GB2294626A - Twin -track cigarette making machine comprising two horizontal channels showering tobacco on to two converging suction bands - Google Patents

Description

1 Cigarette Makinq Machine 2 3 4 5 6 7 8 9 11 12 13 14 16 18 19 22 23 24

26 27 28 29 34 36 37 38 2294626 Cigarette making machines have conventionally for many years operated by forming a continuous cigarette rod comprising tobacco and/or other filler material (referred to here simply as'lobacco") enclosed in a continuous paper wrapper. This rod is then cut at regular intervals to produce separate rod lengths, comprising individual cigarette lengths or multiple cigarette lengths, which are commonly delivered by the cigarette maker to a filter attachment machine, the ultimate product therefore being a filter-tipped cigarette.

In recent years there have been proposals for increasing a cigarette maker output by dividing the tobacco output from the tobacco hopper so as to feed tobacco to two rod-forming devices arranged to form two parallel continuous rods, each of these being cut at regular intervals to produce separate rod lengths which are fed to a common filter attachment machine. A cigarette maker of this general type will be referred to as a"twin track maker". The present invention is concerned with improvements relating to twin track makers.

According to one aspect of this invention, a twin track cigarette maker comprises two substantially horizontal shower channels through which tobacco is arranged to be showered onto two suction bands moving in converging directions in a substantially horizontal plane and presenting substantially vertical tobacco-receiving surfaces so as to form a cigarette filler stream on each of the suction bands, and including means for enclosing each of the filler streams (possibly after trimming) in a continuous wrapper web to form two parallel cigarette rods.

Preferably the filler stream formed on each suction band is received by a further suction band arranged to carry the filler stream on its underneath surface and into a garniture, which may be in a conventional form, by which the filler stream is enclosed in the wrapper web. Alternatively, the converging suction bands may, after the filler stream have been formed on them, pass around pulleys by which the directions of movement of the bands are made parallel, and each band may then be constrained to twist through approximately 90 degrees before returning around a further pulley, so that the twisting of each band results in the filler stream being carried on an underneath surface of the band whereby the filler stream can be delivered directly into the garniture by the same band, thus eliminating the need for a further 1 2 3 4 5 11 12 13 14 16 17 18 19 21 22 23 24 26 27 suction band for each track.

In a preferred arrangement according to the first aspect of this invention, the two shower channels are spaced apart and at least part of the hopper by which tobacco is delivered to the shower channels extends downwards between the shower channels. The tobacco delivered through this part of the hopper is preferably metered at a level below the shower channels, and is then fed into a pair of upwardly extending shower channels communicating with the horizontal shower channels leading to the converging suction bands. Such an arrangement, especially in the preferred form described below with reference to the accompanying drawings, lends itself to convenient access by the operator to at least some parts of the machine to which access is frequently required.

According to a second aspect of this invention, which may be used in combination with the first aspect of this invention, control as between the two tracks in a twin track maker is separated so that each track can operate independently of the other and so that, while both are operating, different control parameters can be applied to the two tracks so that, if desired, different brands of cigarettes can be made on the two tracks. For the last-mentioned purpose, the filter attachment machine is preferably also constructed on a twin-track basis, instead of the cigarette rods from the two tracks being merged, as hitherto, so as to pass through the filter attachment machine along a common track. The two filter assembly tracks may be adjacent to one another or may extend in opposite directions from the position at which the cigarette rod lengths are received by the filter attachment machine.

Examples of twin track cigarette making machines according to 28 this invention are shown in the accompanying drawings. In these 29 drawings:

Figure 1 is a diagrammatic plan view (partly sectioned) of part of one machine; Figure 2 is a diagrammatic elevation of part of the machine shown n Figure 1, again partly sectioned; Figure 3 is an end view of part of a modified machine, equivalent to a view from the right of Figure 2; Figure 4 is a section on the line A - A in Figure 1; Figure 5 shows a modification, on a larger scale, of part of the machine shown in Figure 1; 31 32 33 34 36 37 38 3 1 2 3 4 6 7 11 12 13 14 is 16 17 18 19 21 22 23 24 26 27 28 29 31 32 33 34 35 36 37 38 Figure 6 is a plan view of half of another modified machine; Figure 7 is a section on the line B - B in Figure 6 showing both halves of the machine; Figure 8 is a plan view, similar to Figure 1, of another modified machine; and Figure 9 is an end view of an arrangement for transferring cigarette rods to the filter attachment machine.

