Patent Application
20050127046
This application claims the priority of the commonly owned German patent application Serial No. 103 54 743.6-23-DE filed Nov. 21, 2003.
The disclosure of the above-referenced German patent application, as well as the disclosures of all other patent applications, patents and other publications identified in the specification of the present application, are incorporated herein by reference.
The present invention relates to improvements in methods of and in apparatus for changing the permeability of tubular envelopes or wrappers of rod-shaped articles of the tobacco processing industry. Such articles include plain cigarettes, cigars, cigarillos and analogous smokers' products of unit length or multiple unit length, continuous cigarette rods or the like, tobacco smoke filtering mouthpieces of unit length or multiple unit length as well as continuous filter rods.
It is well known to alter or adjust the permeability of wrapping material (such as cigarette paper or so-called tipping paper) for rod-shaped fillers which consist of or contain shredded tobacco leaf laminae, comminuted reconstituted or substitute tobacco, filter material for tobacco smoke and/or other constituents of rod-shaped smokers' products. It is also well known to select the permeability of such, wrapping material by resorting to adjustable devices which perforate the wrapping material, e.g., mechanically by employing needles or analogous implements, or by resorting to one or more lasers or other suitable radiation sources.
As a rule, a filter cigarette which is provided with an air-transmitting wrapper is permeable in the region of its filter mouthpiece so that, while drawing tobacco smoke from the lighted tobacco-containing portion of such article, the smoker simultaneously draws and normally or often inhales atmospheric air which enters through the perforations in the tubular envelope for filter material. Such mixing of tobacco smoke with atmospheric air in the interior of a filter cigarette exhibits numerous important advantages. Thus, the smoker inhales a smoke which contains less nicotine and/or tar, and the atmospheric air entering the filter cigarette through the perforations in the tubular envelope for filter material reduces the temperature of the column of smoke entering the mouth of the smoker.
The width of the arcuate gap between the convex surface of the rotating drum-shaped wrapping conveyor and the concave surface of the stationary rolling device is less than the diameters of rod-shaped articles in the gap. This is necessary in order to ensure that the groups of coaxial articles are compelled to rotate in a predictable fashion about their common axis during travel through the gap, as well as to ensure predictable convoluting of the adhesive-coated uniting bands around the rod-shaped filter mouthpieces and the adjacent end portions of the respective plain cigarettes of unit length during conversion of such articles into filter cigarettes of double unit length. Thus, the wrapping conveyor and the block-shaped rolling device subject the rod-shaped articles in the gap to rather pronounced mechanical stresses which are apt to adversely affect the appearance and/or the quality of the ultimate products, especially in a modern filter cigarette maker wherein the rod-shaped articles in the gap must advance at a very high speed if the maker is to turn out desired quantities of filter cigarettes per unit of time.
Certain attempts to overcome the drawbacks of the just described machines, i.e., to reduce the stressing of the rod-shaped components and of the wrappers of filter cigarettes or analogous commodities, are disclosed in German patent No. 33 13 064 A1 which proposes to advance the cylindrical parts of the smokers' products in flutes provided in the cylindrical peripheral surface of a rotary drum-shaped conveyor. This conveyor is driven by a first hollow shaft which confines a part of a rotary second hollow shaft. One end portion of the second hollow shaft extends beyond the first hollow shaft and contains a beam divider arranged to direct beams of radiation against a mirror. Each of the just mentioned beam divider and mirror cooperates with a focussing lens, and these parts are confined in the aforementioned end portion of the second hollow shaft. The laser is located at the other ends of the hollow shafts and is arranged to furnish a pulsating beam which is caused to advance through the second hollow shaft and is split into two discrete beams before it reaches the rod-shaped components of the smokers' products. Such discrete beams advance through a slit, which is provided in one of the shafts, prior to impinging upon the exposed filter mouthpiece of a filter cigarette of unit length. The inner shaft is caused to rotate in the direction of rotation of the drum-shaped conveyor but at a higher speed; this is intended to ensure that the wrapper of each discrete filter cigarette is provided with several successive perforations during each revolution of the second (inner) hollow shaft.
