U.S. patent application number 10/967211 was filed with the patent office on 2005-04-21 for unit and a method for forming a continuous cigarette rod in a cigarette maker.
Invention is credited to Dall'Osso, Davide, Draghetti, Fiorenzo, Sartoni, Massimo.
Application Number | 20050081868 10/967211 |
Document ID | / |
Family ID | 34385799 |
Filed Date | 2005-04-21 |
United States Patent
Application |
20050081868 |
Kind Code |
A1 |
Dall'Osso, Davide ; et
al. |
April 21, 2005 |
Unit and a method for forming a continuous cigarette rod in a
cigarette maker
Abstract
A continuous cigarette rod is prepared by a unit comprising a
looped conveyor on which a continuous stream of tobacco particles
advances toward the entry point of a forming station where the rod
is assembled. Also forming part of the unit, ordered in sequence
along a predetermined feed path, are a first trimming device
designed to produce a cyclical skimming action, a compactor device
operating synchronously with the first trimming device, serving to
increase the density of the stream selectively at points coinciding
with the portions skimmed by the first trimming device, and a
second trimming device by which the thickness of the stream is
reduced uniformly to a prescribed value.
Inventors: |
Dall'Osso, Davide; (Bologna,
IT) ; Sartoni, Massimo; (Bologna, IT) ;
Draghetti, Fiorenzo; (Medicina, IT) |
Correspondence
Address: |
Harbin King & Klima
500 Ninth Street SE
Washington
DC
20003
US
|
Family ID: |
34385799 |
Appl. No.: |
10/967211 |
Filed: |
October 19, 2004 |
Current U.S.
Class: |
131/84.4 ;
131/84.1 |
Current CPC
Class: |
A24C 5/1842 20130101;
A24C 5/1814 20130101 |
Class at
Publication: |
131/084.4 ;
131/084.1 |
International
Class: |
A24C 005/18 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 20, 2003 |
IT |
BO2003A000612 |
Claims
What is claimed:
1) a unit for forming a continuous cigarette rod in a cigarette
making machine, comprising a conveyor serving to feed a continuous
stream of tobacco particles toward the entry point of a station
where the cigarette rod is formed, advancing in a predetermined
direction along a predetermined feed path, and incorporating,
ordered in sequence along the feed direction, a first trimming
device designed to reduce the thickness of the advancing stream,
means serving to densify predetermined portions of the stream, and
a second trimming device, wherein the first trimming device
operates cyclically and synchronously with the densifying means,
and is designed to reduce the thickness of the stream at given
portions corresponding to the predetermined densified portions.
2) A unit as in claim 1, wherein the first trimming device
comprises a rotating knife capable of movement cyclically between a
position of interference with the stream and a position distanced
from the stream.
3) A unit as in claim 2, wherein the first trimming device also
comprises a striker element against which the rotating knife
locates when assuming the position of interference with the
stream.
4) A method as in claim 3, wherein the rotating knife comprises a
disc rotatable about its own center, of which the peripheral edge
presents at least one radial blade occupying only a part of the
selfsame peripheral edge.
5) A unit as in claim 4, wherein the striker element is afforded by
a wall set transversely to the plane occupied by the disc.
6) A unit as in claim 4, wherein the striker element is capable of
reciprocating motion parallel to the predetermined direction
followed by the stream and synchronously with the rotating knife,
so as to accompany the movement of the blade and avoid sliding
contact therewith.
7) A unit as in claim 3, wherein the conveyor comprises an
aspirating belt of which a bottom branch is designed to retain the
tobacco particles by suction, also a pair of side walls positioned
to coincide at least with the first trimming device and projecting
from opposite edges of the bottom branch of the aspirating belt in
such a way as to establish a channel that serves to confine the
advancing stream and is enclosable by a bottom wall afforded by the
rotating knife when in the position of interference with the
stream.
8) A unit as in claim 6, wherein one of the side walls is provided
by the striker element.
9) A unit as in claim 1, further comprising means by which to
recover the shredded tobacco removed by trimming.