The machine shown in Figure 1 comprises two horizontal shower channels 310 and 312 defined by upper walls 31 OA,312A and lower walls 31 OB,312B and by side walls 31 0Q31 OID,312C,3121D. The centre lines of the two channels are parallel and are spaced apart so that there is a gap between the inner side walls 31 OD and 312D. A part 314 of the cigarette maker hopper extends downwards between the shower channels, as shown in Figure 1.

Tobacco showered through the shower channels 310 and 312 arrives respectively on suction bands 316 and 318 which lie in a common horizontal plane and converge towards one another at an angle such that the tobacco showered through each of the channels 310 and 312 approaches the bands 316 and 318 in a direction (or average direction) having a significant component in the direction of movement of the bands 316,318. The bands 316,318 pass around pulleys 316A,316B and 318A,318B respectively. Further suction bands 320 and 322 moving at the same speed as the bands 316,318 and located above the bands 316,318 (i.e. overhead) receive the filler streams from the bands 316 and 318 and carry them on their underneath surfaces into a pair of conventional garnitures (not shown) in which the filler streams are enclosed in paper wrappers to form two parallel continuous cigarette rods which may be cut at regular intervals by a common rotary cut-off device while being supported by a common ledger, the rods being close enough for that purpose.

Before being transferred to the overhead bands 320 and 322, the filler streams formed on the converging bands 316,318 may be trimmed by trimming devices 324 as shown in Figure 1. Alternatively, or in addition, the filler streams may be trimmed while being carried by the overhead bands 320,322. Another possibility is that provision may be made for redistributing tobacco from generally high (thick) areas to low areas while each filler stream is being carried beyond the wall 31 OID,312D of the corresponding shower channel to the point at which it 4 1 2 3 11 12 13 is 17 19 21 22 23 24 26 27 28 29 31 32 33 34 36 37 38 is received by the overhead band 320,322; such an arrangement may be as described below with reference to Figure 6 or more generally as described in our French patent application No. 9413327 (or British patent application No. 9422581.0).

The hopper by which tobacco is metered and fed into the shower channels 310,312 is essentially in two similar parts for feeding the respective shower channels. Each of these parts will be referred to as a hopper in its own right and is separately controllable. As shown in Figure 1, the combined part 314 which passes downwards between the shower channels is divided by a wall 314A into channels 314B and 314C of equal size.

Each hopper comprises a tobacco reservoir 328 (Figure 2) from which tobacco is metered and fed downwards by means of three pin-carrying rollers 330, 332 and 334 rotating in the directions shown in Figure 2. As a result, tobacco fed by the rollers slides down an inclined wall 336 and is then transported by a carded drum 340. A tobacco roll 338 is produced between the drum 340 and a refuser drum 342, as a result of which the drum 340 carries a metered carpet of tobacco from the roll 338 and towards a picker roller 344 which removes the tobacco from the drum 310 and projects it horizontally along a guide surface 346, past a perforated block 348 and below a perforated drum 350. Air is blown upwards through the block 348, while at the same time the interior space in the drum 350 communicates with suction so as to induce upward air currents through the tobacco. These currents deflect lighter particles of tobacco upwards into a channel 352, while heavier particles or pieces of stem continue horizontally and drop into a winnowing device 354. The arrangement in the region of the perforated block 348 and winnowing device may be similar to that used in the past in conventional Molins machines, for example as described in U.S. patent No. 3,092,117.

Tobacco carried up into the channel 352 continues into the channel 310 in this half of the machine, the channels 352 and 310 being joined by a curved channel portion 356.

The resulting position of the winnower 354 allows convenient access for the machine operator since it is or may be at the extreme right-hand end of the machine.

Tobacco may be delivered into the reservoir 328 in any convenient way. Figure 2 shows, by way of example, a conveyor band 358 by which a thick carpet 360 of tobacco is fed into the reservoir 328 1 2 3 4 6 7 a 9 13 16 21 22 23 24 26 27 28 29 34 36 37 38 whenever the level of tobacco in the reservoir drops below a photocell detector 362.

It will be understood that the tobacco passing down the inclined wall 336 must also move laterally since the carded drum 340 and all subsequent components of this half of the machine are horizontally aligned with the shower channel 310. For this purpose, the wall 336 has guide vanes 337 or alternatively may be replaced by a series of separate downwardly extending ducts through which portions of the delivered tobacco can be delivered downwards and laterally.

In the event of tobacco choking one of the shower channels 310,312 part of the lower wall 31 OB or 312B in the region below the rollers 330,332, 334 may be arranged to swing downwards to drop the tobacco onto the wall 336 so as to assist in clearing the choke and to recirculate and thus not waste the tobacco.