A drawback of the just described proposal is that the apparatus which is disclosed in this German patent can be utilized only in conjunction with the treatment of filter cigarettes of unit length.
Similar drawbacks are exhibited by the apparatus which is disclosed in German patent No. 35 101 19 C2. This apparatus is designed to drill holes in the wrappers of cigarettes or the like. The patented apparatus employs a source of a laser beam which impinges upon a diffuser lens so that its components act upon (i.e., perforate) rod-shaped articles in discrete flutes turnably arranged on a drum-shaped conveyor for rod-shaped articles.
An object of the instant invention is to provide a method of and an apparatus for enhancing the permeability of wrappers of cigarettes and/or other rod-shaped smokers' products in a manner superior to that achievable by resorting to presently known methods and apparatus.
Another object of the invention is to provide a method of and an apparatus for perforating the wrappers of filter cigarettes or the like which can be utilized to turn out smokers' products or parts thereof superior to those obtainable by resorting to heretofore known methods and apparatus.
A further object of the present invention is to provide a method and an apparatus which can be resorted to for simultaneously making several rod-shaped smokers' products of a quality superior to that of presently obtainable products.
An additional object of the invention is to provide a perforating apparatus for the wrappers of smokers' products which utilizes one or more lasers or analogous energy sources in a novel and improved way.
An ancillary object of our invention is to provide a machine for the making of filter cigarettes or analogous rod-shaped smokers' products which embodies the above outlined apparatus.
A further object of the invention is to provide a novel and improved arrangement of optical elements which can be put to use in the above outlined improved apparatus.
An additional object of our invention is to provide a relatively simple and inexpensive apparatus which can be utilized to perforate the tubular envelopes of filter cigarettes or other rod-shaped smokers' products in a novel and improved way and can be installed in or combined with filter cigarette making or analogous machines in a novel and improved manner.
One feature of the present invention resides in the provision of an apparatus for perforating tubular envelopes of rod-shaped articles (e.g., filter cigarettes of double unit length) of the tobacco processing industry. The improved apparatus comprises at least one substantially drum-shaped carrier which is rotatable about a predetermined axis and the peripheral portion of which is arranged to support a plurality of articles for sidewise movement about the predetermined axis, a source of radiation (e.g., a CO2 laser) which is arranged to emit at least one beam of radiation of the type adapted to perforate the envelopes of articles being borne by the carrier, means (including, e.g., a polygonal laser beam directing or orienting mirror) for directing the at least one beam in a first direction at least substantially radially outwardly of and away from the predetermined axis of the carrier, first deflecting means (such as one or more stationary mirrors) which is arranged to change the orientation of the directed beam at a location radially outwardly of the peripheral portion in a second direction which is at least substantially parallel to the predetermined axis and is radially outwardly adjacent successive articles at the peripheral portion of the carrier, and second deflecting means (e.g., a set of diverting mirrors) arranged to change the orientation of the beam from the second direction into a third direction at least substantially toward the predetermined axis and against the envelopes of articles being borne by the peripheral portion of the carrier.
The improved apparatus preferably further comprises means for influencing the at least one beam between the radiation source and the directing means so that the beam impinges upon the directing means while advancing at least substantially at right angles to the predetermined axis. Such influencing means can comprise at least one cylinder lens which is arranged to focus the at least one beam upon a line coinciding at least substantially with the predetermined axis. The cylinder lens of the influencing means is or can be stationary.
The apparatus can also comprise means (e.g., a set of spherical lenses) for focussing the at least one beam being propagated in the third direction at at least one at least substantially fixed point which is located at the envelopes of articles being supported at the periphery of and being moved sideways by the rotary carrier.
