Note: Descriptions are shown in the official language in which they were submitted.
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SDecification
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Screw Cap
The invention relates to a screw cap consisting of deep-
drawable material, more particularly, aluminum or steel.
Known screw caps of the above-mentioned kind are used
for closing containers, in particular, bottles. They
preferably consist of aluminum. Such screw caps are
manufactured by, for example, so-called cap blanks
without a thread being placed on the opening of the
container or on the bottleneck. With a special device,
a thread which corresponds with the thread of the con-
tainer or of the bottle is rolled in the wall of the
screw cap. The container is opened by screwing off the
screw cap.
Such screw caps have proven their worth in practice. It
has, however, been shown~that in the event of a high
excess pressure in the container, a pressure loss or
even a so-called blow-off may occur which is not always
avoidable by increasing the rolling forces. In addition,
rolling forces which are too strong, place too high a
stress on the mouth region of the container, which may
cause damage to containers which have already suffered
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previous damage. ;
The object of the invention is, therefore, to create a ~ -
screw cap wherein the risk of damage to the container
thread and of a blow-off of the closure is minimized.
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This object is accomplished with a screw cap of the kind -
mentioned at the beginning having the features recited
in claim 1. It is particularly advantageous that the ~ -
screw cap is distinguished by a high stability which -~-
substantially reduces the danger of a blow-off resulting
from outside influence.
In a particularly preferred embodiment of the screw cap, ;;
reinforcing beads are produced in its side wall in such
arrangement that the beads of successive thread turns
lie above one another, thereby creating between the -
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individual beads strip-shaped, continuous regions which
span at least two thread turns and have remained free of
deformation. A special stability is the distinguishing
feature of such a closure.
Moreover, a screw cap is preferred wherein the reinforc-
ing beads of successive thread turns are arranged in -
staggered relation to one another. A high degree of
stability iq achieved with this screw cap design. The
dividing walls located between two successive reinforc-
inq beads are essential to the stability.
The invention furthermore relates to a method for the
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manufacture of a screw cap of the aforementioned type in
accordance with the generic kind set forth in claim 6.
In this method, several reinforcing beads arranged in ~ -
spaced relation to one another along a helical line are
impressed, rolled or shaped in the wall of the screw
cap, thereby forming the thread of the screw cap. This
method is particularly simple and economical to perform.
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Finally, the invention relates to the use of a screw cap
as security closure, the thread of which is comprised of
several reinforcing beads arranged one behind the other
along a helical line in the side wall of the screw cap.
The screw cap is provided with a security ring made, for
example, of plastic which is broken open, for example,
at at least one predetermined breaking point during the
initial opening of the container. Owing to the high sta-
bility of the screw cap, the forces required to break
open the security ring can be safely applied.
Further embodiments and advantages of the invention are
apparent from the subclaims.
The invention will be explained in further detail herein~
below with reference to the drawings which represent two ~ --
embodiments. In the drawings~
igure 1 is a side view of a ~crew cap with a security
ring~
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igure 2 is a cross-section through the screw cap
according to Figure lt and
Figure 3 is a perspective view of a screw cap without ~ ~;
a security ring with a thread representing a
modification of that of Figures 1 and 2.
The inventive screw cap may be used for all types of
closure. Merely by way of example, a screw cap with a
security ring made of plastic is described herein with
reference to Figures 1 and 2.
The screw cap 1 in Figure 1 is of substantially dish-
shaped design. It comprises a bottom 2 and a side wall 3
extending from the latter. A toroidal member 4 serving
to receive at least a region of a security ring 5 is
provided at the end of the side wall opposite the bottom
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Several reinforcing beads 6, in this case, of substanti-
ally rectangular design, are arranged in spaced relation
to one another along a helical line in the side wall 3.
The length of the side of a reinforcing bead is, in this
case, for example, approximately twice the size of its
height or width. The spacing of the individual reinforc-
inglbeads 6 corresponds to approximately half of the
length of the individ~al beads.
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It is, of course, readily possible for the reinforcing
beads to be of practically oval or circular design. The
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stability of the thread is based essentially on the in-
terruptions in the thread turn, in particular on the
dividing walls between each two beads arranged on the
helieal line.
From the illustration it is evident that in the embodi-
ment according to Figure 1, the reinforcing beads of
thread turns located above one another are arranged such
that the spaces between each two beads are located above
one another. In other words, the reinforcing beads of
successive thread turns similarly lie above one another.
Strip-shaped, continuous regions 7 without reinforcing
beads extending over several thread turns are thereby
created in the side wall 3 of the screw cap 1. This re-
sults in particularly high stability of the screw cap
and of the thread.
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From the sectional illustration in Figure 2 it is appar-
ent that the reinforcing beads 6 are designed as hollows
which are produced from outside in the side wall 3 of
the screw cap 1 and form correspondingly arranged pro- `
jections 8 on the inside of the side wall. These pro- -
jections engaqe the thread of the container or bottle
which is to be closed. The cross-section of the projec-
tions is semicircular and adapted to the shape of the
thread.
