- The present invention pertains generally to methods and apparatus for tipping smoking articles, and pertains more especially to such methods and apparatus for tipping oval smoking articles. 
- In the manufacture of smoking articles, particularly cigarettes, it is conventional to make a continuous tobacco rod (a paper tube filled with shredded tobacco or tobacco substitute) and to cut the continuous rod to the length of individual cigarettes. A continuous rod of filter material is extruded and cut into lengths. The resulting filter plugs are collected in trays and placed in the hopper of a tipping machine, which cuts the filter plugs to twice the length of a single filter, joins each double-length filter plug to two filterless cigarettes, and severs the resulting assembly to form two complete cigarettes. 
- The filter plugs are gravity-fed from the hopper into flutes or grooves in the periphery of a rotating drum. The filter plugs are held in place in the flutes by means of vacuum suction exerted from the drum interior. The filter plugs can be passed from one such drum to another by proper timing of the rotations of the two drums, and by simultaneously deactivating the suction applied to a particular groove of the first drum as that groove comes face-to-face with a groove of the second drum. This permits a filter plug in the first flute to be pulled over into the opposing flute of the second drum by the suction applied to the latter. The filter plugs passed in this manner from one drum to another eventually are transferred to the flutes of a feed drum. In each flute two previously-deposited cigarette rods flank the filter plug end-to-end. 
- A web of cork or other tipping material is drawn from a roll thereof and has glue applied to one side. The web is cut off in lengths by cork knives, and one edge of each length is applied to a filter-plug-and-cigarette assembly is such a manner as to extend over the entire length of the filter plug and to overlie a small portion of each cigarette rod, the adhesive on the tipping material sticking to the plug and the rod. 
- The resulting double cigarette assembly is transferred to a rolling drum, beside which is a metallic rolling block. Each cigarette assembly is rolled along the rolling block by the drum. The rolling action wraps the tipping material around the cigarette assembly, to which it adheres as a result of the glue. Suitable heating elements in the rolling block commonly are used to cure the adhesive rapidly. 
- The double cigarette assembly is then transferred to a cutter drum, which moves the assembly past a disc knife that severs it into two complete cigarettes. The cigarettes are then inspected and moved to a discharge point, from which they are taken to another machine for packing. 
- The conventional tipping machine described above is designed to handle cigarettes of circular cross section. It would be desirable to be able to adapt a standard cigarette tipping machine for use in the rapid, economical large-scale manufacture of cigarettes having an oval cross section, which have hitherto largely been a luxury product reguiring special eguipment for virtually every stage of their manufacture. Various problems arise in making such an adaptation. 
- For example, it is difficult to transfer oval filter plugs from the hopper to a drum of the conventional type in such a manner that every flute will contain a filter plug and so that each filter plug will have the same predetermined orientation about its longitudinal axis (hereinafter, "angular orientation"). In addition, it has been found to be impossible, as a practical matter, to wrap tipping material around a cigarette assembly having an oval cross section, using standard tipping machine equipment. 
- EP 0 124 289 addresses the problem of tipping oval cigarettes, and provides a tipping machine comprising a rolling drum over the surface of which an assembly of oval tobacco rod, oval filter and tipping is rolled by contact with a pressure element adjacent a portion of the surface of the rolling drum, the pressure element rotating in the same angular direction as, but at a different angular speed to, the rolling drum. 
- Another problem arises when it is desired to use a standard tipping machine to wrap tipping material around an oval cigarette assembly having a circumference smaller than the circumference of a standard cigarette. The rolling drum of a standard tipping machine has a particular diameter and a particular number of flutes spaced evenly about its circumference for transferring cigarette assemblies on and off the drum. Each cigarette assembly rolls back two flutes along the drum circumference as tipping material is rolled around it. 
- The arc length along the drum circumference between flutes is not critical when rolling a circular cigarette, because the rolling distance, two flutes, for different circumference cigarettes is fixed. The number of revolutions necessary for rolling any given circumference circular cigarette two flutes can be controlled by varying the length of the rolling block. On one standard cigarette making machine, the distance between flutes is one-and-one-half times the circumference of a standard cigarette, so that a standard cigarette makes one-and-one-half revolutions as it rolls from flute to flute. If a circular cigarette having a smaller circumference is rolled on the machine, it will roll a greater number of times but, because it is circular, its angular orientation when it reaches the second and third flutes will be indistinguishable from that of a circular cigarette of any other circumference. 