Figure 3 illustrates a slightly modified overall configuration of the tobacco feed towards each of the carded drums 340. In particular it shows diverging ducts 364 and 366 through which tobacco for the two carded drums 340 is fed. These ducts extend downwards from the separate channel portions 314B and 314C. Each of the ducts 364 and 366 may be subdivided into a number of thinner ducts, or may include guide vanes 368 mounted on the equivalent to the wall 336 in Figure 2; only two guide vanes 368 are shown in each duct by way of example, but there are preferably more.

Figure 3 illustrates an arrangement in which not all of the hopper-fed tobacco passes between the shower channels 310 and 312. By way of example, Figure 3 illustrates an arrangement in which approximately two thirds of the tobacco is fed to each drum 340 via the duct 364 or 366. The remainder is fed via a downwardly extending duct 370 lying on the outside of the corresponding shower channel. Each of the ducts 370 may also be subdivided into a number of narrower ducts, or may have guide vanes for guiding streams of tobacco in the desired manner. In Figure 3 the ducts 370 are shown to be narrower than the ducts 314B,314C; they may alternatively be similar in width so that the ducts 370 feed, for example, half the total tobacco supplied by the hopper.

The tobacco (or other material) fed through the ducts 370 may be different from that fed through the ducts 364,366. For example, the following may apply: tobacco received by the cigarette making machine 6 1 2 3 4 5 6 7 11 12 14 16 17 19 21 22 23 24 26 27 28 32 33 37 is separated into two streams comprising respectively longer and shorter particles of tobacco; the longer tobacco is then fed through the ducts 364,366, while the shorter tobacco is fed through the ducts 370 so that it will form initial layers on the bands 316,318 and will not be removed and thus further broken by the trimming devices 324. Separation of the tobacco for this purpose may be achieved in the manner described in our U. S. patent No. 5,018,538.

Figure 4 illustrates a possible cross-section on the line A-A in Figure 1. It shows the band 316 presenting a vertical face on which tobacco showered through the duct 310 has accumulated to form a filler stream identified as 372. Upon transfer to the overhead band 320, the cross- section of the filler stream 372 changes to that shown by the outline 374. Since the tobacco stream 372 formed on the band 316 is relatively thin (measured in the direction normal to the surface of the band), it is possible to cause tobacco from relatively high portions (measured horizontally) to be redistributed into areas which are relatively thin, as described below with reference to Figure 6, by inducing air to flow along and in the same direction as the tobacco stream 372. This redistribution arrangement may obviate the need for the trimmers 324 adjacent to the bands 316 and 318, but trimmers may alternatively be applied to the tobacco streams while they are being carried by the overhead suction bands 320 and 322.

For the purpose of achieving a useful degree of redistribution the width of the filler stream 372 on the band 316 is preferably at least three times or, better still, at least four times the depth of the filler stream: for example, 18mm and approximately 4mm respectively.

Furthermore, in transferring from the band 316 to the band 320, and by virtue of the change of cross-section which results from the widths of the bands and the positions of side rails (not shown) confining the sides of the tobacco, the tobacco is reorientated; this is believed to improve the filling power of the tobacco in the finished cigarettes, as described in our U.S. patent No. 5,370,136.

As already mentioned, each of the hoppers supplying tobacco to form the two rods is preferably independently controlled. For that purpose, there is preferably independent control (as between the two hoppers) with respect to the initial feeds provided by the conveyors 358, with respect to each set of feed rollers 330,332,334, and also with respect to the speed of each carded drum 340 which determines the 7 1 2 3 4 5 6 7 8 9 10 11 12 13 14 is 18 19 21 22 24 25 29 31 32 33 34 rate at which tobacco is metered into the corresponding shower channel. Thus each hopper operates as though it is an independent single-track machine. This enables thefeed rate to be optimised in response, for example, to a signal representing the rate at which tobacco is removed by the trimmer for the corresponding track in response to the usual rod weight scanning device (commonly a neucleonic device) to produce the desired cigarette rod weight per unit length. Also, it should be appreciated that different tobacco blends can in fact be fed into the two hoppers to produce different cigarettes. Moreover, if only one track is required to be run at any given time, then that can readily be achieved.

Various of the drives in each track are preferably provided by independent electronically controlled motors.

Figure 5 shows a possible modification whereby a band 376 (equivalent to the band 316) is guided around a relatively large-radius guide member 378 instead of the pulley 31613. A similar arrangement applies in place of the band 318. Suction applied through the member 378 (as shown by the arrows) tends to hold the cigarette filler stream on the band against centrifugal force, but allows outer tobacco particles in thicker areas of the filler stream to be carried forward, faster than the filler stream as a whole, by air admitted between parallel vanes 380. After passing around the guide member 378, the band 376 (in the region 382) moves in a direction parallel to the overhead band (not shown) and parallel to the vanes 380, before returning around a pulley (not shown).