Figure 2 shows how the bottom 2 of the screw cap 1 is -~
set back in relation to its side walls 3 so as to pro-
duce a hollow for receiving a seal, for example, in the ;; `
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form of a disc. For reasons of better clarity, this is
not represented in the drawing. Such a screw cap con~
figuration is provided, in particular, for gas-tight - ;
closures.
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An annular groove into which a region of the security - -
ring 5 snaps is formed in the region of the toroidal
member 4 on the inside of the screw cap 1. The security
ring 5 is held in the annular groove by a flanged region
9 of the screw cap 1.
The security ring 5 has on its lower rim a projection
10 which comes to rest underneath a suitable toroidal
member below the threaded region of the container to be
closed when the screw cap is placed on the container.
During the initial opening of the container, this pro-
jection 10 reaches under the aformentioned toroidal
member and becomes hooked there and so a pulling force
is exerted on the security ring. The security ring
thereby breaks open at a predetermined breaking point
provided for this purpose, whereby the initial opening
of the container is indicated.
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A special stability of the screw cap is achieved with
the individual reinforcing beads and the regions or webs
located between the beads and delimited by the side or ~ ;
dividing walls of successive beads arranged on the heli~
cal line. Even in the event of a high excess pressure
inside the container, snap-off or blow-off of the closure
is prevented. On the other hand, with such screw caps,
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high forces can be exerted on a security ring provided
thereon, which ensures that the security ring will break
open during the initial opening.
A second embodiment of a screw cap 1~ is illustrated in
Figure 3. It comprises an essentially flat bottom 2 and
a side wall 3 with reinforcing beads 6 arranged in spaced
relation to one another on a helical line provided in
the latter. These reinforcing beads form projections
which protrude into the interior of the screw cap and en- -
gage the thread of the container or bottle to be closed.
A thread is thus formed in the screw cap 1~ by the rein-
forcing beads 6. -
In this embodiment, the reinforcing beads 6 are arranged
such that the spaces between two beads lie near a bead
of a neighboring thread turn, i.e., the beads of neigh-
boring thread turns are offset in relation to one an-
other.
The length and height of the reinforcing beads 6 are `
freely selectable. In this embodiment, the height or
width of a reinforcing bead is approximately half the
size of the length of the bead. From the aforesaid it
is clear that the beads of this embodiment may also be
of qval or circular design.
In the embodiment shown in Figure 3, the reinforcing ~ - -
beads 6 are arranged on a helical line in such a way
that the beads of thread turns located above one another
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are staggered in relation to one another. The space be-
tween two beads of a thread turn lies approximately half
way between a reinforcing bead 6 of a neighboring thread
turn. With this arrangement of the reinforcing beads, a
very high stability with respect to form and hence pro-
tection against turning the screw cap too far is achieved.
This means that even if such a closure is screwed open
or tightened with high force, the thread is not destroyed. ~-
A security ring 11 connected by thin webs 12 to the side
wall 3 may be provided at the lower rim of the screw cap -
1~. After the filled container or bottle has been closed
by the screw cap 1*, the security ring 11 is flangsd.
This means that after the screw cap has been screwed on-
to the filled container, the security ring is bent un-
derneath a projection provided in the thread region of
the container.
During the initial opening of the screw cap, the flanged
security ring 11 is unable to lift off from the contain- -
er together with the screw cap. Instead, it breaks off
from the screw cap 1~ in the region of the predetermined
breaking line formed by the webs 12. This clearly indi-
cates initial opening of the container to a user.
It is also possible for the security ring 11 to be pro-
~ided with at least one weakened region or vertical cut
which extends parallel to the center axis of the screw -
cap and tears during initial opening of the screw cap.
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The security ring 11 can thereby spread open. It is then
removable together with the screw cap from the container.
Near the bottom 2, the side wall 3 has recesses 13 which
facilitate gripping of the screw cap.
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The screw caps illustrated in Figures 1 to 3 all consist
of deep-drawable material, more particularly, aluminum
or steel. While a security ring 5 made of plastic is
provided in the embodiment according to Figures l and 2,
the security ring ll on the screw cap l* according to
Figurs 3 is likewise made of deep-drawable material.
The stability of the screw cap with respect to form also
ensures that practically with each opening attempt, the
screw cap can be screwed off the closed container. De-
struction of the thread during opening of the container
is virtually excluded. Particularly good opening values
are thereby achievable.
The screw cap described hereinabove is manufactured by
reinforcing beads 6 arranged in spaced relation to one
another on a helical line being produced in its side - -~
wall 3. A screw cap manufactured in this way is screwed
onto a container or onto a bottle. Damage to the con~
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tainer which often occurs during rolling of the thread
after the screw cap has been put on is reliably prevented.
Danger to the user by exposure to glass splinters or
chipped-off thread turns on the container is thu3 elimi- ;
nated. In principle, it is, however, also possible for a "`
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screw cap blank to be provided with the reinforcing
beads after it has been placed on a container. The total
stress on the mouth region of the container is reduced
because only relatively small regions of the screw cap
are subjected to the rolling forces to produce the re-
inforcing beads.
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