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The present invention relates to a cigarette
maker.
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More particularly, the present invention relates
to a cigarette-making machine of the type equipped
with means by which to form two or more continuous
cigarette rods.
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It is the practice when manufacturing cigarettes
to fashion a continuous cigarette rod from starting
materials that consist in a strip of paper decoiled
from a roll on the one hand, and a mass of shredded
tobacco on the other.
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In the course of the following specification, the
term cigarette rod indicates the assemblage of the
paper strip and the tobacco, from the moment when
the tobacco is deposited on the paper through the
step whereby the paper is wrapped around the stream
of tobacco. The continuous rod formed in this way
is fed toward a cutter device and divided up into
single sticks, each of which will provide at least
one cigarette.
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Having undergone further processing operations if
envisaged, such as the attachment of a filter tip,
the cigarettes are conveyed to a further machine,
typically a packer.
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With the recent development of ultra high speed
packers able to turn out several hundred packets
per minute, the need arises to design cigarette
makers such as can keep the new packers supplied
more effectively, and thus ensure their increased
potential can be exploited to the full.
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The problem in question was addressed initially
by coupling a high speed packer to two cigarette
makers operating in parallel, each turning out a
single cigarette rod.
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Though effective functionally, this solution
involved a significantly increased cost burden, due
mainly to the duplication of mechanical components,
but also to the additional testing, servicing and
manning requirements involved.
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To the end of overcoming the drawbacks connected
with the adoption of two cigarette makers operating
in parallel, but without substantially increasing
production costs, the industry adopted new machines
designed to fashion two continuous cigarette rods
simultaneously, utilizing a single strip of paper
decoiled from a roll, on the one hand, and a single
mass of shredded tobacco on the other.
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Further improvements since made to the functional
effectiveness of packers have shown clearly that
even cigarette makers capable of assembling two
rods simultaneously are not capable of matching the
increased output capacity of the new packers.
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In addition, the solution of assembling more than
two cigarette rods one alongside another has been
rendered problematical hitherto by difficulties
connected, in particular, with the step of cutting
the rods into sticks, which typically involves the
use of a single rotating cutter device equipped in
most cases with two peripheral blades.
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In effect, a cigarette maker equipped to assemble
two continuous rods can be likened, for instance,
to a machine producing a single imaginary rod of
which the diameter is equal to the distance between
centres of the two rods, plus the diameter of one
rod, and will measure 3-4 cm or thereabouts.
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The operation of cutting such a rod calls for
faultless adjustment of the cutter device, as the
time for which each cutting edge remains in contact
with the rod would be much longer than in the case
of a conventional single-rod type machine.
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In other words, and by reason also of the high
speed at which the rod advances, the risk of making
an imperfect cut, and in particular of a cut not
generated exactly at right angles to the axis of
the rod, is increased significantly by the diameter
of the imaginary rod.
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The object of the present invention is to provide
a high speed cigarette maker such as will be simple
and economical to implement.
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The stated object is realized according to the
present invention in a cigarette maker of which the
characterizing features are as recited in claim 1.
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The invention will now be described in detail, by
way of example, with the aid of the accompanying
drawings, in which:
- figure 1 illustrates a preferred embodiment of the
cigarette maker according to the invention, viewed
schematically in a side elevation and with certain
parts omitted in the interests of clarity;
- figure 2 illustrates a portion of the cigarette
maker in figure 1, viewed schematically from above
and with certain parts omitted in the interests of
clarity;
- figure 3 is a detail of the cigarette maker in
figure 1, viewed schematically in a section taken
on III-III in figure 1 with certain parts omitted
in the interests of clarity;
- figure 4 illustrates a portion of an alternative
embodiment of the cigarette maker according to the
invention, viewed schematically from above and with
certain parts omitted in the interests of clarity;
- figure 5 illustrates a detail of an alternative
embodiment of the cigarette maker according to the
invention, viewed schematically in section and with
certain parts omitted in the interests of clarity.
