Note: Descriptions are shown in the official language in which they were submitted.
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A closure cap for closing a container
The invention relates to a closure cap for closing a
container, according to the preamble of patent claim 1. In
particular with containers which have an increased inner
pressure, for example on account of drinks containing carbon
dioxide, it must be taken care that on removal of the closure
cap the inner pressure may escape before the closure cap is
completely separated from the opening of the container. With
closure caps known up to now, for this purpose on the inner
side of the closure cap bleeding slots have been incorporated
which permit a gas outflow at a point in time at which the
closure cap is still connected to an essential part of the
container opening. If no such bleeding slots are provided
there exists the danger that the closure cap prematurely pops
off from the opening during the opening procedure on account
of the increased inner pressure.
A disadvantage of such known closure arrangements lies
in the fact that the thread formation on the inner side of
the closure cap as well as on the outer side of the container
opening requires large wall pieces and thus a larger use of
material and thus entails high manufacturing costs. A further
disadvantage lies in the fact that the closure cap must alway
be partly opened and with that the thread partly comes out of
engagement with the container opening by which means there
exists the danger that the closure cap shoots off over the
thread.
"
US 5,135,124 for reducing the material consumption
suggests a closure cap which on its inner side is provided
with two different types of retaining elements. With first
retaining elements the closure is kept in a closed condition
on the container. On opening, the closure is moved into a
bleeding position in which it is held on the container by
second retaining elements. This closure cap however has the
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disadvantage that on transition from the sealing position
into the bleeding position for a certain time it is only
partly engaged with the retaining elements of the container
opening. By way of this again there is the risk of a prema-
ture shooting off of the closure cap before a complete pres-
sure equalisation between the inner space of the container
and the surroundings has taken place. Furthermore such clo-
sure caps on account of the various types of retaining
elements are complicated in their manufacture.
The object of the present invention lies in recognising
the disadvantages of that which is known, thus in particular
in providing a closure cap for closing a container with
increased inner pressure which can be manufactured simply and
with a small use of material and in spite of this prevents a
premature shooting off of the closure cap during the opening
procedure.
According to the invention these objects are achieved
with a closure cap with the features of the characterising
part of claim 1.
The closure cap for closing a container with an
increased inner pressure consists essentially of a cap floor
and a cap wall which on its inner side is provided with a
guide path of a bayonet thread. The guide path can be brought
into engagement with retaining cams on the outer side of the
container opening and comprises a latching position for
bleeding gas before the final screwing'off of the closure
cap. The latching position of the guide path, according to
the invention, is formed by at least one latching edge.
The latching edge limits the screwing off movement in a
manner such that the guide path during the whole gas bleeding
procedure is in engagement with whole retaining surface of
the retaining cams on the container opening. Thanks to the
latching edge, given an opening procedure, it is not possible
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to move the closure cap beyond the latching position before a
complete pressure equalisation has taken place. Since the
closure cap in the latching position is however still in
complete engagement with the retaining cam on the outer side
of the container opening, the danger of a premature popping
off during the gas bleeding procedure is no greater than with
a closed closure cap. With the correct dimensioning of the
closure cap for preventing the popping off in the closed
condition, also the popping off of the closure cap during the
gas bleeding procedure is reliably prevented.
The guide path may for example be formed by two or
several ridges projecting inwardly from the inner side of the
cap wall. The surface of these ridges facing the cap floor
forms the retaining surface with which the closure cap coop-
erates with the retaining cam on the outer side of the con-
tainer opening. Between this surface and the side of a neigh-
bouring ridge, which is distant to the cap floor, there is
defined the guide path.
In a particularly preferred embodiment example the guide
path is defined by four ridges, i.e. that the guide path
consists of four individual part paths. In each case one path
is enclosed between two ridges. With such an arrangement the
retaining cams on screwing on or with the opening procedure
are guided in an exactly defined procedure. with this also
the danger of jamming is reliably ruled out. Each ridge
extends over an angular range of about 160-200~, preferably
180~. With a uniform arrangement of the four ridges on the
circumference there results with this'an overlapping of in
each case two neighbouring ridges by about 90~.
In a particularly preferred embodiment example each
ridge is formed by four sections. Two of these sections
comprise no gradient and run horizontally, i.e. parallel to
the floor of the closure cap. The other two sections have a
gradient. This gradient is necessary in order to press the
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closure from the opened position into a sealing position.
