U.S. patent application number 12/449662 was filed with the patent office on 2011-01-06 for hinged stopper of plastics material.
This patent application is currently assigned to Tetra Holdings & Finance S.A.. Invention is credited to Gregory Antier, Veronique Bernard.
Application Number | 20110000871 12/449662 |
Document ID | / |
Family ID | 38508720 |
Filed Date | 2011-01-06 |
United States Patent
Application |
20110000871 |
Kind Code |
A1 |
Bernard; Veronique ; et
al. |
January 6, 2011 |
HINGED STOPPER OF PLASTICS MATERIAL
Abstract
This stopper (1) comprises a capping lid (20) which, in the back
portion of a tubular base (10) for surrounding a container neck,
forms part of the upper end (10A) of this base, forming a joint
(30) with hinges (31) which defines a geometric axis (A-A) for
pivoting the lid between the open and closed service positions. To
limit the risk that a child, playing with the stopper, could remove
the lid, while at the same time enabling the lid to be opened
reliably and satisfactorily by the joint in relation to the base,
the joint has two lines of least mechanical resistance (14), which
extend from the upper end to the lower end (10B) of the base, being
positioned, at the level of said upper end, on both sides of the
joint, and which are designed to break before the joint can tear
completely when the lid, in open position thereof, is rotated on
itself around a geometric axis transverse to the pivoting axis
(A-A).
Inventors: |
Bernard; Veronique; (Anse,
FR) ; Antier; Gregory; (Trevoux, FR) |
Correspondence
Address: |
DOWELL & DOWELL P.C.
103 Oronoco St., Suite 220
Alexandria
VA
22314
US
|
Assignee: |
Tetra Holdings & Finance
S.A.
Pully
CH
|
Family ID: |
38508720 |
Appl. No.: |
12/449662 |
Filed: |
February 27, 2008 |
PCT Filed: |
February 27, 2008 |
PCT NO: |
PCT/FR2008/000253 |
371 Date: |
August 20, 2009 |
Current U.S.
Class: |
215/235 |
Current CPC
Class: |
B65D 55/16 20130101 |
Class at
Publication: |
215/235 |
International
Class: |
B65D 39/00 20060101
B65D039/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 28, 2007 |
FR |
07 01447 |
Claims
1-11. (canceled)
12. A stopper of plastics material for a neck of a container, the
stopper comprising a generally tubular base for surrounding the
neck and a closure cap that is formed in a peripheral portion of
the base integrally with a first longitudinal end of the base,
forming a hinge with one or more hinge members defining a tilt axis
for tilting the cap relative to the base between open and closed
service positions, wherein the base presents two elongate zones of
weakness that extend lengthwise from the first end of the base
towards the second longitudinal end thereof, being situated at said
first end on either side of the hinge, and that are adapted to
break before the hinge can be torn through when the cap, in the
open position, is turned over around a twist axis extending
transversely to the tilt axis.
13. A stopper according to claim 1, wherein the two zones of
weakness are dimensioned and configured relative to the base in
such a manner that, after breaking, they define between them a
material portion of the base, that carries the hinge and that is
adapted to work in twisting without breaking when the cap is turned
over about the twist axis through at least 180.degree..
14. A stopper according to claim 12, wherein each zone of weakness
presents, in the longitudinal direction of the base, a dimension
that is greater than one-fourth the length of the base.
15. A stopper according to claim 14, wherein said dimension is
greater than half length of the base.
16. A stopper according to claim 12, wherein the two zones of
weakness extend lengthwise converging towards each other on going
away from the first end of the base.
17. A stopper according to claim 16, wherein the two zones of
weakness define, between their ends remote form the first end of
the base and in the peripheral portion of the base associated with
the hinge, a material portion of base, that presents, in a plane
perpendicular to the longitudinal direction of the base, a section
that is greater than or equal to that of the hinge member(s) of the
hinge.
18. A stopper according to claim 16, wherein the two zones of
weakness define, between their ends remote from the first end of
the base and in the peripheral portion of the base associated with
the hinge, a material portion of the base, that presents a
thickness that is strictly greater than the thickness of the hinge
member(s) of the hinge.