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Referring to figure 1 of the drawings, 1 denotes
a portion, in its entirety, of a cigarette making
machine able to fashion a plurality of continuous
cigarette rods 2a, 2b and 2c simultaneously, as
indicated by the section drawing of figure 3.
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In particular, albeit implying no limitation, the
drawings illustrate a machine able to form three
cigarette rods 2a, 2b and 2c simultaneously.
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The machine 1 comprises a frame 3 carrying a feed
unit by means of which to advance three strips 4 of
paper, each marginally greater in width than the
developable circumference of the single rods 2a, 2b
and 2c in production. The feed unit in question is
essentially familiar in embodiment, and indicated
schematically by a block 5 in figure 1.
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The machine 1 further comprises a feeder device 6
supplying shredded tobacco 7, also a table 8 on
which the continuous cigarette rods 2a, 2b and 2c
are assembled.
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The assembly table 8, likewise carried by the
frame 3, comprises three conveyor belts 9a, 9b and
9c associated respectively with each of the three
paper strips 4.
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The three belts 9a, 9b and 9c are looped around a
plurality of rollers 10a, 10b, 10c, 11a, 11b, 11c
and 12 and set in motion by a drive roller 13, in
such a way that the strips 4 are caused to advance
along respective predetermined paths P1, P2 and P3
extending along the assembly table 8 and indicated
in figure 2.
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The feed unit 5 is designed to advance each of
the three strips 4 onto a respective belt 9a, 9b
and 9c, in such a manner that one face 4a of the
strip 4 is offered in contact to a top branch 14 of
the relative belt 9a, 9b and 9c.
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The top branch 14 of each belt 9a, 9b and 9c
extends along the assembly table 8 between sets of
return rollers 10a-10b-10c and 11a-11b-11c located
respectively downstream and upstream relative to
the direction of movement of the selfsame belts.
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Referring to figure 2, each belt 9a, 9b and 9c is
designed to advance a respective strip 4 along a
respective path P1, P2 and P3 in a predetermined
direction F1, F2 and F3, passing through a loading
station 15 (figure 1) located along the selfsame
path P1, P2 and P3.
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The loading station 15 coincides with a point at
which a continuous and substantially uniform stream
of tobacco 7 is released onto the upwardly directed
face 4b of each strip 4 by the feeder device 6
aforementioned.
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The three streams of tobacco are substantially
identical one to another and generated in familiar
manner while clinging to three downwardly directed
faces 16a presented by the bottom branches of three
respective aspirating conveyor belts 16, familiar
likewise in embodiment, forming part of the feeder
device 6 and extending in part above the assembly
table 8.
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As mentioned in the preamble and reiterated here
for additional clarity, the cigarette rod 2a, 2b or
2c is identifiable as the assemblage of the paper
strip 4 and the tobacco 7, from the moment in which
the tobacco is released onto the face 4b of the
strip 4 at the loading station 15 to the moment,
subsequent to the paper being gathered around the
tobacco filler into a tubular wrapper 17, when the
assembled rod is separated by a cutter device into
discrete lengths or sticks, not illustrated, that
will emerge ultimately as single cigarettes.
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As illustrated in figure 1, the aforementioned
cutter device is of conventional type, appearing as
a cylindrical cutter head 18 rotatable about an
axis 19 substantially parallel to the assembly
table 8, and presenting a pair of diametrically
opposed blades 18a. In the plan views of figures 2
and 4, the cutter head is indicated schematically
as a block, likewise denoted 18.
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The machine 1 further comprises guide means 100,
interposed between the downstream rollers 11a, 11b
and 11c and the cutter head 18, serving to direct
the rods 2a, 2b and 2c from the runout ends of the
respective belts 9a, 9b and 9c into the path of the
blades 18a.
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The table 8 and the guide means 100 combine to
establish the aforementioned paths P1, P2 and P3
followed by the respective cigarette rods 2a, 2b
and 2c.
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The assembly table 8 comprises three divisions
consisting in beams on which the three continuous
rods 2a, 2b and 2c are formed, denoted 20a, 20b and
20c respectively.
