Cigarette making machine

A cigarette making machine comprises means for showering tobacco onto two suction bands 610,612 to form tobacco sub-streams of similar width on the respective bands which are then merged to form a cigarette filler stream, and includes rod-forming means for enclosing the cigarette filler stream in a continuous wrapper to form a continuous cigarette rod, and means for forming or feeding onto at least one of the sub-streams, or between the sub-streams as or just before they merge, a layer 628 of core-forming material which is narrower than each of the sub-streams and is centrally located in relation thereto, whereby the core-forming material is surrounded by tobacco in the finished cigarette rod. This invention also encompasses the feeding of additional dense-ending quantities of tobacco instead of a core-forming layer.

This invention is concerned with a number of improvements/modifications 
with respect to the cigarette making machine concept described in our U.S. 
Pat. No. 5,199,446 in which a cigarette filler stream is formed by 
showering tobacco towards two converging bands to form two tobacco 
sub-streams which are merged to form a single cigarette filler stream. 
Reference is also directed in this context to our U.S. Pat. No. 5,141,003. 
One object of this invention is concerned with a method or machine for 
manufacturing cigarettes having a core of tobacco or other material 
different from the tobacco which forms the remainder of the cigarette 
filter and which surrounds the core. The core may comprise particulate 
material or may be a continuous pre-formed rod or string. 
In a method of making cigarettes in accordance with this aspect of the 
invention, tobacco is showered onto two suction bands to form two tobacco 
sub-streams of similar width which are then merged to form a cigarette 
filler stream which is used to form a continuous cigarette rod, including 
the step of forming or feeding onto at least one of the sub-streams a 
continuous or substantially continuous layer of material different from 
the tobacco of the sub-streams, or feeding such a layer (possibly as a 
pre-formed rod or string) between the sub-streams as or just before they 
merge, the said layer or layers being narrower than each of the 
sub-streams and being centrally placed in relation thereto so that each of 
the sub-streams extends laterally beyond the lateral edges of the layer or 
layers, and so that the layer or layers will form a core in the finished 
cigarette filler stream surrounded by tobacco. 
Another object is concerned with a method or machine for manufacturing 
cigarettes with denser end portions. 
Examples of cigarette making machines embodying various aspects of this 
invention are shown in the accompanying diagrammatic drawings in which: 
FIG. 1 is a plan view of one machine; 
FIG. 2 shows a modification of the machine shown in FIG. 1; 
FIG. 3 is a front view of a different machine; 
FIG. 4 is a plan view of another machine; 
FIG. 5 is an enlarged view of part of a machine such as that shown in FIG. 
4; 
FIG. 6 is a sectional view on the line VI--VI in FIG. 5; 
FIG. 7 is plan view of a different machine; 
FIG. 8 is a plan view illustrating a machine in which the merged 
sub-streams are conveyed further by a third suction band; 
FIG. 9 is a section on the line IX--IX in FIG. 8; 
FIG. 10 is a section on the line X--X in FIG. 8; 
FIG. 11 is a cross-sectional view similar to FIG. 9 but showing a modified 
machine; 
FIG. 12 is a front view of another machine; 
FIGS. 13 and 14 are plan views of two other machines; 
FIG. 15 is a plan view of yet another machine including, like FIG. 8, a 
third suction band for receiving the merged sub-streams; 
FIG. 16 is a section on the line XVI--XVI in FIG. 15; 
FIG. 17 is a section on the line XVII--XVII in FIG. 15; 
FIG. 18 shows a top suction band arranged to receive the merged sub-streams 
from the apparatus shown in FIG. 15. 
FIG. 19 is a diagrammatic plan view of a different machine; 
FIG. 20 is a diagrammatic plan view of another machine; 
FIG. 21 is a diagrammatic plan view of another machine; 
FIG. 22 is a section on the line A--A n FIG. 21; 
FIG. 23 is a section on the line B--B in FIG. 21; 
FIG. 24 is a diagrammatic plan view of another machine; 
FIG. 25 is a diagrammatic plan view of another machine; and 
FIG. 26 shows a modification on a larger scale of part of the machine shown 
in FIG. 25.

FIG. 1 of the accompanying drawings shows diagrammatically a cigarette 
making machine in which tobacco is showered substantially horizontally 
through a shower channel 8 towards converging suction bands 9 and 10. 
Instead of each of these bands being arranged-to move along a linear path 
in the region where it receives showered tobacco, as described in our 
earlier patents, it is constrained by a guide member 11 or 12 to move 
along a curved path presenting a convex surface to the showered tobacco. 