When the closure cap with the first horizontal section is in
engagement with a retaining cam of a container opening a
sealing position is defined. By way of the second horizontal
section a gas bleeding position is defined. The two horizon-
tal sections are connected to an obliquely running section so
than on screwing on the closure cap between the gas bleeding
position and the sealing position by way of the gradient the
necessary sealing pressure is achieved. The second obliquely
running section is arranged at the beginning of each ridge
and permits a simple introduction of the retaining cam into
the guide paths. The latching edge is preferably arranged at
the end of the second horizontal section, this end being
distant to the first horizontal section. So that the screwing
off movement of the closure cap may be stopped until a com-
plete pressure equalisation is achieved, the latching edge is
arranged on the surface of at least one ridge, which faces
the cap floor.
So that on placing on the closure cap no complications
arise by way of jamming, the four ridges would each have to
be formed equally. It is however conceivable only to provide
a single ridge with a latching edge. In order to interrupt
the screwing off movement as reliably as possible however
preferably each individual ridge is provided with such a
latching edge.
Advantageously the second horizontal section is formed
longer than the first horizontal section. By way of the
length of the second horizontal sectioh the angular range of
the rotational movement is defined with which a bleeding of
the gas takes place before the screwing off movement is
interrupted. The longer the horizontal section is formed the
more comfortable is the screwing off of the closure cap for
the user. If the closure cap is screwed off with a relatively
slow rotational movement, with a long second horizontal
section the pressure equalisation is made before the retain-
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ing cams of the container opening meet the latching edge. In
this case the user hardly notices the limiting of the screw-
ing off movement. A slight pressing down of the closure cap
is sufficient in order to overcome the latching edge. If
however the closure cap is quickly screwed off the retaining
cams meet the latching edges before a complete pressure
equalisation is made. By way of this the opening movement of
the closure cap is stopped and the rotational movement of the
hand of the user is likewise interrupted.
As long as a complete pressure equalisation has not been
made, it is not possible to overcome the latching edge. On
account of the still high inner pressure the closure cap may
not at all be pressed downwards in order to overcome the
latching. ~ompellingly one must wait until a complete or
almost complete pressure equalisation is achieved. It has
been shown that a second horizontal section which extends
over an angular range of 55-70~, preferably 65~, with a
normal screwing off speed of the closure hardly leads to an
abrupt stop of the screwing on movement by the latching edge.
The distance between the neighbouring ridges is prefer-
ably not kept constant over the whole length of the ridge. In
particular the distance between the two horizontally running
sections is selected smaller than the distance between the
obliquely running sections. With this it is to be achieved
that the guiding cams may be uniformly guided through the
guide path formed between the ridges. By way of this there
results a minimal distance between thè ridges in the region
of the latching edge. The maximum dist?ance between two ridges
is achieved in the region of the obliquely running sections.
This is necessary since the retaining cams on the outer side
of the container opening may have a certain lateral exten-
sion, and would otherwise would jam with oblique sections
lying too close.
In a further embodiment example each ridge may be pro-
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vided with a relief on an underside distant to the cap floor
in the region of the latching edge of the ridge lying there-
under in each case. By way of this the guiding of the retain-
ing cam in the guide path is additionally increased. In this
manner the distance betwen the horizontal sections of two
neighbouring ridges may be selected such that the intermedi-
ate space corresponds to the thickness of the retaining cams
of the container to be closed.
The invention is hereinafter described in more detail by
way of the drawings and in embodiment examples. There are
shown:
Fig. 1 a schematic representation of a closure cap accord-
ing to the invention and of a container opening,
Fig. 2 a cross section through the closure cap according to
the invention,
Fig. 3 a developed view of the inner side of the closure
cap of Figure 2,
Fig. 4 an enlarged cutout of the developed view of Figure
3,
Fig. 5a a developed view with indicated retaining cams in
the sealing position,
Fig. 5b a developed view with indicatèd retaining cams in a
bleeding position, and '
Fig. 6 a cutout from a developed view of an alternative
embodiment example.
