Note: Descriptions are shown in the official language in which they were submitted.
CA 03234342 2024-04-02
1
Filter for smoking products and method for producing such filters
The invention relates to a filter for smoking products, having a filter body
which
has a tubular covering body which radially surrounds a filling made of filter
mate-
rial. The invention further relates to a method for producing such a filter.
Such filters are known in various configurations and may either already be ar-
ranged in the factory in smoking products, such as cigarettes, or as loose
filters
for use by the end consumer for customer production of the smoking product.
The present invention relates in particular to the loose filters last
mentioned.
Such filters generally have a cylindrical shape, in particular having a
diameter
which remains constant over the respective entire length thereof. Accordingly,
such filters generally also have a circular diameter. Furthermore, filters
having a
conical outer shape are also known. Such conical filters are typically
produced
from a solid material and have no separate covering body.
In the filter bodies which are in the form of solid material filters, the
entire filter
generally comprises a filter material. Furthermore filter bodies which have a
sleeve member in which the filter material is received or arranged at the
inner
side are generally known. Such sleeve bodies are typically in the form of a
cylin-
drical pipe having end elements which are arranged at the end side. The filter
Date Recue/Date Received 2024-04-02
CA 03234342 2024-04-02
2
material is in this instance arranged inside the pipe between the end
elements.
These end elements generally have the same diameter.
In particular with smoking products which are produced by end consumers, it
has
been found that, when cylindrical filters are used and there is even only a
slight
deviation from a linear twisting of the cigarette paper around the filter, a
gap
may be produced between the filter and cigarette paper which is often undesira-
ble and can lead to a decreased or completely absent filter effect.
It has further been found that the production complexity, in particular for
coni-
cally constructed filters and the shaping thereof, and the orientation of
conical
filters in a correct manner during the production of smoking products during
in-
sertion in the factory is considerable and such filters are therefore still
relatively
complex and cost-intensive in terms of production and further processing, in
par-
ticular handling.
An object of the present invention is therefore to provide a filter for
smoking
products which is improved with regard to at least one of the mentioned disad-
vantages and which in particular enables a non-complex application and a cost-
effective production.
The object set is achieved by the invention with a filter having the features
of the
main claim and by a method having the features of claim 10. Advantageous em-
bodiments and further development of the invention are disclosed in the depend-
ent claims, the description and the Figures.
According to the invention, there is provision for the in particular
separately con-
figured covering body to radially surround the filling made of filter material
at the
outer side and to have in the longitudinal extent of the filter body a
cylindrical
inner circumference and a substantially conical outer circumference. In
particu-
lar, the covering body has a cylindrical inner form and a substantially
conical
outer form. On the one hand, an always identical filter effectiveness is
thereby
enabled, in particular even with a cigarette paper which is produced by the
end
consumer and which is in this instance not quite precisely twisted.
Furthermore,
with a first, preferred embodiment, a particularly cost-effective production
is en-
Date Recue/Date Received 2024-04-02
CA 03234342 2024-04-02
3
abled by the covering body first being produced and subsequently an end ele-
ment being fitted to a first axial end of the covering body, subsequently from
a
second axial end filter material being introduced into the inner space
surrounded
by the covering body and, in order to finish the filter, finally the inner
volume
being closed by fitting a second end element to a second axial end. Since the
covering body has a cylindrical inner shape, the first and second end elements
may be configured identically, which minimizes the production complexity. In
another conceivable embodiment, in which the filter material is configured in
a
dimensionally stable, cylindrical manner, for example, from a porous material,
the filter body may be formed by directly fitting the covering body radially
around the filter material and the associated production of the conical outer
form
of the filter. Thus, with the covering body which is fitted directly around
the fill-
ing of the filter material and optionally around two end elements, a
cylindrical
filter body may in a particularly simple manner be additionally provided with
a
conical outer form.
Generally, the axial end of the conical filter body, also referred to below as
the
first axial end, which has the comparatively smaller outer diameter, is
arranged
at the axial side facing the end consumer or smoker, and the other axial end
of
the filter, also referred to below as the second axial end, which has the
compara-
tively larger outer diameter, is arranged at the axial side, facing away from
the
end consumer, of the filter.