Thus, where tobacco first arrives on each band, in the regions of the 
arrows 13 and 14, each band (being almost at right angles to the direction 
of movement of tobacco) has almost no forward component with respect to 
the arriving tobacco: i.e., component of movement in the direction of the 
tobacco movement. On the other hand, tobacco subsequently arriving on the 
band, for example in the regions of further arrows 15 and 16 lands on 
portions of the bands which have a significant forward component with 
respect to the arriving tobacco. This results in the strands of some 
tobacco (forming outer zones of the merged filler stream) tending to be 
longitudinally orientated with respect to the cigarette rod, while tobacco 
in the middle of the cigarette will tend to be more randomly orientated. 
While the former is beneficial with respect to ends retention, the latter 
is beneficial with respect to tobacco filling power giving rise to firm 
cigarettes. 
An alternative to the FIG. 1 construction, giving the same effect, would 
involve two large suction wheels in place of the suction bands 9 and 10. 
A similar effect may alternatively be achieved by arranging for the path of 
each band to have two or more linear portions at different angles to the 
showered tobacco, the transition for each band being achieved by pulleys 
or by curved fixed guides. FIG. 2 is a diagrammatic illustration of the 
former example. It shows tobacco being showered substantially horizontally 
through a shower channel 108 towards bands 109 and 110 passing around 
pulleys so that each is constrained to move initially along a linear path 
109A or 110A which is almost at right angles to the direction of movement 
of the tobacco (giving only a slight forward component), and subsequently 
along a linear path 109B or 110B which has a substantial forward component 
with respect to the showered tobacco. As mentioned above, the pulleys in 
the active region of the bands (i.e. pulleys 112 to 115) may be replaced 
by curved guides. 
Each of the examples shown in FIGS. 1 and 2 may, if desired, include air 
outlets for pneumatically separating at least some of the tobacco of the 
two tobacco sub-streams from the respective bands before the streams 
merge, so as to reorientate at least some of the tobacco strands and, to 
some extent, to interengage or mix the tobacco strands of the two 
sub-streams on the respective bands before the merged tobacco stream 
begins to be compressed by the substantially a parallel-moving portions of 
the bands (109C and 110C in FIG. 2). Such air flows are illustrated by 
arrows 119. 
FIG. 1 also shows an air pressure chamber 30 from which air is blown 
through the merged tobacco stream (passing through the bands) into a 
chamber 31. The pressure drop between the chambers 30 and 31 is measured 
and gives an indication of the mass/density of the merged tobacco stream. 
This signal may be used to control tobacco trimmers (not shown) operating 
on the respective tobacco sub-streams on the bands 11 and 12, or a trimmer 
acting on the merged tobacco stream, for example as in FIGS. 8-10 or in 
FIG. 13 or 14 or in FIGS. 15 to 18. 
This feature of an air pressure chamber for determining the mass/density of 
the cigarette filler stream may be used in cigarette making machines which 
are not in accordance with the present invention in general terms, we 
envisage that the conventional nucleonic device for monitoring the mass of 
the finished cigarette rod may be replaced by a pressure drop measurement 
device in the region where the cigarette filler stream is set at a 
predetermined cross section. In order to calibrate the pressure drop 
measurement (preferably automatically and at regular or random intervals), 
provision may be made for automatically removing a finished cigarette at 
regular intervals for automatic weighing, this signal being used to 
calibrate the on-line measurement device; there may also be provision for 
returning each weighed cigarette to the cigarette flow stream, for example 
in the filter attachment machine. In place of pressure drop measurement, 
use may be made of infra red or other mass/density measurement, again with 
automatic regular calibration as described above. 
FIG. 3 shows an alternative machine involving the use of two suction bands 
for forming two sub-streams (not necessarily identical in weight per unit 
length) which are merged on one of the suction bands which then conveys 
the merged stream (preferably after trimming) to a rod-forming device in 
which it is enclosed in a wrapper web. 
As shown in FIG. 3, tobacco is showered pneumatically up a shower channel 
140 towards suction bands 141 and 142. The pronounced inclination of the 
band 142 to the horizontal will result in a sub-stream 142A forming on the 
band 142 having tobacco particles of somewhat random orientation, whereas 
the particles arriving on the band 141, forming sub-stream 141A, will tend 
more to be aligned to the band. A trimming device 144 is arranged to trim 
the merged filler stream before it is deposited on a wrapper web 145 
carried by a garniture tape 146 by which, with the aid of a conventional 
tongue, the merged tobacco stream is further compressed and is shaped to 
the cross-section of a finished cigarette. 
If desired, suction holding the sub-stream 142A on the band 142 may 
terminate in the region of the downstream pulley 143 so that the tobacco 
of sub-stream 142A can fly off the band under centrifugal force (as shown 
by the spray 142C) and be reorientated to some extent before arriving on 
the band 141. 
As a modification of FIG. 3, the channel 140 may be inclined to the 
vertical so as to deliver a tobacco shower substantially at right angles 
to the band 142. The band 141 will then have a significant forward 
component with respect to tobacco arriving on it. 