10) A method of forming a continuous cigarette rod in a cigarette
maker, comprising the step of feeding a continuous stream of
tobacco particles to the entry point of a forming station where the
cigarette rod is assembled, advancing in a predetermined direction
along a predetermined path, also the steps of subjecting the stream
to a first trimming action, then densifying predetermined portions
of the stream and thereafter subjecting the stream to a second
trimming action, wherein the first trimming step serves to reduce
the thickness of the stream of tobacco along given portions
corresponding to the predetermined densified portions.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a unit and to a method for
forming a continuous cigarette rod in a cigarette-making machine,
whether equipped with a single processing line or with two such
lines.
[0002] A conventional cigarette maker of the type that operates by
forming a continuous cigarette rod will generally comprise a
vertical riser duct fed at the bottom end with a continuous flow of
tobacco fibers and communicating at the top end with an aspirating
conveyor belt on which a continuous stream of loose tobacco filler
is formed.
[0003] The stream of tobacco filler is carried by the aspirating
belt along a predetermined path toward a feed unit supplying a
continuous strip of paper, which is directed onto and along a
forming block and wrapped progressively around the stream of
tobacco to generate a continuous cigarette rod.
[0004] To ensure that cigarettes have compact ends, thus minimizing
the loss of tobacco during successive steps of the manufacturing
process and when handled by the smoker, the cigarette maker is
equipped with suitable compression means, positioned along the
aforementioned path, of which the function is to densify and
compact predetermined portions of the tobacco stream that will
ultimately form the ends of the cigarettes.
[0005] The tobacco is attracted by a bottom branch of the
aspirating conveyor belt and gathered into a stream that does not
present a uniform thickness, but will be of thickness greater at
any given point than a prescribed value enabling it to be enveloped
by the paper. This non-uniformity of thickness is attenuated at a
first trimming station positioned upstream of the compression
means, which removes a part of the tobacco so as to render the
thickness of the stream more consistent and thus ensure that the
compacted portions are of uniform density.
[0006] Finally, the conventional machines in question comprise a
second trimming station downstream of the compression means, of
which the function is to adjust the stream of tobacco to the
aforementioned prescribed thickness before it is enveloped by the
paper strip.
[0007] The tobacco removed at the two trimming stations is
reclaimed by appropriate recovery means and put back into the cycle
at a given point upstream of where the stream is formed, for
example added to the continuous flow of tobacco fibers supplied to
the riser duct.
[0008] The reclaimed tobacco is however significantly degraded as
the result of undergoing two trimming steps, the particles being
unable to bind either with one another or with more fibrous
material and thus easily lost from the cut ends of a cigarette, so
that the compression step included precisely in order to prevent
such losses is rendered fruitless.
[0009] Due to the presence of extremely small particles, moreover,
the reclaimed tobacco has limited filling capacity and is not of
constant density, factors which jeopardize the quality of the
cigarettes.
[0010] In addition, the foregoing considerations apply for each of
the single lines in a cigarette maker generating two cigarette
rods, where the two lines run mutually parallel and at an extremely
short distance one from another for accepted reasons of structural
and functional optimization.
[0011] The object of the present invention is to provide a unit and
a method for forming a continuous rod in a cigarette maker such as
will be unaffected wholly or at least in part by the aforementioned
drawback.
[0012] One object of the invention in particular is to provide a
unit for forming a continuous cigarette rod in a cigarette maker,
and a relative method, such as will ensure that the reclaimable
degraded tobacco is not shredded to excess.
SUMMARY OF THE INVENTION
[0013] The stated object and others besides are realized according
to the present invention in a unit for forming a continuous
cigarette rod in a cigarette maker, equipped with a conveyor
serving to feed a continuous stream of tobacco particles toward the
entry point of a station where the cigarette rod is formed,
advancing in a predetermined direction along a predetermined feed
path.
[0014] Also forming part of the unit disclosed, ordered in sequence
along the feed direction, are a first trimming device designed to
reduce the thickness of the advancing stream, means serving to
densify predetermined portions of the stream, and a second trimming
device, of which the first trimming device operates cyclically and
synchronously with the densifying means and serves to reduce the
thickness of the stream at given portions corresponding to the
predetermined densified portions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The invention will now be described in detail, by way of
example, with the aid of the accompanying drawings, in which:
[0016] FIG. 1 is a schematic elevation view of a unit for forming a
continuous cigarette rod, embodied in accordance with the present
invention;
[0017] FIG. 2 shows a detail of the unit in FIG. 1, viewed from
above with certain parts omitted better to reveal others;
[0018] FIG. 3 is the section on III-III in FIG. 2;
[0019] FIGS. 4a, 4b, 4c and 4d illustrate successive processing
steps performed on the tobacco rod by the unit according to the
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] FIG. 1 of the drawings illustrates a unit 1 for forming a
continuous cigarette rod 2, constituting part of a cigarette-making
machine.
