Method and apparatus for regulating the permeability of wrapping material for rod-shaped smokers' products

A web which is converted into wrappers of plain or filter cigarettes, or the wrapper or each cigarette is perforated by needles, teeth, punching tools, sparks or laser beams prior to arrival of corresponding cigarettes at a pneumatic testing station. The testing device at such station transmits signals which denote the permeability of successive wrappers, and the signals are compared with a reference signal denoting the desired permeability of wrappers. If the monitored permeability deviates from the desired permeability, the device which makes holes in the web or in the wrappers is automatically adjusted to change the combined area of holes.

CROSS-REFERENCE TO RELATED APPLICATION 
The method and apparatus of the present invention constitute an improvement 
and a further development of the method and apparatus disclosed in the 
commonly owned copending application Ser. No. 735,166 filed Oct. 26, 1976 
by Alfred Hinzmann now U.S. Pat. No. 4,110,448. 
BACKGROUND OF THE INVENTION 
The present invention relates to a method and apparatus for providing the 
wrappers of rod-shaped smokers' products with perforations or other types 
of holes which admit atmospheric air into the column of tobacco smoke 
entering a smoker's mouth. More, particularly, the invention relates to a 
method and apparatus for regulating and maintaining at a desired level the 
rate of admission of cool atmospheric air into the column of tobacco smoke 
in a region which is preferably close to one end of a rod-shaped smoker's 
product, such as a plain or filter tipped cigarette, cigarillo or cigar. 
Still more particularly, the invention relates to improvements in a method 
and apparatus for regulating the permeability of wrapping material for 
rod-shaped smokers' products to insure that the wrapper of each and every 
product which leaves the maker (or at least the great majority of such 
products) will exhibit an optimum permeability. 
The provision of the wrappers of cigarettes or like rod-shaped smokers' 
products (hereinafter called cigarettes or filter cigarettes) with 
so-called climatic zones (i.e., with zones which are perforated in order 
to permit energy of cool atmospheric air) is becoming increasingly 
popular; in fact, many manufacturers of cigarettes demand that each 
machine for the making of cigarettes be equipped with apparatus which can 
perforate selected portions of the wrappers in a region close to one or 
both ends of a plain cigarette or in a region close to (and including) the 
mouthpiece of a filter cigarette. The admission of cool atmospheric air 
into the column of tobacco smoke flowing into the smoker's mouth reduces 
the percentage of nicotine and condensate. Furthermore, atmospheric air 
reduces the temperature of the smoke column. Presently known proposals to 
perforate the wrappers of cigarettes or the like are not entirely 
satisfactory, mainly because the quantity of admitted atmospheric air 
varies from cigarette to cigarette or from cigarettes in one pack or 
carton to cigarettes in another pack or carton. This is an irritant to the 
purchaser of cigarettes, especially if the differences between the 
permeabilities of wrappers of successively lighted cigarettes are readily 
detectable. 
OBJECTS AND SUMMARY OF THE INVENTION 
An object of the invention is to provide a novel and improved method which 
insures that the wrapper of each and every cigarette or an analogous 
article of a long series of articles exhibits identical permeability, 
i.e., that each such article can admit identical quantities of atmospheric 
air into the column of tobacco smoke in a lighted article. 
Another object of the invention is to provide a method of the just outlined 
character which renders it possible to rapidly change the permeability of 
wrappers when the detected permeability deviates from an optimum value. 
A further object of the invention is to provide a method which can be 
resorted to irrespective of the exact nature of instrumentalities which 
are used to perforate the wrappers. 
An additional object of the invention is to provide a method which can be 
practiced by resorting to relatively simple and compact apparatus. 
Another object of the invention is to provide a novel and improved 
apparatus for regulating the permeability of wrappers of plain or filter 
cigarettes or analagous rod-shaped smokers' products. 
An ancillary object of the invention is to provide an apparatus which can 
include one or more conventional component parts of presently known makers 
of cigarettes or the like and which can be incorporated in such makers 
with a minimum of cost. 
A further object of the invention is to provide an apparatus which can 
regulate the permeability of wrapping material at any one of several 
convenient locations in a cigarette maker or the like so that the 
installation of such apparatus contributes little to the bulk of existing 
makers. 