FIG. 4 illustrates diagrammatically a different machine having two 
converging bands 17 and 18 arranged to move initially along a linear path, 
and then along a curved path defined by a fixed guide 19 or 20. Further 
direction changes of the bands are achieved by pulleys as shown. Suction 
is applied through the bands, as indicated by the flow arrows, and in this 
connection it is particularly important to note that suction continues to 
be applied in the region 21 where the bands are moving along substantially 
parallel paths and acts to compress and shape the merged tobacco stream. 
In that region the drawing also illustrates the provision of openings 22 
which admit air streams vertically into the space between the bands, thus 
limiting or controlling the induction of an air flow in the direction of 
the parallel-moving portions of the bands, as shown by the arrow 24. The 
flow of air through the inlets 20 may be adjustable so as to vary the 
strength of the axial air flow 24 and thus vary the degree of longitudinal 
compacting of the merged tobacco stream produced by the air flow 24. 
In addition, air may be blown outwards through the bands 17 and 18 (arrows 
25 and 26) so as to tend to blow each tobacco sub-stream off its 
respective band, thus allowing or promoting a degree of reorientation of 
the tobacco strands just before the two tobacco substreams merge; this 
feature is illustrated more clearly in FIG. 5, which is an enlargement of 
part of FIG. 4 in the region of the merger zone for the two tobacco 
sub-streams. Instead of the tobacco sub-streams on the bands 17 and 18 
being disturbed by air jets (at arrows 25 and 26), they may be disturbed 
simply by reducing or releasing the suction applied to them as they pass 
around the curved guides 19, 20 so that they are disturbed by centrifugal 
force, by being partly or entirely flung off the bands, or so as simply to 
be able to expand. 
FIG. 4 also illustrates an arrangement for splitting the showered tobacco 
stream in the middle to form two portions which arrive on the respective 
bands 17 and 18. Specifically, the tobacco stream is split by a divider 23 
having diverging surfaces 23A and 23B extending from a small-diameter 
roller 23C which rotates in the direction of the arrow and ensures that 
tobacco arriving on the roller is not caught on the divider 23, but 
instead passes to the left so as to slide along the surface 23A. In the 
example shown, the angle between the surfaces 23A and 23B is 20.degree., 
but this angle may be reduced or possibly increased. 
The divider 23 may be replaced by two diverging walls (effectively extended 
forms of the surfaces 23A, 23B) extending to positions close to the bands 
17 and 18 and forming between them a space free from showered tobacco. 
That space may contain trimming devices for the two tobacco sub-streams on 
the bands 17, 18, as shown in FIG. 5. 
FIG. 5 shows the bands 17 and 18 of FIG. 4 as they approach the merger area 
for the two tobacco sub-streams on the bands 17 and 18. Each of the 
sub-streams is trimmed by a trimming device centred on one of the axes 80. 
Each of these trimming devices may be substantially in the form shown in 
FIGS. 4 to 6 of our U.S. Pat. No. 4,276,891. 
After trimming, at least part of each sub-stream is blown off its carrier 
conveyor band by air blown through apertures 81 and 82 in guide plates 83 
and 84 respectively. In the area where the merged tobacco stream is 
progressively compressed by the bands, suction continues to be applied 
through the bands, as shown by arrows 85. Below the merged tobacco stream 
there is a wall 86 (see FIG. 6), and above the tobacco stream there is 
wall 87 formed with air inlet openings 88 which lie at regular intervals 
and are inclined so that the air flowing in through the openings 88 has a 
component of motion in the direction of motion of the tobacco. Beyond the 
upper wall 87 there is a continuation wall 89 which is likewise formed 
with inlet openings 89A inclined, in this case, at a greater angle to the 
vertical. 
The air streams emitted through the apertures 81 and 82 serve to blow the 
tobacco off the bands 17 and 18, thus permitting at least some of the 
tobacco strands to become reorientated and to interengage or mix with 
strands of the other stream before the two sub-streams merge in the region 
where the bands continue in substantially parallel directions. 
Each of the air inlet apertures 81 and 82 may extend across the, whole 
width of the tobacco sub-stream, so as to disturb and re-orientate all the 
tobacco. Alternatively, each of the apertures may extend across only part 
of the width of the corresponding sub-stream: for example, the upper part 
of one and the lower part of the other. Another possibly is that one 
aperture may be in two parts acting on the side portions of the 
corresponding sub-stream, while the other may act on only the middle 
portion of the other sub-stream. 