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The forming beams 20a, 20b and 20c are identical
one to another, conventional in embodiment and not
illustrated in detail. The three beams extend one
beside another along the relative paths P1, P2 and
P3 downstream of the loading station 15, following
the feed directions F1, F2 and F3 of the strips 4.
The three paths P1, P2 and P3 are convergent, as
will be explained in due course, and in particular,
the two lateral divisions 20a and 20c are disposed
symmetrically and convergently on opposite sides of
the central division 20b.
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The cigarette rods 2a, 2b and 2c are illustrated
in section, in figure 3, and in plan in figures 1
and 4.
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As discernible from figure 3, which presents a
sectional view of the central or middle beam 20b,
each beam 20a, 20b and 20c affords a corresponding
groove 21 proportioned to accommodate a relative
belt 9a, 9b and 9c. The groove 21 presents a cross-sectional
profile of varying geometry that narrows
to the point of assuming an essentially cylindrical
shape with a radius of curvature substantially
matched to the radius of the single cigarette.
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Each belt 9a, 9b and 9c thus extends along a
respective groove 21 in contact with the concave
profile, and is caused to bend progressively until
forced into the substantially cylindrical shape
aforementioned.
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As a result of the transverse deformation of the
belt, the relative paper strip 4 is caused likewise
to roll around the respective stream of tobacco 7
and form the corresponding tubular wrapper 17.
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At least one longitudinal edge of each paper
strip 4 is engaged by a gumming device of familiar
embodiment (not illustrated), and thereupon joined
to the other edge to seal the rod 2a, 2b and 2c.
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Figure 3 is a schematic representation showing
the cross-sectional profile of the central beam 20b
at a point along the feed direction F2 beyond the
formation of the substantially cylindrical section
described above. In effect, the section shown in
figure 3 illustrates a moment in which the belt 9b,
rolled previously into a cylindrical tube to form
the rod 2b, begins opening out again gradually to a
flat profile before passing around the cylindrical
return roller 11b.
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More exactly, the upstream rollers 10a, 10b and
10c and the downstream rollers 11a, 11b and 11c at
the opposite ends of the respective branches 14 are
necessarily cylindrical, presenting an axial length
substantially equal to the width of the respective
belt 9a, 9b and 9c, since a roller of any shape
other than cylindrical will not allow the belt 9a,
9b and 9c to form a clean loop.
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Conventionally, the cutter device 18 operates in
conjunction with a striker device by which the
continuous rods 2a, 2b and 2c are supported and
guided during the step of cutting the sticks.
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As illustrated in figure 3, the feed paths P1, P2
and P3 lie substantially in a common plane G, at
least on a line coinciding with or immediately
upstream of the cutter head 18.
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The feed paths P1, P2 and P3 and the relative
beams 20a, 20b and 20c are shown in figures 2 and 4
as being positioned one relative to the next, in
the common plane G, at an angle α of convergence
that has been accentuated in the drawings for the
sake of clarity, but which in practice will be less
than 5°.
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Preferably, the angle α of convergence will be
less than 1°.
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Experimental trials have shown that particularly
advantageous results are obtained with the paths
disposed at an angle α of convergence in the order
of 0° 30'.
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In an alternative embodiment of the machine 1,
not illustrated in detail, the feed paths P1, P2
and P3 might not occupy a common plane, at least on
a line coinciding with or immediately upstream of
the cutter head 18. In a preferred embodiment of
this type, the central or middle path P2 of the
three paths P1, P2 and P3 will lie above or below
the level of the plane occupied by the two outer or
lateral paths P1 and P3.
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With reference to figure 5, which illustrates
schematically how the cigarette rods 2a, 2b and 2c
are arranged in an example of the aforementioned
alternative embodiment, the three paths P1, P2 and
P3 followed by the three cigarette rods 2a, 2b and
2c combine, in a plane perpendicular to at least
one of the paths P1, P2 and P3 and coinciding with
or immediately upstream of the cutter head 18, to
describe corresponding points T1, T2 and T3 on a
circumference C of predetermined diameter.