The filter body may have an overall length between 10 mm and 40 mm, prefera-
bly between 20 mm and 30 mm, in a particularly preferred manner approximate-
ly 25 mm. The filter body may in particular have a length which corresponds to
the length of the entire filter. The outer diameter of the filter body may in
its
longitudinal extent, for example, vary between 5 mm and 8 mm, in particular
increase in an axial direction. Preferably, the diameter of the filter body at
the
first axial end is approximately 6 mm and at the second axial end is approxi-
mately 7 mm. The filter body is preferably formed exclusively by the covering
body and the two end elements at the ends. The filling of the filter material
is
located in particular in an inner space formed between the inner circumference
of
the covering body - and the optionally provided two end elements. The end ele-
ments are in particular configured to be permeable to air. Furthermore, they
may
Date Recue/Date Received 2024-04-02
CA 03234342 2024-04-02
4
be configured in a dimensionally stable manner. For example, the end elements
are formed from ceramic material. Both end elements of a filter may be con-
structed and configured in an identical manner, in particular have the same di-
mensions.
The covering body is configured with relatively thin walls so that the filter
body
may be in the form of a pipe. In particular, the covering body has a thickness
in
a radial direction which with respect to a diameter of the entire filter is
signifi-
cantly smaller. This thickness of the covering body which is pronounced in a
ra-
dial direction changes in the longitudinal extent of the filter. In
particular, the
covering body has at the first axial end of the filter a smaller thickness
than at
the second axial end of the filter. For example, the thickness of the covering
body at the first end is approximately 0.11 mm and at the second end approxi-
mately 0.6 mm. The covering body may be constructed at least partially over
the
longitudinal extent of the filter in layers, in particular in a manner
building up in
the direction of the outer circumference. The thickness of the covering body
which increases in the longitudinal extent of the filter body may consequently
be
produced by layers of different thicknesses in the longitudinal extent. The
cover-
ing material may thus in the region of the first axial end, for example, be
config-
ured only in a single layer and, at the second axial end, for example, in a
plurali-
ty of layers which are arranged in a radial direction one above the other. In
par-
ticular, the layers of the covering material may increase in the direction
from the
first axial end to the second axial end in steps and/or in a substantially
continu-
ous manner. It is thereby possible for the covering body to have a cylindrical
shape at an inner circumference and a conical shape at an outer circumference.
The filter material may, for example, be configured in a granular and/or
porous
manner. In particular, the filter material may comprise activated carbon or in-
clude activated carbon components.
The smoking product may comprise plant components, such as, for example, to-
bacco, or be formed thereby. The smoking product may comprise medically ef-
fective substances. It has been found that, as a result of the activated
carbon
filter, although a significant portion of harmful substances can be filtered
out of
Date Recue/Date Received 2024-04-02
CA 03234342 2024-04-02
the inhaled smoke, a large portion of the medically effective substances can
pass
through the filter.
Preferably, the covering body is formed by winding a blank to form a dimension-
5 ally stiff sleeve body in order to be able to receive the filter material
in the inner
space thereof. An effective filter action and a particularly cost-effective
produc-
tion of the filter are thereby enabled. To this end, the blank may in
particular be
in the form of in particular a thin, flat body, for example, made of paper.
The
covering body may also be wound at least partially, preferably, completely
around the filling made of filter material.
In a particularly preferred manner, the covering body is arranged or wound at
least partially in an overlapping manner, in particular overlapping with
itself. In
this instance, the covering body may at the beginning of the winding extend
over
.. substantially the entire length of the filter body. The covering body may
bear on
the end elements and/or on the filling made of filter material, and in the
remain-
ing extent of the windings be arranged to overlap with itself, in particular
in-
creasingly overlapping. The overall thickness of the covering body can thereby
be
increased in a radial direction over the longitudinal extent of the filter
body in a
particularly simple manner so that the covering body, as a result of the
windings
which increasingly overlap in the longitudinal extent of the filter, on the
whole
receives a conical outer shape.
The covering body is preferably formed from a paper blank. A material which is
particularly suitable for the lateral, in particular radial closure of the
filter materi-
al, a precise and precisely fitting closure of the covering body at the outer
sides
of the filter, in particular the axial ends, and a cost-effective production
of the
filter are thereby enabled. The paper blank may, for example, be produced as a
blank or piece of a paper strip. The paper blank preferably has, in particular
for
.. the overlapping winding around the filling made of filter material and the
option-
ally provided end elements, an overall length between 80 mm and 300 mm,
preferably between 100 mm and 200 mm, in a particularly preferred manner of
approximately 150 mm. The paper blank or the paper strip preferably has a
width which corresponds to the length of the filter body. Consequently, the
paper
blank can be placed with a wide side in a precisely fitting manner on the
filling
Date Recue/Date Received 2024-04-02
CA 03234342 2024-04-02
6
made of filter material and the optionally provided end elements and, in the
lon-
gitudinal extent thereof in the circumferential direction of the filter body
which is
intended to be formed, can be wound around the filling made of filter
material.