19. A stopper according to claim 12, wherein a longitudinal
material portion of the base, that extends between the longitudinal
end of at least one of the zones of weakness opposite from the
first end of the base, and the second end of the base, presents, in
the longitudinal direction of the base, a dimension that is greater
than 10% of the length of the base.
20. A stopper according to claim 12, wherein at least one of the
zones of weakness is extended at its longitudinal end remote from
the first end of the base by an elongate opening formed in the
base, said opening extending lengthwise from said zone of weakness
in a direction that is substantially peripheral relative to the
base and away from the other zone of weakness.
21. A stopper according to claim 12, wherein each zone of weakness
comprises firstly a through slot that extends lengthwise from the
first end towards the second end of the base, and secondly at least
one breakable element connecting together the longitudinal sides of
the slot, and adapted to break before the hinge can be torn through
when the cap in its open position is turned over about the twist
axis.
22. A stopper according to claim 21, wherein the at least one
breakable element is disposed at the longitudinal end of the slot
that is situated at the first end of the base.
23. A stopper according to claim 12, wherein the two zones of
weakness define between them a material portion of the base, that
carries the hinge and that is provided, in its middle portion
around the periphery of the base, with a through orifice of
elongate shape in the longitudinal direction of the base.
Description
[0001] The present invention relates to a plastics material stopper
for a container neck. The invention applies more particularly to
so-called "hinged" stoppers, i.e. stoppers that include a cap that
can be tilted relative to a base that is designed to surround the
neck of the container in permanent manner, by deforming a hinge
having one or more members connecting the base integrally with the
cap. Examples of stoppers of this type are given in WO-A-03/006333
and WO-A-03/059770.
[0002] That type of stopper can raise safety problems with
children: if a child is playing with the hinged stopper and
subjects it to stresses other than the normal stress for tilting
about its hinge member(s), such as stressing in twisting and/or in
traction, the hinge member(s) might tear, thereby separating the
cap from the base. The child then inhales the cap through the mouth
and runs the risk of choking.
[0003] The object of the present invention is to propose a hinged
plastics stopper that not only provides reliable and satisfying
hinging between its cap and its base for opening and closing the
stopper, but also limits any risk that a child might manage to tear
off the cap when playing with the stopper. In particular, the
invention seeks to provide a hinged plastics stopper that satisfies
the French standard relating to child safety, referenced NF EN
71-1, or classified under the reference S 51-212, that makes
provision for applying a twisting force and then a traction force
on an article under test, and under certain test conditions.
[0004] To this end, the invention provides a stopper of plastics
material for a neck of a container, the stopper comprising a
generally tubular base for surrounding the neck and a closure cap
that is formed in a peripheral portion of the base integrally with
a first longitudinal end of the base, forming a hinge with one or
more hinge members defining an axis for tilting the cap relative to
the base between open and closed service positions, the stopper
being characterized in that the base presents two elongate zones of
weakness that extend lengthwise from the first end of the base
towards the second longitudinal end thereof, being situated at said
first end on either side of the hinge and adapted to break before
the hinge can be torn through when the cap, in the open position,
is turned over around a twist axis extending transversely to the
tilt axis.
[0005] In order to guarantee safety of a child playing with a
hinged stopper of the above-mentioned type, in particular in
accordance with the above-specified French standard, such a stopper
is required to present a cap that either presents a diameter
greater than a predetermined value chosen to ensure that if the cap
is torn from the base it cannot be inserted into a child's wind
pipe, or else sufficient strength in its connection with the base
to ensure that cannot be completely separated from the base when
the connection zone is subjected to a predetermined level of
twisting, or the cap is even twisted right over about a test axis
perpendicular to the normal tilt axis of the cap between its open
and closed position. The idea on which the invention is based is to
guarantee that the cap of the stopper in accordance with the
invention can be turned over, i.e. twisted about a twist axis, in
particular under the conditions specified by the above-mentioned
standard, without applying significant stresses to the hinge
member(s), and thus ensuring that the hinge is not torn through
even though it presents low breaking strength given its relative
flexibility. If it is considered that the base of the stopper in
accordance with the invention extends lengthwise in a vertical
direction, with the cap on top, the base has two elongate zones of
weakness on either side of the peripheral portion of its top end
that is hinged to the cap, which zones of weakness extend from its
top end towards its bottom end. When the cap is tested in bending,
each of these two zones breaks almost immediately, i.e. before the
hinge is subjected to significant levels of twisting stress. As a
result, instead of concentrating at the high end of the base, i.e.
at the hinge, twisting stresses are distributed over a portion of
plastics material carrying the hinge and defined between the two
zones of weakness, over the entire length of those zones. This
greatly limits the risk of the material connection connecting the
cap to the base being torn right through under the effect of excess
local stresses when the connection is subjected to twisting, in
particular with the cap being turned over while in its open
position.
