GB1588980A

GB1588980A - Method and machine for producing smokable rod-like articles

Info

Publication number: GB1588980A
Application number: GB4202677A
Authority: GB
Original assignee: Hauni Werke Koerber and Co KG
Current assignee: Koerber AG
Priority date: 1976-10-13
Filing date: 1977-10-10
Publication date: 1981-05-07
Also published as: DE2734643C2; JPS617315B2; FR2367437A1; JPS5347600A; IT1087251B; DE2734643A1

Description

(54) METHOD AND MACHINE FOR PRODUCING SMOKABLE ROD-LIKE ARTICLES (71) We, HAUNI-WERKE KORBER & BR< Co KG., a German Company of Kampchaussee 12-22, 2050 Hamburg 80, Germany (Fed. Rep.) do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: The invention relates to a method for producing smokable rod-like articles with a wrapping material having a predetermined permeability to air, which wrapping material is withdrawn from a store and wound around a filling for the smokable article or around the smokable article and/or around a component for the smokable article.

The invention also relates to a machine for producing smokable rod-like articles with a wrapping material having a predetermined permeability to air, which is withdrawn from a store and wound by means of a wrapping device around a filling for the smokable article or around the smokable article and/or around a component for the smokable article.

The term "smokable rod-like article" is intended to mean cigarettes, cigarillos and cigars with and without filters and filter rods.

The term "wrapping material" includes both the wrapping material enclosing the tobacco and filter as well as the connecting material, by which the tobacco rod and filter are connected.

Providing smokable articles with wrapping material having a predetermined permeability to air is gaining increasing significance. In this case, either the entire wrapping material has a predetermined porosity, which is no longer natural beyond a predetermined magnitude, but is introduced artificially into the wrapping material, or else only certain regions of the wrapping material, generally in the vicinity of the mouthpiece of the smokable article, have a predetermined permeability to air as a result of perforations which have been introduced.

Owing to the permeability to air of the wrapping material, cool air is drawn in through the wrapping material at the time of smoking and mixes with the tobacco smoke, due to which the proportions of nicotine and condensate in the smoke are influenced.

Now in order to be able to maintain predetermined values of the nicotine and condensate in the smoke of a smokable article, it is necessary to keep the proportion of secondary air drawn in through the wrapping matenal at the time of smoking as constant as possible in proportion to the smoke for smokable articles of one type. This presupposes that the wrapping material of smokable articles of one type has a predetermined permeability to air, which as far as possible should not be subject to any fluctuations, but at least, should not fall below a predetermined value. However, in practice, it has always been observed that particularly after changing the reel of wrapping material, the permeability to air of the wrapping material varies from a reference value to an inadmissible extent.

An object of the invention is to provide smokable articles with a wrapping material whose permeability to air guarantees the proportion of secondary air drawn in through the wrapping material at the time of smoking, in the air smoke mixture, to the desired extent.

This object is fulfilled according to the invention due to the fact that the permeability to air of the wrapping material is checked after withdrawal from the store, that a measurement signal corresponding to the respective permeability to air is formed, that the measurement signal is compared with a reference value and a comparison signal is formed and that the permeability to air of the wrapping material is kept constant depending on the comparison signal by controlled perforation of the wrapping material.

The permeability to air of the wrapping material can be checked on the finished smokable article, in that a pressure drop between a space outside the wrapping and a space inside the wrapping is produced pneumatically. However, the permeability to air of the wrapping material may also be checked on the wrapping material strip itself before the wrapping operation. There arc two possibilities for influencing the permeability to air of the wrapping material, namely controlling the size of the holes introduced and/or controlling the number of holes introduced per unit of surface area. If the permeability to air of the wrapping material is only to be altered after completion of the smokable article, then this can be achieved by rolling the smokable article about its lon gltudinal axis and puncturing or cutting the wrapping material.On the other hand, the permeability to air of the wrapping material can also be altered before completion of the smokable article, after withdrawing the wrapping material strip from a store. The following methods are available for introducing holes into a strip of wrapping material moving continuously: mechanical puncturing of the wrapping material, perforation by means of sparks emanating from electrical discharges and perforation by means of laser beam pulses. The invention is particularly suitable for the production of smokable articles with a so-called climatic area, in that the wrapping material is perforated in the vicinity of one end of the smokable article or of the smokable article to be produced, this perforation being checked and altered when differing from a reference value.

