Method and apparatus for making filter cigarettes

The web of tipping paper which is being advanced in a filter tipping machine from a source to the station where the web is subdivided into uniting bands ready for draping around groups of coaxial plain cigarettes and filter rod sections is provided with projecting portions which are at least partially removed by a rotary grinding tool to provide the web with a pattern of perforations which determine the degree of ventilation of the filter cigarettes. The position of the running web relative to the tool and/or vice versa is adjustable in dependency upon one or more parameters of the finished filter cigarettes to thus vary the permeability of the uniting bands when the one or more monitored parameters of the filter cigarettes depart from the desired values.

BACKGROUND OF THE INVENTION 
The invention relates to improvements in methods of and in apparatus for 
making rod-shaped smokers' products of the type wherein a 
tobacco-containing section is attached to one end of a filter material 
containing section by an adhesive-carrying uniting band. A large majority 
of such smokers' products constitute (and will hereinafter be referred to 
as) filter cigarettes. 
Apparatus which are presently utilized for the mass production of filter 
cigarettes are known as filter tipping machines or filter assemblers. Well 
known types of such machines are MAX 70, MAX 90, MAX 100 and MAX-S filter 
assemblers which are produced and distributed by the assignee of the 
present application. Such machines are normally assembled with plain 
cigarette makers and filter rod makers into production lines (e.g., those 
known as PROTOS 2, PROTOS 70, PROTOS 90 and PROTOS 100, all produced and 
distributed by the assignee of the present application) which are capable 
of turning out huge quantities of filter cigarettes per unit of time. 
A MAX filter assembler is designed to transport a continuous series of 
successive groups of coaxial plain cigarettes and filter rod sections 
sideways, i.e., transversely of the longitudinal axes of such groups. Each 
group can contain plain cigarettes of single or multiple (e.g., double) 
unit length and a corresponding number of filter rod sections of unit 
length or multiple unit length. It is presently preferred to assemble 
groups wherein a filter rod section of double unit length is flanked by 
two plain cigarettes of unit length. Successive groups of the series are 
provided with adhesive-carrying uniting bands made of so-called tipping 
paper, and the bands are convoluted around the filter rod sections of 
double unit length as well as around the adjacent portions of the plain 
cigarettes to convert each group into a filter cigarette of double unit 
length. Each such filter cigarette of double unit length is thereupon 
severed midway across its filter rod section of double unit length to 
yield a pair of filter cigarettes of unit length. The uniting bands are 
obtained by advancing a continuous web of tipping paper (e.g., imitation 
cork) from a bobbin, reel or another suitable source, first past an 
adhesive applying station and thereupon past a severing or subdividing 
station wherein the leader of the web is subdivided into a series of 
successive uniting bands ready to be draped around selected portions of 
successive groups of rod-shaped tobacco containing and filter material 
containing sections. 
It is also known to employ apparatus of the above outlined character for 
the making of so-called ventilated filter cigarettes having tubular 
wrappers which permit cool atmospheric air to penetrate into the column of 
tobacco smoke flowing from the lighted end of the filter cigarette into a 
smoker's mouth. The inflowing atmospheric air is to reduce condensate and 
nicotine contents of tobacco smoke, i.e., to produce a diluting effect 
upon tobacco smoke. 
Heretofore known procedures for the making of ventilated filter cigarettes 
include the making of perforations in the tubular wrappers of filter 
cigarettes of unit length or multiple unit length or the utilization of 
preperforated tipping paper. The tubular wrappers of the filter rod 
sections and the filter material of such sections must exhibit an adequate 
permeability to the inflow of air if the ventilated filter cigarettes are 
to be provided with convoluted uniting bands made of preperforated tipping 
paper. A drawback of apparatus which produce ventilated filter cigarettes 
by using off-line perforated tipping paper is that it is not possible to 
immediately influence the permeability of the wrappers of filter 
cigarettes if the testing of ventilated cigarettes downstream of the 
station for the application of uniting bands made of preperforated tipping 
paper indicates that the actual permeability is insufficient or excessive. 
The testing can involve a determination of the so-called draw resistance 
of filter cigarettes or directly the rate of inflow of air into their 
filter mouthpieces. 
Commonly owned U.S. Pat. No. 4,825,883 (granted May 2, 1989 to Hinz et al. 
for "Method of and machine for making filter cigarettes from pairs of 
plain cigarettes of double unit length") discloses an apparatus wherein 
the ventilating unit includes a device for making perforations in the 
tubular wrappers of filter cigarettes of multiple unit length or in the 
web of tipping paper upstream of the location where the leader of the wed 
is subdivided into discrete uniting bands. The details of the device which 
is to perforate the web of tipping paper are not disclosed; in fact, 
applicant is not aware of any apparatus capable of making perforations in 
a running web of tipping paper in a filter cigarette maker or assembler. 