- However, when tipping oval or other non-circular cigarettes, it is desirable to have all cigarettes in a particular angular orientation on the various drums (except while they are actually being rolled), especially at the transfer points between drums. One preferred orientation for all oval cigarette is that in which the major axis of the cross section of the cigarette is parallel to a line tangent to the drum surface at the point of contact between the drum and the cigarette. 
- If a cigarette has the circumference of a standard cigarette for which the machine was designed, it will make one-and-one-half revolutions as it rolls between flutes, even if it is oval. Assuming that it starts at the preferred angular orientation, it will finish at that orientation. However, if an oval cigarette has a circumference smaller than the standard circumference and it starts at the preferred angular orientation, it will finish at an angular orientation other than that which is desired. 
- This problem can be solved by making the rolling drum smaller to decrease the distance between the flutes while maintaining the same number of flutes, or by adding flutes to the drum. However, implementing either of these alternatives would require changing the size, location, and/or speed of rotation of some or all of the other drums in the machine. Further, additional flutes can only be added to the drum without changing its size in those cases where the ratio of the desired circumference to the standard circumference is equal to the ratio of the standard number of flutes to the desired number of flutes, so that the flutes can be spaced evenly about the drum. 
- It is therefore the principal object of the invention to provide a method and apparatus for applying tipping material to a filter plug and tobacco rod of oval cross section and wrapping the tipping material therearound, while rolling the cigarette assembly a predetermined number of times to maintain a desired angular orientation, regardless of the circumference of the cigarette, and so that a change in cigarette circumference can be accomplished simply by changing the rolling drum. 
- Another object of the invention is to achieve the foregoing objects in a manner which permits the ready and easy adaptation of existing tipping machines to the production of oval cigarettes of non-standard circumference. 
- According to the invention, there is provided a tipping machine for securing non-circular filter plugs to non-circular tobacco rods with an adhesive tipping sheet, the apparatus comprising: a rolling drum provided on its periphery with a plurality of uniformly spaced apart receiving plates each for receiving an assembly comprising non-circular filter plugs held in axial alignment with a non-circular rod by an edge of an adhesive tipping sheet; and a 1st pressure element adjacent the rolling drum defining a rolling path between the 1st pressure element and the rolling drum; characterised in that the rolling drum is also provided on its periphery with a plurality of uniformly spaced apart discharge flutes each discharge flute positioned at a pre-determined distance from a corresponding receiving flute, whereby by rotation of the rolling drum and the 1st pressure element in the same angular direction at different but angular speeds about the axis of the rolling drum, an assembly held in a receiving plate is caused to roll along the rolling path into a discharge flute counting the tipping sheet to become overlappingly wrapped around the filter plug and the tobacco rod to secure them together. 
- Preferably, the distance between adjacent discharge flutes is the same as the distance between adjacent receiving flutes. 
- According to the invention there is also provided a method for rolling a non-circular cigarette assembly including a tobacco rod and a filter plug joined by a piece of tipping material to overlapping wrap the tipping material around the cigarette assembly to secure the filter plug firmly to the tobacco rod, comprising the steps of: providing such a cigarette assembly at a feed point, with a first predetermined angular orientation to a receiving flute on a rolling drum, the peripheral surface thereof having a plurality of uniformly spaced-apart receiving flutes and a plurality of uniformly spaced-apart discharge flutes, the discharge flutes being distinct from the receiving flutes, the distance between adjacent discharge flutes being the same as the distance between adjacent receiving flutes; applying suction selectively from the interior of the drum exclusively to the receiving flutes in the region of the feed point; advancing the drum rotationally until the cigarette assembly contacts a first pressure element; deactivating the suction on the receiving flute; rotating the rolling drum in a first direction with a predetermined angular speed about the axis of the rolling drum; simultaneously moving the first pressure element generally parallel to the peripheral surface of the rolling drum with a second predetermined angular speed with respect to the axis of the drum the second angular speed being different from the first angular speed, to roll the cigarette assembly along the peripheral surface of the rolling drum from the receiving flute in which it is received toward the first discharge flute following the said receiving flute; advancing the rolling drum rotationally until the said cigarette assembly clears the first pressure element; applying suction selectively from the interior of the rolling drum exclusively to the discharge flutes in the region in which the said cigarette assembly clears the first pressure element; rotating the rolling drum until the said cigarette assembly reaches a transfer point; deactivating the suction on the said discharge flute; and transferring the said cigarette assembly to a transfer drum. 