Another object of the invention is to provide an apparatus which reduces 
the number of rejects in a cigarette maker or the like by insuring that 
the permeability of the wrapper of each and every article which leaves the 
maker matches or closely approximates a desirable optimum value. 
One feature of the invention resides in the provision of a method of 
regulating the permeability of wrappers of rod-shaped articles (e.g., 
plain cigarettes and especially filter cigarettes) which constitute or 
form part of smokers' products. The method comprises the steps of making 
holes in the wrappers so as to permit entry of atmospheric air when the 
respective products are lighted at one end and a column of tobacco smoke 
is drawn through the other end of the products, testing the articles with 
a gaseous fluid including establishing a pressure differential between the 
interior and exterior of the wrappers (at least in the region of the 
holes) so that the testing fluid flows through the wrappers at a rate 
which is a function of the combined area of holes in the wrappers, 
monitoring the rate of fluid flow through the wrappers (e.g., by means of 
an electropneumatic transducer) and producing first signals which are 
indicative of the monitored rate, comparing the first signals with a 
preferably variable reference signal denoting the desired or optimum rate 
of fluid flow through the wrappers, generating a third signal (e.g., at 
the output of a signal comparing stage) which denotes the differences 
between the first signals and the selected reference signal, and utilizing 
the third signals to change the combined area of holes in the wrappers; 
this last mentioned step includes increasing the combined area of holes 
when the desired rate exceeds the monitored rate and reducing the combined 
area of holes when the desired rate is less than the monitored rate. The 
aforementioned steps are carried out automatically in the above-given 
sequence. 
The last mentioned step (of utilizing the third signals) can include 
changing the size and/or the number of holes in the wrappers. The size of 
holes can be changed in a number of ways, for example, by resorting to 
needles or analogous piercing instrumentalities whose cross-sectional area 
varies along their length, by burning holes into the material of the 
wrappers as a result of spark discharge whose intensity can be changed to 
thus change the size of the holes, or by changing the intensity of a beam 
of coherent radiation (preferably a laser beam) which is caused to impinge 
upon the material of the wrappers. The number of holes, too, can be 
changed in any one of several ways, for example, by increasing or reducing 
the number of piercing instrumentalities which penetrate into successive 
wrappers, by changing the number of punching tools which cooperate with 
suitable anvils to remove material from the wrappers, by changing the 
frequency of spark discharge per wrapper or by changing the frequency at 
whch a laser beam impinges upon successive wrappers. 
The first mentioned (hole making) step can also include rotating the 
articles about their respective axes and making holes in the wrappers of 
rotating articles, preferably by resorting to teeth, needles or analogous 
mechanical piercing instrumentalities. Such instrumentalities do not 
remove any material from the wrappers; they merely puncture the wrappers 
and bend the material around the locus of penetration. 
Still further, the first mentioned (hole making) step may include rotating 
the articles about their axes and removing material from the wrappers of 
rotating articles. Alternatively, such first step may comprise withdrawing 
a continuous web of cigarette paper, imitation cork or other flexible 
wrapping material from a reel or another suitable source of supply and 
providing holes (by means of punching tools, needles, spark discharge or 
laser beam) in selected portions of the web. The method then further 
comprises the step of converting the web into wrappers of rod-shaped 
articles prior to the testing step. The web may constitute flexible 
material which is draped around tobacco fillers or fillers consisting of 
filter material, or flexible material which is converted into uniting 
bands serving to connect filter plugs with wrapped tobacco fillers to form 
filter cigarettes, cigarillos or cigars. The subdivision of the web into 
portions of or entire wrappers (either prior or subsequent to draping) is 
carried out in such a way that each wrapper is formed with the same number 
of holes. 
As mentioned above, if the first (hole making) step includes subjecting the 
wrappers (or the material of the wrappers) to a mechanical piercing action 
(of conical needles or the like), the last step (of utilizing the third 
signals) includes varying the extent of the piercing action or the number 
of holes which are formed by the needles. 
If the first step includes effecting a spark discharge across the material 
of the wrappers so that the holes are formed by combustion of selected 
portions of the wrappers (preferably prior to draping of the web around 
one or more rod-like fillers), the last step includes changing the 
frequency and/or intensity of spark discharge per wrapper. 
If the first step includes directing at least one laser beam against 
successive wrappers (preferably before the web is draped around one or 
more rod-like fillers), the last step includes changing the intensity 
and/or the number of impingements of the beam upon successive wrappers. 