OBJECTS OF THE INVENTION 
An object of the invention is to provide a method of influencing the 
permeability of a web of tipping paper which is used in a filter cigarette 
assembler. 
Another object of the invention is to provide a method which can be 
resorted to in line, i.e., while a web of tipping paper is in the process 
of advancing in a filter cigarette assembler toward the station where its 
leader is divided into a series of uniting bands ready to be applied to 
groups of coaxial rod-shaped articles of the tobacco processing industry. 
A further object of the invention is to provide a method which renders it 
possible to select in advance, or to vary, the ability of a running web of 
tipping paper to permit the flow of atmspheric air into a column of 
tobacco smoke. 
An additional object of the invention is to provide a novel and improved 
apparatus for the practice of the above outlined method. 
Still another object of the invention is to provide a filter assembler 
which is provided with an apparatus for making perforations in a running 
web of tipping paper. 
Another object of the invention is to provide a filter cigarette production 
line which embodies one or more apparatus for influencing the permeability 
of a running web of tipping paper serving to connect coaxial plain 
cigarettes and filter rod sections to each other. 
A further object of the invention is to provide an adjustable apparatus for 
influencing the permeability of a running web of tipping paper in a filter 
cigarette maker. 
An additional object of the invention is to provide the apparatus with 
novel and improved means for determining the locations and/or the size of 
perforations to be made in a running web of tipping paper. 
Still another object of the invention is to provide filter cigarettes 
employing uniting bands made from tipping paper which has been perforated 
in the above outlined apparatus and in accordance with the above outlined 
method. 
A further object of the invention is to provide a wed perforating apparatus 
which can be installed in existing filter tipping machines to influence 
the permeability of a running web of tipping paper, such as imitation cork 
or the like. 
SUMMARY OF THE INVENTION 
One feature of the present invention resides in the provision of a method 
of making filter cigarettes of the type wherein groups of plain cigarettes 
and filter rod sections are held in axial alignment by convoluted 
adhesive-carrying uniting bands. Each group can comprise one or more plain 
cigarettes and one or more filter rod sections of unit length or multiple 
unit length. The method comprises the steps of conveying a series of 
successive groups (preferably sideways) along a first path, advancing a 
web of coherent uniting bands from a source (such as a bobbin or reel) 
along a second path, displacing selected portions of the web and at least 
partially removing at least some of the displaced selected portions to 
thus provide the web with perforations the number and the dimensions of 
which determine the permeability of the thus treated web, subdividing the 
perforated web into discrete uniting bands, and convoluting the discrete 
uniting bands around the groups in the first path. 
The removing step can include grinding and/or similarly treating the at 
least some displaced portions of the web in the second path. 
The web is advanced along the second path in a predetermined direction and 
the displacing step is carried out in a first portion of the second path. 
The removing step can be carried out in or at the first portion of the 
second path; however, in accordance with a presently preferred embodiment 
of the improved method, the removing step is carried out in a second 
portion of the second path downstream of the first portion (as seen in the 
predetermined direction). 
The conveying step includes moving the groups along the first path in a 
preselected direction and the convoluting step is carried out in a first 
portion of the first path. The method can further comprise the steps of 
monitoring at least one variable parameter of the groups in a second 
portion of the first path downstream of the first portion (as seen in the 
preselected direction), generating signals denoting the at least one 
parameter of the groups, and utilizing the signals for regulation of the 
removing step so that the permeability of uniting bands varies as a 
function of variations of the at least one parameter. For example, the at 
least one parameter can constitute the permeability of tubular wrappers of 
groups of plain cigarettes and filter rod sections downstram of the locus 
of the convoluting step. The utilizing step can include regulating the 
removing step so that the at least one variable parameter at least 
approximates a predetermined value; for example, the permeability of the 
tubular wrappers of the groups downstream of the locus of the convoluting 
step can be maintained at or close to a predetermined value by the 
expedient of regulating the removing step, e.g., by increasing the number 
and/or the dimensions of the perforations. 
Another feature of the invention resides in the provision of an apparatus 
for making filter cigarettes wherein groups of plain cigarettes and filter 
rod sections are held in axial alignment by convoluted adhesive-carrying 
uniting bands. The improved apparatus comprises means for conveying a 
series of successive groups along a first path, means for advancing a web 
of coherent uniting bands from a source along a second path, means for 
displacing selected portions of the advancing web relative to the second 
path, means for at least partially removing material from at least some of 
the displaced selected portions to thus provide the web with perforations 
which determine the permeability of the web, means for subdividing the 
perforated web into discrete uniting bands, and means for convoluting the 
discrete uniting bands around the groups in the first path. 
