COUVERCLE A VISSER

SCREW TOP

Abrégé anglais

The invention relates to a screw top comprising
essentially two elements formed by a skirt and a sealing ring connected
together in a number of places by means of small cross-elements
which can be broken when unscrewing the top, characterised in that
of said two elements, either the skirt (2) or the sealing ring (3) compri-
ses prolongations (8-10) which extend sufficiently far towards and
beyond the opposite element so as to prevent any deformation of
the sealing ring (3) in the radial direction of the top.

Revendications

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS
1. A screw top having a longitudinal axis comprising:
a skirt disposed about said axis;
a sealing ring disposed about said axis and spaced
from the skirt leaving an axial gap therebetween;
a predetermined number of cross-elements extending
between a lower edge of said skirt and an upper edge of said
sealing ring for being broken when unscrewing the skirt due to
their small section;
prolongation means extending from said lower edge of
said skirt towards and beyond said upper edge of said sealing
ring along an innermost side of said sealing ring for preventing
any deformation of said sealing ring in a radial direction so as
to avoid rupture of said cross-elements.
2. A screw top as claimed in claim 1, wherein said
prolongations extend in a direction substantially parallel to
said longitudinal axis of said top.
3. A screw top as claimed in claim 1, wherein the
prolongation means comprises a plurality of circumferentially
spaced prolongations.

Description

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SCREW TOP
The present invention relates to a screw top compris-
ing essentially two elements formed by a skirt and a sealing
ring which is in a predetermined number of places connected to
said skirt by means of small cross-elements which can be
broken when unscrewing the top due to their small section.
A top which offers this particularity has been the
subject of the Luxemburg Patent Application No. 87469 of March
8, 1989 in the name of the applicant.
The top described in this patent application has such
a structure that the displacements of the skirt with respect
to the sealing ring according to the geometrical axis of the
top do not cause a too early and thus untimely separation of
these two top elements. The tops of this type, conceived by
the applicant, form thus from this point of view a remarkable
amelioration.
However, it appeared that the sealing ring could
still come loose from the skirt due to shocks transmitted to
these tops during their transfer in distribution machines.
Indeed, the lateral shocks transmitted to these tops can cause
the rupture of some of the small cross-elements to which is
referred to in the preamble.
The present patent application has for its object to
remedy this serious disadvantage, i.e. that which causes that
too many tops to be removed and which requires inspections
which would be preferably avoided.
Therefore this invention seeks to provide a screw top
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having a longitudinal axis comprising:
a skirt disposed about said axis;
a sealing ring disposed about said axis and spaced
from the skirt leaving an axial gap therebetween;
a predetermined number of cross-elements extending
between a lower edge of said skirt and an upper edge of said
sealing ring for being broken when unscrewing the skirt due to
their small section;
prolongation means extending from said lower edge of
said skirt towards and beyond said upper edge of said sealing
ring along an innermost side of said sealing ring for
preventing any deformation of said sealing ring in a radial
direction so as to avoid rupture of said cross-elements.
Other details and advantages of the invention will
appear from the following description of a screw top equipped
with a sealing ring according to the invention. This
description is only given by way of example and does not limit
the invention. The reference numerals relate to the annexed
figures.
Figure 1 is partly a section and partly an
elevational view of the top according to the invention in a
first embodiment.
Figure 2 is an analogous view related to a first
variant.
Figure 3 is an analogous view related to a second
variant.
Figure 4 is an analogous view related to a third
variant.
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The screw top 1 shown in these four figures comprises
a skirt 2 and a sealing ring 3.
On the skirt or on the sealing ring can be provided
protective backing elements 4 which prevent that the skirt 2
approaches completely the sealing ring 3 whereby some of the
small cross-elements 5 connecting the sealing ring to the
skirt would break.
All these details, such as the presence of a tooth 6
projecting into a cutout 7 of the sealing ring 2, have been
described in the above-mentioned Luxemburg application.
It is to be noted that the present invention aims at
improving these but also other types of tops provided that
they comprise a skirt, a sealing ring and small cross-elements
connecting these elements together.
In order to avoid that one or more of these small
cross-elements would be broken during mechanical
manipulations, means are provided, according to the present
patent application, which prevent any radial displacement of
the sealing ring 3, i.e. any
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movement towards the in - or the outside of the top.
This object can be reached by different possible,
technical embodiments but it will be clear that some of them ~vill
give problems with respect to the design of the injection moulds.
5Referring to Figure 1, it can be seen that the skirt
2 comprises a prolongation 8 directed towards the sealing ring 3.
When the top and the sealing ring take the position shown in the
figure, i.e. when the small cross-elements aren't broken yet, the
prolongation 8 of the skirt 2 of the top extends sufficiently far so
10as to prevent ai~y radial deformation of the sealing ring. Thereto
it is enough that the prolongation 8 extends a tenth of a millimeter
or some tenths of a millimeter beyond the edge of the sealing ring
which is directed towards the skirt.
A f irst variant of the top according to the invention
15is represented in Figure 2 wherein the prolongation, indicated here
by reference 9, is provided at the outer side of the sealing ring 3.
It's enough that the prolongation 9 extends very slightly beyond the
free edge of the sealing ring 3 to prevent any radial movement of
this sealing ring. In the two cases, the sealing ring keeps perf ectly
20its circular shape and no rupture of the small cross-elements 5 is
to be feared.
The same situation is created by the second variant
shown in Figure 3 wherein it is on the contrary the sealing ring 3
which is provided with a prolongation, indicated by reference 10,
25at the outsider of the part of the top skirt 2 which is directed towards
the sealing ring.
It will be clear that even when the most logical
embodiments consist in providing prolongations 8-10 extending circularly
over the total periphery either of the skirt of the top or of the sealing
30ring, these prolongations could also be provided at some places only.
In a last variant it would also be possible to prolong
all the ribs 11 or some of them. By rib it has to be understood the
vertical projections, the skirt of certain tops present at the outside,
generally with the object to make screwing and unscrewing easier.
35Although several embodiments have been described,

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some of which have to be considered as preferred embodiments from
the point of view of realising pieces which permit the injection of
tops according to the invention, it will be noted that all these embodi-
ments realise the same object which is to prevent any radial movement
of the sealing ring, these movements being the cause of the rupture
of the small cross-elements 5.
In principle, the invention is thus not limited to
the described embodiments and many modifiations could be brought
thereon without leaving the scope of the present Patent Application.

Dessin représentatif