As already mentioned hereinbefore, the means for directing the at least one beam at least substantially radially outwardly of and away from the predetermined axis can include a polygonal mirror, and such mirror is arranged to rotate about a second axis which is at least substantially parallel with the predetermined axis and is provided with facets arranged to direct the at least one beam across and about the predetermined axis. The carrier can be arranged to rotate about the predetermined axis in a first direction, and the mirror can be arranged to rotate about the second axis in a second direction counter to the direction of rotation of the carrier. At least one optical component can be provided in the path of the at least one beam from the predetermined axis toward the first deflecting means; the focus of such at least one optical component is or can be located on a line which at least substantially coincides with the predetermined axis, and such optical component can include a cylinder lens which is arranged to transform pivotal movements of the at least one beam about the predetermined axis into a parallel shifting of the at least one web. The cylinder lens is or can be stationary, and such apparatus can further comprise means for focussing the beam being propagated in the third direction at a plurality of at least substantially fixed focal points which are located at the envelopes of articles being supported at the periphery of and being moved sidewise by the carrier. The focussing means and the at least one optical component can be constructed and arranged to cooperate in such a way that the focussing means effects a parallel shifting of the at least one beam and the focal points constitute a series of points, as seen in the direction of rotation of the carrier. For example, the focussing means can be arranged to establish five focal points and the radiation source can include means for interrupting the emission of the at least one beam between the focal points of the series. The number of facets on the polygonal mirror can be selected in such a way that, while impinging upon any one of such facets, the at least one beam is caused to turn about the predetermined axis through a predetermined angle; for example, the mirror can comprise eight facets and the aforementioned angle can match or approximate 90°.
The improved apparatus can further comprise five optical components which are located in the path of the at least one beam from the predetermined axis toward the first deflecting means, and such optical components can include a series of discrete cylinder lenses which are located in the path of propagation of the at least one beam in the first direction toward the first deflecting means. The directing means of such apparatus can include the aforementioned rotary mirror which has a plurality of facets arranged to direct the at least one beam upon discrete cylinder lenses, and such cylinder lenses have foci on a line which at least substantially coincides with the predetermined axis. The radiation source of such apparatus can include means for interrupting the emission of the at least one beam between impingements of the at least one beam upon successive lenses of the series of discrete cylinder lenses.
If the apparatus includes directing means comprising a polygonal mirror which is arranged to rotate about the aforementioned second axis that is at least substantially parallel to the predetermined axis, the facets of such mirror can be arranged to direct the at least one beam across and to turn the at least one beam about the predetermined axis, and the mirror can be arranged to return the at least one beam back to a starting position during each transition from directing the beam by one of the facets to directing the beam by another of the facets. The radiation source can include or cooperate with means for turning off the at least one beam at each return to the starting position.
The improved apparatus is or can be set up to perforate tubular envelopes of articles which are spaced apart from each other at the peripheral portion of the carrier. The number of facets on the polygonal mirror of the directing means, the speeds of rotation of the carrier and of the polygonal mirror about the respective axes, the length of the peripheral portion of the carrier and the spacing between the articles at the peripheral portion of the carrier can be related to each other in such a way that, during directing of the at least one beam by one of the facets, the at least one beam impinges upon and perforates the envelopes of selected articles at the peripheral portion of the carrier and the envelopes of other articles at the peripheral portion of the carrier are perforated during impingement of the at least one beam upon another facet of the polygonal mirror following the one facet, as seen in the direction of rotation of the mirror about the second axis. The selected articles can include the first, third, fifth, etc. articles at the peripheral portion of the carrier. Such apparatus can further comprise means for focussing the beams being propagated in the third direction at at least one at least substantially fixed point which is located at the envelopes being supported at the periphery of and being moved by the carrier. The relationship between the number of facets, the speeds of the carrier and the facetted mirror, the length of the peripheral portion of the carrier and the spacing between the articles can be such that the envelopes which are not perforated during directing of the at least one beam by the one facet are perforated not earlier than upon the start of the next-following movement of the at least one beam and not later than upon arrival of the respective articles at the focal points of focussing means which were employed to focus the at least one beam upon the envelopes of articles immediately preceding the articles having envelopes already perforated by the at least one beam during directing of the at least one beam by the one facet. The aforementioned relationship can be such that the envelope of each article is perforated only when the envelope portion to be perforated is located at the at least one at least substantially fixed point at which the at least one beam is focussed by the focussing means.
