FILTER FOR SMOKING PRODUCTS AND METHOD FOR PRODUCING SUCH FILTERS

Abstract

A filter for a smoking product. The filter includes a filling which is made of a filter material, and a filter body having a tubular covering body which is arranged to radially surround the filling. The tubular covering body has a cylindrical inner circumference and a substantially conical outer circumference.

Claims

1-10. (canceled)

11: A filter for a smoking product, the filter comprising: a filling which is made of a filter material; and a filter body comprising a tubular covering body which is arranged to radially surround the filling, wherein, the tubular covering body comprises a cylindrical inner circumference and a substantially conical outer circumference.

12: The filter as recited in claim 11, wherein the tubular covering body is formed from a planar blank.

13: The filter as recited in claim 12, wherein the planer blank is wound at least partially in an overlapping manner.

14: The filter as recited in claim 13, wherein the planer blank comprises a first region which is configured in a substantially rectangular manner, and a second region which is configured in a substantially triangular manner and which adjoins the first region.

15: The filter as recited in claim 14, wherein, the second region comprises a longitudinal side, and a portion of the longitudinal side forms an outer circumferential face of the tubular covering body.

16: The filter as recited in claim 15, wherein the outer circumferential face of the tubular covering body is a visible region which is configured to be printed.

17: The filter as recited in claim 13, wherein the planer blank is a paper blank.

18: The filter as recited in claim 17, wherein the planer blank comprises a first region which is configured in a substantially rectangular manner, and a second region which is configured in a substantially triangular manner and which adjoins the first region.

19: The filter as recited in claim 18, wherein, the second region comprises a longitudinal side, and a portion of the longitudinal side forms an outer circumferential face of the tubular covering body.

20: The filter as recited in claim 19, wherein the outer circumferential face of the tubular covering body is a visible region which is configured to be printed.

21: The filter as recited in claim 11, wherein, the filter body further comprises an axial end and an end element, and the cylindrical inner circumference of the tubular covering body bears, in a region of the axial end of the filter body, on the end element of the filter body.

22: The filter as recited in claim 11, wherein the cylindrical inner circumference of the tubular covering body bears on the filling which is made of the filter material so as to form, with the substantially conical outer circumference, a circumferential outer face of the filter body.

23: The filter as recited in claim 22, wherein the circumferential outer face of the filter body is of an entire filter.

24: The filter as recited in claim 11, wherein, the filter body further comprises at least one end element, and the tubular covering body is at least one of, connected in a non-positive-locking manner to the at least one end element of the filter body, and at least partially connected to itself in a materially engaging manner.

25: A method for producing a filter having an inner circumference which is cylindrical in a longitudinal extent, an outer circumference which is conical in the longitudinal extent, a first axial end, and a second axial end which is opposite to the first axial end, the method comprising: winding a blank in an increasingly overlapping manner toward a tubular covering body in a direction of the first axial end or the second axial end of the filter and is connected to itself; fitting a first end element to the first axial end; intruding a filling made of a filter material into an inner space which is surrounded by the tubular covering body and the first end element; and fitting a second end element to the second axial end.

26: The method as recited in claim 25, wherein, the winding of the blank in the increasingly overlapping manner toward the tubular covering body in the direction of the first axial end or the second axial end of the filter and being connected to itself is performed in a materially engaging manner, the fitting of the first end element to the first axial end is performed in a non-positive-locking manner, and the fitting of the second end element to the second axial end is performed in a non-positive-locking manner.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The present invention is described in greater detail below on the basis of embodiments and of the drawings in which:

[0011] FIG. 1 shows a side view of a filter according to the present invention;

[0012] FIG. 2 shows a sectioned illustration of the filter according to FIG. 1; and

[0013] FIG. 3 shows a plan view of a paper blank for the covering body of the filter.

DETAILED DESCRIPTION

[0014] The present invention provides for the in particular separately configured 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. The covering body in particular has a cylindrical inner form and a substantially conical outer form. 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. In a first embodiment of the present invention, a particularly cost-effective production is furthermore provided by the covering body first being produced and an end element then being fitted to a first axial end of the covering body, and subsequently, from a second axial end, filter material being introduced into the inner space surrounded by the covering body and, to finish the filter, the inner volume finally 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 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. With the covering body which is fitted directly around the filling of the filter material and optionally around two end elements, a cylindrical filter body may thus be additionally provided in a particularly simple manner with a conical outer form.

[0015] 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 generally 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 comparatively larger outer diameter, is generally arranged at the axial side, facing away from the end consumer, of the filter.

