U.S. patent application number 09/809282 was filed with the patent office on 2001-10-11 for mould for producing bottle caps with tucked-in tabs, and resulting cap.
This patent application is currently assigned to ASTRA PLASTIQUE. Invention is credited to Claude, Benoit-Gonin, Pascal, Champagnon.
Application Number | 20010028902 09/809282 |
Document ID | / |
Family ID | 9488707 |
Filed Date | 2001-10-11 |
United States Patent
Application |
20010028902 |
Kind Code |
A1 |
Pascal, Champagnon ; et
al. |
October 11, 2001 |
Mould for producing bottle caps with tucked-in tabs, and resulting
cap
Abstract
A mould for forming a cap having a cylindrical skirt, the skirt
being provided with at least one screw thread, a top and a
tamper-proof ring linked to the free end of the skirt by breakable
linking elements includes a movable part or mould top, a stripping
part or stripper ring and a core. The stripper ring has, on the
side facing the top of the mould, on the lower edge of the skirt
and in at least two separate places, at least one notch or at least
one projection so as to create a mortise-and-tenon linkage between
the skirt and the stripper ring during moulding and demoulding of
the cap.
Inventors: |
Pascal, Champagnon;
(Saint-Jean-D'Ardieres, FR) ; Claude, Benoit-Gonin;
(Odenas, FR) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
277 S. WASHINGTON STREET, SUITE 500
ALEXANDRIA
VA
22314
US
|
Assignee: |
ASTRA PLASTIQUE
|
Family ID: |
9488707 |
Appl. No.: |
09/809282 |
Filed: |
March 16, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09809282 |
Mar 16, 2001 |
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09101432 |
Jul 9, 1998 |
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09101432 |
Jul 9, 1998 |
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PCT/FR97/00126 |
Jan 22, 1997 |
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Current U.S.
Class: |
425/556 ;
425/577 |
Current CPC
Class: |
B29L 2001/00 20130101;
B29L 2031/565 20130101; B29C 2045/0056 20130101; B29C 45/4407
20130101; B29C 45/0055 20130101; B29C 57/12 20130101; B65D 41/3433
20130101 |
Class at
Publication: |
425/556 ;
425/577 |
International
Class: |
B29C 045/44 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 26, 1996 |
FR |
96/01189 |
Claims
What is claimed:
1. (Amended) Mould for forming a cap having a cylindrical skirt,
this skirt being provided with at least one screw thread and closed
off at one end by a top, as well as a tamperproof ring linked to
the free end of the skirt by breakable linking elements, the
tamperproof ring including tabs intended to interact with an
annular rib situated on the neck of a container intended to receive
the cap, having: a movable part or mould top, the internal wall of
which corresponds to the external surface of the skirt and of the
top, a stripping part or stripper ring the internal surface of
which corresponds to the outer surface of the tamperproof ring, and
which has, on the side facing the top of the mould, on the lower
edge of the skirt and in at least two separate places, at least one
notch and/or at least one projection in order to create a
mortise-and-tenon linkage between the skirt and the stripper part
or ring during moulding and demoulding of the cap, and a core
designed to be removed by a translation movement but with no
rotation, the external surface of which corresponds to the internal
surface of the top of the skirt and of the tamperproof ring.
2. (Amended) Mould according to claim 1, characterized in that the
stripper ring includes three notches distributed on the periphery
of an upstand on which, in the closed position of the mould, the
lower edge of the skirt bears.
3. (Amended) Mould according to claim 1, characterized in that the
stripper ring includes three projections distributed on the
periphery of an upstand on which, in the closed position of the
mould, the lower edge of the skirt bears.
4. (Amended) Mould according to claim 2, the core of which includes
three grooves in order to form three threads on the inner face of
the skirt, characterized in that each notch or projection is placed
between the ends, situated on the side of the stripper ring, of two
adjacent grooves of the core.
5. (Amended) Mould according to claim 1, characterized in that each
notch or projection is placed between two adjacent recesses in the
mould these being provided in order to produce the breakable
linking elements which link the tamperproof ring to the skirt.
Description
[0001] The subject of the present invention is a mould for the
production of tamperproof caps having tabs turned up in the mould,
as well as a cap formed in such a mould.
BACKGROUND OF THE INVENTION
[0002] One solution for making a screw cap, having a top and a
threaded skirt, tamperproof is to provide the threaded skirt, on
its free edge opposite the top of the cap, with a tamperproof ring.