- The selective application of suction is controlled by a vacuum valve within the rolling drum. The valve has at least one orifice in the first region which is located to communicate with a vacuum chamber within the valve and with ports leading exclusively to the receiving flutes as they pass through that region, and at least one orifice in the second region, which is located to communicate with the vacuum chamber within the valve and with ports leading exclusively to the discharge flutes as they pass through that region. Preferably, there is one orifice in fluid communication with the vacuum chamber and the ports leading to the receiving flutes and there are two narrow elongated orifices in fluid communication with the vacuum chamber and the ports leading to the discharge flutes. 
Brief Description of the Drawings- These and other objects and features of the invention are shown in the following detailed description of the preferred embodiment of the invention, taken in conjunction with the accompanying figures, in which like reference characters refer to like elements throughout, and in which: 
- FIG. 1 is a somewhat schematic elevational view of a tipping machine incorporating apparatus for carrying out the method of the invention; 
- FIG 2 is a detail of FIG. 1 showing the preferred embodiment of the apparatus for carrying out the method of the invention; 
- FIG. 2a is an elevational view of an alternate embodiment of the rolling drum of FIG. 2; 
- FIG. 3 is a section view of the rolling drum assembly of FIG. 2; 
- FIG. 4 is a section view of the rolling drum assembly taken from line 4-4 of FIG. 2; 
- FIG. 5a is an elevational view of the vacuum valve of the invention seen from the right side as shown in FIG. 1; and 
- FIG. 5b is an elevational view of the vacuum valve of the invention seen from the left side as shown in FIG. 1. 
Detailed Description of the Preferred Embodiment- A tipping machine incorporating the invention moves oval filter plugs from a hopper along a path on which they are cut to twice the length of a single filter and mated end to end with oval filterless cigarettes supplied from a cigarette maker, in a predetermined orientation. Tipping material in sheet form, such as cork or tipping paper, is drawn from a roll and has an adhesive applied to one side of it. The tipping material is then cut into lengths, or patches, each of which is attached to an assembly comprising two filterless cigarettes abutting a double-length filter plug between them end-to-end. The rolling drum assembly of the present invention is used to wrap the patch of tipping material around the oval cigarette assembly, firmly securing the filter plug to the tobacco rods. The cigarette assembly is then cut into two oval cigarettes and delivered to the output point of the tipping machine to be transported to the next work station. 
- FIG. 1 shows an overview of such atipping machine 10. The tippingmachine 10 has ahopper 12 in which filter plugs two, four times or six times as long as needed for one cigarette are received. Adjacent the bottom opening of thehopper 12, on one side, is a continuous belt 14 mounted on tworollers 16, 18, which drive the belt 14 so as to feed filter plugs downward toward the bottom opening of thehopper 12. 
- Aplug drum 20, described in detail in copending application Serial No. 480,809, is mounted for rotation about a horizontal axis below the bottom opening of thehopper 12. Theplug drum 20 has evenly spaced flutes (not shown) around its circumference and includes a conventional mechanism in its interior for applying vacuum suction to selected flutes. As the filter plugs reach the bottom of thehopper 12, each is received in a flute on theplug drum 20 and is held there by means of suction. The rotation of thedrum 20 carries the plug out of thehopper 12. To prevent filter plugs not firmly seated in flutes from leaving thehopper 12, a refuser roller 24 is disposed adjacent the hopper opening on the side toward which the filter plugs move as they leave the hopper, i.e., the side opposite the feeder belt 14. The refuser roller 24 rotates in such a direction as to tend to knock filter plugs back into the hopper 12 (clockwise in FIG. 1), and is spaced from theplug drum 20 such a distance that a filter plug seated in a flute will clear the refuser roller 24 while a filter plug lying on the periphery of the drum and not in a flute will be kept in thehopper 12 by the refuser roller 24. 