The apparatus can further comprise means for rotating the articles about their longitudinal axes and relative to the peripheral portion of the carrier through an angle of n×360°. For example, the articles can be rotated about their longitudinal axes through angles of 360° or 1080°. This renders it possible to provide each envelope with perforations at a plurality of locations at the circumferences of the articles.
The radiation source can be arranged to emit at least two at least substantially parallel beams each of which is arranged to provide perforations in the envelopes of articles at the peripheral portion of the carrier. The second deflecting means of such apparatus can be arranged to direct the at least two beams in at least slightly convergent third directions which are at least substantially normal to the peripheral portion of the carrier.
The single beam or at least one of plural beams can be arranged to have an at least substantially circular cross-sectional outline.
The first deflecting means of the improved apparatus can comprise at least one stationary mirror which is located radially outwardly of the peripheral portion of the carrier. The second deflecting means can also comprise at least one stationary mirror which is disposed radially outwardly of the peripheral portion of the carrier and is spaced apart from the first deflecting means.
The aforementioned means for focussing the beam or beams being propagated in the third direction at at least one substantially fixed point which is located at the envelopes of articles being supported at the periphery of and being moved sidewise by the carrier can comprise at least one spherical lens.
Another feature of the present invention resides in the provision of a method of perforating tubular envelopes of rod-shaped articles of the tobacco processing industry. The improved method comprises the steps of advancing a series of successive parallel articles sideways along an arcuate path, directing at least one beam of radiation—having energy sufficient to perforate the envelopes—from an axis of the path at least substantially radially outwardly toward and beyond the path, thereupon deflecting the at least one beam in at least substantial parallelism with the axis and radially outwardly of the path, and thereafter diverting the at least one deflected beam at least substantially radially inwardly toward the envelopes of articles in the path.
The directing step can include advancing the at least one beam at least substantially at right angles to the axis. Such directing can involve focussing the at least one beam upon a line which at least substantially coincides with the axis.
The method can further comprise the step of focussing the diverted beam upon at least one point on the envelopes of the articles in the path to thus perforate the envelopes.
The directing step can include pivoting the at least one beam about the axis, and the advancing step of such method can include moving the articles along the arcuate path in one of two directions including clockwise and counterclockwise; the step of pivoting the at least one beam about the axis then preferably includes moving the at least one beam in the other of the two directions. The pivoting step can include repeatedly pivoting the at least one beam through one of a plurality of angles including at least 35° and at least 90°. The repeated pivoting can include directing the at least one beam against and through a plurality of discrete optical components having foci on a line which at last substantially coincides with the axis. The number of such discrete optical elements is at least two, preferably at least five. Such method can further comprise the step of temporarily turning off the at least one beam between repeated pivotings against and through the plurality of optical components.
The method can further comprise the step of imaging the at least one beam by at least one optical element while the at least one beam is being directed from the axis of the aforementioned path; the focus of such at least one optical element can be located on a line which at least substantially coincides with the axis. This method can also comprise the step of causing the at least one optical element to convert a pivotal movement of the at least one beam into a parallel shifting of such beam and the steps of focussing the parallel shifted beam upon a plurality of successive focal points located on the envelopes of articles advancing sideways along the arcuate path. The number of such focal points can be between two and five, and such focal points can be elongated. Still further, the just discussed embodiment of the method can comprise the step of temporarily turning off the at least one beam between the focussing steps.
The directing step of the improved method can include the aforementioned pivoting of the at least one beam about the axis of the path through a predetermined angle in a first direction from a starting position, and thereupon pivoting the at least one beam about the axis through the predetermined angle in a second direction counter to the first direction and back to the starting position. Such embodiment of the method can also comprise the step of temporarily turning off the at least one beam at least during pivoting in the second direction.