Automatic regulation of the hole making step insures that the number of 
articles (if any) whose wrappers exhibit unsatisfactory permeability is 
reduced to a minimum. Therefore, the number of rejects is also minimal and 
the consumer invariably receives a product which is less likely to affect 
his or her health because the column of smoke is mixed with a 
predetermined quantity of cooler atmospheric air. The manner in which 
articles having defective wrappers are segregated from acceptable articles 
subsequent to repeated testing is disclosed, for example, in commonly 
owned U.S. Pat. No. 3,847,044 granted Nov. 12, 1974 to Rudszinat. The 
number of segregated articles is reduced because many types of ejecting 
mechanisms for cigarettes or the like segregate articles whose wrappers 
exhibit excessive or insufficient porosity or permeability. The improved 
method insures that the permeability of each wrapper equals or exceeds a 
predetermined minimum value. 
The novel features which are considered as characteristic of the invention 
are set forth in particular in the appended claims. The improved apparatus 
itself, however, both as to its construction and its mode of operation, 
together with additional features and advantages thereof, will be best 
understood upon perusal of the following detailed description of certain 
specific embodiments with reference to the accompanying drawing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 shows a filter cigarette making machine of the type known as "MAX S" 
produced by Hauni-Werke Korber & Co. KG, Hamburg, Federal Republic 
Germany. The machine comprises a frame 5 which supports a rotary 
drum-shaped row forming conveyor 1. This conveyor can be said to form part 
of a cigarette maker which turns out plain cigarettes of unit length, for 
example, a machine known as GARANT (trademark) produced by Hauni-Werke. 
The conveyor 1 has peripheral flutes which are parallel to its axis and 
carry plain cigarettes of unit length in such a way that the cigarettes 
form two rows. The evenly numbered flutes transport a first row of plain 
cigarettes which are nearer to one axial end, and the oddly numbered 
flutes carry a second row of plain cigarettes which are nearer to the 
other axial end of the conveyor 1. 
Successive plain cigarettes of one row are introduced into successive 
flutes of one of two rotary drum-shaped aligning conveyors 2 which are 
mounted in the frame 5 adjacent the conveyor 1, and successive plain 
cigarettes of the other row transferred into successive flutes of a second 
rotary drum-shaped aligning conveyor 2. The conveyors 2 are driven at 
different speeds and/or transport the plain cigarettes of the respective 
rows through different distances so that each plain cigarette of one row 
is transferred into a peripheral flute of a rotary drum-shaped assembly 
conveyor 3 simultaneously with a plain cigarette of the other row. The 
transfer station between the conveyors 2 on the one hand the conveyor 3 on 
the other hand is shown at T1. Each flute of the assembly conveyor 3 which 
advances beyond the transfer station T1 contains two coaxial plain 
cigarettes of unit length which are preferably separated from each other 
by a gap whose width slightly exceeds the length of a filter mouthpiece or 
filter plug of double unit length. 
The upper portion of the frame 5 supports a magazine or hopper 4 for a 
supply of parallel filter rod sections FS of six times unit length. The 
outlet 4a of the magazine 4 receives a portion of a rotary drum-shaped 
severing conveyor 6 having peripheral flutes which receive filter rod 
sections FS and transport such sections sideways in a clockwise direction, 
as viewed in FIG. 1. Successive sections FS are moved seriatim past two 
rotary disk-shaped knives 7 which are disposed in different planes 
extending at right angles to the axis of the conveyor 6 and serve to 
subdivide the sections FS into groups of three coaxial filter rod sections 
or filter plugs of double unit length. 
Groups of three coaxial filter plugs each are transferred into the 
peripheral flutes of three rotary drum-shaped staggering conveyors 8 (only 
one shown in FIG. 1) which transport the respective plugs at different 
speeds and/or through different distances so as to shift the originally 
aligned plugs of each group in the circumferential direction of the 
illustrated conveyor 8. Individual plugs are thereupon transferred into 
successive flutes of a rotary drum-shaped shuffling conveyor 9 which 
conveyor 9 which cooperates with stationary cams 9a to shift some or all 
of the filter plugs axially and to thus array the plugs in the form of a 
single row wherein the plugs travel sideways and are in exact register 
with each other, i.e., the end faces of each preceding plug are coplanar 
with the end faces of the next-following plug. 