FIG. 5 also illustrates the provision of a control device 81A for 
controlling the supply of air to the aperture 81; the same control device 
or a separate one may similarly control the supply of air to the aperture 
82. The control device 81A may comprise an electrically or mechanically 
controlled valve or other flow-control means whereby the flow of air is 
stopped or reduced while cigarette end portions of the tobacco streams are 
passing the apertures 81 and 83. This feature may be applied to other 
examples described in this specification, and particularly to FIGS. 1 and 
2, to ensure or help to ensure that generally longitudinally orientated 
strands of tobacco at the cigarette end portions tend to remain in that 
orientation. 
Instead of two entirely separate trimming devices being used to trim the 
two sub-streams as shown in FIG. 5, a common trimming device may be used 
as follows. The device would consist of a frusto-conical drum arranged 
with its axis in alignment with the central axis of the merged tobacco 
stream, and with blades on the frusto-conical surface which, in 
cooperation with stationary blades, would shear off excess tobacco from 
each of the sub-streams, substantially in the manner of the trimmer 
described in our above-identified U.S. patent. The stationary blades for 
this purpose may lie obliquely across the respective sub-streams. Movement 
of the entire device (including the drum and the blades) in the direction 
of the axis of the drum would vary the amount of tobacco removed from both 
sub-streams. Alternatively, the device may comprise a rotary member having 
an axis of rotation transverse to the central axis of the merged tobacco 
stream, and two frusto-conical bladed portions cooperating with stationary 
blades for trimming the respective sub-streams. 
FIG. 7 shows diagrammatically, on a larger scale, a modification of part of 
the machine shown in FIG. 4. After passing around fixed guides 419 and 
420, the bands 417 and 418 pass around scraper guides 424 and 425 each of 
which serves to scrape tobacco from the corresponding band and thus 
deflect the tobacco towards the tobacco on the other band. Thus, the 
tobacco particles are disturbed and reorientated in accordance with the 
main aspect of this invention and are more loosely conveyed by the bands 
after the bands pass around the guides 424, 425 and past additional fixed 
guides 426 and 427. This is particularly suitable for use in a machine in 
which the merged tobacco stream passes from the bands 417 and 418 and is 
carried further by a band above the merged stream in cooperation with a 
garniture tape below it; for example, as shown in FIGS. 8-10. 
Alternatively, the upper band may, for example, be a moulded (non-suction) 
band having a concave underneath surface so as to shape the tobacco 
stream, and this band may converge towards the garniture tape so as to 
compress the tobacco stream vertically. 
Displacement of the tobacco from the bands 417 and 418 may be assisted (or 
achieved) by restricting the level of suction applied through the guides 
419 and 420 so that the tobacco, or some of it, flies off under 
centrifugal force. 
FIG. 8 is a diagrammatic plan view of part of a machine including a channel 
90 through which tobacco is showered in a substantially horizontal 
direction towards two converging suction bands 91 and 92 passing around 
pulleys 93 to 96. As shown in FIG. 9, each of the tobacco sub-streams 97 
and 98 formed on the respective bands 91 and 92 is relatively wide 
(vertically) but thin (horizontally), and the two sub-streams are slightly 
spaced apart at the downstream ends of the bands 91 and 92 (space 99 shown 
in FIG. 9). 
A top suction band 100 receives the sub-streams 97 and 98 to form a merged 
stream 101 of more nearly square cross-section shown in FIG. 10, which is 
a cross-section immediately ahead of a trimming device 100A by which the 
merged stream is trimmed at approximately the level shown in FIG. 10 by 
the chain dotted line 102. 
In separating from the bands 91 and 92 to form the merged tobacco stream 
100, the tobacco of each of the sub-streams moves laterally upwards from 
the respective bands 91 and 92 and, in the process, is disturbed and is 
able to be reorientated at least to some extent, thus improving the 
filling power of the tobacco in the finished cigarette. In effect, this 
may be expressed in terms of the sub-streams 97 and 98 folding into one 
another in passing to the overhead suction band 100. 
After trimming, the cigarette filler stream 100 is deposited on a cigarette 
wrapper web carried by a conventional garniture tape (not shown). 
FIG. 11 shows a modification of the example shown in FIGS. 8 to 10, being a 
cross-section corresponding to FIG. 9. In this case, bands 150 and 152 
carrying tobacco sub-streams 154 and 156 are vertically spaced from a 
suction band 158 to which the tobacco passes via a short chimney defined 
by rails 160 and 162. Air sucking the tobacco upwards for this purpose 
results from suction applied above the band 158, and there are also air 
inlets 164 and 166. As an idea of scale, the distance D through which 
tobacco moves to reach the band 158 may be approximately 25 mm. 
FIG. 12 illustrates another modification of FIG. 8. In this example, 
tobacco is showered vertically upwards through two parallel shower 
channels 200 (only the nearer channel being visible) towards two parallel 
suction bands 202 each of which passes around three pulleys 204, 206 and 
208. In passing from the pulley 206 to the pulley 208, each band is 
twisted through 90.degree., the two pulleys 208 being angularly displaced 
in opposite directions. Thus the two suction bands present two sub-streams 
to a further suction band 210 in substantially the manner shown in FIG. 9 
or FIG. 11. The band 210 carries a merged tobacco stream past a trimming 
device 212 and into a conventional garniture 214 including a garniture 
tape 216 carrying a wrapper web 218. 