In accordance with a modification, the directing step includes repeatedly pivoting the at least one beam about the axis of the path through a predetermined angle which is sufficient to ensure perforation of the envelopes of first, third, etc. articles of the series during a first pivoting of the at least one beam and to perforate the envelopes of second, fourth, etc. articles during a next-following pivoting of the at least one beam.
If the directing step includes repeatedly pivoting the at least one beam about the axis of the path through a predetermined angle, such method can further comprise the step of focussing the diverted at least one beam upon the envelopes of alternate articles in the aforementioned path, particularly of focussing the at least one beam upon the envelopes of those articles in the path whose envelopes were not perforated during the preceding pivoting of the at least one beam. The focussing step can include resort to sets of lenses which are located in the path of the diverted beam.
The improved method can also include the step of focussing the diverted at least one beam upon the envelopes of articles in the path by way of a plurality of stationary lenses.
Still further, the improved method can include the steps of rotating the articles about their longitudinal axes through angles of at least 360° in the course of the diverting step, and focussing the at least one beam upon the articles while the articles rotate about their respective longitudinal axes. The rotating step can include turning the articles about their longitudinal axes through several revolutions.
The directing, deflecting and diverting steps can include resort to at least two beams, e.g., two laser beams furnished by a CO2 laser. The diverting step of such method can include propelling the at least two beams toward the envelopes of articles in the aforementioned path along discrete at least slightly convergent paths.
The at least one beam or at least one of several beams can have an at least substantially circular cross-sectional outline.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and the modes of assembling and utilizing the same, together with numerous additional important and advantageous features and attributes thereof, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawing.
The apparatus 1 comprises a drum-shaped carrier 6 which is arranged to rotate counterclockwise (as viewed in
The apparatus 1 further comprises a polygonal laser beam directing or orienting mirror 8 which serves to deflect (orient) two parallel pulsating laser beams 10a, 10b issuing from a suitable source 100, e.g., a CO2 laser of the type disclosed, for example, in commonly owned U.S. Pat. No. 4,889,140 granted Dec. 26, 1989 to Lorenzen et al. for “APPARATUS FOR MAKING PERFORATIONS IN ARTICLES OF THE TOBACCO PROCESSING INDUSTRY”. The mirror 8 has a plurality of facets 14 (
The CO2 laser 100 constitutes one presently preferred source of pulsating beams 10a and 10b.
The apparatus 1 of
Each of the cylinder lenses 18a to 18e cooperates with one of five stationary first beam deflecting means 20a to 20e each of which is a mirror inclined at an angle of 45° to the peripheral surface of the drum-shaped carrier 6 and spaced apart radially outwardly from such peripheral surface. The purpose of the first deflecting mirrors 20a to 20e is to deflect or direct the beams 10a, 10b in directions at least substantially parallel to the axis 4 and in such a way that the thus deflected beams are spaced apart radially outwardly from the peripheral surface of the carrier 6.
The beams 10a, 10b which are deflected by the first deflecting mirrors 20a to 20e respectively impinge upon and are deflected radially inwardly toward the articles 2 at the periphery of the carrier 6 by a second set of stationary deflecting mirrors 22a to 22j which are spaced apart from the mirrors 20a to 20e, as seen in the direction of the axis 4. The mirrors 22a to 22e serve to deflect the laser beam 10a radially (or at least substantially radially) inwardly toward the articles 2 on the rotating carrier 6, and the mirrors 22f to 22j perform a similar function in connection with the beam 10b.
The characters 24 denote in
The operation of the apparatus 1 which is shown in
The CO2 laser 100 (or an equivalent thereof) furnishes the laser beams 10a, 10b which impinge upon the stationary beam influencing cylinder lens 12 serving to focus the beams upon a line which coincides essentially with the axis 4 of the drum-shaped carrier 6.