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Advantageously, this arrangement is particularly
convenient when transferring the cigarette sticks
onto the infeed drum of a filter tip attachment
machine and/or when dividing up the rods 2a, 2b and
2c with a cutter device 18 that consists in a rotor
of cylindrical shape carrying a pair of peripheral
blades 18a, as described above.
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In the example of figure 2, the central belt 9b
associated with the middle beam 20b extends further
along the relative path P2 in the respective feed
direction F2 than the two belts 9a and 9c located
on either side.
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The central belt 9b reassumes its flat profile,
beyond the relative groove 21 of varying geometry,
along a part of the respective feed path P2 that
lies downstream of the part of each path P1 and P3
along which the lateral belts 9a and 9c reassume
their flat profile after leaving the grooves 21.
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In short, thanks to this arrangement, there is no
interference of the three belts one with another
notwithstanding the convergence of the three feed
paths P1, P2 and P3. In other words, the runout end
of the middle belt 9b extends a certain distance
beyond the corresponding ends of the two lateral
belts 9a and 9c.
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In practice, the belts 9a, 9b and 9c are made of
a material such that they cannot be looped around
rollers tending to induce deformation (rollers with
concave surfaces, for example), reducing the width
at the point where the three paths P1, P2 and P3
converge. Accordingly, given that the three belts
must be looped over cylindrical rollers of which
the axial length will be matched to the width of
the belts, as aforementioned, the three runout
portions must present the type of configuration
illustrated in figures 2 and 4.
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Figure 4 illustrates the assembly table 8 in an
embodiment alternative to the one illustrated in
figure 2 and described in detail above. The table 8
of figure 4 again presents three belts 9a, 9b and
9c extending substantially one alongside the other
along the relative paths P1, P2 and P3, from the
upstream rollers 10a, 10b and 10c to the downstream
rollers 11a, 11b and 11c. In contrast to the table
of figure 2, however, the downstream rollers 11a,
11b and 11c are positioned substantially alongside
one another so that there is no projection of the
central belt 9b beyond the lateral belts 9a and 9c.
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In the context of the machine 1, the belts 9a, 9b
and 9c constitute means 22 by which the rods 2a, 2b
and 2c are conveyed along the corresponding feed
paths P1, P2 and P3.
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The guide means 100, indicated schematically in
figures 1 and 4 as blocks, can also be embodied so
as to incorporate the striker device supporting and
guiding the rods 2a, 2b and 2c during the step of
cutting the rods into sticks.
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The operation of the machine 1 is easily deduced
from the foregoing description, and therefore will
not be described further.
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It will be noted all the same that the convergent
arrangement of at least one part of the paths P1,
P2 and P3 is instrumental in enabling the cigarette
rods 2a, 2b and 2c to be kept particularly close
together on reaching the cutter head 18, and thus
ensuring that the sticks are cut correctly.
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In further possible embodiments of the present
invention, not illustrated but falling nonetheless
within the scope of the disclosure, the convergent
part of the feed paths P1, P2 and P3 could extend
along the table 8 only, in which case the rods 2a,
2b and 2c would advance parallel one with another
downstream of the convergent part, oriented by the
guide means 100, or alternatively, the convergence
could be limited to the guide means 100 only, in
which case these would be equipped with suitable
means by which to take up the cigarette rods 2a, 2b
and 2c from beams 20a, 20b and 20c substantially
parallel one with another.
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In particular, and referring to the examples of
figures 2 and 4, even if the angle of convergence
between the two outermost paths P1 and P3 can be
considered negligible in relation to the overall
length of the forming beams and therefore having no
influence on correct adjustment of the transverse
cut made through the rods 2a, 2b and 2c, the rods
could nonetheless be diverted immediately upstream
of the cutter head 18, by the guide means 100, in
such a manner as to bring the paths P1, P2 and P3
parallel one with another.