The afore-mentioned machine, which is particularly suitable for carrying out the afore-described method, is characterised by the fact that a checking device for monitoring the permeability to air of the wrapping material and an evaluation arrangement for monitoring changes in the permeability to air are provided, that a perforating device is provided for perforating the wrapping material, which device comprises control means for controlling the perforation of the wrapping material and that a correcting element of the control means is connected to the evaluation arrangement. According to one embodiment of the invention, the machine comprises a conveyor for conveying the smokable articles at right-angles to their axes with an associated pneumatic checking device for monitoring the permeability to air of the wrappings of the smokable articles.

According to one variation of the invention, the checking devices located between the wrapping material store and the wrapping device, where it monitors the permeability to air of the wrapping material strip withdrawn from the store. The control means of the perforating device can be constructed to alter the size of the holes of the perforation and/or to alter the number of holes per unit of surface area of the perforation. Filter cigarettes in particular are provided with wrapping material which is permeable to air, the provision of a corresponding device on a filter attachment machine being suitable for inserting a perforation in the latter.In this case, the perf < .rating device comprises a rotating conveyor for conveying the articles at right-angles to their axes, the peripheral surface of which conveyor is constructed as a rolling surface at least in sections and comprises retaining means for the articles, the latter also comprising a counter rolling surface extending over part of the periphery of the conveyor, which according to the diameter of the smokable articles is located at a distance from the rolling surface of the conveyor such that the smokable articles are positively engaged between the two surfaces and rolled as a result of a relative movement of the two surfaces with respect to each other, in which case perforation means project from one of the two surfaces, which penetrate the wrapping of the smokable articles as they are rolling.In a perforating device of this type, it is possible to influence the number of holes forming the climatic area due to the fact that perforating means can be moved into or out of an operative position by the control means. If necessary, two or even more perforating means can naturally be activated or de-activated. The side of the holes forming the perforation can be altered with the afore-described perforating device due to the fact that the perforation means can be moved in the direction of the surface towards which they are pointed and that the control means are constructed to vary the spacing of the points of the perforation means from said surface.Thus, with this type of control, the penetration depth of the perforation means (needles or saw tooth-like cutting edges) is controlled, whereby owing to the natural shape of the perforation means, a greater penetration depth results in larger holes in the wrapping material. However, the invention also provides that a wrapping material for the smokable articles, for example in the case of filter cigarettes, the tipping paper connecting the tobacco rod and filter plug, or in the case of plain cigarettes or filter rods, the cigarette paper or wrapping paper itself, is perforated before completing the articles. Such a machine according to the invention is characterised in that the perforating device precedes the wrapping device and is constructed to perforate a strip of wrapping material supplied continuously to the wrapping device. In this case, for perforation, it is possible to use either a controllable mechanical perforating device able to be driven in synchronism with the movement of the wrapping material strip, a controllable electrical discharge device producing sparks or a controllable pulse laser.

The invention is described in detail hereafter with reference to the drawings illustrating several embodiments: Figure 1 shows a production machine producing filter cigarettes with a perforating device for filter cigarettes, shown diagrammatically, Figure 2 shows the perforating device of the filter attachment machine according to figure 1, to an enlarged scale.

Figure 3 is a section through the perforating device of figure 2, on line III-III, but once more to an enlarged scale, Figure 4 is a partial section of a checking drum in the region of a holder with a control arrangement for the perforating device according to figures 2 and 3, Figure 5 shows a variation of the perforating device according to figure 2 Figure 6 shows a perforating device for a continuously moving strip of wrapping material of the filter attachment machine according to figure 1, Figures 7 and 8 show variations of perforating devices, which can be used in place of that in figure 6, Figure 9 shows a cutaway portion of a rod machine with a perforating device and monitoring device for a wrapping material strip.

Figure 1 shows a machine for producing filter cigarettes, which is known by the name "MAX S" of the cigarette industry and is described hereafter with reference to its most important functional units.

An intake drum 1 transfers the cigarettes produced on a cigarette production machine to two grading drums 2, which rearrange the cigarettes supplied in staggered manner and supply them to an assembly drum 3 in rows of two with a gap between the cigarettes.

Filter rods pass from a magazine 4 to a cutter drum 6, are cut by two circular cutters 7 to form filter plugs of double length, rearranged on a grading drum 8, arranged by a shifter drum 9 to form a row of plugs located one behind the other, and deposited by an accelerator drum 11 in the gaps in the cigarette rows on the assembly drum 3. The cigarette/filter/cigarette groups are moved together so that they are located axially side-by-side. They are then received by a transfer drum 12. A tipping paper strip 13 is withdrawn from a tipping paper reel 14 bv means of a pair of withdrawal rollers 16.