- Adjacent theplug drum 20 are twoslitter disc knives 26, 28 mounted for rotation about respective horizontal axes. Theknives 26, 28 are positioned so as to cut each filter plug into three segments of equal length. (If the filter plugs in thehopper 12 are only four times the length of one filter, only one of the two slitter knives shown is needed). Grindingwheels 30, 32 adjacent eachslitter disc 26, 28 sharpen the knives. 
- Each double length filter plug is transferred from theplug drum 20 to agrading drum 34, which staggers the two or three filter plugs cut from one original plug. Two guide blocks 36, 38 between theplug drum 20 and thegrading drum 34 are used to give each oval filter plug the same angular orientation, as disclosed in detail in copending application Serial No. 480,809. After staggering the plugs, thegrading drum 34 transfers them in a known manner to a shiftingdrum 40, where vacuum suction is used in known manner to draw each filter plug toward the middle portion of the surface of thedrum 40, thus combining the two or three staggered parallel series of filter plugs into a single series. The filter plugs are then transferred in the known manner to an acceleratingdrum 42, which accelerates them to the desired speed and passes them conventionally to the feed drum 44. 
- At the same time, oval tobacco rods cut to the length of individual cigarettes are received from a cigarette maker. The maker feeds the filterless tobacco rods individually in staggered relationship, longitudinally onto a take-off drum 46. The single-length filterless tobacco rods then pass in the known way to the grading drums 48, where the individual tobacco rods are transferred to permit alignment for transfer to the feed drum 44. The grading drums 48 then transfer them in a known fashion or manner to the feed drum 44, on which the filter plugs are placed in the manner described. The resulting combination of filter plug and tobacco rods is moved to theswashplate drum 50, on which the tobacco rods are moved toward each other so that they abut the filter plug end-to-end. While on thisdrum 50, the resulting double cigarette assembly (the combination of double length filter plug and tobacco rods) receives a piece of adhesive-coated tipping material. 
- The tipping material is supplied in the following known manner. Aroll 52 of tipping material is mounted for rotation about a horizontal axis. (Two rolls 52 are shown. As one is used up, the second is spliced to the first.) the material is pulled from theroll 52 and is led along a path defined byvarious rollers 54, past abath 56 of adhesive, which is preferably heat-activatable. Aroller 58 partially immersed in thebath 56 and rotating about a horizontal axis coats anadjacent applicator roller 60 with adhesive. The tipping material web is passed along the surface of theapplicator roller 60 so that one surface of the web is coated with the adhesive. The tipping material is then transported to thecork drum 62, which serves as a platen to permit the tipping material, held against thedrum 62 by suction, to be cut into lengths by means of knives 64 mounted on a rotating knife drum 66. Rotary brushes 68, 70 adjacent the cork knife drum 66 remove debris, dust and the like from the cork knives 64. 
- The rotation of thecork drum 62 brings each patch of tipping material (not shown), with the adhesive side exposed, into contact with a cigarette assembly on theswashplate drum 50. The cork drum suction on the tipping material is terminated at the moment of contact with the cigarette assembly, to which the adhesive sticks. The material contacts and adheres to the assembly along a single line, and extends from the assembly like a tab (not shown). The tipping material is then wrapped around the assembly by the rollingdrum 71 of the invention, as described below. 
- After completion of the wrapping process, the cigarette assemblies are passed to atransfer drum 72 and thence to a cutting drum 74 adjacent which is aslitter disc knife 76. Theslitter knife 76 cuts each double cigarette assembly into two cigarettes. A grinder wheel 78 adjacent theslitter disc knife 76 maintains its sharpness. The cigarettes are then moved by an additional transfer drum 80 to a turning drum 82, which reverses one of the two parallel mirror-image series of cigarettes so that all the cigarettes have the same orientation. The cigarettes proceed to an inspection drum 84, thence to an ejection drum 86 that removes any cigarette identified as defective, and finally to acatcher drum 88 that places the remaining cigarettes on twocatcher belts 90 to be taken to the next machine. Aguide wheel 92 above thebelts 90 decelerates the cigarettes as they are placed on thebelts 90. 