The shuffling conveyor 9 introduces successive plugs of the thus obtained 
now into successive flutes of a rotary drum-shaped accelerating conveyor 
11 which inserts plugs into successive flutes of the assembly conveyor 3 
at a second transfer station T2 located ahead of the station T1. The 
position of the accelerating conveyor 11 is such that the plugs which are 
admitted into successive flutes of the assembly conveyor 3 are located in 
the gaps between successive pairs of coaxial plain cigarettes of unit 
length as soon as the respective flutes of the conveyor 3 reach the 
transfer station T1. In other words, each flute of the conveyor 3 which 
advances beyond the transfer station T1 contains a group of three coaxial 
rod-shaped components including a centrally located filter plug of double 
unit length and two plain cigarettes of unit length. Such groups advance 
between two stationary condensing cams 3a which shift the plain cigarettes 
of successive groups axially toward each other to thereby move the inner 
end faces of the plain cigarettes into abutment with the adjacent end 
faces of the respective plug. The condensed groups are introduced into 
successive flutes of a rotary drum-shaped transfer conveyor 12 which is 
driven in a counterclockwise direction, as viewed in FIG. 1, and advances 
the groups past a rotary suction drum 19 serving to provide each group 
with an adhesive-coated uniting band. 
The upper left-hand portion of the frame 5 supports a spindle 15 for a reel 
14 consisting of a convoluted web material 13, such as cigarette paper, 
artificial cork or the like. The web 13 is withdrawn from the reel 14 by 
two advancing or transporting rolls 16 at least one of which is driven and 
the other of which is preferably biased against the one roll to advance 
the web 13 lengthwise in the direction indicated by arrow H. Successive 
increments of the web 13 which advance toward the nip of the rolls 16 move 
past and are flexed by the preferably sharp edge of a so-called curling 
tool 17 which may be of the type disclosed in commonly owned U.S. Pat. No. 
3,962,957 granted June 15, 1976 to Alfred Hinzmann. The purpose of the 
tool 17 is to equalize internal stresses in the material of the web and to 
impart to the web a tendency to curl in a direction which is desirable 
when the web is converted into a series of discrete uniting bands. The 
leader of the web 13 adheres to the periphery of the drum 19 which is 
formed with suction ports and rotates at a speed slightly exceeding the 
speed of lengthwise movement of the web under the action of advancing 
rolls 16. This insures that successive uniting bands are separated from 
each other by narrow clearances and the next-following bands cannot 
interfere with the application of preceding bands to successive groups of 
rod-shaped components in the flutes of the transfer conveyor 12. 
The suction drum 19 draws the web 13 through a paster 18 which coats one 
side of the web with a suitable adhesive (the adhesive is applied by a 
roller-shaped applicator 18a serving to coat that side of the web 13 which 
faces away from the periphery of the drum 19). The drum 19 cooperates with 
a rotary drum-shaped knife 21 having one or more blades which subdivide or 
sever the leader of the web 13 at regular intervals to form a succession 
of adhesive-coated uniting bands. Each band is applied to the oncoming 
group of rod-shaped components in a flute of the transfer conveyor 12 in 
such a way that the web extends tangentially of the group and adheres to 
the periphery of the respective filter plug of double unit length as well 
as to the inner end portions of the respective plain cigarettes of unit 
length. 
The transfer conveyor 12 delivers successive groups (each of which carries 
an adhesive-coated uniting band) into the flutes 22a (see FIG. 2) of a 
rotary drum-shaped wrapping conveyor 22 which cooperates with a stationary 
or mobile rolling device 23 to rotate successive groups about their 
respective axes and to thus convert the uniting bands into tubes which 
sealingly surround the respective filter plugs and the adjacent inner end 
portions of the respective plain cigarettes. Thus, each group is converted 
into a filter cigarette 39 (see FIGS. 2 and 3) of double unit length which 
is transported sideways. 
Successive filter cigarettes 39 are transferred onto a rotary drum-shaped 
rolling conveyor 24 cooperating with a perforating unit 25 which is 
constructed, assembled and adjustable in accordance with one embodiment of 
the invention. The purpose of the unit 25 is to provide portions of 
wrappers of successive filter cigarettes 39 of double unit length with 
perforations or holes which admit atmospheric air into the column of 
tobacco smoke flowing into the smoker's mouth. 