FIG. 13 is a diagrammatic plan view of another form of machine according to 
this invention in which two converging suction bands 50 and 51, passing 
around pulleys 53 to 58, receive tobacco showered through a horizontal 
shower channel 52. The band 50 continues beyond the pulley 57 for the band 
51, and carries the merged tobacco stream past trimmer disks 59 (of 
conventional construction) arranged vertically. The trimmed tobacco stream 
60 is then brought into engagement with a wrapper web 61 conveyed by a 
garniture tape 62 which becomes progressively concave in cross-section to 
shape the tobacco stream. Shaping of the tobacco stream on the side 
opposite to the garniture tape may be achieved partially by the band 50, 
but is completed by a tongue 63 which also compresses the tobacco stream 
to the final cross section at which the wrapper web 61 can be wrapped 
around the tobacco stream in the usual manner. 
Alternatively, after leaving the pulley 53, the band 50 may be twisted 
through 90.degree. so as to carry the merged tobacco stream below it and 
thus be able to deposit the tobacco stream on a conventionally orientated 
garniture tape. The trimmer discs 59 will in this case be appropriately 
orientated so as to be parallel to the adjacent portion of the band 50. 
An air jet 56A may be directed through the band 51 to disturb the tobacco 
on the band 51 before it is merged with the tobacco on the band 50. 
FIG. 14 shows a different construction in which, as before, tobacco 
sub-streams are formed on two suction bands 70 and 71. The difference is 
that the band 71, after the tobacco sub-streams have been merged and are 
being carried by the band 70, is deflected around a pair of trimmer disks 
72 by pulleys 73 and 74, and then assists in the further conveyance of the 
merged tobacco stream until the merged stream is engaged between an upper 
band 75 and a garniture tape below it. As described above, the upper band 
75 may be of moulded form presenting a concave underneath surface for 
shaping the tobacco stream, and may converge towards the garniture tape. 
Thus the upper band in effect serves as a "moving shoe". An air jet 76 may 
be provided to serve the same purpose as the air jet 56A in FIG. 13. 
FIG. 15 is a plan view of another machine having some similarities to the 
example shown in FIGS. 8 to 10. In this example, tobacco is showered 
through two separate diverging horizontal channels 300 and 302 towards two 
suction bands 304 and 306 respectively to form tobacco sub-streams 305 and 
307. After emerging from the shower channels 300, 302, the tobacco 
sub-streams on the two bands are trimmed by trimming devices 309 each of 
which may be as described in our above-mentioned U.S, Pat. No. 4,276,891. 
Both trimmed sub-streams are then received by a top suction band 310 shown 
on its own in FIG. 18 without, for the purpose of simplification, the 
suction bands 304 and 306. However, it should be noted that substantially 
parallel runs 306A and 308A of the bands continue to confine the sides of 
the merged tobacco stream until shortly before the merged stream is 
deposited on a continuous wrapper web 312 carried by a garniture tape 314, 
and the suction band 310 then continues and may further compress and shape 
the cigarette filler stream until it reaches a pulley 316 following which 
a fixed tongue 318 completes the compression and shaping of the filler 
stream. 
A pulley 319 for the band 310 has its axis in a vertical plane containing 
the axes of pulleys 311 and 313 for the bands 304 and 306. 
In order to shape the top of the merged filler stream while it is being 
conveyed and compressed between the top band 310 and the garniture tape 
314, the following may apply. Top guides (not shown) for the active run of 
the band 310, for example rollers or fixed guides, may be shaped so as to 
allow the band, after it passes the bands 304, 306, to assume a 
progressively concave cross-section so as to shape the top surface of the 
merged filler stream. At this stage the band 310 may pass between fixed 
side rails (not shown) confining the sides of the tobacco stream until the 
garniture tape has become sufficiently trough-like to serve that purpose. 
The pulley 316 has a corresponding concave peripheral cross-section to 
match that of the band 310 at that point. As it passes over the fixed 
tongue 318 (which also serves as a "shoe" for scraping the tobacco stream 
off the band 310) the tape is allowed progressively to assume a flatter 
cross-section; it may be flat, or may possibly curve the other way, as it 
passes around a further pulley 321. 