The latter includes tabs turned up towards the top of the cap and
interacting with an annular rib made on a bottle intended to
receive the cap. The tamperproof ring is linked to the skirt by
breakable linking elements. Thus, on first opening the bottle, when
the cap is unscrewed for the first time, the tabs come into
abutment against the annular rib on the bottle, thus making it
impossible to follow the cap in its translational movement. The
breakable linking elements are then broken. This irreversible
breaking makes it possible to see that the bottle has already been
opened at least once.
[0003] French Patent FR-2,525,565 describes a cap of this type.
[0004] In order to produce such a cap, it is known to use a
three-part mould: a movable part or mould top matching the external
shape of the cap without the tamperproof ring, a stripping part or
stripper ring matching the external shape of the tamperproof ring
and a fixed mould core matching the internal shape of the cap and
of the tamperproof ring.
[0005] With such a mould, it is possible to remove the cap from the
mould without unscrewing, by moving the movable part and the
stripper ring away from the fixed core in a translational movement.
On demoulding, the tabs are forced into a radial position pointing
towards the inside of the tamperproof ring. This position is
undesirable. The tabs are then turned up in such a way that they
are almost parallel to the skirt and to the tamperproof ring, the
tabs pointing towards the top of the cap. In order to bring the
tabs into the desired position, the tamperproof ring and the cap
which is fastened to it are moved closer to the core in such a way
that the tabs are bent up towards the inside of the cap by the core
of the mould.
[0006] During this operation of bending the tabs up, the assembly
formed by the cap and the tamperproof ring is only held in place on
the tamperproof ring by the stripper ring. This is because the part
of the mould must be removed at the start of the demoulding
operation in order to allow deformation of the cap when it is
removed from the core in a translational movement. During the
bending-up operation, it sometimes happens that the cap inclines,
thus making it impossible for all the tabs to be bent up. This
inclination is encouraged by a slight clearance which is formed
between the stripper ring and the tamperproof ring during
demoulding. This clearance is due to the contraction of the
material of which the tamperproof ring is made as a result of it
cooling.
SUMMARY OF THE INVENTION
[0007] The object of the invention is therefore to prevent the
assembly formed by the cap and the tamperproof ring from inclining
during the operation of bending up the tabs. It is hence a question
of providing better retention of this assembly in the stripper
ring.
[0008] For this purpose, the invention provides a mould and a cap
intended to be produced in this mould.
[0009] The mould according to the invention is of the mould type
for forming a cap having a cylindrical skirt, this skirt being
provided with at least one screw thread and closed off at one end
by a top, as well as a tamperproof ring linked to the free end of
the skirt by breakable linking elements, the tamperproof ring
including tabs intended to interact with an annular rib situated on
the neck of a container intended to receive the cap, having a
movable part or mould top, the internal wall of which corresponds
to the external surface of the skirt and of the top, a stripping
part or stripper ring, the inner surface of which corresponds to
the external surface of the tamperproof ring, and a core, the
external surface of which corresponds to the internal surface of
the top, of the skirt and of the tamperproof ring.
[0010] According to the invention, the stripper ring has, on the
side facing the top of the mould, on the lower edge of the skirt
and at two separate places, at least one notch and/or at least one
projection so as to create a mortise-and-tenon linkage between the
skirt and the stripper ring during moulding and demoulding of the
cap.
[0011] In this way, perfect stability of the cap is ensured. This
is because, during moulding, the material making up the cap matches
the shape of the mould, especially the shape of the stripper ring,
and when, after cooling, the material shrinks slightly, the
mortise-and-tenon linkages remain and ensure excellent retention of
the cap.
[0012] Advantageously, the stripper ring includes three notches or
three projections distributed on the periphery of an upstand on
which, in the closed position of the mould, the lower edge of the
skirt bears. In this way, the cap is held in place at three points,
guaranteeing good stability without there being a risk of the cap
jamming.
[0013] When the core of the mould includes three grooves in order
to form three threads in the skirt of the cap, each notch or
projection is placed between the ends, situated on the side of the
stripper ring, of two adjacent grooves in the core. In this way,
when extracting the core from the cap, the projections or notches
produced on the cap are subjected to a minimal stress.
[0014] Likewise, each notch or projection is placed between two
adjacent recesses in the mould, these being provided in order to
produce the breakable linking elements which link the tamperproof
ring to the skirt, so as to be able to demould the cap without
there being a risk of damaging it.
[0015] The cap according to the invention is of the type having a
cylindrical skirt, this skirt being provided with at least one
screw thread and closed off at one end by a top, as well as a
tamperproof ring linked to the free end of the skirt by breakable
linking elements, the tamperproof ring including tabs intended to
interact with an annular rib situated on the neck of a container
intended to receive the cap.