[0016] The filter body may have an overall length between 10 mm and 40 mm, for example, between 20 mm and 30 mm, in particular, for example, approximately 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 vary in its longitudinal extent, for example, between 5 mm and 8 mm, and in particular increase in an axial direction. The diameter of the filter body at the first axial end can, for example, be approximately 6 mm and at the second axial end can, for example, be approximately 7 mm. The filter body can, for example, be formed exclusively by the covering body and the two end elements at the ends. The filling of the filter material is in particular located in an inner space which is formed between the inner circumference of the covering body and the (optionally provided) two end elements. The end elements are in particular configured to be permeable to air. They may also be configured in a dimensionally stable manner. The end elements can, for example, be formed from ceramic material. Both end elements of a filter may be constructed and configured in an identical manner, and can in particular have the same dimensions.

[0017] The covering body is configured with relatively thin walls so that the filter body may be in the form of a pipe. The covering body in particular has a thickness in a radial direction which, with respect to a diameter of the entire filter, is significantly smaller. This thickness of the covering body which is pronounced in a radial direction changes in the longitudinal extent of the filter. The covering body in particular 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 approximately 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. For example, the covering material may thus in the region of the first axial end be configured only in a single layer and, at the second axial end, in a plurality of layers which are arranged in a radial direction one above the other. The layers of the covering material may in particular increase in the direction from the first axial end to the second axial end in steps and/or in a substantially continuous 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.

[0018] The filter material may, for example, be configured in a granular and/or porous manner. The filter material may in particular comprise activated carbon or include activated carbon components.

[0019] The smoking product may comprise plant components such as, for example, tobacco, or be formed thereby. The smoking product may comprise medically effective 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 the inhaled smoke, a large portion of the medically effective substances can pass through the filter.

[0020] The covering body can, for example, be formed by winding a blank to form a dimensionally 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 production of the filter are thereby provided. The blank may in particular be in the form of an in particular thin, flat body, for example, made of paper. The covering body may also be wound at least partially, for example, completely, around the filling made of filter material.

[0021] The covering body can, for example, be 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 remaining extent of the windings be arranged to overlap with itself, in particular increasingly 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.

[0022] The covering body can, for example, be formed from a paper blank. A material which is particularly suitable for the lateral, in particular radial, closure of the filter material, 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 provided. The paper blank may, for example, be produced as a blank or piece of a paper strip. The paper blank can, for example, have, in particular for the overlapping winding around the filling made of filter material and the optionally provided end elements, an overall length between 80 mm and 300 mm, for example, between 100 mm and 200 mm, and in particular, for example, approximately 150 mm. The paper blank or the paper strip can, for example, have a width which corresponds to the length of the filter body. The paper blank can therefore be placed with a wide side in a precisely fitting manner on the filling made of filter material and the optionally provided end elements and, in the longitudinal 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 can, for example, be approximately 0.11 mm. In addition to an effective filter action, a visually appealing filter can consequently be achieved.

[0023] In an embodiment of the present invention, the paper blank can, for example, comprise a first region which is per se configured in a substantially rectangular manner or in terms of its shape corresponds to a rectangle, and a second region which is per se configured in a substantially triangular manner or in terms of its shape corresponds to a triangle and adjoins the first region. The paper blank can, for example, consequently extend in a coherent manner over the first region and the second region.

[0024] The second region in the region of a longitudinal side, in particular a longitudinal side opposite the rectangular region, can, for example, have 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, which is also referred to as the visible region. The portion which forms the visible region of the paper blank has a width which can, for example, be between 1 mm and 5 mm, for example, between 2 mm and 4 mm, and in particular, for example, approximately 3.5 mm. The circumferential face of the covering body or the filter can, for example, be 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 with a continuous printing.

[0025] The covering body can, for example, bear 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 provide a particularly effective filter action.

[0026] Only the covering body can, for example, surround the filling made of filter material and the optionally provided end elements. This means that the tubular portion of the filter body may be exclusively formed by the covering body. A filter with particularly few individual components and consequently a particularly cost-effective production can thereby be achieved. The covering body may furthermore 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 provided. There may be provision in this instance 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, for example, in particular to a, standardized length of the filter.

[0027] The covering body can, for example, form with the cylindrical inner circumference the inner space for the filter material and form with the substantially conical outer circumference a circumferential outer face of the filter body, in particular of the entire filter. The covering body may in particular delimit over almost the entire length of the filter body an inner space for the filter material and, where applicable, 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.

[0028] At least one of the axial ends of the covering body can, for example, be connected in a non-positive-locking manner to an end element at the end. The end element may in particular be pressed into the axial end of the covering body.