The tipping paper strip 13 is guided around a pre-treater 17 having a sharp edge, glued by a glueing device 18 and cut on a tipping roller 19 by a cutter drum 21. The cut tipping paper pieces are stuck to the cigarettes/filter groups on the transfer drum 12 and rolled around the cigarettes/filter groups on a wrapping device in the form of a rolling drum 22 by means of an over rolling device in the form of a roll hand 23. The finished groups of double filter cigarettes are supplied to a cutter drum 26 by way of a conveyor in the form of a further rolling drum 24, which with a rolling block 25 forms a perforating device described in detail hereafter with reference to figures 2 and 3 and on this cutter drum are made into individual filter cigarettes by cutting centrally through the filter plug, faulty filter cigarettes being ejected simultaneously.A turning device 29 co-operating with a transfer drum 27 and collecting drum 28 turns one row of filter cigarettes and simultaneously transfers them into the unturned row of filter cigarettes travelling by way of the transfer drum 27 and the collecting drum 28. The filter cigarettes pass by way of a pneumatic checking device in the form of a checking drum 31 to an ejection drum 32, on which the heads of the filter cigarettes are scanned before the ejection operation. A catcher drum 34 co-operating with a brake drum 33 deposits the filter cigarettes on a catcher belt 36.

Figures 2 and 3 show details of the perforating device according to the invention.

On its periphery, the rolling drum 24 comprises rolling surfaces 38 defined by cross pieces 37, the respective length of which rolling surfaces corresponds at least to the circumference of a group 39 of filter cigarettes.

Vacuum bores 41 and 42 (shown in dotdash line) open in the region of the cross pieces 37 for retaining the groups of filter cigarettes 39 before or after the rolling process. The rolling block 25 consists of two assembled parts 25a and 25b, which define a recess 43, in which a support 44 for perforation means in the form of conical needles 46 is located (saw-tooth-like cutters may also be used in place of the needles). The support 44 is mounted on the one hand by means of a slot 47 on a bolt 48 and on the other hand on control means in the form of a journal 51 arranged eccentrically with respect to a shaft 49. The shaft 49 is guided through the part 25b and connected to a drive shown in figure 4. The rolling block 25 is mounted to tilt away from the rolling drum 24 about a pin 53, for which purpose a stop in the form of a withdrawable bolt 54 can be released.The rolling block 25 is adjusted with respect to the rolling drum 24 such that the surfaces 56a and 56b of the parts 25a, 25b forming a counter rolling surface are at a distance from the rolling surfaces 38 of the rolling drum 24 which is somewhat smaller than the diameter of the filter cigarette groups 39. The two rows of needles 46 in the support 44 are arranged such that they produce holes in the mouth pieces F in the regions of the filter cigarette groups 39 adjacent the tobacco rods T, so that after cutting the groups into individual filter cigarettes, each individual cigarette has a perforation in the form of a row of holes.

In place of the rolling drum 24 provided with cross pieces 37, a rolling drum with flat recesses can be used, so that with a longer construction of the rolling block 25, multi ple over-rolling can be achieved. in which further rows of needles staggered with respect to the first rows, can provide additional holes in the smokable articles.

Figure 4 shows details of the checking drum 31 in section in the region of a holder for filter cigarettes Z. One holder 57 of the checking drum 31 comprises two cross pieces 58, in which vacuum bores 59 for retaining the cigarettes are guided by way of a stationary control ring (not shown) to a source of vacuum. By means of control slots 61a and 61b in stationary control rings 62a, 62b and sealing tubes 63, which can be pushed against the filter ends F of filter cigarettes Z against the action of springs 66 by mechanical control means known per se and therefore not shown (for example a cam guide), the filter cigarettes Z can be supplied with checking air, which can be supplied in pipes 64a, 64b (shown diagrammatically) from a source of checking air 67 (source of compressed air) by way of a control valve 68 and a restrictor 69.A restrictor 70 in the pipe 64b ensures that the greatest sensitivity of the checking system, with respect to the filter cigarette Z, is located in the region of its perforation (climatic area) P. The reference numeral 71 designates a measuring device for the checking air pressure, which is advantageously constructed as a pneumatic/electrical transducer in the form of a checking membrane receiving checking air, whose position is scanned capacitively. The measuring device can be constructed as described in the Applicant's U.S. Patent Specification 3,412,856. For each filter cigarette Z, the measuring device 71 sends a measurement signal to an integration arrangement 72, whose output signal substantially reproduces the permeability to air of the wrapping in the region of the perforation P of a predetermined number of filter cigarettes Z.A comparison arrangement 73 is connected firstly to the integration arrangement 72 and secondly to a reference value transmitter 74, the comparison arrangement 73 also being connected to a control unit 76. The control unit 76 is connected to a correcting element in the form of an electric motor 77, which is controlled by the control unit 76 according to the input signal of the comparison arrangement 73 (control deviation). The integration arrangement 72, comparison arrangement 73 and reference value transmitter 74 form an evaluation arrangement 79. The electric motor 77 is connected by way of reduction gearing 78 to the shaft 49 for adjusting the support 44 with the needles 46 in the rolling block 25 according to figures 2 and 3.