The displacing means can include a rotary displacing member having a 
surface which is adjacent a predetermined portion of the second path and 
projections extending from such surface and into the web in the 
predetermined portion of the second path. The aforementioned surface can 
constitute a peripheral surface of the rotary displacing member and the 
projections can be arrayed to jointly form a predetermined pattern of web 
displacing portions on the peripheral surface of the rotary displacing 
member. The displacing means can further comprise means for biasing the 
web against the projections; the rotary displacing member and the biasing 
means are or can be disposed at opposite sides of the second path. The 
biasing means can comprise a second rotary member having a resilient 
web-contacting radially outer portion of rubber or other suitable 
elastomeric material. 
The removing means can comprise a grinding device or an analogous material 
removing tool. The advancing means can include means for moving the web 
along the second path in a predetermined direction and the displacing 
means is adjacent a first portion of the second path. In accordance with a 
presently preferred embodiment, the removing means is adjacent a second 
portion of the second path downstream of the first portion (as seen in the 
predetermined direction). The grinding device can include a material 
removing tool which contacts at least the at least some displaced selected 
portions of the web in the second portion of the second path. 
The material removing means is or can be adjustable, and such apparatus can 
further comprise means for adjusting the removing means and/or the web in 
the second path relative to each other to thus select the extent of 
material removal at least from the at least some displaced selected 
portions of the running web. The adjusting means includes or can include 
suitable signal processing means. The conveying means can comprise means 
for moving the groups along the first path in a predetermined direction 
past and beyond the convoluting means and such apparatus can further 
comprise means for monitoring at least one variable parameter of the 
groups downstream of the convoluting means (as seen in the predetermined 
direction) and for generating signals which denote the monitored 
parameters of successive groups. Still further, this apparatus can 
comprise means (such as the aforementioned signal processing means) for 
influencing the adjusting means in response to the signals from the 
monitoring means. The influencing means can be designed in such a way that 
it maintains the at least one variable parameter at least close to a 
predetermined value by way of the adjusting means. The at least one 
parameter can constitute the permeability of tubular wrappers forming part 
of the groups downstream of the convoluting means. The removing means can 
include the aforementioned grinding or other suitable material removing 
tool, and the means for advancing the web along the second path can 
include means for looping the web around the tool to a variable extent to 
thus determine the extent of material removal at least from the at least 
some displaced selected portions of the web. Such apparatus can further 
comprise means for adjusting the looping means. For example, the looping 
means can comprise an adjustable roller and the adjusting means can embody 
means for moving the at least one roller and the tool relative to the 
other of the roller and the tool. The web is trained over the roller. It 
is presently preferred to employ adjusting means which is designed to move 
the roller relative to the tool and to thus vary the area of contact 
between the web and the tool. 
The removing means can include adjustable means (such as the aforementioned 
biasing means) for varying the tension of the web in the second path, 
means for monitoring the tension of the web in the second path, and means 
for adjusting the tension varying means when the monitored tension departs 
from a predetermined value. The tension varying (biasing) means can 
comprise a rotary member having a peripheral web-engaging surface, and the 
adjusting means can include means for varying the rotational speed of such 
rotary member. 
Still further, the apparatus can comprise means for evacuating the material 
which is being removed at least from the at least some displaced selected 
portions of the running web. For example, the evacuating means can 
comprise a fluid-operated evacuating device such as a vacuum cleaner. 
The novel features which are considered as characteristic of the invention 
are set forth in particular in the appended claims. The improved filter 
cigarette making apparatus itself, however, both as to its construction 
and its mode of operation, together with numerous additional features and 
advantages thereof, will be best understood upon perusal of the following 
detailed description of certain presently preferred specific embodiments 
with reference to the accompanying drawings.

DESCRIPTION OF PREFERRED EMBODIMENTS 
FIG. 1 shows a portion of an apparatus 1 which is a filter cigarette 
assembler (also called filter tipping machine) and is designed to assemble 
plain cigarettes, filter rod sections and adhesive-carrying discrete 
uniting bands into filter cigarettes of unit length or multiple unit 
length. The apparatus of FIG. 1 is similar to that disclosed in the 
aforementioned commonly owned U.S. Pat. No. 4,825,883 to Hinz et al. as 
well as to that disclosed in commonly owned U.S. Pat. No. 5,135,005 
granted Aug. 4, 1992 to Oesterling et al. for "Method of and apparatus for 
making filter cigarettes". The disclosures of these patents, as well as of 
all other patents mentioned in this specification, are incorporated herein 
by reference. 