Figure 1 shows a closure cap 1 and a container opening 2
which can be closed with the closure cap 1. The closure cap 1
consists essentially of a cap floor 3 and a cap wall 4 incor-
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porated on the outer edge of the cap floor 3. On the inner
side 5 of the cap floor 4 there is provided a guide path
which can be brought into engagement with retaining cams 7 on
the outer side 8 of the container opening 2. The guide path 6
is limited by ridges 11. For limiting the screwing off move-
ment and for defining a latching procedure for bleeding gas
the guide path 6 comprises latching edges 9. The latching
edges are incorporated onto each ridge 11 on the side of the
ridge 11, which faces the cap floor 3. The whole arrangement
is formed such that the closure cap 1 during the complete gas
bleeding procedure is held by the entirety of the retaining
surfaces 10 of the retaining cams 7. The number of ridges 11
may vary in the individual case although three to six ridges
11, but particularly four ridges as a rule lead to an optimal
handling and a secure engagement.
Figure 2 shows a cross section through a closure cap
according to the invention. In Figure 2 the latching edge 9
limiting the screwing off movement is clearly visible. The
closure cap 1 also comprises a sealing lip 17.
Figure 3 shows a developed view of the inner side of the
closure cap of Figure 2. The guide path 6 consists of four
individual part guide paths which are formed by four ridges
11. Each ridge comprises a latching edge 9 which limits the
screwing off movement. In Figure 4 the course of the ridges
11 is more accurately viewable. Each ridge 11 comprises two
sections 13a, 13c with a gradient as well as two horizontal
sections 13b, 13d running without a gradient. The first
horizontal section 13d defines a sealing position and the
second horizontal section 13b a gas bleeding position. The
two horizontal sections 13b, 13d are connected amongst one
another to the section 13c running with a gradient. The
latching edge 9 is arranged at the end 14 of the second
horizontal section 13b, which is distant from the first
horizontal section 13d, on the surface of the ridge 11, which
faces the cap floor. The section 13a running with a gradient
,
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defines the beginning of the thread and simplifies the intro-
duction of the retaining cams at the beginning of the screw-
ing on movement thanks to its oblique position. The obliquely
running section 13c with a sealing means which is not shown
in more detail (for example a sealing lip 17 as shown in
Figure 2 and/or a liner seal which is not shown or an outer
seal) produces the sealing pressure necessary for the seal-
ing .
The distance between two neighbouring ridges 11 is not
constant over their whole length. In a reqion 16 of the
obliquely running sections 13a, 13c the distance between the
ridges 11 is larger than in a region 15 with the horizontal
sections 13b, 13d. This is necessary so that a somewhat
elongate retaining cam (cam 7 as is shown in Figure 1) does
not jam in the region 16 of the sections 13a, 13c running
with a gradient. The minimum distance between two neighbour-
ing ridges 11 is defined by the latching edge 9.
Figures 5a and 5c show a developed view of the inner
side of a closure cap according to the invention with sche-
matically shown retaining cams 7 of a container closure in a
sealing position (Figure 5a) and in a gas bleeding position
(Figure 5b). In the sealing position the horizontal sections
13d are in engagement with the retaining cams 7. So that the
screwing on movement is limited in each case an end section
20 connects to the horizontal sections 13d. The end section
20 here is likewise formed as a slant so that together with
the oblique section 13c lying thereunder there is formed an
exactly defined guide path 6. Basicall~ it is however also
conceivable to form the end section 20 vertically.
With the opening procedure the retaining cams 7 are
guided from the sealing position shown in Figure 5a into the
bleeding position shown in Figure 5b. By way of the sections
13c running with a gradient the complete closure cap, thus
also the sealing means which is not represented here, is
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lifted up by which means with an high inner pressure there
results a bleeding of gas. The movement of the retaining cams
7 is limited by the latching edges 9. As long as there exists
an increased inner pressure in the container closed by the
closure cap, the ridges ll with their surface facing the cap
floor are pressed by the inner pressure firmly against the
retaining cams 7. Only with a complete reduction of the inner
pressure can the closure cap be easily pressed downwards,
which permits an overcoming of the latching edges 9.
In Figure 6 there is shown an alternative embodiment
example of the formation of the guide path 6. The first
horizontal section 13d on its side distant to the cap floor
comprises a relief 18 which is vertically flush with the
latching edge 9. With such a design the width of the guide
path 6 between the two horizontal sections 13b, 13d may be
reduced such that it corresponds to the thickness of the
retaining cams on the outer side of a container. With such an
arrangement these retaining cams are guided through the guide
path 6 in an exactly fitting manner.