[0006] Thus, the safety of a child playing with a stopper in
accordance with the invention, in particular a child twisting the
cap relative to the base at its hinge, is improved whatever the
maximum transverse dimension of the cap, in particular regardless
of its diameter if the cap has a circular base. In other words, the
invention can be applied to stoppers of plastics material having a
wide variety of dimensions. In addition, unlike a solution to the
above-posed problem that consists in increasing the strength of the
hinge between the cap and the base, in particular by reinforcing
the portions adjoining said hinge by ribs or extra thickness of
plastics material, the zones of weakness in accordance with the
invention are made by reducing the amount of plastics material that
is used, thereby reducing the total weight of the stopper.
[0007] Furthermore, it can be understood that when the cap of the
stopper in accordance with the invention is stressed in its normal
conditions of service, i.e. when it is tilted between its open and
closed positions relative to the base, the presence of two zones of
weakness in accordance with the invention has no effect, i.e. these
zones do not disturb normal titling of the cap and do not impose
any limit on its mechanical performance relating to tilting. In
particular, the two zones of weakness in accordance with the
invention may be incorporated in a hinged stopper that presents the
advantageous arrangements described in WO-A-03/006333. In other
words, when two successive hinge members around the periphery of
the base of the stopper in accordance with the invention are
provided to constitute the hinge between the cap and the base, the
cap is advantageously provided with a projection that is adapted to
come to bear against a tongue formed by the first end of the base,
between the two hinge members, to hold the cap in its open position
with an opening angle of at least 180.degree..
[0008] In a preferred embodiment, the two zones of weakness are
dimensioned and configured relative to the base in such a manner
that, after breaking, they define between them a portion of base
material that carries the hinge and that is adapted to work in
twisting without breaking when the cap is turned over about the
twist axis through at least 180.degree.. As a result, the cap can
be turned right over relative to the base without it being possible
to separate it from the base, in particular by breaking the hinge,
thereby satisfying the twist test of the above-specified
standard.
[0009] With advantageous practical dimensions, each zone of
weakness presents, in the longitudinal direction of the base, a
dimension that is greater than one-fourth, and preferably greater
than half the length of the base.
[0010] In a preferred arrangement, the two zones of weakness extend
lengthwise converging towards each other on going away from the
first end of the base. As a result, when the cap is turned over
about the twist axis, a major fraction or even substantially all of
the twisting stress on the material connection between the base and
the cap is concentrated in the portion of material between the
bottom ends of the two zones of weakness. In other words, the
twisting stresses are taken up longitudinally in the main portion
of the base at a good distance from the hinge member(s), thereby
correspondingly preserving the structural integrity of said
member(s).
[0011] With advantageous practical dimensions concerning the
portion of material of the base that is defined by the two zones of
weakness, between their ends remote from the first end of the base
and in the peripheral portion of the base associated with the
hinge: [0012] said portion presents, in a plane perpendicular to
the longitudinal direction of the base, a section that is greater
than or equal to the section of the hinge member(s); and/or [0013]
said portion presents a thickness that is strictly greater than the
thickness of the hinge member(s).
[0014] To enable the cap of the stopper in accordance to withstand
a traction force applied along the twist axis, in particular in the
context of a traction test performed subsequent to the twist test
as set out by the above-mentioned French standard, a longitudinal
portion of the material of the base that extends between the
longitudinal ends of at least one of the zones of weakness remote
from the first end of the base, and the second end of the base
presents a dimension in the longitudinal direction of the base that
is greater than 10% of the length of the base. As a result, after
the zones of weakness in accordance with the invention have
performed their role of preserving the structural integrity of the
hinge between the cap and the base, these zones are dimensioned
relative to the base so as to limit any risk of the turned-over cap
being torn off when pulled away from the base. Nevertheless, it can
be understood that even when applying the traction force leads to
the base tearing, by cracks propagating through the plastics
material downwardly extending the zones of weakness to the bottom
end of the base, the resulting torn-off stopper presents a
transverse dimension that is very large, thus, in practice,
preventing the stopper from being inhaled by a child.