[0016] According to the invention, this cap furthermore has, on the
lower edge of the skirt and in at two separate places, at least one
projection and/or at least one notch.
[0017] Advantageously, the projections and/or notches are situated
on zones .alpha. corresponding to 30% of the circumference of the
cap, at the utmost, and preferably to approximately 10% of the
circumference of the cap. Moreover, the height h of the projection
or notches is less than or equal to 0.6 mm, and is, preferably,
approximately 0.5 mm.
[0018] Indeed, the point is to give the projections or notches such
dimensions as to ensure a good retention of the cap, without,
however, the cap being caught too strongly on the stripper ring,
which would be the case if the projections or notches were too
big.
[0019] This amounts to a cap which can be manufactured in a mould
such as defined hereinabove.
[0020] Preferably, the lower edge of the skirt includes three
projections or three notches distributed on its periphery.
[0021] Advantageously, when the skirt includes three threads on its
internal face, each projection or notch is placed between the ends,
situated on the side of the free edge of the skirt, of two
threads.
[0022] By analogy with the characteristics of the mould, each
projection or notch is placed between two adjacent breakable
linking elements.
[0023] However, the invention will be more clearly understood with
the aid of the description which follows, with reference to the
appended diagrammatic drawing representing, by way of non-limiting
example, two embodiments of a mould according to the invention, as
well as a cap produced using one of these moulds.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIGS. 1 to 3 represent, in cross-section, a mould according
to the invention during the various steps of demoulding;
[0025] FIG. 4 is a view of the detail A in FIG. 1 on a larger
scale;
[0026] FIG. 5 is a view of the detail B in FIG. 3 on a larger
scale;
[0027] FIGS. 6 and 7 correspond to FIGS. 4 and 5 and show an
alternative embodiment of the mould;
[0028] FIG. 8 represents, in perspective and on a larger scale, a
cap according to the invention;
[0029] FIG. 9 is a bottom cross-section view of the cap shown in
FIGS. 6 and 8; and
[0030] FIG. 10 is a bottom cross-section view of the cap shown in
FIGS. 4 and 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] FIGS. 1 to 3 and 8-10 show a cap 1 which has been produced
in a mould according to the invention, as depicted in FIGS. 1 to 3
and FIGS. 6 and 7.
[0032] This cap 1 has, in a manner known per se, a top 2 extended
by a skirt 3 having internal threading formed by three threads 4.
The skirt 3 is linked, at its free end, by a plurality of linking
elements 5, uniformly distributed on its periphery, to a
tamperproof ring 6. These linking elements can be broken under a
certain stress. This cap 1 is intended to equip a container, the
neck of which includes threading having three external ribs, as
well as an annular rib situated beneath the external threading.
[0033] The tamperproof ring 6 has several uniformly distributed
tabs 7. The ring is linked to each tab by a thinned region of
material 8 forming a film hinge, allowing the tab to be bent
inwards. In FIGS. 5, 7 and 8, the tabs 10 are depicted in their
final position, as they will be on the neck of the container. They
are bent up towards the top 2 of the cap and are substantially
parallel to the wall of the tamperproof ring 6 and to the skirt
3.
[0034] These tabs 7 are intended to interact with the annular rib
on the neck of the container on unscrewing the cap 1 for the first
time. During this first unscrewing, the tabs butt up against the
annular rib before complete unscrewing, thus preventing the
tamperproof ring from going beyond this rib. By continuing to exert
an unscrewing torque on the skirt 3, the breakable linking elements
5 yield. The ring 6 then remains beneath the annular rib and the
skirt 3 may be unscrewed, allowing access to the content of the
container.
[0035] Furthermore, on the free edge of the skirt 3, facing the
tamperproof ring 6, the cap includes three small-sized projections
9 (FIGS. 6 to 8). These projections 9 extend over a few millimeters
and have a height h of less than 0.6 millimeter. Each of these
projections 9 is situated between two successive breakable linking
elements 5. As indicated hereinabove, the threading 4 in the skirt
includes three threads. The latter have a first end close to the
top 2 of the cap and a second end close to the free edge of the
skirt 3. There are consequently three ends of threads on the side
of the free edge of the skirt. Each of the projections lies
substantially halfway between two of these ends.
[0036] FIGS. 1 to 3 show, in cross-section, a mould for producing a
cap such as the one described hereinabove. This mould includes
three essential parts: a first part designated by the mould top or
movable part 20, a second part called the stripping part or
stripper ring 21 and a third part constituting the core 22 of the
mould.