The paper thickness is preferably approximately 0.11 mm. Consequently, in addi-
tion to an effective filter action, a visually appealing filter can be
achieved.
The paper blank comprises in a preferred embodiment of the invention a first
region which per se is configured in a substantially rectangular manner or in
terms of its shape corresponds to a rectangle, and a second region which per
se
is configured in a substantially triangular manner or in terms of its shape
corre-
sponds to a triangle and adjoins the first region. The paper blank
consequently
preferably extends in a coherent manner over the first region and the second
region.
Preferably, the second region in the region of a longitudinal side, in
particular a
longitudinal side opposite the rectangular region, has a portion which in a
state
in which the covering body is completely wound around the filling made of
filter
material and the optionally provided end elements forms an outer
circumferential
face of the covering body, also referred to as the visible region. The
portion,
which forms the visible region, of the paper blank has a width which is
preferably
between 1 mm and 5 mm, preferably between 2 mm and 4 mm, in a particularly
preferred manner of approximately 3.5 mm. In a particularly preferred manner,
the circumferential face of the covering body or the filter is formed
exclusively by
a portion of the paper blank which forms the visible region. This portion or
this
visible region may be provided with an imprint, in particular a continuous
print-
ing.
Preferably, the covering body bears in the region of at least one of the axial
ends
of the filter body with the cylindrical inner circumference on an end element
of
the filter at the end. It is thereby possible to give the filter body a
dimensional
stability in a particularly simple and appropriate manner and at the same time
to
enable a particularly effective filter action.
In a particularly preferred manner, only the covering body surrounds the
filling
made of filter material and the optionally provided end elements. This means
Date Recue/Date Received 2024-04-02
CA 03234342 2024-04-02
7
that the tubular potion of the filter body may be exclusively formed by the
cover-
ing body. A filter with particularly few individual components and
consequently a
particularly cost-effective production can thereby be achieved. Furthermore,
the
covering body may terminate in a particularly appropriate manner flush with
the
axial ends of the filter body so that a visually appealing shape - which can
in
particular be identified as one unit - is enabled. In this instance, there may
be
provision for the covering body to be connected at the end of the filter body
to
the end elements which are arranged at that location, in particular at least
in an
end region. The covering body, in particular a covering body which is in the
form
of a paper blank may to this end be adapted in a particularly simple manner to
a
preferred, in particular standardized length of the filter.
Preferably, the covering body forms with the cylindrical inner circumference
the
inner space for the filter material and forms with the substantially conical
outer
circumference a circumferential outer face of the filter body, in particular
of the
entire filter. In particular, the covering body may delimit over almost the
entire
length of the filter body an inner space for the filter material and where
applica-
ble also bear on the filling made of filter material. The inner space
available for
the filling of the filter material can thereby be particularly large and a
particularly
effective filter action can be achieved.
In a particularly preferred manner, at least one of the axial ends of the
covering
body is connected in a non-positive-locking manner to an end element at the
end. In particular, the end element may be pressed into the axial end of the
coy-
ering body.
Furthermore, the covering body - in a particularly preferred manner - may be
connected to itself in a materially engaging manner, for example, by means of
adhesive-bonding, in particular in the region of the overlapping winding
thereof.
To this end, on a flat side of the blank adhesive may be arranged at least in
re-
gions. Alternatively or additionally, adhesive may also be arranged on at
least
one of the end elements, in particular on a radial outer side or
circumferential
face of the end element. A particularly effective fixing of the end element on
the
covering body can thereby be achieved and consequently a particularly
effective
dimensional stability and filter action, and a visually appealing filter can
be
Date Recue/Date Received 2024-04-02
CA 03234342 2024-04-02
8
brought about. Furthermore, the filter is thereby particularly easy to handle
both
during production and during use.
The method according to the invention for producing a filter having the
features
of at least one of claims 1 and 9 makes provision, in order to form a filter
body
having a conical outer circumference, for a blank to be wound in an
increasingly
overlapping manner toward the covering body in the direction of one of the
axial
ends of the filter and to be connected to itself in a materially engaging
manner,
for an end element to be fitted to a first of the axial ends, preferably in a
non-
positive-locking manner, for a filling made of filter material to be
introduced into
an inner space surrounded by the covering body and the end element and for
another end element to be fitted to a second of the axial ends, preferably in
a
non-positive-locking manner.