[0015] In an arrangement that can be used as an alternative to or
in conjunction with the above arrangement, for the purpose of
improving retention of the structural integrity of the base when
the cap is thus stressed in traction, at least one of the zones of
weakness is extended at its longitudinal end remote from the first
end of the base by an elongate opening formed in the base, said
opening extending lengthwise from said zone of weakness in a
direction that is substantially peripheral relative to the base and
away from the other zone of weakness. As a result, cracks in the
material started at the bottom ends of the zones of weakness in
accordance with the invention are guided by said openings around
the periphery of the base, i.e. in a direction allowing the tears
to progress through a large amount of material before compromising
the structural integrity of the base.
[0016] In a practical embodiment, each zone of weakness comprises
firstly a through slot that extends lengthwise from the first end
towards the second end of the base, and secondly at least one
breakable element connecting together the longitudinal sides of the
slot, and adapted to break before the hinge can be torn through
when the cap in its open position is turned over about the twist
axis. Advantageously, the breakable element(s) is/are disposed at
the longitudinal end of the slot that is situated at the first end
of the base.
[0017] In a possible embodiment, the two zones of weakness define
between them a portion of material of the base that carries the
hinge and that is provided, in its middle portion around the
periphery of the base, with a through orifice of elongate shape in
the longitudinal direction of the base. This through orifice makes
it possible, so to speak, to subdivide the above-mentioned portion
of material into two sub-portions of material, that are disposed on
either side of the orifice. As a result, when the above-mentioned
portion of the base is subjected to twisting while the cap is being
turned over, each of the sub-portions deforms in a manner that is
particularly flexible, thereby limiting the appearance of local
excess stresses.
[0018] In addition, this through orifice may be arranged in
accordance with the teaching of WO-A-03/059770, i.e. this through
orifice forms a passage for inserting a tamperproofing tongue into
a storage space defined between the base and the neck, the
tamperproofing tongue associating the base with the cap away from
the hinge, being connected to said base and to said cap via
breakable means that are adapted to break so as to enable the
tongue to be removed on first use of the stopper in order to open
the cap.
[0019] The invention can be better understood on reading the
following description, given purely by way of example and made with
reference to the drawings, in which:
[0020] FIG. 1 is a perspective view of a stopper in accordance with
the invention;
[0021] FIG. 2 is an elevation view looking along arrow II of FIG.
1;
[0022] FIG. 3 is a longitudinal section view of the neck of a
container closed by the stopper of FIGS. 1 and 2;
[0023] FIG. 4 is a view analogous to FIG. 3, showing a cap of the
stopper in an open position relative to a base of the stopper;
[0024] FIG. 5 is a perspective view of the stopper of FIGS. 1 and
2, showing the cap being turned over while in the open position;
and
[0025] FIGS. 6 to 9 are views analogous to FIG. 2 showing
respective embodiments variants of the stopper in accordance with
the invention.
[0026] In FIGS. 1 to 5, a stopper 1 is shown either on its own or
else mounted on the neck 2 of a container 3, such as a bottle,
which is shown in part only. For convenience, the description below
is oriented on the assumption that the terms "top" and "bottom",
and analogous terms, are defined with reference to a stopper placed
flat on a surface that is generally horizontal in the position of
FIGS. 1, 2, and 5, which amounts to assuming that the stopper is
mounted on the neck 2 when the neck extends vertically lengthwise
in an upward direction from the remainder of the container 3, in
the configuration shown in FIGS. 3 and 4. As a result, the top side
of the device 1 faces upwards in the figures, whereas its bottom
side faces downwards.