The conveyor 24 delivers successive filter cigarettes 39 into successive 
flutes of a rotary drum-shaped severing conveyor 26 which cooperates with 
a rotary disk-shaped knife 26a to sever each cigarette 39 midway between 
its ends (i.e., across the respective tube and filter plug of double unit 
length) so that each cigarette 39 yields two coaxial filter cigarettes Z 
(FIG. 4) of unit length. The severing conveyor 26 may form part of a 
testing device which detects defective filter cigarettes 39 (e.g., 
cigarettes having wrappers with open seams or cigarettes wherein one of 
the rod-shaped components is missing) and segregates defective cigarettes 
from satisfactory cigarettes 39. 
The conveyor 26 delivers satisfactory pairs of filter cigarettes Z of unit 
length into the flutes of a rotary drum-shaped conveyor 27 forming part of 
a turn-about device 29 of the type disclosed in commonly owned U.S. Pat. 
No. 3,583,546 granted June 8, 1971 to Koop. The purpose of the device 29 
is to turn one filter cigarette of each pair of coaxial filter cigarettes 
Z of unit length end-for-end and to place the inverted cigarettes between 
the non-inverted cigarettes (in the flutes of a drum 28 forming part of 
the device 29) so that the drum 28 transports a single row of filter 
cigarettes of unit length wherein all filter plugs or mouthpieces F' of 
unit length (see FIG. 4) face in the same direction. 
Successive filter cigarettes Z of the thus obtained single row are 
transferred onto a rotary drum-shaped conveyor 31 forming part of a 
pneumatic testing device which examines successive filter cigarettes and 
effects or causes segregation of satisfactory articles from defective 
articles. The ejection of defective filter cigarettes of unit length 
preferably takes place during transport in the flutes of a further rotary 
drum-shaped conveyor 32 which receives cigarettes from the conveyor 31 and 
delivers satisfactory filter cigarettes of unit length onto the upper 
reach of a belt conveyor 36 trained over several pulleys (one shown at 
34). The illustrated pulley 34 cooperates with a braking roller 33. The 
row of filter cigarettes on the upper reach of the belt conveyor 36 is 
transported into storage, into so-called chargers or trays, or directly 
into the magazine of a packing machine, not shown. 
The frame 5 further supports a second spindle 15A for a fresh reel 14A 
consisting of convoluted web material 13A. The leader of the web 13A is 
held in a position of readiness at a splicing station SD which comprises 
suitable means (not shown) for attaching the leader to the trailing 
portion of the web 13 when the supply of web on the expiring reel 14 is 
reduced to a predetermined minimum value. 
FIGS. 2 and 3 show the details of the perforating unit 25. The conveyor 24 
has ribs or projections 37 which alternate with convex rolling surface 
sections or facets 38 forming part of the cylindrical peripheral surface 
of the conveyor 24. The direction of rotation of the conveyor 24 is 
indicated by an arrow. The body of the conveyor 24 has suction ports 41 
which communicates with the sections 38 upstream of each rib 37 and 
suction ports 42 which communicate with the sections 38 downstream of each 
rib 37. The conveyor 22 delivers filter cigarettes 39 of double unit 
length in such a way that each cigarette 39 is attracted by a suction port 
41 immediately upstream of the neighboring rib 37. It is clear that the 
body of the conveyor 24 can be provided with rows of suction ports 41 and 
42, i.e., with two or more suction ports 41 upstream of each rib 37 and 
with two or more suction ports 42 downstream of each rib. The manner in 
which the suction ports 41, 42 are connected with a suction generating 
device (e.g., a suction fan, not shown) while the corresponding ribs 37 
travel from the transfer station between the conveyors 22, 24 to the 
transfer station between the conveyors 24, 26 is known from the art of 
machines for the transport and processing of rod-shaped smokers' products. 
As a rule, the body of the conveyor 24 will be formed with blind bores 
which are parallel to the axis of the conveyor 24 and communicates with 
the arcuate groove of a stationary valve plate which is adjacent to one 
end face of the conveyor 24. The groove of the valve plate is connected 
with the suction intake of a fan or the like. 
The length of each section or facet 38 (as considered in the 
circumferential direction of the conveyor 24) at least equals the 
circumference of a filter cigarette 39 of double unit length. The 
reference characters T denote the plain cigarettes and the reference 
character F denotes the filter plug or mouthpiece of the filter cigarette 
39 which is shown in FIG. 3. 