The method of operation of the perforating and checking device of the filter attachment machine of figure 1 according to figures 2 to 4 is as follows: groups 39 of filter cigarettes interconnected on the rolling drum 22 are transferred to the rolling drum 24 in the region of the cross pieces 37 and held there by means of reduced pressure at the vacuum bores 41. When the groups 39 of filter cigarettes come into contact with the surfaces 56a and 56b of the rolling block 25, as a result of positive guidance between these surfaces and the rolling surfaces 38 of the rolling drum 24, they are rolled to the respective subsequent cross piece 37, whereby the two rows of needles 46 penetrate the wrapping material of the groups 39 of filter cigarettes in the region of the filters F.The groups 39 of filter cigarettes are then held on the vacuum bores 42 by means of reduced pressure and subsequently discharged to the cutting drum 26. After passing the turning device 29, all filter cigarettes Z are checked pneumatically individually on the checking drum 31, a mean value for the permeability to air of the perforation P of a predetermined number of filter cigarettes Z being formed by means of the integration arrangement 72.If the comparison in the comparison arrangement 73 between the reference value and actual value produces a deviation, then the electric motor 77 is activated by the control unit 76 according to this deviation, due to which, by way of the reduction gearing 78, the shaft 49 is tilted and the support 44 with the needles 46 is moved towards the rolling drum 24 when the permeability to air of the perforations P is too low and away from the rolling drum 24 when the permeability to air of the perforations P is too great. As a result of the penetration depth of the needles 46 in the wrapping material of the filter cigarettes Z, changed in this way, caused by the conical shape of the needles 46, the diameter of the holes produced in the wrapping material, which form the perforation P, becomes larger or smaller.

Figure 5 shows a variation of the perforating device of figure 2, in which parts corresponding to those of figure 2 are provided with the same reference numerals, increased by 100 and are not described again in detail.

In contrast to figure 2, a support for the needles 146 consists of support parts 181a, 181b and 181c. The support parts 181a and 181b are fixed in the rolling block 125 and form lateral guides for the support part 18 1c mounted therebetween with two needles 146 arranged one behind the other, i.e. with one needle for each filter cigarette of the filter cigarette groups 139. By means of the shaft 149 and the eccentric 151, on which the support part 181c is mounted, the latter can be moved up and down with its needles 146 by tilting of the shaft 149, so that according to the position of the support part 181c, a smaller or larger hole is provided in each filter cigarette of the filter cigarette groups 139.For this purpose, the control device 76 shown in figure 4 is modified such that the electric motor 77 carries out a predetermined number of revolutions in one or other direction, when the actual value exceeds or falls short of the reference value by a predetermined amount.

The perforating device shown in figure 6 can be located in the filter attachment machine of figure 1 at the place indicated by the box drawn in dot-dash lines, i.e. before the rolling drum 22 considered as a wrapping device, in which case the rolling block 25 is dispensed with and the rolling drum 24 is replaced by a normal grooved drum. A controllable mechanical perforating device 186 is provided for punching holes in the tipping paper strip 13, which device comprises essentially two rollers 187a and 187b with punching tools 188a, 188b, which can be arranged in one or more rows on the periphery of the rollers 187a, 187b, which rollers co-operate with rollers 189a, 189b serving as an abutment. The roller 187a serves for providing a so-called basic perforation and is provided with a correspondingly high number of punching tools 188a.