[0027] The stopper 1 is made as a one-piece plastics molding and
comprises a bottom base 10 of tubular shape on a circular base
about a central longitudinal axis X-X. The base 10 is provided with
internal ribs 11 that are situated at the same longitudinal level
of the base, and that are distributed around the periphery of the
base, as can be seen in FIG. 5. As shown in FIGS. 3 and 4, these
ribs 11 are adapted to co-operate with an outer annular rim 4 on
the neck 2 so as to prevent the base from moving around the
neck.
[0028] The stopper 1 also has a top cap 20 that is hinged to the
top end 10A of the base 10 in a small peripheral zone of the base,
corresponding in practice to the rear portion of the stopper 1. For
this purpose, the corresponding rear hinge, referenced 30, between
the base and the cap comprises two flexible strips 31 connecting
the top end 10A of the base directly to the bottom end 21A of a
main tubular wall 21 of the cap, being formed integrally with said
ends. The strips 31 form respective hinges that, by deforming,
enable the cap 20 to be tilted between a closed position, as shown
in FIGS. 1 to 3, in which the cap closes the neck 2, and an open
position, shown in FIG. 4, in which the liquid contained in the
container 3 can be poured out freely from the container through the
neck 2 without being retained by the cap. The strips 31 thus define
an axis A-A about which the cap tilts between its closed and open
positions, it being understood that in practice, and given the way
the strips deform flexibly, the position of this axis A-A is not
absolutely stationary relative to the base 10, but that throughout
the tilting movement of the stopper, this axis is defined
instantaneously on the rear side of the stopper 1, extending in a
direction that is circumferential relative to the axis X-X.
[0029] Advantageously, the strips 31 are of smaller thickness than
the ends 10A and 21A of the base and of the cap, making them easier
to deform.
[0030] In order to make it easier for a user to cause the cap 20 to
tilt, the front peripheral portion of the cap is provided with a
tab 22 that projects forwards from the main wall 21. When the user
seeks to open the stopper 1, it is then possible to direct an
upwardly-directed force F.sub.1 against the bottom face of the tabs
22, as shown in FIG. 3.
[0031] In the embodiment shown in FIGS. 1 to 5, the stopper 1
advantageously presents arrangements in accordance with the
teaching of WO-A-03/006333, to which the reader may refer for more
details and corresponding variant embodiments. According to that
teaching, the cap 20 is provided, opposite from the tab 22, i.e. in
its rear peripheral portion, with a tab 23 that projects rearwards
from the main wall 21, while the base 10 includes, in its rear
peripheral portion, a tongue 12 integrally molded with the base and
projecting upwards from the top end 10A. Going around the periphery
of the base, this tongue 12 is located between the two hinge strips
31. While the cap is tilting about the axis X-X, the tab 23 comes
to bear on the outside against the tongue 12 under the effect of an
elastic force exerted by the strips 31. As a result of this force,
the tongue 12 is pressed against the outside surface of the neck 2,
said surface then exerting a reaction force on the tab 23 such that
this force, in combination with the elastic force exerted by the
strips 31, serves to hold the cap in its open position, as shown in
FIG. 4. Advantageously, the cap 20 is then held at an opening angle
of more than 180.degree., such that access to the neck is clearly
disengaged.
[0032] The stopper 1 also has a tamperproofing tongue 40 that,
prior to the first opening of the cap, associates the base 10 and
the cap 20 around the major fraction of the periphery of the
stopper 1, with the exception of the rear peripheral portion of the
base where there are formed the hinge 30 and a crenellation 41
formed integrally with the base and projecting upwards from the top
end 10A. This tongue 40 thus forms a connection of peripheral
material between the base and the cap during molding of the
stopper. Breakable means, designed to be broken when the tongue is
withdrawn, connects said tongue to the top end 10A of the base and
to the bottom end 21A of the cap, in particular in the form of
respective tearable lines 42 and 43 extending continuously around
the periphery of the stopper. So long as these lines 42 and 43 have
not been torn, the tongue 40 prevents the cap 20 from being tilted
away from its closed position. When the user desires to open the
stopper for the first time, it is necessary to grasp the
longitudinal end of the tongue, which is advantageously formed as a
grip tab 44, and remove the tongue completely by tearing the lines
42 and 43, thereby releasing the cap, which can then be tilted into
the open position. When the cap is subsequently tilted back into
the closed position, its bottom end 21A comes into abutment against
the crenellation 41 to stop its tilting movement.