- FIG. 2 shows the apparatus of the invention in greater detail. Abelt 94 runs overrollers 96, 98, 100 and 102. In the absence ofcigarette assemblies 104 around the periphery ofdrum 71,belt 94 rests againstdrum 71. 
- On a standard cigarette tipping machine, drum 71 might have 22 flutes spaced evenly around the circumference. Each flute would be spaced 37.2 mm from the next, which is one-and-one-half times the standard cigarette circumference of 24.8 mm. 
- In order to produce non-circular cigarettes of smaller circumferences, drum 71 of this invention has two distinct sets of flutes which are offset from each other. Receivingflutes 106 are each 37.2 mm from each other, as are discharge flutes 108. The two sets offlutes 106, 108 are in turn offset from each other by a distance Q, which is one-and-one-half times the circumference of the cigarettes to be tipped. Although the distance Q in FIG. 2 is such that thedischarge flute 108 of eachflute pair 106, 108 is immediately adjacent the receivingflute 106 of thenext flute pair 106, 108, FIG. 2a shows that if a cigarette with a still smaller circumference is desired, theflutes 106, 108 of each pair can be separated by a smaller distance Qʹ, so that thedischarge flute 108 of one flute pair is further from the receivingflute 106 of the next pair. However, the size ofdrum 71 is the same in FIGS. 2 and 2a, and each receiving flute is separated from its adjacent receiving flutes by 37.2 mm, as is each discharge flute from its adjacent discharge flutes, in both figures. 
- In operation,swashplate drum 50, rollingdrum 71 andtransfer drum 72 rotate as shown by the arrows in FIG. 2.Belt 94 is driven byroller 102 in the same direction as the surface ofdrum 71, but at a slightly slower angular speed, so that an object betweenbelt 94 anddrum 71 will roll counterclockwise along the surface ofdrum 71 while it is being advanced clockwise by the rotation of the drum. Suction is applied from withindrum 71 to those receivingflutes 106 which are present in the region betweenswashplate drum 50 androller 96, but not to the discharge flutes 108 in that region. Similarly, suction is applied to those discharge flutes 108 which are present in the region betweenroller 102 and transferdrum 72, but not to the receivingflutes 106 in that region. No suction is applied to any flutes in other regions ofdrum 71. The reason for this selective application of suction, and the valve system by which it is accomplished, will be described below in connection with FIGS. 3-5b. 
- Cigarette assemblies 104 are aligned in flutes (not shown) onswashplate drum 50 such that the major axis of the cross section of each is parallel to a line tangent to drum 50 at the point where thecigarette assembly 104 meets thedrum 50. At the point where eachassembly 104 is transferred fromswashplate drum 50 to rollingdrum 71, the same relationship exists between the major axis of the cross section of theassembly 104 and a line tangent to drum 71. Eachassembly 104 is held in its respective flute by suction. At the transfer point, the suction on the flute ondrum 50 is deactivated and suction is applied to receivingflute 106 ofdrum 71. 
- Thecigarette assembly 104 remains aligned in receivingflute 106 until the rotation ofdrum 71 brings it to the nip betweenroller 96 anddrum 71. Theassembly 104 enters betweenbelt 94 anddrum 71. The suction on receivingflute 106 is deactivated, which allowscigarette assembly 104, while continuing to advance, to roll backwards along the surface ofdrum 71, as described above, towarddischarge flute 108. This rolling motion wraps the piece of tipping material around theassembly 104. Niproller 110, which is adjustably positioned inradial slot 112, is positioned so that thecigarette assembly 104 passes between it and drum 71 after theassembly 104 has rolled 360°, so that niproller 110 can exert pressure along the tipping material overlap seam to seal it.Assembly 104 continues to roll backwards as it advances, completing 540°, or one-and-one-half full revolutions, by the time it reachesdrive roller 102, at which point it has rolled into thefirst discharge flute 108 following the receivingflute 106 in which it started, and is at the desired angular orientation. Suction is applied to dischargeflute 108 at that point and holdscigarette assembly 104 in place in theflute 108 until theassembly 104 is transferred to transferdrum 72, at which point the suction ondischarge flute 108 is deactivated, and suction is applied to a flute (not shown) ondrum 72. 