[0021] Such a unit 1 comprises a conveyor 3 by which a continuous
stream 4 of tobacco particles is fed toward the entry point 5 of a
forming station 6 serving to generate a continuous cigarette rod 2,
advancing in a predetermined direction 7 along a predetermined path
8. The forming station 6 is of conventional embodiment and
therefore not described further.
[0022] The conveyor 3 preferably takes the form of an aspirating
belt 9 looped around rollers 10 at each end (one only of which is
illustrated in FIG. 1) rotatable about mutually parallel and
horizontal axes. The aspirating belt 9 establishes a closed loop
compassing a chamber 11 connected by way of a relative duct 12 to a
source of negative pressure (not illustrated) and delimited at the
bottom by a wall 13 pierced with suction holes 14.
[0023] The bottom branch 15 of the conveyor belt 9 runs in sliding
contact with the wall 13 and is able to retain the fibrous tobacco
particles P by suction as they emerge from a vertical riser duct 16
(of which only the left hand part is shown in FIG. 1) positioned
beneath the bottom branch 15, so that the tobacco particles are
formed into a continuous stream 4.
[0024] Operating at the entry point 5 of the station 6 where the
continuous cigarette rod 2 is formed, the unit 1 comprises a looped
conveyor 17 of which one branch extends beneath the bottom branch
15 of the aspirating belt 9, occupying a zone of convergence with
this same belt 9.
[0025] The looped conveyor 17 passes around rollers 18 (one only of
which is illustrated in FIG. 1) and includes a top branch 19
located in sliding contact with a table 20, which serves to support
a strip of cigarette paper 21 decoiled from a roll 22.
[0026] The stream 4 of tobacco filler is released by the aspirating
conveyor 9 onto the strip of paper 21 and carried into the forming
station 6, where it is enveloped by the selfsame paper 21.
[0027] To prepare the stream 4 of tobacco filler for the subsequent
step of being enveloped in the paper 21, predetermined portions C
of densified consistency are created (see FIGS. 4b to 4d), such as
will prevent the filler being shed from the cut ends of the single
cigarettes during subsequent steps of the manufacturing process.
Accordingly, the unit 1 comprises a first trimming device 23
installed on the predetermined path 8 followed by the stream 4 and
operating upstream of the forming station 6, also means 24
operating downstream of the first trimming device 23 relative to
the feed direction 7 and serving to densify parts of the tobacco
filler coinciding with the portions C aforementioned, and a second
trimming device 25 operating downstream of the densifying means
24.
[0028] The first trimming device 23 brings about a first reduction
in thickness of the stream 4 of tobacco filler at predetermined
areas, as will become clear in due course.
[0029] The densifying means 24 and the second trimming device 25
are of conventional type. In the example illustrated, the
densifying means 24 consist in cam-operated forcing elements (one
for each line) and the second trimming device 25 comprises a pair
of contrarotating circular blades.
[0030] Located in conventional manner beneath the first trimming
device 23 and second trimming device 25 are respective recipients,
indicated schematically as blocks denoted 26, positioned to collect
the shredded tobacco removed by the trimming operation. The
reclaimable shredded tobacco is directed back into the processing
cycle through the action of conventional recovery means not
illustrated in the drawings.
[0031] As illustrated in FIGS. 2 and 3 and FIG. 4, the first
trimming device 23 serves to reduce the thickness of the stream 4
at predetermined areas corresponding to the aforementioned
predetermined densified portions C, and is therefore synchronized
in operation with the densifying means 24.
[0032] The densifying means 24 and the first trimming device 23
operate synchronously with a cutter of familiar type, not
illustrated, located downstream of the forming station 6 and timed
to divide the continuous cigarette rod into single sticks in such a
manner that the densified areas coincide with the cut ends of the
sticks.