[0033] In the embodiment shown in the figures, the stopper 1
advantageously presents arrangements in accordance with the
teaching of WO-A-03/059770, to which the reader may refer for
details and corresponding embodiment variants. According to that
teaching, an orifice 13 is formed through the wall of the base 10
in its rear peripheral portion, at a longitudinal level that is
substantially halfway up the base. This orifice 30 forms a passage
for the tongue 40 once the lines 42 and 43 have been completely
torn, in the sense that the tongue can be inserted through the
orifice 13 into a storage space 45 defined radially between the
outside face of the neck 2 and the inside face of the base 10, as
shown in FIG. 4.
[0034] In order to limit the risk that the cap 20 in the open
position can be torn completely away from the base 10, in
particular when said cap is stressed other than to perform its
normal tilting movement about the axis X-X, e.g. by a child playing
with the cap 1, the base 10 is provided with two lines of weakness
14 situated in the rear peripheral portion of the base. The two
lines 14 are symmetrical to each other about a diametral
longitudinal plane of the base corresponding to the section plane
of FIGS. 3 and 4, it being observed that for the two hinge strips
31, this plane corresponds to a plane of mutual symmetry, and also
serves as a plane of symmetry both for the tongue 12 and for the
orifice 13. Each line of weakness 14 includes a slot 15 that passes
radially through the wall of the base 10 and that extends generally
in a longitudinal direction of said base from its top end 10A
towards its bottom end 10B. In the example shown in FIGS. 1 to 5,
the slots 15 extend lengthwise in respective directions that are
not accurately parallel to the axis X-X, but that are slightly
curved in projection onto a diametral plane perpendicular to the
plane of symmetry of the lines 14, having their concave sides
facing towards the hinge 30, with the straight line interconnecting
their opposite ends 14A and 14B forming an angle .alpha. with the
axis X-X (FIG. 2), which angle faces upwards and has a value of
less than 45.degree.. Thus, as can clearly be seen in FIG. 2, the
two slots 15 converge towards each other on going away from the top
end 10A of the base, each presenting a longitudinal outline that is
slightly curved, with its concave side generally centered on the
hinge 30.
[0035] The respective top ends 14A of the lines of weakness 14,
corresponding respectively to the top ends of the corresponding
slots 15, open out into the top 10A of the base 10 and are situated
on either side of the hinge 30, i.e. on the outside of the
respective side edges of the strips 31 that are furthest apart from
each other. In the examples shown in the figures, each line of
weakness 14 opens out at its top end 14A into a gap between the
corresponding strip 31 and either the tamperproofing tongue 40 or
the crenellation 41.
[0036] Each line of weakness 14 also includes a breakable bridge 17
connecting together the two longitudinal edges of the corresponding
slot 15 at the top end 14A of the line of weakness. The bridges 17
are configured and dimensioned so that the presence of the lines of
weakness 14 does not disturb the dynamic behavior of the hinge 30
when the cap 20 is tilted about the axis A-A between its open and
closed positions. In contrast, when the cap 20 in the open position
is twisted to rotate about an axis B-B that is simultaneously
substantially perpendicular to the axis A-A and that extends in a
diametral plane of the cap 20, as represented by arrow F.sub.2 in
FIG. 5, the bridges 17 are configured and shaped so as to break
almost immediately, i.e. so as to break before the strips 31 of the
hinge 30 are subjected to stresses that would tear through the
strips. As a result, once the bridges 17 have broken, the portion
of material 10.sub.14/14 of the base 10 that lies between the two
lines of weakness 14 around the periphery of the base and that
carries the hinge 30, is no longer connected to the remainder of
the base over the entire longitudinal dimension l.sub.15 of the
slots 15. This portion of material 10.sub.14/14 can then be
subjected to twisting about the axis B-B over the entire length
l.sub.15 of the slots 15, in particular until the cap 20 has been
turned right over by turning F.sub.2 through 180.degree. about the
axis B-B, as shown in FIG. 5.