The apparatus 1 of FIG. 1 comprises a drum-shaped transfer conveyor 2 which 
receives plain cigarettes 3 of double unit length from a suitable maker 
(not shown), such as a cigarette making machine utilized in one of the 
aforementioned production lines known as PROTOS. The conveyor 2 advances a 
series of successive equidistant plain cigarettes 3 sideways (i.e., at 
least substantially at right angles to their longitudinal axes) in a 
predetermined or preselected direction (as indicated by the arrow) into 
the peripheral flutes of a rotary drum-shaped cutting or severing conveyor 
4 cooperating with a rotary circular knife 6 to subdivide each plain 
cigarette 3 of double unit length into two coaxial plain cigarettes of 
unit length. Successive pairs of coaxial plain cigarettes of unit length 
are transferred into the axially parallel flutes in the peripheral surface 
of a rotary drum-shaped spreading conveyor 7 which cooperates with a 
stationary spreading cam or cooperates with or embodies other suitable 
means for moving the pairs of coaxial plain cigarettes of unit length 
axially and away from each other so that the thus separated pairs of plain 
cigarettes define clearances or gaps wide or long enough to receive filter 
rod sections of double unit length. The spreading conveyor 7 delivers 
successive pairs of axially spaced apart plain cigarettes of unit length 
into successive flutes in the peripheral surface of a rotary drum-shaped 
assembly conveyor 8 which is driven to rotate in a clockwise direction as 
viewed in FIG. 1. 
The frame of the apparatus 1 carries a magazine 9 for a supply of parallel 
filter rod sections (not specifically shown) of six times unit length. 
Such filter rod sections can be supplied by a filter rod production line 
known as AF2/KDF2 or AF3E/KDF3e (both produced and distributed by the 
assignee of the present application). The outlet of the magazine 9 admits 
filter rod sections of six times unit length into the flutes of a rotary 
drum-shaped severing conveyor 11 which cooperates with two axially and 
circumferentially spaced-apart rotary disc-shaped knives 12 to subdivide 
each filter rod section of six times unit length into three coaxial filter 
rod sections of double unit length. The severing conveyor 11 delivers sets 
of three coaxial filter rod sections each to a staggering conveyor 13 
which staggers the filter rod sections of each set in a circumferential 
direction and delivers discrete filter rod sections of double unit length 
into successive flutes of a rotary drum-shaped shuffling conveyor 14 
whereon at least some of the filter rod sections are caused to move 
axially in order to jointly form a single file or row of filter rod 
sections which are located one behind the other and move sideways toward 
and into the axially parallel peripheral flutes of a rotary drum-shaped 
accelerating conveyor 16. The latter introduces discrete filter rod 
sections of double unit length into the aforementioned spaces between 
successive pairs of coaxial plain cigarettes of unit length on the 
assembly conveyor 8 so that the latter accumulates groups of three coaxial 
rod-shaped articles each, namely two axially spaced apart plain cigarettes 
of unit length and a filter rod section of double unit length between 
them. The assembly conveyor 8 cooperates with stationary cams or with 
other suitable means for moving the plain cigarettes of successive groups 
axially and toward each other and into abutment with the adjacent end 
faces of the respective filter rod sections of double unit length so that 
the overall length of each thus condensed group matches the combined axial 
length of two plain cigarettes of unit length and a filter rod section of 
double unit length. The assembly conveyor 8 delivers such condensed groups 
of coaxial rod-shaped sections into successive flutes of a rotary 
drum-shaped transfer conveyor 17 which is driven to rotate in a 
counterclockwise direction (as viewed in FIG. 1). The conveyor 17 defines 
that portion of a (first) path for groups of coaxial rod-shaped sections 
in which successive groups receive and entrain discrete adhesive-carrying 
uniting bands constituting portions of a continuous web 18 of tipping 
paper (e.g., imitation cork or the like). 
The web 18 is being drawn from a suitable source here shown as an expiring 
reel 19 carrying a supply of convoluted tipping paper and being removably 
mounted in the frame of the filter cigarette making apparatus 1. In 
accordance with the invention, successive increments of the web running 
along its (second) path from the source 19 toward the transfer conveyor 17 
are caused to advance through a novel and improved in-line perforating or 
permeability influencing unit 21 the details of which are illustrated in 
FIGS. 2, 3 and 5. The thus perforated increments of the web 18 are 
thereupon caused to advance through a device 22 wherein selected portions 
of one side of the web are provided with films of a suitable adhesive in a 
manner well known in the art and not specifically shown in FIG. 1. The 
means for advancing the web 18 along its (second) path includes certain 
components of the perforating unit 21 and a rotary drum-shaped suction 
conveyor 23 cooperating with a rotary cylindrical cutter 24 to subdivide 
the leader of the adhesive-carrying and properly perforated web 18 into a 
series of discrete uniting bands ready to be affixed to successive groups 
of axially aligned rod-shaped sections being transported by the transfer 
conveyor 17 in a direction from the assembly conveyor 8 toward a 
convoluting or rolling station including a further rotary drum-shaped 
conveyor 29 forming part of the means for conveying the groups of axially 
aligned rod-shaped sections along their (first) path. 