In contrast, the roller 1 87b comprises only a few, for example only two punching tools 188b, as shown. The rollers i87a, 189a and 189b can be driven in the direction of the arrow by the drive of the filter attachment machine, whereas the roller 187b, which is mounted on an arm 192 able to tilt about a shaft 191 of the roller 187a, is driven by the roller 187a by way of a toothed belt drive 193. Control means in the form of a pneumatic drive 194 (piston cylinder system) are provided for tilting the arm 192 towards the stop 195 or away from the stop 195, which drive is connected by way of a control member in the form of an electropneumatic valve 196 to a source of compressed air 197.The electropneumatic valve 196 can be controlled by way of a threshold value member 198, the threshold value member 198 and the electropneumatic valve 1 96 adjoining the evaluation arrangement 79 of figure 4, in place of the control unit 76 or of the electric motor 177.

The method of operation of the perforating device according to figure 6 is as follows: one or more rows of holes are punched in the tipping paper strip 13 by the punching tools 188a of the roller 187a. (Glueing then takes place between or adjacent the rows, so that subsequently the holes are not stuck).

Normally, the punching tools 188b of the roller 187b do not take part in the punching operation, so that the position of the arm 192, of the pneumatic drive 194 and of the electropneumatic valve 196 shown in the drawing is provided. If the checking device shown in figure 4 is used to measure that the air flowing through the perforations in the tipping paper strip 13 on the finished filter cigarettes is below a predetermined value, which can be caused for example by individual punching tools 188a of the roller 187a being worn or even by a punching tool 188a breaking-off, which has the result that the signal sent to the threshold value member 198 exceeds a certain value, then the electro-pneumatic valve 196 is excited by the threshold value member 198, which changes its switching position, so that the pneumatic drive 194 swings the arm 192 towards the stop 193.The punching tools 188b of the roller 187b now punch additional holes in the tipping paper strip 13.

The perforating device shown in figure 7 is formed by a controllable electrical discharge device 201 producing sparks and can be used in place of the device shown in figure 6. The tipping paper strip 13 is guided between two rollers 202 and 203 located at a distance apart, which rollers are driven by the drive of the filter attachment machine according to figure 1. The rollers 202 and 203 each have an insulating boss 204, 206 and an outer ring 207, 208 of electrically conducting material, possibly brass. The rings 207 and 208 are respectively con nected to a source of high voltage 211 by way of slip rings (not shown in detail) and brushes via a circuit breaker 209.The circuit breaker 209 is connected by way of control means in the form of an infinitely controllable transmission 212 to the drive of the filter attachment machine, which is illustrated by the lines 213 and 214 drawn in dot-dash line. A correcting element in the form of a servo motor 215 is associated with the infinitely variable transmission 212, which motor in this embodiment replaces the electric motor 77 in figure 4, i.e. it is controlled by the control unit 76 shown in the latter.

The method of operation of the perforating device according to figure 7 is as follows: according to the operation of the circuit breaker 209, sparks jump between the rings 207 and 208 of the rollers 202, 203, which sparks penetrate the tipping paper strip 13 and produce one or more rows of holes in the tipping paper strip 13 according to the shape of the rings 207 and 208 (strips for the application of glue remain free of holes).

The number of holes introduced in the tipping paper strip 13 per unit length is thus controlled depending on the checking device shown in figure 4 by way of the infinitely controllable transmission 212, by which the circuit breaker 209 is driven.

A further possibility of introducing a row of holes in the continuously moving tipping paper strip 13 is shown in figure 8. A laser 216 is provided as the means for perforating the tipping paper strip 13, a CO2-laser being particularly suitable, whose beam of light can be controlled by a perforated disc for example, which is illustrated in broken line and designated by the reference numeral 217. The perforated disc 217 can be driven by control means in the form of an infinitely controllable transmission 218, as illustrated by the line 219 drawn in dot-dash lines, the transmission 218 being able to be driven by the machine drive of the filter attachment machine shown in figure 1 (functional line 221 drawn in dot-dash line) and comprises a servo motor 222 for adjusting its reduction ratio.In this embodiment, the servo motor 222 replaces the electric motor 77 of figure 4. In this embodiment, the monitoring device with its evaluation arrangement 79 shown in figure 4 modifies the speed of the perforated disc 217 and thus the holes produced by the laser 216 per unit length of the tipping paper strip 13, in the latter. A plate 223 of aluminium with a rough surface for catching the laser beams is located on the side of the tipping paper strip 13 opposite the laser 216.