One exemplary embodiment of the invention is explained in greater detail below
with reference to the Figures. Reference numerals which are the same refer to
identical components. In the schematic drawings:
Figure 1 - shows a side view of a filter according to the invention;
Figure 2 - shows a sectioned illustration of the filter according to Figure 1;
and
Figure 3 - shows a plan view of a paper blank for the covering body of the
filter.
Figures 1 and 2 show an exemplary embodiment of a filter 1 according to the
invention for use on smoking products, such as cigarettes. Such a filter 1 may
be
inserted into smoking products either in the factory or be provided as a loose
filter for use by the end consumer for customer assembly of the smoking prod-
uct.
The filter 1 is used during smoking particularly to filter out harmful
substances or
at least a portion of harmful substances from the smoke inhaled by a smoker.
In
a finished smoking product, such as a cigarette, the present filter 1 is
advanta-
geously located in a region, which faces the smoker, of a body which forms the
smoking product and which is not illustrated in this instance, such as a paper
Date Recue/Date Received 2024-04-02
CA 03234342 2024-04-02
9
blank and is surrounded thereby. The region, which faces away from the smoker,
of the body which forms the smoking product which is not illustrated may, for
example, surround tobacco.
The filter 1 has a tubular filter body 2, comprising a filling made of filter
material
5, in each case an end element 6a, 6b which delimits at the axial ends 7a, 7b
of
the filter 1 the filling made of filter material 5, and a covering body 3
which sur-
rounds the filling made of filter material 5 radially at the outer side. The
covering
body 3 is in this instance configured in such a manner that the filter body 2
has a
conical outer form.
As shown in Figure 2, the covering body 3 and the end elements 6a, 6b form a
supporting structure of the filter body 2. The filter body 2 is thereby
advanta-
geously configured in a dimensionally stable manner. The filling made of
filter
material 5 is arranged in an inner space 8 which is surrounded by the covering
body 3 and the end elements 6a, 6b.
The first end element 6a is in particular arranged at a first axial end 7a,
facing
the smoker, of the filter 1 and a second end element 6b is arranged at a
second
axial end 7b, facing away from the smoker and in particular facing the
tobacco,
of the filter 1. The end element 6a, 6b advantageously has holes so that it is
configured at least in an axial direction of the filter 1 in an air-permeable
man-
ner. An inner space 8 for the filter material 5 is arranged between its two
axial
ends.
The filter material 5 serves to filter the harmful substances when smoking.
The
filter material 5 may in this instance comprise a plurality of different
filter com-
ponents. In a particularly preferred manner, the filter material 5 comprises
acti-
vated carbon, wherein a frequently preferred, selective filtering is enabled.
In order to bring about a particularly effective filtering, it is advantageous
for the
tubular portion of the filter body 2 on an inner circumference 9 which faces
the
filter material 5 to have a cylindrical form and on an outer circumference 10
which faces away from the filter material 5 to be configured in a conical
manner
over the longitudinal extent of the filter 1. In particular, it is
advantageous for
Date Recue/Date Received 2024-04-02
CA 03234342 2024-04-02
the outer diameter D1 of the filter 1 to be smaller at the first axial end 7a,
facing
the smoker, of the filter 1 than the outer diameter D2 of the filter 1 at a
second
axial filter end 7b facing away from the smoker. For example, the diameter D1
is
approximately 6 mm und the diameter D2 is approximately 7 mm.
5
According to the invention, there is provision for the portion, which confers
on
the filter 1 a conical outer form or which forms a conical outer form of the
filter
1, of the filter body 2 to be produced by the covering body 3 which is
arranged
around the filter material 5. In particular, the conical shaping is achieved
by
10 means of a winding of the covering body material 3 in an overlapping manner
which increases in the longitudinal extent of the filter 1. To this end, the
covering
body 3 is wound from a thin-walled blank 4, such as, for example, a paper
blank,
in particular in such a manner that the covering body 3 in the longitudinal
extent
of the filter 1 has a substantially conical outer circumference or a conical
circum-
ferential face 10.
At the inner circumference 9 thereof, in particular on the first winding, the
covering body 3 has a substantially cylindrical form. The covering body 3
bears
with the cylindrical inner circumference 9 in the region of the first axial
end 7a on
the first end element 6a and in the region of the second axial end 7b on the
second end element 6b in such a manner that the end elements 6a, 6b are
connected to the covering body 3 in a non-positive-locking manner. Not least
as
a result of the cylindrical inner circumference 9 of the covering body 3, the
two
end elements 6a, 6b of the filter 1 may be constructed and configured in an
identical manner, in particular have the same dimensions. With the
substantially
conical outer circumference 10, the covering body 3 forms the circumferential
outer face of the filter body 2, in particular of the entire filter 1.