While the band is moving parallel to the top band, tobacco carried forward by the air streams admitted between the vanes tends to settle on shallower areas of the tobacco filler stream, giving the redistribution effect described above, before the entire filler stream is released by the band 376 and is then drawn upwards onto the overhead band.

The application of suction to the band 376 may be such that the tobacco, when transferring to the overhead band, is released progressively from the band 376, starting with tobacco closest to the overhead band.

Each overhead band may have regularly spaced regions of higher porosity so that the tobacco attracted by suction to those regions, corresponding to the end portions of the cigarettes, is at a greater 36 density than elsewhere.

37 38 Figure 6 is a plan view of half of a different form of machine.

Tobacco in this example is showered substantially horizontally through a 8 1 2 3 4 5 6 7 11 12 13 14 16 17 18 19 21 22 23 24 26 27 28 29 31 32 33 34 36 37 shower channel 200 to form a wide but shallow filler stream on a suction band 202 passing around pulleys 204 and 206 which have substantially vertical axes of rotation. The machine includes a redistribution area 208 (as described in our above-mentioned patent application) in which suction- induced air streams flow in between inclined vanes 208 and cause air to flow along and in the same direction as the filler stream on the band 202; this tends to cause tobacco from relatively high areas in the filler stream to be distributed into lower areas. The filler stream is then transferred to a narrow overhead suction band 210 which carries the filler stream onto the wrapper web (not shown). While being carried by the band 210, the filler stream may be trimmed.

Figure 7 illustrates the change of filler stream cross-section in the region of the transfer from the band 202 to the band 210. As shown in Figure 7, the band 202 is vertically orientated in cross-section and carries a wide but shallow filler stream 212. This transforms into a narrower but deeper filler stream on the band 210 of which an approximate outline 214 is shown.

Figure 7 also shows a second wide band 216 for forming a filler stream 218 which is transferred to a second overhead band 220 to form a second cigarette rod parallel to the first rod. The arrangement for this purpose, in plan view, would be substantially a mirror image of that shown in Figure 6.

Figure 8 is a plan view of a machine partly similar to that shown in Figure 1, the same reference numerals being used for identical parts. In this example each of the suction bands 31Cand 318'continues to carry the corresponding filler stream beyond the pulley 31613,31813 and then twists through 90 degrees so as to end up carrying the filler stream on a bottom surface of the band. The bands then pass around pulleys having a horizontal axis of rotation 319 before returning to the pulleys 316A,318A. Thus the bands 31C,318' can deposit the filler streams directly onto wrapper webs (not shown) in the region of the pulley centred on the axis 319 to form two parallel cigarette rods moving in the direction of the parallel arrows as indicated.

The transfer of cigarette rod lengths (or double cigarette lengths) from each of the tracks may be achieved in the manner illustrated in Figure 9.

Cigarette rods 400 and 402 produced by the two tracks of the 38 machineare received respectively by fluted drums 404 and 406.

9 1 7 9 11 13 14 is 16 17 18 19 21 22 24 26 27 28 29 31 32 33 34 36 37 38 Associated with each fluted drum is an accelerator cam 408 which has suction ports for accelerating each rod in turn, and at the same time deflects each rod upwards by virtue of a cam action. The fluted drums 404 and 406 rotate in opposite directions and transfer the rods to respective further fluted drums 410 and 412. The drum 410 in turn transfers the rods arriving on it to the drum 412, and the rods are then all received by a further fluted drum 414 forming part of the filter attachment machine.

This arrangement can be used for a single-track filter attachment machine or alternatively for a twin-track machine. In the first example, the flutes of the drums 404 and 410 are positioned and timed so as to deliver rods 400 into flutes between rods 402 already received on the drum 412; for this purpose the two accelerator cams 408 may be adjacent to one another. The alternative of a twin-track filter attachment machine can be satisfied by offsetting the positions of the two cams 406 in the direction of the axes of the rods 400 and 402, so that the rods are delivered to the drums 404 and 406 with their centres in different vertical but parallel planes which will form the planes of the respective separate tracks in the filter attachment machine; for this purpose it will be understood that the drum 412 (as also the drum 414) would be at least twice as long as each of the drums 404, 406 and 410, and that the drums 404 and 410 would lie with their centres in the appropriate plane offset from that of the drum 406.