A fresh reel 26 containing a web 27 of tipping paper is mounted in the 
frame of the filter cigarette making apparatus 1 adjacent the expiring 
reel 19. The leader of the web 27 is threaded through a splicer 28 which 
automatically attaches such leader to the web 18 when the supply of web on 
the reel 19 is about to expire. 
The transfer conveyor 17 delivers successive groups of rod-haped sections, 
each of which carries an adhesive-carrying uniting band, to the 
convoluting station including the aforementioned conveyor 29 and a rolling 
member 31. The parts 29 and 31 cooperate to roll the uniting bands around 
the respective filter rod sections of double unit length and around the 
adjacent inner end portions of the respective plain cigarettes of unit 
length to thus convert each group into a filter cigarette of double unit 
length. Such cigarettes of double unit length are taken over by a rotary 
drum-shaped transfer conveyor 32 which delivers them into the peripheral 
flutes of a rotary drum-shaped severing conveyor 33. The latter cooperates 
with a rotary disc-shaped knife 34 which severs each filter cigarette of 
double unit length midway between its ends so that each such cigarette 
yields two filter cigarettes of unit length having filter mouthpieces of 
unit length adjacent one another. The thus obtained pairs of coaxial 
filter cigarettes of unit length are transferred onto a further rotary 
drum-shaped conveyor 36 on which at least one of the two filter cigarettes 
of each pair is moved axially and away from the other filter cigarette to 
establish between them a gap of predetermined width or of a width 
exceeding a predetermined minimum width. 
The conveyor 36 delivers successive pairs of axially spaced-apart filter 
cigarettes of unit length onto a first rotary drum-shaped testing conveyor 
37 which, in turn, transfers such pairs onto a second rotary drum-shaped 
testing conveyor 38. The conveyor 37 transports pairs of filter cigarettes 
past a first signal generating monitoring device 37a which can be designed 
to generate signals denoting at least one parameter of each tested filter 
cigarette, for example, the density of the free axial ends of 
tobacco-containing sections of the filter cigarettes. The conveyor 38 
transports pairs of once tested filter cigarettes of unit length past a 
second signal generating monitoring device 38a which can comprise suitable 
pneumatically operated means for ascertaining deviations of one or more 
additional parameters of filter cigarettes from predetermined optimal 
values. For example, the monitoring device 38a can be designed to 
ascertain the density of the wrappers of the filter cigarettes, the degree 
of ventilation (i.e., the rate at which atmospheric air can penetrate into 
a column of tobacco smoke when the respective filter cigarette is 
lighted), the so-called draw resistance and/or other variable parameters. 
The signals which are generated by the monitoring devices 37a and 38a are 
transmitted to a signal processing unit 39 which is shown in FIG. 2 and 
which can be said to form part of the aforementioned perforating or 
permeability influencing unit 21 for the web 18 of tipping paper. The 
details of the monitoring devices 37a, 38a are known in the relevant art. 
The thus repeatedly tested pairs of coaxial and axially spaced apart filter 
cigarettes of unit length are taken over by a rotary drum-shaped 
intermediate conveyor 41 which delivers them onto a rotary drum-shaped 
transfer conveyor 42. The latter forms part of a conventional turn-around 
or inverting device 44 which inverts one filter cigarette of each pair 
end-for-end and inserts the thus inverted cigarette between two successive 
non-inverted cigarettes. As shown in FIG. 1, the conveyor 42 delivers one 
filter cigarette of each pair onto a rotary drum-shaped conveyor 43 which 
cooperates with a conical inverter 46. The conveyor 42 delivers the other 
filter cigarette of each pair onto a rotary drum-shaped conveyor 48 which, 
in turn, delivers such filter cigarettes into alternate axially parallel 
flutes in the peripheral surface of a further conveyor 47. The other 
flutes of the conveyor 47 receive inverted filter cigarettes from the 
inverter 46 by way of the conveyor 43 so that the flutes of the conveyor 
47 contain a single file of filter cigarettes of unit length having filter 
mouthpieces facing in the same direction. Successive filter cigarettes of 
such single file are delivered onto the upper reach of a take-off belt or 
chain conveyor 49 which delivers them to storage or directly to a packing 
machine, not shown. 