The divergence of the slower channels 300 and 302 (as shown in FIG. 15) 
leaves a space 303 which may accommodate means for adding dense ending 
extra quantities of tobacco into the merged filler stream, for example as 
described in our above mentioned U.S. Pat. No. 5,141,003, and/or for 
injecting, between the sub-streams 305, 307 as or immediately before they 
merge, a continuous or intermittent stream of liquid or foam containing 
adhesive and/or tobacco-flavouring material. Another possibility is that a 
stream of tobacco or other material, or a preformed continuous rod or 
string, may be introduced between the substreams 305, 307 so as to form a 
core in the finished cigarette rod, which core is substantially surrounded 
by the tobacco of the substreams 305, 307; for this purpose each of the 
sub-streams may, as it collapses from the high/narrow cross-section shown 
in FIG. 17, be induced by the application of increased suction at the 
sides of the band 304, 306 to form a concave outer cross-section with a 
greater thickness of tobacco at the sides than at the middle. 
FIG. 16 shows the cross sectional shape of the tobacco sub-stream 307 on 
the suction band 306 at the line XVI; the same applies to the sub-stream 
305 on the band 304. The sides of the sub-stream are confined by rails 320 
and 322 defining a relatively narrow gap (approximately 5 mm) so that the 
filler stream has a substantial height (approximately 9 to 10 mm). In the 
region of the trimmer, the rails are cut away (to about the line 324) to 
allow the trimmer to remove tobacco projecting beyond a predetermined 
distance from the band. 
Immediately after trimming, extensions 320A and 322A of the rails 320 and 
322 change in cross-section (either abruptly or progressively) to the 
cross-section shown in FIG. 17. This allows the trimmed sub-stream to 
collapse, so that the two sub-streams and the top suction band which 
receive them become similar to FIG. 9. 
Instead of the rails 320 and 322 being shaped so as to permit the trimmed 
sub-stream to collapse symmetrically after trimming, they may be arranged 
to allow or guide the trimmed sub-stream to fold over towards one side. 
For that purpose the rails 322, 324 would be asymmetrical so as to form 
the narrow/high sub-streams along or near one side edge of the band 304, 
306, one being possibly near the upper edge of its band and the other near 
the lower edge so that they fold over downwards and upwards respectively 
to form approximately the wide/low cross-section shown in FIG. 17. 
Any of the above-described methods of reforming each of the sub-streams 
before merging may be used in a machine without the top band 310, for 
example as basically described in our above-mentioned U.S. Pat. No. 
5,199,446. 
As described with reference to FIGS. 4 to 6, there may be provision for 
introducing air vertically into the space between the parallel runs 306A 
and 308A of the bands 306 and 308 to control the degree to which suction 
applied through the bands 306 and 308 and also through the top band 310 
induces an axial air flow into the space between the band runs 306A and 
308A. The air inlets in this case are preferably formed in a fixed bottom 
wall corresponding to the wall 86 in FIG. 6. 
In order to form denser end portions in the finished cigarettes, spaced 
mounds of additional tobacco may be fed onto the top suction band 310 
(e.g. by a pocketed wheel) before it receives the two substreams from the 
bands 304 and 306. 
Instead of each of the bands 304 and 306 being flat in cross-section where 
it receives the showered tobacco, each may be curved or may become 
progressively curved so as to present a deeply concave upper surface (in 
cross-section) to receive the showered tobacco and thereby form a 
relatively narrow tobacco stream 307 of which the sides are confined at 
least partly by the side portions of the band. Suction may be applied to 
those side portions so as to grip the tobacco there as well as at the 
centre of the band corresponding to the bottom of the concave. After 
trimming, each of the bands is progressively flattened so as to arrive at 
the pulleys 311, 313 in the condition shown approximately in FIG. 16. 
During this flattening process the trimmed filler stream 307 divides 
approximately through the middle to form an approximately even low-height 
wide stream as shown in FIG. 17 in preparation for the merging of the two 
sub-streams as already described. 
The curving of the bands in this manner may be controlled by support 
rollers having the appropriate straight or concave peripheries as viewed 
in longitudinal section. The suction which draws the tobacco onto the 
bands also pulls the bands onto the rollers; however, to ensure that the 
bands do curve in cross-section in the described manner, the path of each 
band may be slightly curved in the sense shown in FIG. 1, but with a 
larger radius of curvature, so that tension in the bands assists their 
cross-sectional curving. 
FIG. 19 shows a machine comprising converging suction bands 510 and 512 
onto which tobacco is showered from a shower channel 514. Tobacco 
sub-streams (not shown) build up on the bands 510 and 512 and are combined 
or merged as the bands move along parallel paths starting from a merger 
zone 516. The merged cigarette filler stream thus formed is enclosed in a 
paper wrapper as described above. 