[0037] Since the stresses associated with twisting the portion of
material 10.sub.14/14 are distributed over the entire length
l.sub.15 of the slots 15, the intensity of the stress on the strips
31 remains moderate, and in practice is not sufficient to tear
through them, and consequently tear the cap 20 away from the base
10. For this purpose, and with practical dimensioning, the length
l.sub.15 is not less than one-fourth, and is preferably half the
length of the total length L of the base measured between its top
and bottom ends 10A and 10B.
[0038] In practice, the presence of the through orifice 13
subdivides the portion of material 10.sub.14/14 into two individual
sub-portions 10.sub.14/13 and 10.sub.13/14 on either side of the
orifice around the peripheral direction of the base, such that each
of these sub-portions is worked individually in twisting, thereby
limiting potential excess stress, particularly in the middle
peripheral zone of the portion 10.sub.14/14. When the stopper 1
reaches the configuration of FIG. 5, these sub-portions
10.sub.14/13 and 10.sub.13/14 cross each other.
[0039] In addition, insofar as the two lines of weakness 14
converge towards each other at their bottom ends 14B, it will be
understood that the most intense twisting stresses to which the
portion of material 10.sub.14/14 is subjected are applied to the
portion 10.sub.14B/14B that extends between the bottom end 14B
around the periphery of the base, as represented by a horizontal
shaded region in FIG. 2. In the embodiment of FIGS. 1 to 5, this
portion 10.sub.14B/14B is interrupted in its middle by the orifice
13. Thus, the dimensioning of this portion 10.sub.14B/14B is
critical in the sense that it must conserve its structural
integrity during twisting about the axis B-B. In particular, in
comparison with the strips 31, that are designed to conserve their
structural integrity while being subjected to a level of stress
intensity that is minimized given the downward convergence of the
lines of weakness 14, this portion 10.sub.14B/14B advantageously
presents a total section of material in a plane perpendicular to
the axis X-X that is less than or equal to the section of the
strips 31 and/or a thickness that is strictly greater than the
thickness of the strips.
[0040] Advantageously, in addition to conserving the structural
integrity of the hinge 30 when the cap 20 is turned over about the
axis B-B, the lines of weakness 14 are designed to limit any risk
of the portion 10.sub.14/14 being torn away when the cap 20, after
being turned over, and being pulled away from the base 10 along the
axis B-B, as represented by arrow F.sub.3 in FIG. 5. With reference
to the stopper 1 in its FIG. 5 configuration, if traction is
applied to the cap 20 along arrow F.sub.3, the low portion of the
base 10 withstands the corresponding traction stresses
longitudinally in line with the slots 15. In order to guarantee a
high level of traction strength, each slot 15 is extended by an
elongate opening 18 that is formed in the base and that extends
lengthwise from the bottom end 14B of the corresponding line of
weakness 14 in a direction that is substantially peripheral
relative to the base and away from the other line of weakness 14.
As a result, when traction F.sub.3 is applied to the cap, the tears
and cracks in the plastics material constituting the base 10 do not
propagate longitudinally to extend the slots 15 directly, but are
deflected by the openings 18 in a peripheral direction relative to
the base 10, axially between the level of the ends 14B of the lines
of weakness 14 and the bottom end 10B of the base. In practice, and
as clearly visible in FIG. 2, the openings 18 extend lengthwise in
respective directions that are not accurately circumferential
relative to the axis X-X but that, in projecting on a diametral
plane perpendicular to the plane of symmetry of the lines of
weakness 14, form respective downwardly-facing angles .beta.
relative to said axis, the angle .beta. having a value lying in the
range 45.degree. to 90.degree..
[0041] Thus, the stopper 1 satisfies, amongst others, the
requirements of French standard NF EN 71-1 or S 51-212 relating to
child safety, in the sense that its cap 20 can be turned over, in
particular through 180.degree., and can be pulled away from the
base 10 under predetermined conditions laid down by the standard,
without the material connection between the cap and the base being
completely broken, in particular at the hinge strips 31 of the
hinge 30, even though these are portions of the stopper 1 that are
fragile because of their small relative thickness.
[0042] FIGS. 6 to 9 respectively show four variants of the stopper
1. Below, only the differences between each of these variants and
the embodiment of FIGS. 1 to 5 are described in detail.