The perforating devices shown in figures 6, 7 and 8 can also be used on a rod machine for producing smokable rod-like articles, in that they are located before or after a printing unit, which is customarily provided on these machines, for providing the wrapping material with a trade mark reference. n this case, the devices are modified such that they produce rows of holes in the wrapping material, at right-angles to the feed direction and at intervals.Monitoring of smokable articles produced in this way with a climatic area and thus the control of the perforating device is possible if a checking drum according to that shown on the filter attachment machine according to figure 1 is located after an insert drum provided on the rod machines, which receives the articles leaving the rod machine in the direction of their longitudinal axes and discharges them in a direction at right-angles to their axes.

Figure 9 shows the part of a cigarette rod machine (whose construction is substantially the same as that of a filter rod machine), on which the guidance of the wrapping material in the form of a cigarette paper strip 302, withdrawn from a reel 301 (store) and the wrapping of a tobacco rod 303 in the cigarette paper strip 302 is undertaken. For this, the tobacco rod 303 is conveyed on the underside of an air permeable conveyor belt 304, on whose rear side reduced pressure prevails, so that the tobacco rod 303 is retained on the conveyor belt 304 by vacuum. After the transfer of the tobacco rod 303 to the cigarette paper strip 302, the latter is wrapped in a continuous movement around the tobacco rod 303 in a wrapping device in the form of a shaping part 305.

The projecting edge is provided with glue by the glueing device 306, then wrapped around and stuck for closing the cigarette rod 307. The adhesive seam is then heated by a so-called seam plate 308, so that the glue is able to harden and the cigarette rod no longer opens. Transportation of the cigarette rod is undertaken by an endless so-called shaper belt 310, which travels through the shaping part 305 under the cigarette paper strip 302. A cutter device 309 cuts individual cigarettes Z from the cigarette rod 307, which are transferred by an accelerator 311 into the holders 312 of a catcher drum 313, which simultaneously gives the cigarettes a feed direction at right-angles to their axes and guides them to a filter attachment machine in which the filter plugs are attached to the cigarettes.

A checking device in the form of a photo-electric measuring arrangement 315 for the permeability to air of the cigarette paper strip 302 is located in the path of movement of the cigarette paper strip 302, at a measuring point A. The latter comprises a light-emitting gallium-arsenide diode 314 as the light source and a photodiode 316 as the photo-electronic receiver arrangement.

Since both diodes have a much smaller illuminated surface or light-sensitive surface than the surface which is to be scanned on the cigarette paper strip, an optical system consisting of lenses 31 and 318 is located between the two diodes. A pulse emitter 319 serves for controlling the galliumarsenide diode 314 with voltage pulses (for example 5000 Hz). The photodiode 316 is followed by a peak voltmeter 321, which is connected to an evaluation arrangement 322 for the occurrence of a characteristic value. This evaluation arrangement 322, which consists of a comparison member 323 and a reference value transmitter 324, serves for ascertaining a variation in the quality of the illuminated part of the cigarette paper strip from a desired quality (permeability to air). The evaluation arrangement 322 is connected to a control unit 326 of a perforating device 327, which precedes the measuring point A at a perforating point B in the path of movement of the cigarette paper strip 302. The perforating device 27 is constructed as an electrical discharge device producing sparks and it comprises electrodes 328 and 329 located respectively on one side of the cigarette paper strip 302 staggered over the width of the strip, which electrodes are connected to a high voltage source 332 by way of a circuit breaker 331. The circuit breaker 331 is connected by control means in the form of an infinitely controllable transmission 333 to the drive of the cigarette rod machine, which is represented by the functional lines 334 and 336 drawn in dot-dash line. The functional line 334 starts from a pair of withdrawal rollers 337 for the cigarette paper strip 302.Associated with the infinitely controllable transmission 333 is a correcting element in the form of a servo motor 338 which is controlled by the control unit 327. According to the operation of the circuit breaker 331, sparks jump between the electrodes 328 and 329, which penetrate the cigarette paper strip 302 and thus produce rows of holes in the cigarette paper strip 302 over the width of the cigarette paper strip 302, according to the number of electrodes 328, 329 (areas of the cigarette paper strip intended for the application of glue are not provided with holes). The number of holes introduced in the cigarette paper strip 302 per unit length is thus controlled depending on the photo-electric measuring arrangement 315 by way of the infinitely controllable transmission 333, by which the circuit breaker 331 is driven.For this, the gallium- arsenide diode 314 emits light pulses at the measuring point A, which light pulses are enlarged as regards their surface area by the lens 317 and directed towards the cigarette paper strip 302. The quantity of light passing through the cigarette paper strip 302 depends on its permeability to air (porosity). The light which passes through is focused on the photodiode 316 by the lens 318 and transformed into an electrical signal, which has the shape of electrical pulses. As a result of the pulsating operation of the gallium-arsenide diode 314, the amplitudes of the pulses can be selected higher than in the case of continuous operation.