The blank 4 may be an elongate paper strip which tapers in the longitudinal ex-
tent thereof and in the longitudinal extent thereof is wound about itself and
con-
nected together in a materially engaging manner, in particular by means of ad-
hesive bonding.
Such a paper blank 4 is shown, for example, in Figure 3.
Date Recue/Date Received 2024-04-02
CA 03234342 2024-04-02
11
The paper blank 4 shown comprises a first region 4a, which per se resembles a
rectangle, and a second region 4b which per se resembles a triangle and
adjoins
the first region 4a at a side thereof. The second region 4b has at a
longitudinal
side a portion 4c which in a state, in which the covering body 3 is wound com-
pletely around the end elements 6a, 6b and the filling made of filter material
5,
forms the outer circumferential face 10 of the covering body 3, in particular
a
visible region. This portion 4c or this visible region is indicated with
shading in
Figure 3. The portion 4c may be provided with an imprint, in particular a
contin-
uous printing. In the above-mentioned completed state of the filter 1, the cir-
cumferential face 10 of the covering body 3 is in particular exclusively
formed by
the portion 4c. The paper blank 4 consequently extends in a coherent manner
over the regions 4a and 4b, including 4c.
The paper blank 4 has in the case shown an overall length L2 of approximately
150 mm. The first region 4a extends over a length L3 of approximately 36 mm.
The paper blank 4 has a width B1 of approximately 25 mm, which advantageous-
ly corresponds to the length of the filter body 2. The portion 4c has in this
in-
stance a width B2 of approximately 3.5 mm.
Consequently, the paper blank 4 can be wound in order to form the covering
body 3. The first winding completely covers in this instance in the case of
the
completed filter 1 with the first region 4a the filling made of filter
material 5. In
the case of the other winding of the paper blank 4, in particular with the
second
region 4b, the windings are carried out in the direction of the longitudinal
extent
of the filter in an increasingly overlapping manner, wherein the region at the
first
axial end 7a may also be formed without any overlapping of the paper blank 4.
The paper blank 4 thus overlaps with the second region 4b at least partially
ini-
tially the first region 4a and subsequently at least partially the second
region 4b
with itself. The portion 4c ultimately remains as the visible circumferential
face,
that is to say, the portion 4c is not covered or overlapped.
Consequently, the conical outer circumference of the filter 1 is formed in
that the
material which forms the covering body 3, in this instance in particular the
paper
blank 4, is wound in such a manner that the covering body material 3, that is
to
say, in particular the paper blank 4, is wound in an increasingly overlapping
Date Recue/Date Received 2024-04-02
CA 03234342 2024-04-02
12
manner in the direction of one of the axial ends, in particular in the
direction to-
ward the second axial end 7b facing away from a smoker. In particular, the
wind-
ings of the paper blank 4 overlap each other in the longitudinal extent of the
fil-
ter 1 at least partially and on the whole increasingly. The conical shape is
thus
achieved by the increasing number of windings. The overlapping portion of the
covering body 3 is in this instance in particular formed by the second region
4b
of the paper blank 4.
The overlapping windings are preferably distributed in a uniform manner over
the
longitudinal extent of the filter 1 so that in the longitudinal extent of the
filter 1 a
uniformly increasing thickness of the covering body 3 and consequently on the
whole a uniformly conical outer form of the filter 1 is formed.
Depending on requirements, in order to form a larger or smaller diameter of
the
filter 1 at the second end 7b, in a particularly simple manner, the number of
windings which are located one above the other can thus also be adjusted, in
particular by the number of windings being adapted. The latter is in
particular
enabled by the length of the second region 4b of the paper blank 4 and/or the
angle at the end, which is illustrated on the right in Figure 3, of the second
re-
gion 4b being adapted, in particular increased and/or decreased. After the
cover-
ing body 3 is formed, an end element 6a is fitted, in particular by means of
pressing into the first axial end 7a. Subsequently, filter material 5 is
introduced
into the inner space 8, and this is then closed by another end element 6b,
which
to this end can also be pressed in.
Date Recue/Date Received 2024-04-02
CA 03234342 2024-04-02
13
List of reference numerals:
1 Filter
2 Filter body
3 Covering body
4 Blank
4a First region
4b Second region
4c Portion
5 Filter material
6a End element
6b End element
7a First axial end
7b Second axial end
8 Inner space
9 Inner circumference
10 Outer circumference
Li Length
L2 Length
L3 Length
B1 Width
B2 Width
D1 Diameter
D2 Diameter
Date Recue/Date Received 2024-04-02