[0033] More precisely, and referring to FIGS. 4a, 4b, 4c and 4d,
because the stream 4 transported away from the riser duct 16 is of
irregular thickness and presents a non-uniform profile,
deliberately accentuated in FIG. 4a, it is subjected to a first
trimming step (FIG. 4b) only along the predetermined portions C
destined to undergo the action of the densifying means 24, in such
a way as to render the thickness of these same portions C uniform
at a predetermined value S1 (FIG. 4c).
[0034] Following the compression step, the stream 4 undergoes a
second trimming step (FIG. 4d) along its entire length, in such a
way as to establish a predetermined thickness denoted S2.
[0035] In this way, the portions N not subjected to the action of
the densifying means 24 are trimmed once only, with the result that
the quantity of tobacco ultimately degraded is substantially
reduced.
[0036] Referring to FIGS. 2 and 3, the first trimming device 23,
designed to carry out the first trimming step, comprises a rotating
knife 27 spaced apart from the bottom branch 15 of the aspirating
belt 9 at a distance equivalent to the first thickness S1.
[0037] More exactly, the rotating knife 27 comprises a disc 28
furnished with at least one blade 30 that extends radially from the
peripheral edge 29 of the disc 28.
[0038] As illustrated in FIG. 2, the disc 28 presents just one
blade 30 appearing as an arc to a circle concentric with the disc.
The number of individual blades 30 presented by the disc 28, the
angular distance compassed by each blade 30 on the edge 29 of the
disc 28, and the radius of the blade 30, are design parameters that
can vary, without prejudice to the scope of the present invention,
according to the characteristics of the cigarettes in production or
to the specifications of the machine.
[0039] The disc 28 rotates about an axis X coinciding with its
center, extending at right angles to the wall 13 of the suction
chamber 11 and the bottom branch 15 of the aspirating belt 9.
[0040] When the rotating knife 27 assumes the position of
interference with the stream 4 of tobacco, the blade 30 brushes
against a locating or striker element 31 afforded by a wall 32 set
transversely to the plane occupied by the disc 28 and extending
parallel to the stream 4. To advantage, the striker element 31 is
also capable of reciprocating motion in a direction parallel to the
predetermined feed direction 7 followed by the stream 4 of tobacco,
generated synchronously with the rotating knife 27, so as to avoid
sliding contact with the movement of the blade 30 by accompanying
its movement.
[0041] In effect, as the blade 30 skims the stream 4 of tobacco,
the striker element 31 shifts in the same direction V1 and at the
same speed as the blade 30. As the blade 30 then completes a full
revolution and rotates toward the position of interference, the
striker element 31 will shift in the opposite direction V2 so as to
regain its starting position (FIG. 2).
[0042] In the preferred embodiment illustrated, the stream 4 of
tobacco advances along a confining channel 34 created between side
walls denoted 33a and 33b. With the knife 27 in the position of
interference, the blade 30 functions as a third wall 35 enclosing
the channel 34.
[0043] It will be evident that the drawbacks associated with the
prior art are overcome by the invention and that the stated objects
are realized in a first trimming device 23 as described and
illustrated, which operates cyclically and synchronously with the
densifying means 24 in such a way as to reduce the thickness of the
stream 4 of tobacco filler at selected areas coinciding with the
predetermined densified portions C aforementioned.
[0044] The method and the unit according to the present invention
are instrumental in improving the quality of reclaimed tobacco.
[0045] In practice, the only parts of the stream 4 of tobacco
filler subjected to two trimming actions are the compacted portions
C.
[0046] It follows that the average size of the recycled tobacco
particles will be larger than that of the particles constituting
the fraction removed by two successive trimming steps.
[0047] Given the increased average size of the particles in
question, the filling capacity of the tobacco is improved compared
to the prior art and the finished cigarettes will present a more
uniform distribution of tobacco filler from end to end.
[0048] Finally, the generally larger reclaimed tobacco particles
will bind more securely with the fibrous material, rather than
being easily shed from the ends of the cigarette during subsequent
processing operations or when handled by the smoker.
[0049] It will be seen that in FIGS. 2 and 3, which refer to a
cigarette maker with two cigarette rod forming lines, a second
stream 4 of tobacco filler, a second channel 34 and a second knife
23 are shown in phantom lines.
* * * * *