The amplitudes of the electrical output signal of the photodiode 316 are monitored by the peak voltmeter 321 and converted into a corresponding continuous signal. In the case of a change in the permeability to air of the cigarette paper strip 302, which generally takes place only very gradually, the servo motor 338 is controlled by way of the control unit 327 according to the output signal of the comparison member 323, i.e.

due to a corresponding change of the perforations produced in the cigarette paper strip 302 (holes per unit surface area or length) the change in the permeability to air of the cigarette paper strip 302 is returned to the desired value.

The permeability to air of the wrapping material strip may naturally also be monitored with the checking device according to figure 4, in which case the restrictor 70 in the pipe 64b, shown in the latter, is dispensed with.

The advantage achieved by the invention consists in that by monitoring and controlling the permeability to air of the wrapping material of smokable articles, it is possible to ensure that the smokable articles leaving the production machine have a perforation which is necessary for retaining the desired values of nicotine and condensate in the smoke. The production of waste owing to faulty perforations can be eliminated with the solutions according to the invention.

WHAT WE CLAIM IS: 1. Method for producing smokable rodlike articles with a wrapping material having a predetermined permeability to air, which is withdrawn from a store and wound around a filling for the smokable article or around the smokable article and/or around a component for the smokable article, wherein the permeability to air of the wrapping material is checked after withdrawal from the store, a measurement signal corresponding to the respective permeability to air is formed, the measurement signal is compared with a reference value and a comparison signal is formed and the permeability to air of the wrapping material is kept constant depending on the comparison signals by controlled perforation of the wrapping material.

2. Method according to Claim 1, wherein the permeability to air of the wrapping material is checked pneumatically on the finished smokable article by producing a pressure drop between a space outside the wrapping and a space inside the wrapping.

3. Method according to Claim 1, wherein the permeability to air of the wrapping material is checked before wrapping.

4. Method according to any one of the preceding Claims, wherein the permeability to air of the wrapping material is changed by controlling the size of the holes introduced.

5. Method according to any one of the preceding Claims 1 to 3, wherein the permeability to air of the wrapping material is changed by controlling the number of holes introduced per unit of surface area.

6. Method according to any one of the preceding Claims, wherein the permeability to air is changed by rolling the smokable article about its longitudinal axis and puncturing or cutting the wrapping material.

7. Method according to any one of the preceding Claims 1 to 5, wherein the permeability to air of the wrapping material is changed after withdrawal from a store.

8. Method according to any one of the preceding Claims, wherein the permeability to air of the wrapping material is changed by controlled mechanical perforation.

9. Method according to any one of the preceding Claims 1 to 7, wherein the permeability to air of the wrapping material is changed by sparks penetrating the wrapping material, which sparks emanate from controlled electrical discharges.

10. Method according to any one of the preceding Claims 1 to 7, wherein the permeability to air of the wrapping material is changed by means of controlled laser beam pulses.

11. Method according to any one of the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. paper strip 302. Associated with the infinitely controllable transmission 333 is a correcting element in the form of a servo motor 338 which is controlled by the control unit 327. According to the operation of the circuit breaker 331, sparks jump between the electrodes 328 and 329, which penetrate the cigarette paper strip 302 and thus produce rows of holes in the cigarette paper strip 302 over the width of the cigarette paper strip 302, according to the number of electrodes 328, 329 (areas of the cigarette paper strip intended for the application of glue are not provided with holes).The number of holes introduced in the cigarette paper strip 302 per unit length is thus controlled depending on the photo-electric measuring arrangement 315 by way of the infinitely controllable transmission 333, by which the circuit breaker 331 is driven. For this, the gallium- arsenide diode 314 emits light pulses at the measuring point A, which light pulses are enlarged as regards their surface area by the lens 317 and directed towards the cigarette paper strip 302. The quantity of light passing through the cigarette paper strip 302 depends on its permeability to air (porosity). The light which passes through is focused on the photodiode 316 by the lens 318 and transformed into an electrical signal, which has the shape of electrical pulses.As a result of the pulsating operation of the gallium-arsenide diode 314, the amplitudes of the pulses can be selected higher than in the case of continuous operation. The amplitudes of the electrical output signal of the photodiode 316 are monitored by the peak voltmeter 321 and converted into a corresponding continuous signal. In the case of a change in the permeability to air of the cigarette paper strip 302, which generally takes place only very gradually, the servo motor 338 is controlled by way of the control unit 327 according to the output signal of the comparison member 323, i.e. due to a corresponding change of the perforations produced in the cigarette paper strip 302 (holes per unit surface area or length) the change in the permeability to air of the cigarette paper strip 302 is returned to the desired value. The permeability to air of the wrapping material strip may naturally also be monitored with the checking device according to figure 4, in which case the restrictor 70 in the pipe 64b, shown in the latter, is dispensed with. The advantage achieved by the invention consists in that by monitoring and controlling the permeability to air of the wrapping material of smokable articles, it is possible to ensure that the smokable articles leaving the production machine have a perforation which is necessary for retaining the desired values of nicotine and condensate in the smoke. The production of waste owing to faulty perforations can be eliminated with the solutions according to the invention. WHAT WE CLAIM IS:

1. Method for producing smokable rodlike articles with a wrapping material having a predetermined permeability to air, which is withdrawn from a store and wound around a filling for the smokable article or around the smokable article and/or around a component for the smokable article, wherein the permeability to air of the wrapping material is checked after withdrawal from the store, a measurement signal corresponding to the respective permeability to air is formed, the measurement signal is compared with a reference value and a comparison signal is formed and the permeability to air of the wrapping material is kept constant depending on the comparison signals by controlled perforation of the wrapping material.

11. Method according to any one of the

preceding Claims, wherein the wrapping material of smokable rod-like articles is provided in the vicinity of one end with a climatic area by perforation of the wrapping material and the perforation is checked and changed when it varies from a reference value.

12. Machine for producing smokable rod-like articles with a wrapping material having a predetermined permeability to air, which is withdrawn from a store and wrapped by means of a wrapping device about a filling for the smokable article or about the smokable article and/or about a component for the smokable article, wherein a checking device for monitoring the permeability to air of the wrapping material and an evaluation arrangement for monitoring changes in the permeability to air are provided, a perforating device is provided for perforating the wrapping material, which device comprises control means for controlling the perforation of the wrapping material and a correcting element of the control means is connected to the evaluation arrangement.

13. Machine according to claim 12, comprising a conveyor for conveying the smokable articles at right-angles to their axes with an associated pneumatic checking device for monitoring the permeability to air of the wrappings of the smokable articles.

14. Machine according to claim 12, wherein the checking device is located between the store and wrapping device and monitors the permeability to air of the wrapping material strip withdrawn from the store.

15. Machine according to any one of the preceding claims, wherein the control means are constructed to vary the size of the holes of the perforations.

16. Machine according to any one of the preceding claims 12 to 14, wherein the control means are constructed to vary the number of holes per unit of surface area of the perforations.

17. Machine according to any one of the preceding claims 12 to 16, wherein the perforating device comprises a rotating conveyor for conveying the articles at rightangles to their axes, the circumferential surface of which is constructed as a rolling surface at least in sections and comprises retaining means for the articles and comprises a counter rolling surface extending over part of the circumference of the conveyor, which counter rolling surface is located at a distance from the rolling surface of the conveyor, according to the diameter of the smokable articles, such that the smokable articles are positively engaged between the two surfaces and are rolled as a result of a relative movement of the two surfaces with respect to each other, in which case perforating means project from one of the two surfaces, which penetrate the wrapping of the smokable articles as they are rolled.

18. Machine according to claim 17, characterised in that a perforation member of the control means is brought into or out of an operative position.

19. Machine according to claim 17, wherein the perforation means can be moved in the direction of the surface, towards which they are pointed and the control means are constructed to vary the spacing of the points of the perforation means with respect to said surface.

20. Machine according to any one of the preceding claims 12 to 19, wherein the perforating device precedes the wrapping device and is constructed to perforate a wrapping material strip supplied continu ousl to the wrapping device.

2. Machine according to claim 20, wherein the perforating device is a controllable mechanical perforating device which can be driven in synchronism with the movement of the wrapping material strip.

22. Machine according to claim 20, wherein the perforating device is a controllable electrical discharge device producing sparks.

23. Apparatus according to claim 20, wherein the perforating device is a controllable pulse laser.

24. A method for producing smokable rod-like articles, substantially as herein described with reference to the accompanying drawings.

25. A machine for producing smokable rod-like articles, substantially as herein described with reference to and as illustrated in the accompanying drawings.