That facet 14 of the polygonal directing or orienting mirror 8 which is located at the focus of the cylinder lens 12 projects the laser beams 10a, 10b upon one of the five optical components (cylinder lenses) 18a to 18e. In
Since the polygonal mirror 8 of
As already mentioned hereinbefore, the first deflecting mirrors 20a to 20e divert the laser beams 10a, 10b coming from the cylinder lenses 18a to 18e through angles of substantially 90° so that these beams propagate themselves radially outwardly of and in at least substantial parallelism with the axis of the drum-shaped article carrier 6. The beam 10a which is diverted by the first deflecting mirrors 20a to 20e impinges upon and is reoriented by the second deflecting mirrors 22a to 22e so that this beam advances at least substantially radially inwardly toward the articles 2 in the peripheral flutes of the carrier 6.
The beams 10a, 10b which are deflected by the mirrors 20a to 20e and thereupon by the mirrors 22a to 22e and 22f to 22j respectively advance radially inwardly toward the axis 4 and are focussed, by the spherical lenses 24, upon the external (peripheral) surfaces 2a of tubular wrappers forming part of the rod-shaped smokers' articles 2 which are advanced sideways by the carrier 6.
In the positions which the carrier 6, the mirror 8 and the articles 2 assume in
A perusal of
The angle at which the laser beam 10a of
When those parts of the apparatus 1 which are shown in
The laser beam 10a is thereupon further influenced by the cylinder lens 18b (as a result of angular movement of the polygonal mirror 8 and the conversion of such angular movement into a further parallel shifting of the beam by the cylinder lens 18b in a direction to the right, as viewed in
The article 2′ continues to move sideways (clockwise, as viewed in
The wrapper of the article 2′″ between the articles 2′ and 2″ shown in
The rod-shaped articles 2 are borne by the drum-shaped carrier 6 in such a way that they rotate about their respective longitudinal axes. This can be accomplished, by way of example, in a manner as disclosed and shown in German patent No. 35 101 19 C2 or in German patent No. 33 130 64 C2. Such rotary movements of the articles 2 relative to their carrier 6 ensure that a different section of the wrapper of each article is perforated while the laser beams are influenced by the spherical lenses 24a, 24b, 24c, 24d and 24e. The arrangement is preferably such that each of the articles 2 turns about its longitudinal axis through an angle at least approximating 360° (or a multiple thereof) during travel from the rotary supplying conveyor 5 to the rotary receiving or removing conveyor 7. All that counts is to ensure that each article 2 turns at least once about its longitudinal axis through an angle of at least close to 360° while it is being influenced by the laser beams 10a, 10b and while these beams are influenced by the lenses 24a to 24e. Such arrangement ensures that the perforations in the envelopes of all articles 2 form uniform patterns, e.g., at least in those portions of the envelopes which surround the filter mouthpieces. One such pattern is shown in
An important advantage of the improved method and apparatus is that they avoid numerous serious disadvantages of presently known methods and apparatus including those of known apparatus described in the preceding passages of this specification. For example, it is not necessary (even though often preferred) to roll the articles 2 at the periphery of the rotating carrier 6 about their respective longitudinal axes between such carrier and a stationary block or the like. A further apparatus which can be utilized to turn cigarettes or the like around their longitudinal axes while the articles travel with a rotary drum-shaped conveyor or carrier is disclosed in commonly owned U.S. Pat. No. 4,825,882 granted May 2, 1989 to Hinz for “APPARATUS FOR ROLLING UNITING BANDS AROUND GROUPS OF ROD-SHAPED ARTICLES”.
Furthermore, the improved apparatus can be utilized for the making of perforations in rod-shaped smokers' products of unit length or multiple unit length, for example, for the making of perforations in filter cigarettes of double unit length in the apparatus disclosed in commonly owned U.S. Pat. No. 5,135,008 granted Aug. 4, 1992 to Oesterling et al. for “METHOD OF AND APPARATUS FOR MAKING FILTER CIGARETTES”. This is made possible because the improved apparatus embodies means for directing one or more beams of suitable radiation radially or substantially radially inwardly toward the envelopes 2a of articles 2,2′, 2″, . . . at the periphery of the rotary carrier 6.