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Claims (20)

Claims:

1. A twin track cigarette making machine comprising two substantially horizontal shower channels through which tobacco is arranged to be showered onto two suction bands moving in converging directions in a substantially horizontal plane and presenting substantially vertical tobacco-receiving surfaces so as to form a cigarette filler stream on each of the suction bands, and including means for enclosing each of the filler streams (possibly after trimming) in a continuous wrapper web to form two parallel cigarette rods.

2. A machine according to claim 1, in which the filler stream formed on each suction band is received by a further suction band arranged to carry the filler stream on its underneath surface and into a rod forming device by which the filler stream is enclosed in the wrapper web.

3. A machine according to claim 1 or claim 2, in which the two shower channels are spaced apart and at least part of a hopper by which tobacco is delivered to the shower channels extends downwards between the shower channels.

4. A machine according to claim 3, in which the tobacco delivered through the said part of the hopper is arranged to be metered at a level below the shower channels, and is then fed into a pair of upwardly extending shower channels communicating with the horizontal shower channels leading to the first-mentioned suction bands.

5. A machine according to any one of claims 2 to 4, in which each of the first-mentioned suction bands is arranged to form and carry a cigarette filler stream which is substantially wider than its depth, and in which each filler stream becomes deeper and less wide on transferring to the corresponding further conveyor.

6. A machine according to claim 5, including means for inducing an air flow along each filler stream while being carried by one of the firstmentioned suction bands, whereby tobacco from peaks in the filler stream tends to be carried forward and to be attracted to the suction 11 1 2 3 bands by suction drawn through the band in regions of less tobacco.

7. A machine according to claim 6, in which the width of each 4 filler stream on the corresponding first-mentioned suction band is at least twice the average depth of the filler stream.

6 7

8 9 11 12 13 14 is 21 22 23 24 26 27 28 31 32 33 34 36 37 38 8. A machine according to claim 7, in which the width of each filler stream on the corresponding first-mentioned suction band is at least three times the average depth of the filler stream.

9. A machine according to claim 8, in which the width of each filler stream on the corresponding first-mentioned suction bands is at least four times the average depth of the filler stream.

10. A machine according to any one of claims 6 to 9, in which air forming the air flow along each filler stream is drawn through inclined vanes or other means whereby it enters a space adjacent to the filler stream with a component of motion in the direction of movement of the corresponding band.

11. A machine according to anyone of claims 2 to 10, in which each of the further bands has regularly spaced regions of higher porosity so that the tobacco attracted by suction to those regions, corresponding to the end portions of the cigarettes, is at a greater density than elsewhere.

12. A machine according to any one of claims 2 to 11, in which each of the first-mentioned suction bands moves along a curved path bringing the two bands into parallel paths before the filler streams are transferred to the further suction bands.

13. A machine according to claim 12, in which the radius of each curved path and an amount of suction drawn through each band as it moves along the curved path are such that tobacco from peaks in the filler stream tends to fly off under centrifugal force, and including air flow means for carrying forward along the filler stream any such tobacco which separates from the filler stream.

12 1 2 3 4 6 7 11 12 13

14 15 16 17 18 19 21 22 23 26 29 31 32 33 34 36 37 38 14. A machine according to claim 13, in which the air flow means comprises vanes parallel to the said parallel paths of the bands.

15. A machine according to claim 1, in which each of the suction bands, after the filler streams have been formed on them, passes around pulleys or guides by which the directions of movement of the bands are made parallel, and each band is then constrained to twist before returning around a further pulley, so that the twisting of each band results in the filler stream being carried on an underneath surface of the band whereby the filler stream can be delivered directly into a garniture by the same band.

16. A twin track cigarette making machine in which control as between the two tracks is separated whereby each track can operate independently of the other and so that, while both are operating, different control parameters can be applied to the two tracks so that, if desired, different brands of cigarettes can be made on the two tracks.

17. A process for the manufacture of cigarettes along twin tracks, comprising forming two cigarette filler streams by showering tobacco substantially horizontally onto two suction bands moving in converging directions in a substantially horizontal plane and presenting substantially vertical tobacco-receiving surfaces so as to form a cigarette filler stream on each of the suction bands.

18. A process according to claim 17, in which each filler stream formed on the said suction bands is transferred to a further suction band which carries the filler stream to a cigarette rod forming device, and in which the cross-sectional shape of each filler stream becomes narrower and deeper as a result of the transfer.

19. A machine according to claim 1 or claim 16 and substantially in accordance with any one of the examples described with reference to the accompanying drawings.

20. A process according to claim 17 and substantially in accordance with any one of the examples described with reference to the accompanying drawings.