[0029] The covering body can, for example, be connected to itself in a materially engaging manner, for example, via adhesive-bonding, in particular in the region of the overlapping winding thereof. Adhesive may be arranged at least in regions on a flat side of the blank therefor. Adhesive may alternatively or additionally 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 brought about. The filter is thereby particularly easy to handle both during production and during use.

[0030] The method according to the present invention for producing a filter as described above 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, for example, 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.

[0031] An exemplary embodiment of the present invention is explained in greater detail below with reference to the drawings. Reference numerals which are the same thereby refer to identical components.

[0032] FIGS. 1 and 2 show an exemplary embodiment of a filter 1 according to the present 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 product.

[0033] The filter 1 is used during smoking in particular 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 advantageously 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 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.

[0034] 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 surrounds the filling made of filter material 5 radially at the outer side. The covering body 3 is in this instance configured so that the filter body 2 has a conical outer form.

[0035] As shown in FIG. 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 advantageously 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.

[0036] 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(s) 6a, 6b advantageously has/have holes so that it is configured at least in an axial direction of the filter 1 in an air-permeable manner. An inner space 8 for the filter material 5 is arranged between its two axial ends.

[0037] 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 components. The filter material 5 can, for example, comprise activated carbon which provides a selective filtering.

[0038] 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 a conical 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. It is in particular advantageous for 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 end 7b facing away from the smoker. For example, the diameter D1 is approximately 6 mm und the outer diameter D2 is approximately 7 mm.

[0039] According to the present 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. The conical shaping is in particular achieved via a winding of a material of the covering body 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 so that the covering body 3 in the longitudinal extent of the filter 1 has a substantially conical outer circumference 10 or a conical circumferential face 10.

[0040] 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 so 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.

[0041] The paper blank 4 may be an elongate paper strip which tapers in the longitudinal extent thereof and in the longitudinal extent thereof is wound about itself and connected together in a materially engaging manner, in particular via adhesive bonding.

[0042] Such a paper blank 4 is shown, for example, in FIG. 3.

[0043] 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 portion 4c which, in a state in which the covering body 3 is wound completely 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 FIG. 3. The portion 4c may be provided with an imprint, in particular with a continuous printing. In the above-mentioned completed state of the filter 1, the outer circumferential 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.

[0044] 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 advantageously corresponds to the length of the filter body 2. The portion 4c has in this instance a width B2 of approximately 3.5 mm.

[0045] The paper blank 4 can consequently be wound in order to form the covering body 3. The first winding in this instance completely covers 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 initially 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, i.e., the portion 4c is not covered or overlapped.

[0046] The conical outer circumference of the filter 1 is consequently formed in that the material which forms the covering body 3, in this instance in particular the paper blank 4, is wound so that the material of the covering body 3, i.e., in particular the paper blank 4, is wound in an increasingly overlapping manner in the direction of one of the axial ends, in particular in the direction toward the second axial end 7b facing away from a smoker. The windings of the paper blank 4 in particular overlap each other in the longitudinal extent of the filter 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.

[0047] The overlapping windings can, for example, be 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.

[0048] Depending on requirements, in order to form a larger or smaller diameter of the filter 1 at the second axial 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 provided 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 FIG. 3, of the second region 4b being adapted, in particular increased and/or decreased. After the covering body 3 is formed, an end element (i.e., first end element 6a) is fitted, in particular via pressing into the first axial end 7a. Filter material 5 is subsequently introduced into the inner space 8, and this is then closed by another end element (i.e., second end element 6b), which to this end can also be pressed in.

[0049] The present invention is not limited to embodiments described herein; reference should be had to the appended claims.

LIST OF REFERENCE CHARACTERS

[0050] 1 Filter [0051] 2 Filter body [0052] 3 Covering body [0053] 4 Paper blank [0054] 4a First region [0055] 4b Second region [0056] 4c Portion [0057] 5 Filter material [0058] 6a First end element/End element [0059] 6b Second end element/End element [0060] 7a First axial end [0061] 7b Second axial end [0062] 8 Inner space [0063] 9 Inner circumference [0064] 10 Conical outer circumference/Conical circumferential face [0065] L1 Overall length of paper blank 4 [0066] L2 Overall length of paper blank 4 [0067] L3 Length of first region 4a [0068] B1 Width of paper blank 4 [0069] B2 Width of portion 4c [0070] D1 Outer diameter of first axial end 7a of filter 1 [0071] D2 Outer diameter of second axial end 7b of filter 1