The feature that the rotating means 106, 108 are caused to turn the carrier 6 and the polygonal mirror 8 in opposite directions contributes to simplicity and reliability of the improved method.
An advantage of the lenses 18a to 18e is that they ensure that the beams 10a, 10b impinge upon the first stationary deflecting mirrors 20a to 20e so that such beams can be caused to propagate themselves radially outwardly of the carrier 6 and in substantial parallelism with the peripheral portion of such carrier. This ensures that the two beams 10a, 10b can be caused to advance along discrete paths, that their (preferably circular or slightly oval) cross-sectional outlines are best suited for the making of satisfactory perforations 30, as well as satisfactory polarization.
The positions of the stationary focussing lenses 24a to 24j are selected in such a way that they further ensure the making of satisfactory perforations 30 at optimal locations of the envelopes or wrappers of the articles 2, 2′, 2″, etc. The relationship between the cylinder lenses 12′ and 18a to 18e and other constituents of the improved apparatus 1 is preferably such that the parallel shifting of beams 10a, 10b which is effected by the lenses 18a to 18e enables the lenses 24a to 24j to effect the making of at least two but preferably five successive focal points. As already mentioned hereinbefore, the source 100 or another suitable part of the apparatus 1 interrupts the beams 10a, 10b between the focal points.
It is often desirable to select the relationship between the rotational speeds of the polygonal mirror 8 and of the drum-shaped carrier 6, the dimensions of the periphery of the carrier 6, the number of facets 14 on the mirror 8, the distances between neighboring articles 2, 2′, 2″, etc. as well as (if necessary) certain other parameters in such a way that, during each pivoting of a beam (e.g., the beam 10a) while it impinges upon one of the facets 14, perforations 30 are provided on the first, third, fifth, etc. articles of the series of articles on the carrier 6. The wrappers of the second, fourth, sixth, etc. articles are perforated during the next pivoting of such beam, i.e., by the next-following facet 14 of the polygonal mirror 8.
The just described relationship between the rotational speeds of the carrier 6 and mirror 8, the dimensions of the peripheral portion of the carrier 6 and other parameters is preferably such that the articles which are not perforated during a given pivoting of the beam (e.g., the beam boa) are perforated earliest at the start of the next pivoting of such beam and not later than upon arrival of the still not perforated articles into proper positions relative to the focussing lenses 24a to 24j) which were active in connection with the making of perforations in the envelopes of immediately preceding articles. The perforating operation upon a group of articles (such as 2, 2″, . . . and 21, 2′″, . . . ) should take place when the lenses 24a to 24j are in the process of focussing the beam or beams directly upon the envelopes or wrappers of the respective groups of articles.
The means for rotating the articles 2, 2′, 2″, etc. about their respective longitudinal axes while the articles advance with the carrier 6 is preferably designed in such a way that the perforating operation upon an article takes place while the latter turns through an angle of 360°, most preferably 3×360°, while such article is being supported by the carrier. The operation of the means for rotating the articles relative to the carrir 6 should be related to the operation of other component parts of the apparatus 1 in such a way that each beam is caused to turn about its axis of rotation through a pedetermined angle, such as the aforementioned angle of 360° or n×360° (wherein n is preferably three). This ensures that each of the selected focussing lenses 24a to 24j focusses the beam(s) upon different (predetermined) portions of the envelopes of the articles on the carrier 6. Such arrangement can ensure that the entire envelope (or a selected portion of each envelope) can be provided with uniformly or otherwise distributed perforations. The cross-sectional area of the beams 10a and/or 10b is or can be at least substantially circular. However, it is also possible, and often acceptable, to employ beams having an oval or substantially oval cross-sectional outline.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specific aspects of the above outlined contribution to the art of changing the permeability of envelopes of rod-shaped smokers' products and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 103 54 743.6 | Nov 2003 | DE | national |
