subjected to an electromagnetic field that causes
electrical currents to be induced in the aluminum disk 11, thereby
melting the layer 12, at least in part. On cooling, the layer 12
bonds the remainder of the membrane 10 to the inner zone 61 of the
lip 6.
[0043] The receptacle is thus closed hermetically and can be
transported to its site of sale, or more generally to its place of
final use. Compared with prior art devices in which the membrane is
of greater diameter in order to enable it to be wedged against the
end wall of the cap, the membrane 10 of the device 1 is of smaller
diameter and is therefore of lower cost.
[0044] When the user of the receptacle 2 seeks to open the
receptacle for the first time, the cap 20 is unscrewed to give
access to the membrane 10 that is secured to the neck 3. The user
takes hold of the tab 14 to separate the membrane by peeling off
the layer 12. This peel-off operation can leave residues of
peelable material on the inner zone 61 of the lip 6.
[0045] No residue remains on the outer zone 62.
[0046] After pouring out a fraction of the content from the
receptacle 2, the user recloses the receptacle by screwing the cap
20 onto the neck 3 as shown in FIG. 2C. By tightening the cap 20 a
standard amount, the user can easily bring the top bulging surface
243 of the skirt 24 to bear against the outer zone 62 of the lip 6,
as represented by arrow F.sub.1, thereby forming a first line of
sealing between the neck 3 and the cap 20. In addition, in a manner
that is generally independent of how tightly the user turns the
cap, the lower bulging surface 244 is caused to bear against the
outer zone 62 of the lip 6, as represented by arrow F.sub.2,
thereby forming a second line of sealing.
[0047] It should be observed that the bearing force F.sub.2 in the
second line of sealing is related essentially to co-operation
between the skirt 24 in its flared configuration and the lip 6 of
the neck 3. Insofar as the skirt 24 is deformed plastically while
the cap 20 is being assembled onto the neck 3 as described above,
and during subsequent storage of the bottle in the closed
configuration, there is no need for the user to tighten the cap on
hard to ensure that the bearing force F.sub.2 transmitted by the
skirt 24 against the outer zone 62 of the lip, via the surface 243
is non-negligible. Conversely, it will be understood that the
tighter the cap is screwed back on, the greater the bearing force
F.sub.1.
[0048] In addition, being plastically deformed in the flared
configuration, the skirt 24 does not run any risk of forming an
abutment for the neck 3, and therefore does not impede the user
when screwing the cap 20 back on.
[0049] As shown in FIG. 2C, the flexibility of the inner skirt 25
is advantageously designed to that when reclosing the bottle, the
outer face 252 of this skirt comes to bear against the inner zone
61 of the lip 6, e.g. when a strong tightening force is applied to
the cap 20. A third line of sealing is thus formed, but its quality
nevertheless remains limited because of the possible presence of
residue of the peelable material 12 in said zone of the lip 6.
[0050] Two variants of the device 1 are shown respectively in FIGS.
3A and 3B and in FIG. 4. In these variants, elements that are
common with the device of FIGS. 1 and 2A to 2C are given the same
references.
[0051] In the variant of FIGS. 3A and 3B, the inner skirt 24,
instead of having the top bulging surface 243, is provided with an
annular bed 249 projecting radially from the inside face of the
skirt. The bottom face of this bead presents a surface 243' that
acts in a manner analogous to the surface 243. More precisely, the
surface 243' is adapted to transmit the bearing force F.sub.1
associated with the clamping torque applied to the cap 20 when the
user recloses the receptacle 2.
[0052] This variant of FIGS. 3A and 3B also differs from the device
of the preceding Figures in the profile of the outside face 252 of
the second inner skirt 25. The bottom portion 253 of this face is
shaped in a manner that is substantially complementary to the inner
zone 61 of the lip 6 in such a manner that firstly when the cap 20
is initially assembled on the neck 3 the membrane 10 is pressed in
uniform manner against the zone 61, and secondly, when the membrane
is peeled off and the cap is screwed back on, a large bearing area
is formed between the skirt 25 and the zone 61.
[0053] In the variant of FIG. 4, the bottom face of the end 21 of
the cap 20 is provided in its center with a projecting disk 26 on
the axis X-X made integrally with said end wall. The axial
dimension x.sub.26 of the disk relative to the bottom face of the
end wall is substantially equal to the axial dimension of the skirt
25 in its non-deformed state. The bottom face of the disk is
covered in a slightly sticky substance 261 for facilitating
assembly of the membrane 10 in the cap 20. When the membrane is
inserted into the skirt 24, it is then taken upwards until its top
face comes into contact with the sticky substance 261 which then
serves to hold the membrane to the end wall of the cap until the
cap is assembled on the neck 3. Once the membrane 10 has been
heat-sealed, there is no longer any need for the adhesive bond
between the membrane 6 and the central disk 26 of the cap to be
maintained. In addition, when the cap 20 is unscrewed for the first
time, this adhesive bond is very easily broken, since the strength
of the peelable heat-sealed connection between the membrane and the
lip is much greater.
[0054] This variant makes it possible to omit accurately
controlling the relative dimensions of the membrane diameter and
the inside diameter d.sub.242 of the root 242 of the skirt 24 since
the root no longer acts alone to hold the membrane 10 against the
end wall of the cap. In addition, the adhesive layer 261 serves to
hold the membrane in a manner that is more stable than being wedged
by the root 242, in particular to hold it in a manner that is less
sensitive to vibration and to the jets of compressed air that might
be used to drive the caps along a bottling line.
[0055] Various improvements and variations to the above-described
devices can be envisaged. For example, the projections 246 could be
replaced by a flexible lip extending continuously around the entire
periphery of the inside face of the skirt 24, in particular in the
form of an olive-type lip. Similarly, the pull-tab 14 of the
membrane 10 can be replaced by a pull-fringe made integrally out of
the same material as the top layer 13 over a fraction of its
peripheral outline and suitable for being folded down onto the top
face of said layer when the membrane is assembled into the cap.
* * * * *