A turn-around device 44 of the type shown in FIG. 1 (utilizing a conical 
inverter 46) is disclosed, for example, in U.S. Pat. No. 3,625,103 granted 
Dec. 7, 1971 to Giatti for "Cigarette turn around". Another suitable 
turn-around device is disclosed in U.S. Pat. No. 3,585,546 granted Jun. 8, 
1971 to Koop for "Apparatus for inverting cigarettes or the like". 
The conveyor 49 can deliver the inverted and non-inverted filter cigarettes 
of unit length into a path wherein the filter cigarettes form a 
multi-layer (mass) flow and advance toward the next processing station. 
The reference character 51 denotes in FIG. 1 a further conveyor which 
serves to remove from the intermediate conveyor 41 those filter cigarettes 
which have been found to be detective by the monitoring means 37a and/or 
38a. The thus removed defective filter cigarettes can be transported to a 
collecting receptacle for defective articles or to a station where the 
tobacco particles are recovered for renewed processing in a cigarette 
making machine. The conveyor 51 need not serve the purpose or the sole 
purpose of removing defective filter cigarettes. For example, in addition 
to or in lieu of such function, the conveyor 51 can be actuated at regular 
or at random intervals for withdrawal of series of filter cigarettes which 
are to be tested in a laboratory for the potential presence of additional 
defects or for testing in order to ascertain the quality of the testing 
action of the monitoring means 37a and/or 38a. 
Save for the provision, the construction and the mode of operation of the 
perforating unit 21, the structure which is shown in FIG. 1 can constitute 
or form part of one of the aforementioned MAX filter tipping machines 
being produced and distributed by the assignee of the present application. 
The unit 21 comprises a device 52 which serves to displace selected 
portions (shown at 58 in FIG. 3) of the running web 18 from its path 
between the reel 19 and the adhesive applying device 22, and a device 53 
which serves to remove at least certain parts of at least some of the 
selected portions 58 to thus provide the web with an array of perforations 
(such as the array of perforations 71, 72 shown in FIG. 4) which determine 
the permeability of the thus treated web 18 upstream of the location (at 
the suction conveyor 23) where the leader of the web is severed by the 
knives of the rotary cutter 24 to yield a succession of discrete 
adhesive-carrying uniting bands ready to be affixed to the groups 
advancing with the transfer conveyor 17. 
The device 52 of the unit 21 which is shown in FIGS. 2, 3 and 5 comprises a 
rotary drum-shaped or roller-shaped displacing member 54 having a 
cylindrical peripheral surface provided with an array of suitably 
distributed raised portions 57 together constituting a pattern of 
projections which displace the selected portions 58 of the running web 18 
from the general plane of such web, e.g., in a manner as best shown in 
FIG. 5. The illustrated projections 57 of the member 54 can constitute 
conical or pyramidal protuberances which cause the adjacent portions of 
the running web 18 to penetrate into the elastically yieldable radially 
outermost portion or layer of a second rotary member 56 forming part of 
the displacing device 52. The rotary menders 54 and 56 confront each other 
and are located at opposite sides of the (second) path for the advancement 
of the web 18 from the reel 19 toward the adhesive applying device 22. The 
radially outermost portion of the rotary member 56 can constitute a layer 
of rubber or a suitable elastomeric synthetic plastic material. 
The dimensions, the number and/or the distribution of the projections 57 
will depend upon the desired permeability of the web 18, and such 
permeability is a function of the material removing action of the removing 
device 53 which is located downstream of the device 52, as seen in the 
direction of advancement of the web 18 through the unit 21. For example, 
the illustrated conical projections 57 can be replaced by or used jointly 
with cubical and/or trapezoidal projections having a square, rectangular 
or other suitable outline. The deformed portion 58 which is shown in FIG. 
5 has been drawn to a greatly enlarged scale for the sake of clarity. In 
actual practice, the deformed portions 58 are or can be so small that they 
are hardly detectable or not detectable by the naked eye. 
The illustrated device 53 comprises a rotary material removing tool 59, 
e.g., a grinding wheel or an equivalent of a grinding wheel which can be 
positioned to remove portions of or the entire projections 58 on the 
adjacent increments of the advancing web 18. FIG. 5 shows one possible 
position of the severing plane 69 of the rotary tool 58; the position of 
this plane is selected in such a way that the tool 59 removes the tip of 
the hollow conical projection 58 which is caused to move past and beyond 
the device 53. This provides the projection 58 with a centrally located 
round hole or perforation having a predetermined diameter. 