- By substituting a rolling drum made according to the present invention for the standard drum of a cigarette machine, an oval or any other non-circular rounded cigarette having any desired circumference less than or equal to the standard circumference can be made by choosing the offset distance Q properly. 
- Suction is applied selectively toflutes 106, 108 as follows: No suction is applied to the flutes in the arc betweendrums 72 and 50, where nocigarette assemblies 104 are present. Suction is also not applied to the arc betweenrollers 96 and 102 because thecigarette assemblies 104 are held againstdrum 71 bybelt 94, and because in the absence of cigarette assemblies between thedrum 71 and thebelt 94, the belt would be sucked against the drum, causing it to overridedrive roller 102. In the arc betweenswashplate drum 50 androller 96, suction is applied only to receivingflutes 106. This is done because cigarette assemblies are present only in those flutes in that arc. If suction were applied to dischargeflutes 108 in that arc, there would be a loss of vacuum in the vacuum system because the discharge flutes 108 in that arc are open to the atmosphere, and there would also be a possibility that some of the cigarette assemblies would fall from thedrum 71 at production speed. For the same reasons, in the arc betweenroller 102 and transferdrum 72, suction is applied only to dischargeflutes 108 and not to receivingflutes 106. 
- The vacuum valve system for applying suction selectively as explained above is described with reference to FIGS. 3-5b. 
- Suction ports 114 and 116 extend from receivingflutes 106 and dischargeflutes 108, respectively, to theinterior 118 ofdrum 71. As can be seen in FIG. 4, each flute has a pair of suction ports, one for each half of adouble cigarette assembly 104. 
- Withindrum 71 is acylindrical vacuum valve 120, connected at 122 to a source of vacuum (not shown).Valve 120 is a hollow cylinder, enclosing avacuum chamber 124. In the arc betweenswashplate drum 50 androller 96,valve 120 has a receivingflute suction orifice 126 in its cylindrical wall. Receivingflute suction orifice 126 is positioned and dimensioned to that receivingflute suction ports 114 pass over it, but dischargeflute ports 116 do not, thereby applying suction only to the receivingflutes 106 in the arc betweenswashplate drum 50 androller 96. In the arc betweenroller 102 and transferdrum 72,valve 120 has two narrow, elongated dischargeflute suction orifices 128 in its cylindrical wall. Dischargeflute suction orifices 128 are positioned and dimensioned so that dischargeflute suction ports 116 pass over them, but receivingflute ports 114 do not, thereby applying suction only to the discharge flutes 108 in the arc betweenroller 102 and transferdrum 72. As shown in FIG. 4, receivingflute suction ports 114 are bored at an angle to increase the separation distance between them and dischargeflute suction ports 116 on the inner surface ofdrum 71. This is necessary because although the clearance between the inner surface ofdrum 71 and the outer surface ofvalve 120 is sufficient to allow thedrum 71 to rotate freely about thevalve 120, it is not small enough to prevent bleed-over of vacuum betweenports 114 andports 116. 
- The present invention thus enables the production of non-circular cigarettes having any circumference smaller than the circumference of a standard cigarette by providing separate receiving and discharge flutes on the rolling drum of a standard cigarette machine, and a vacuum system for selectively applying suction to desired sets of flutes. 
- With the present invention, it has been found possible to wrap oval cigarettes at rates (up to 5,000 cigarettes per minute) comparable to those attained with round cigarettes using conventional machinery. 
- Although the invention has been particularly described with reference to the preferred embodiments thereof, many modifications and variations thereof will now be apparent to those skilled in the art. Accordingly, the scope of the invention is to be determined not by the details of the illustrated embodiment described herein, but only by the terms of the appended claims.