[0043] The stopper of the FIG. 6 variant does not have elongate
openings 18. This disposition makes the stopper easier to
fabricate. In order to guarantee that the portion of material
10.sub.14/14 has sufficient traction strength, the respective
bottom ends 14B of the lines of weakness 14 are provided far enough
away from the bottom end 10B of the base 10 to ensure that the two
longitudinal portions of material 14.sub.14B/10B extending between
the bottom end 14B of each line of weakness 14 and the bottom end
10B of the base, and represented by two vertical shaded regions in
FIG. 6, withstand high levels of traction stress without breaking.
For this purpose, the longitudinal dimension l.sub.14B/10B of these
portions 10.sub.14B/10B is not less than 10% of the length L of the
base.
[0044] Naturally, this longitudinal dimensioning of the portions
10.sub.14B/10B may be provided in the embodiment of FIGS. 1 to 5,
thus advantageously being combined with the presence of the two
openings 18.
[0045] In FIG. 7, there can be seen a variant of the stopper 1 that
associates one of the lines of weakness 14, specifically the lines
shown in the left-hand portion of the figure, with the presence of
one of the elongate openings 18, while the other line of weakness
14, i.e. the line shown on the right, is not associated with such
an opening, while nevertheless dimensioning the length
l.sub.14B/10B as shown in FIG. 6. In this way, the behavior of the
portion 10.sub.14/14 remains substantially uniform on either side
of the orifice 13, the sub-portions 10.sub.14/13 and 10.sub.13/14
being symmetrical to each other when the cap 20 is subjected to
twisting F.sub.2 about the axis B-B. In contrast, when it is
subjected to traction F.sub.3 along the axis B-B, the low portion
of the base 10 between the ends 14B of the two lines of weakness 14
and the end 10B of the base behave asymmetrically on either side of
the plane of symmetry of the lines 14: on the side provided with
the opening 18, tears and cracks in the plastics material are
guided in a direction that is substantially peripheral relative to
the base, as described in greater detail above with reference to
FIG. 2, whereas on the side that does not have an opening such as
the opening 18, the tears and cracks in the plastics material
propagate directly to extend the corresponding line of weakness 14
longitudinally, essentially within the corresponding longitudinal
portion 10.sub.14B/10B, as represented by a vertical shaded region
in FIG. 7.
[0046] In comparison, for traction of given intensity F.sub.3, the
tears in the low portion of the base 10 are more marked and come
closer to the end 10B of the side of the base shown in the
right-hand portion of FIG. 7 than to the side shown in the
left-hand portion. In the limit, if the traction intensity is great
enough, the base 10 breaks in the portion 10.sub.14B/10B that does
not have the opening 18, but it does not break in line with the
opening 18, such that the stopper 1 together with its base as
broken in this way over its entire length L remains as a single
piece, in particular with its cap 20 securely connected to the
base, it being observed that this piece may be of dimensions such
that it is practically impossible for a child to inhale it.
[0047] The variant stopper 1 shown in FIG. 8 does not have the
through orifice 13, thus preventing the tongue 40 being stowed
between the neck 2 and the base 10 after the tongue has been torn
off, but enabling the portion of material 10.sub.14B/14B to be of a
continuous shape without any interruption at an orifice 13.
[0048] The variant stopper 1 shown in FIG. 9 differs from the
embodiment of FIGS. 1 to 5 by the facts that firstly the hinge 30
has only one hinge strip 31, and secondly the two lines of weakness
14 that extend from the top end 10A of the base 10 on either side
of the hinge 30 are accurately parallel to the axis X-X.
[0049] It is also possible to envisage rearranging and varying the
stopper 1 and its variants as described above. For example,
elongate shapes other than the lines 14 may be provided for the
zones of weakness provided in the base 10 so as to allow the cap 20
to be turned over without tearing through the hinge 30. In
addition, the slots 15 of the lines of weakness 14 do not need to
be curved as shown in FIGS. 1 to 8 in order to be effective: they
may be curved in the opposite direction relative to that shown in
the figures, or as shown in FIG. 9, these slots may equally well be
rectilinear, or the slots may include successive segments that are
rectilinear and/or curved, and it is possible for them to have
curvature that is positive or negative. Similarly, a plurality of
breakable bridges such as the bridge 17 may be formed in the zones
of weakness, in particular depending on the precise shape of these
zones.
* * * * *