The unit 21 further comprises an adjustable guide roller 61 which is 
located downstream of the tool 59 and can be moved to any one of a 
plurality of different positions in each of which the peripheral surface 
of the tool 59 contacts a different portion of the running web 18. From 
the guide roller 61, the path for the web 18 extends toward and partially 
around a deflecting roller 62, thereupon around an adjustable floating or 
dancer roller 63, and thereafter over additional deflecting rollers 64 
which direct the web toward the adhesive applying device 22. 
The means for adjusting the guide roller 61 relative to the material 
removing tool 59 comprises a lever 66 which is turnable about the axis of 
a shaft 68 under the action of a prime mover 67 connected to an output of 
the signal processing unit 39. As mentioned above, pivoting of the guide 
roller 61 about the axis of the shaft 68 entails a change in the area of 
contact between the running web 18 and the peripheral surface of the 
material removing tool 59, i.e., the signal processing unit 39 can 
cooperate with the prime mover 67 (e.g., a reversible electric motor) to 
select the extent of the material removing action of the tool 59 upon some 
or all of the deformed portions 58 of the web 18. 
An advantage of conical or pyramidal projections 57 and deformed portions 
58 is that the dimensions of the perforations in the deformed portions 58 
can be varied in response to relative movement between the severing or 
material removing plane 69 (FIG. 5) of the tool 59 and the path for the 
web 18. The path for the web 18 moves closer to the severing plane 69 if 
the guide roller 61 is pivoted in a counterclockwise direction as viewed 
in FIG. 2. This results in the making of larger perforations or holes in 
the displaced portions 58 of the web 18. Inversely, the diameters of the 
perforations in the displaced portions 58 are reduced if the signals from 
the signal processing unit 39 induce the prime mover 67 to pivot the lever 
66 and the guide roller 61 in a clockwise direction. Since the unit 39 
receives signals from the signal generating means 37a, 38a which monitor 
the parameters of the groups of rod-shaped sections downstream of the 
convoluting station (at 29, 31), the unit 21 is capable of selecting the 
permeability of the uniting bands as a function of the extent of deviation 
of one or more parameters of the finished products (filter cigarettes) 
from a desired or optimum value. For example, the arrangement can be such 
that the signal processing unit 39 induces the prime mover 67 to change 
the position of the guide roller 61 relative to the material removing tool 
59 in a manner to ensure that the permeability of the wrappers of finished 
filter cigarettes to the flow of air into their interior will at least 
approximate a desired value. Alternatively or in addition to adjustment in 
dependency upon changes of the permeability of wrappers of finished filter 
cigarettes, the unit 39 can be designed to transmit to the prime mover 67 
signals which are necessary to ensure that the so-called draw resistance 
of the filter mouthpieces of finished filter cigarettes will at least 
approximate a desired or optimum resistance. 
It will be appreciated that the array of perforations 71, 72 shown in FIG. 
4 is but one of the practically infinite number of different formations or 
patterns which can be obtained by resorting to the unit 21 of FIGS. 2, 3 
or an equivalent or analogous unit. Furthermore, and as already mentioned 
before, it is possible to provide the peripheral surface of the rotary 
displacing member 54 with projections having a configuration other than a 
conical or pyramidal shape. Still further, it is possible to provide the 
member 54 with two or more sets of projections having different sizes 
and/or shapes. 
FIG. 2 shows that the shaft for the displacing member 54 is mounted on at 
least one lever or arm 73 which is pivotable about the axis of a fixed 
shaft 74. The means for changing the angular position of the lever 73 (and 
for thus changing the magnitude of force with which the projections 57 are 
urged into the material of the running web 18) includes a preferably 
adjustable device 76, e.g., a hydraulically or pneumatically operated 
cylinder and piston assembly. The latter can further serve as a means for 
moving the displacing member 54 away from the rotary member 56, e.g., to 
replace the member 54 with a member having a different array of 
projections 57 or a different number of projections and/or to replace the 
rotary member 56 with an intact member or with a member having a 
peripheral layer exhibiting a different resistance to deformation by the 
projections 57 or other types of web deforming protuberances. 
FIG. 2 further shows that the unit 21 can be provided or combined with a 
material evacuating device 77 (e.g., a fluid-operated evacuating device 
such as a vacuum cleaner) which has an intake at the region of contact 
between the running web 18 and the material removing tool 59 to collect 
and withdraw the material which is being removed from the displaced 
portions 58 when the unit 21 is in use. The reference character 78 denotes 
a flexible or rigid conduit which forms part of the evacuating device 77 
and establishes a path for withdrawal of removed material from the station 
including the material removing tool 59. 