[0037] The internal surface of the top of the mould 20 corresponds
to the external surface of the skirt 3 and of the top 2. The inner
surface of the stripper ring corresponds to the external surface of
the tamperproof ring 6. Finally, the core 22 imparts its shape to
the internal surface of the cap, that is to say of the top 2, of
the skirt 3 and of the tamperproof ring 6.
[0038] In FIG. 1, the cap 1 has already been moulded and the mould
is open. In order to open the mould, the movable part 20 is first
of all removed. Next, the stripper ring 21 is moved in the
direction of the arrow 23 in FIG. 1. The core 22 remains
stationary.
[0039] The core 22 is removed in a process known per se by a
translational movement of the stripper ring 21, without unscrewing.
During this step, the skirt 3 deforms. It is in order to allow free
deformation of the skirt 3 that the movable part 20 of the mould is
removed before extracting the core. The tabs 7 of the tamperproof
ring 6 are forced by the core 22 to adopt a substantially radial
position, as depicted in FIGS. 4 and 6.
[0040] In order to bend the tabs 7 up and to bring them into a
position in which they are substantially parallel to the skirt 3
and to the tamperproof ring 6 (FIGS. 5, 7 and 8), the stripper ring
21 is provided with a translational movement in the direction of
the arrow 24 in FIGS. 2 and 3, in such a way that the tabs 7 move
closer to the core 22. FIG. 2 illustrates the moment when the tabs
7 come into contact with the core 22 and FIGS. 3, 5 and 7 show the
core 22 bending up the tabs 7 as well as the ejection of the cap
from the mould.
[0041] FIGS. 6 and 7 show, on a larger scale, the details A and B
in FIGS. 1 and 3 respectively. In these figures, the cutting plane
passes through a projection 9 on the cap.
[0042] The stripper ring 21 includes an upstand 25 on which the
free edge of the skirt 3 bears. This upstand 25 has a notch 26 in
which a projection 9 is held. The stripper ring 21 includes three
notches of this type. They are distributed on the periphery of the
upstand 25. Each of these notches 26 lies between two adjacent
breakable linking elements 5. In addition, these notches are, in
each case, situated substantially halfway between two ends of a
thread of the internal threading of the skirt, these ends being
situated on the side of the free edge of the skirt.
[0043] In FIGS. 1 to 3, it may be seen that the cap is held in
place only by the stripper ring 21. On bending up the tabs 7, in
the absence of the projections 9 and the notches 26, the cap 1 may
incline and consequently it is no longer possible to bend the tabs
up. By virtue of the projections 9 and the notches 26, the cap 1 is
stable and held in place perfectly. FIG. 9 is a bottom
cross-section view of the cap shown in FIGS. 6-8 with the cutting
plane passing through the projections 9.
[0044] An alternative embodiment is depicted in FIGS. 4 and 5.
According to this alternative embodiment, the mortise-and-tenon
linkage formed between the stripper ring 21 and the cap 1 is no
longer produced by placing the tenon on the cap 1 and the mortise
on the stripper ring 21, but by placing the tenon on the stripper
ring and the mortise on the cap. The projections 9 are therefore
each replaced by a notch 10 and the notches 26 are each replaced by
a projection 27. FIG. 10 is a bottom cross-section view of the cap
shown in FIGS. 4-5 with the cutting plane passing through the skirt
3.
[0045] Of course, the invention is not limited to the embodiments
described hereinabove by way of non-limiting examples but, on the
contrary, embraces all variants thereof.
[0046] Thus, for example, the number of projections or of notches
on the cap is not limited to three. There could be two or four of
them thereon. A larger number is conceivable, but there is a risk
of leading to problems such as the cap jamming in the mould during
ejection from the mould or during extraction of the core.
[0047] It is also conceivable to have one or two notches and one or
two projections on the cap.
[0048] The shape of the cap may be different. The top of the cap
may, for example, have a skirt intended to go inside the neck of
the container in order to perfect the sealing. The shape of the
tabs may also be other than that depicted in the drawing. In
various exemplary embodiments of the invention, the projections or
the notches 10 are situated on zones corresponding to 30% of the
circumference of the cap 1. In various other exemplary embodiments
of the invention, the projections 9 or notches 10 are situated on
zones corresponding to approximately 10% of the circumference of
the cap 1.
[0049] In various exemplary embodiments of the invention, the
height of the projection 9 or the notches 10 is less than or equal
to 0.6 mm. In various other exemplary embodiments of the invention,
the height of the projection 9 or the notches 10 is approximately
0.5 mm.
* * * * *