Tobacco showered approximately along the middle of the channel 514 is used 
to form dense-ending mounds of tobacco 518 on a band 520. For this 
purpose, a channel is formed between a fixed wall 522 and a parallel run 
of the band 520, tobacco being drawn into that channel partly by the 
action of a supercharger louvre 524 formed in a bottom wall of the channel 
514. Suction is applied through the band 520 to hold the dense end 
portions 518 on the band until they are ready to be released onto the band 
510. The quantity of tobacco drawn into the channel to form dense ends may 
be controlled by controlling the level of suction applied to the louvre 
524 and/or by controlling the level of suction applied through the band 
520. 
Rollers 526 and 528 rotate in the indicated directions so that tobacco 
which might otherwise be caught on the edges of the adjacent fixed walls 
530 and 532 are instead directed as shown. 
The band 520 is of woven nylon so as to be air-pervious along its entire 
length. However, a non-pervious carrier band inside the nylon band is 
formed with apertures at regular intervals which define the areas at which 
dense-ending tobacco is collected on the nylon band. The carrier band is 
tensioned by a pulley 534 and returns around a pulley 536, while the nylon 
band extends further and returns around a pulley 538. The nylon band may 
also include a separate tensioning arrangement and may be driven 
separately from the carrier band. 
FIG. 20 shows an alternative construction which differs in that 
dense-ending tobacco is showered directly onto a band 540 arranged to pass 
around pulleys 542 and 544. As in FIG. 19, dense end portions of tobacco 
546 form on the band 540 and are delivered onto the sub-stream carried by 
band 510 before the sub-streams carried by the bands 510 and 512 are 
combined or merged to form the complete cigarette filler stream. A roller 
like roller 526 or 528 in FIG. 19 may be included at the junction of two 
fixed walls 548 and 550. The band 540 is inclined to the tobacco shower by 
an angle .alpha. which may be increased if so desired. 
The band 540 may be of non-porous material which has perforated areas for 
picking up dense-ending portions of tobacco. Alternatively, as mentioned 
with respect to FIG. 19, there may be two bands, the inner band being 
non-porous but having apertures at regular intervals, while the outer band 
is possibly of woven nylon. 
FIG. 21 shows a machine which is used to manufacture core-centred 
cigarettes. As before, it has converging suction bands 610 and 612 onto 
which tobacco is showered, in this case through two separate channels 614 
and 616 defined by parallel upper and lower walls and by side walls 
614A,614B and 616A,616B respectively. This tobacco forms a wide shallow 
layer of tobacco on each of the bands 610 and 612. FIG. 22 shows the layer 
of tobacco 618 which is formed on the band 612 and is held on the band by 
suction applied through the band from a suction chamber 620. A similar 
arrangement applies to the band 610. 
The wide layers formed on the bands 610 and 612 may be trimmed by trimming 
devices 611 and 613 mounted in spaces formed by the walls 614B and 616B 
and additional walls 614C and 616C. Alternatively, the thicknesses of the 
wide tobacco layers may be controlled or evened out by other means, for 
example as described in British patent application No. 9422581 and U.S. 
application Ser. No. 388144, filed 9 Nov. 1994, which is incorporated by 
reference. 
Between the shower channels 614 and 616 there is a shower channel 622 
through which additional particulate material (tobacco and/or other 
material) is showered towards both of the bands 610 and 612. In the 
regions where this additional particulate material arrives on the band 
612, the shower channel is reduced in width by rails 624 and 626 (see FIG. 
23) having inner surfaces 624A and 626A which define the width of a layer 
628 of the additional particulate material which forms along a central 
region of the tobacco layer 618. The same applies to the other half of the 
machine in the region of the band 610. 
Thus each layer 618 of tobacco arrives at a merger point between pulleys 
610A and 612A carrying on it a centrally positioned layer of the 
additional particulate material. The two layers of that material are 
brought together and combined to form a core in the finished cigarette 
filler stream surrounded by tobacco. Excess particulate material may be 
removed by a pin-carrying wheel 630 rotating about a horizontal axis and 
sheltered from showered particulate material by a V-shaped cover 631. 
In moving from the pulleys 610A and 612A to further pulleys 610B and 612B 
(which have concave peripheral cross-sections), the bands become 
progressively concave in cross-section so as to wrap the side edge 
portions of the layers 618 around the sides of the core and to shape the 
cigarette filler stream towards a circular cross-section. After passing 
the pulleys 610B and 612B the bands become progressively flat again in 
cross-section as they approach further pulleys 610C and 612C, and they 
remain flat as they move from the latter pulleys to further pulleys 610D 
and 612D. 
The cigarette filler stream thus formed may be carried into a conventional 
garniture as described in the earlier examples, for example as in FIG. 18. 
Alternatively, the entire core layer may be formed on one of the bands 610 
or 612. 