The floating roller or dancer roller 63 is mounted on a lever or arm 79 
which is pivotable about the axis of a fixed shaft 81. The latter is 
mounted in the frame of the filter cigarette making apparatus, the same as 
the shafts 68 and 74. The position (i.e., the level) of the roller 63 is 
indicative of the tensional stress upon the running web 18, and such 
position is monitored by a sensor 82 which is operatively connected to the 
lever 79 and transmits corresponding signals (denoting the tensional 
stress upon the web 18) to the signal processing unit 39. The latter 
cooperates with a servomotor 83 to constitute a means for adjusting the 
RPM of the pressure applying rotary member 56 and more specifically the 
peripheral speed of the member 59. If the floating roller 63 descends to 
lower level, this indicates that the tensional stress upon the web 18 is 
reduced. The signal processing unit 39 then cooperates with the servomotor 
83 to reduce the peripheral speed of the rotary member 56 accordingly. 
Inversely, the peripheral speed of the rotary member 56 is increased by 
the adjusting means 39, 83 when the floating roller 63 rises to a higher 
level because this indicates that the tensional stress upon the running 
web 18 has been increased. An advantage of adjustability of the peripheral 
speed of the rotary member 56 is that the unit 21 can establish more 
satisfactory and more predictable conditions for the making of 
perforations by the material removing tool 59. In other words, such 
adjustment of the tensional stress upon the web 18 can enhance the quality 
of the filter cigarettes which are being delivered to the take-off 
conveyor 49. 
An important advantage of the improved method and apparatus is that they 
can be resorted to in order to provide uniting bands exhibiting the 
desired permeability to the inflow of atmospheric air into the filter 
mouthpieces of the filter cigarettes in a relatively simple and 
inexpensive way. In addition, it is possible to select the pattern of 
perforations not only for the purpose of ensuring adequate ventilation but 
also to avoid detection of perforations (e.g., by increasing their number) 
or by selecting for the perforations an eye-pleasing pattern. 
Another important advantage of the improved method and apparatus is that, 
by resorting to a grinding or an analogous material removing tool, one can 
select the degree of ventilation with a very high degree of accuracy and 
it is further possible to vary the rate of flow of air into the filter 
mouthpieces in a simple but highly predictable manner. 
Though it is possible to place the material removing tool 59 directly 
opposite the rotary displacing member 54 (i.e., to cause the tool 59 to 
occupy the position occupied in FIGS. 2 and 3 by the rotary member 56), 
the positioning of the tol 59 downstream of the material displacing member 
54 brings about the important advantage that the projections 57 are 
subject to less pronounced wear or no wear at all which, in turn, ensures 
that the member 54 can provide the running web 18 with a pattern of 
deformed portions 58 having an optimum size and shape for a long period of 
time. 
An advantage of the feature that the signal processing unit 39 can receive 
signals from monitoring means 37a, 38a which are adjacent the path of 
finished filter cigarettes is that the characteristics of finished filter 
cigarettes can be readily and practically instantaneously influenced as 
soon as the need arises, i.e., as soon as the monitoring means 37a and/or 
38a indicates that one or more monitored characteristics of the finished 
products depart from the desired optimum characteristics or from a range 
of acceptable characteristics. 
Practically instantaneous influencing of permeability of the uniting bands 
is made possible by installing the unit 21 in the filter cigarette making 
apparatus 1, i.e., the unit 21 can achieve in line influencing of 
permeability of the web 18 which is running from the source 19 toward the 
convoluting station at 29, 31. 
The improved method and apparatus are susceptible of numerous additional 
modifications without departing from the spirit of the invention. For 
example, the permeability of the web 18 can be monitored immediately 
downstream of the tool 59 and the material removing action of this tool 
can be altered as soon as the monitored permeability departs from a 
desired range of acceptable values. 
It has been found that the improved method and apparatus can be resorted to 
for the making of perforations in a web which is being advanced along its 
path at a speed necessary in modern high-speed filter cigarette making 
apparatus which are capable of turning out huge quantities of such 
products per unit of time. Moreover, the apparatus can be installed in 
existing types of filter tipping machines and/or production lines 
employing available filter cigarette assemblers. Still further, the 
utilization of mechanical material removing means contributes 
significantly to the simplicity, compactness and lower cost of the unit 21 
and of the apparatus which employs such unit. However, it is also within 
the scope of the invention to provide the unit 21 with material removing 
means other than one or more grinding tools or the like or to employ 
mechanical as well as other suitable material removing means. 
Without further analysis, the foregoing will so fully reveal the gist of 
the present invention that others can, by applying current knowledge, 
readily adapt it for various applications without omitting features that, 
from the standpoint of prior art, fairly constitute essential 
characteristics of the generic and specific aspects of the above outlined 
contribution to the art and, therefore, such adaptations should and are 
intended to be comprehended within the meaning and range of equivalence of 
the appended claims.