As a further alternative, the additional particulate material may be 
showered onto a separate suction band lying between the converging bands 
610 and 612 (for example, like the band 520 shown in FIG. 19) to form a 
narrow layer of additional particulate material which is then laid onto 
one of the tobacco streams on the band 610 or 612 before the tobacco 
streams arrive at the merger zone 630. Another possibility is that the 
additional particulate material may be showered onto two converging bands 
situated above or below the bands 610 and 612 to form a stream which may 
be fed between the tobacco layers, in the region of the pulleys 610A,612A, 
by a suction wheel or through a guide tube. 
The additional particulate material may comprise, for example, relatively 
long stands of low-quality tobacco or other material which will assist in 
preventing ends fall-out of tobacco from the finished cigarettes. 
Alternatively, or in addition, it may comprise or include stems and other 
heavier pieces of tobacco winnowed out of the tobacco used to form the 
tobacco layers, or tobacco with any desired additional substance for 
modifying one or more characteristics of the finished cigarettes. 
FIG. 24 shows a different form of machine for producing core-centred 
cigarettes. Tobacco is showered onto converging suction bands 710 and 712 
through horizontal shower channels 714 and 716 to form identical layers of 
tobacco on the bands 710,712 as in the FIG. 21 example. Also as before, 
the tobacco layers maybe trimmed by trimming devices 711 and 713 before 
the layers are brought together around a core of additional particulate 
material. 
In this example a stream of core material is showered through a shower 
channel 722 formed by horizontal top and bottom walls and by converging 
side walls 722A and 722B. Thus particulate material showered through the 
channel 722 converges to form a core stream at the downstream ends of the 
walls 722A,722B, and this core stream enters a gap between the tobacco 
layers carried by the bands 710,712. 
Tobacco arriving on the bands 710,712 is held on the bands by suction 
transmitted through the bands from suction manifolds 730 and 732. Suction 
continues to be applied to the bands from further suction manifolds 
734,736 as the bands move along slightly converging paths and then along 
parallel paths extending along guide walls 738,740, these are perforated 
so that air can be drawn through them from the manifolds 734,736, as shown 
by the air flow arrows. The air drawn through the bands in this region 
induces an axial air flow which draws the additional particulate material 
through the channel 722 and into the gap between the tobacco layers formed 
on the bands 710,712. 
The guide walls 738,740 may be concave in cross-section, or may become 
progressively concave, to fold the side edge portions of the tobacco 
layers around the core, as described with reference to FIG. 21. The 
core-centred cigarette filler stream thus formed may, as in the previous 
example, be carried into a conventional garniture by a further suction 
band (not shown) to enable the filler stream to be sealed in a continuous 
paper wrapper. 
FIG. 25 shows a machine which is similar in that tobacco is showered onto 
suction bands 810,812 through horizontal shower channels 814,816. Tobacco 
layers thus formed on the bands may be trimmed by trimming devices 811,813 
before being brought together while moving along guide members 838,840 for 
the two bands. 
This example differs from FIG. 24 principally in that additional 
particulate material is showered through a horizontal channel 822 
extending towards additional converging suction bands 842,844 to form two 
separate sub-streams of particulate material on the two bands which are 
merged as the bands move along parallel paths beyond a merger point 846. 
The complete core stream thus formed then passes through a nozzle 848 to 
enter the gap between the tobacco layers formed on the bands 810,812. As 
in the FIG. 24 example, the flow of core material into that gap is 
assisted by an axial air flow induced by air drawn through the bands 
810,812 from suction manifolds 834,836. 
The construction of the machine shown in FIG. 25 is preferably as shown in 
FIG. 26. This figure shows tobacco layers 810A and 812A which have been 
formed on the bands 810,812 and between which the core stream is injected 
as the bands 810,812 proceed beyond guide pulleys 810B,812B. 
The member 848 through which the core material passes before entering the 
gap between the tobacco layers is in the form of a tube of which the outer 
surface at both ends converge so as to end as a relatively sharp edge. The 
bands 842,844 carrying the merged stream of core material are constrained 
by suitably shaped guide members (not shown) so as to diverge at 842A,844A 
as they approach guide pulleys 842B,844B on opposite sides of the tubular 
member 848. 
The centre bore in the member 848 has a square or rectangular 
cross-section. 
Another possibility is that a layer of particulate core material may be 
formed on a suction band and then be fed (possibly after trimming) onto 
one of the tobacco sub-streams. Alternatively two sub-streams of core 
material may be formed by showering particulate material, for example, 
onto two diverging suction bands, the two core sub-streams being deposited 
respectively on the tobacco sub-streams (preferably after these have been 
trimmed) before these are merged to form a complete core-centred cigarette 
filler stream. In comparison with FIG. 25, the latter alternative would in 
effect involve the showering of core material through the channel 822 onto 
two short diverging bands, instead of onto converging bands 842,844, so 
that each core sub-stream can be deposited on its respective tobacco 
sub-stream before the merger point; the cross-section through each main 
band just before the merger point may thus be similar to FIG. 23.