The perforating unit 25 comprises a housing having two sections 25a, 25b 
which define a compartment 43 for a carrier 44 of needle-like conical 
perforating or piercing elements 46. The elements 46 can be replaced by 
wedge-like teeth similar to those on a saw-tooth blade. Thus, instead of 
using two or more rows of needles, one can employ two or more serrated 
metallic or plastic strips having toothed (i.e., tapered) perforating 
elements. The carrier 44 has an elongated slot 47 (indicated in FIG. 2 by 
broken lines) which receives a guide pin 48 of the housing 25a, 25b. The 
pin 48 allows the carrier 44 to pivot relative to the housing 25a, 25b as 
well as to move lengthwise of the compartment 43. The slot 47 is adjacent 
to one end portion of the carrier 44, and the other end portion of the 
carrier has a transverse cylindrical bore 44a for a cylindrical eccentric 
51 on a shaft 49 which extends from the housing 25a, 25b. The shaft 49 is 
journalled in the housing section 25b. The housing 25 a, 25b is pivotable 
on a pin 53 which is mounted in or on the frame 5 (not shown in FIGS. 2 
and 3) so that the entire unit 25 can be pivoted (anticlockwise) away from 
the operative position of FIG. 2 or (clockwise) toward such operative 
position. A bolt 54 or other suitable means is provided for locking the 
unit 25 in the operative position of FIG. 2. If the attendant wishes to 
pivot the unit 25 to an inoperative position, e.g., to gain access to the 
exposed portions of the perforating elements 46, the bolt 54 is removed 
from its socket in the frame 5 and the unit 25 is pivoted anticloskwise, 
as viewed in FIG. 2. 
The operative position of the perforating unit 25 is selected in such a way 
that, when the bolt 54 extends into the aforementioned socket of the frame 
5, the width of the elongated gap G between the adjacent rolling facet or 
section 38 and the concave surfaces 56a, 56b of the housing sections 25a, 
25b is slightly less than the diameter of a filter cigarette 39 of double 
unit length. Thus, when a cigarette 39 reaches the perforating station 
between the conveyor 24 and unit 25, it is caused to roll about its own 
axis because it is engaged by the corresponding section 38 as well as by 
the surfaces 56a, 56b. This causes the cigarette 39 to roll backwards, 
i.e., from the rib 37 at the front end toward the rib 37 at the rear end 
of the respective section 38. The center of curvature of concave surfaces 
56a, 56b is located on the axis of the shaft 24a, the same as the centers 
of curvature of the convex sections 38. The perforating elements 46 form 
two rows which extend circumferentially of the conveyor 24 and are in 
register with the filter plugs F of successive filter cigarettes 39 of 
double unit length. The holes or perforations which are made by the 
elements 46 are preferably adjacent to the respective end portions of the 
filter plugs F, i.e., close to the locations where the filter plugs F abut 
against the inner ends of the respective plain cigarettes T. This insures 
that the mouthpiece of each filter cigarette of unit length has an annulus 
of perforations. 
In accordance with a slight modification which is not shown in the drawing, 
the illustrated conveyor 24 can be replaced with a conveyor having 
relatively shallow peripheral flutes and the unit 25 can be replaced with 
a unit which is longer (as considered in the circumferential direction of 
the associated conveyor) so that each cigarette 39 is caused to roll 
several times about its own axis during travel through the gap between the 
conveyor and the perforating unit. The latter is then preferably provided 
with one or more additional rows of needles or analogous perforating 
elements which make holes in successive filter plugs F in regions other 
than those which are perforated by the illustrated elements 46. For 
example, the arrangement may be such that each cigarette 39 is caused to 
complete two full revolutions about its own axis and the perforating unit 
may comprise four rows of needle-like perforating elements which may but 
need not perforate the corresponding portions of successive plugs F at the 
same time, i.e., one or more rows can perforate successive filter plugs F 
during a first stage of movement of each filter plug between the conveyor 
and the perforating unit and the other row or rows may perforate 
successive filter plugs F during the next-following stage or stages of 
such movement. 
The sections 38 together constitute a first surface at one side of the gap 
G and the surfaces 56a, 56b together constitute a second surface at the 
other side of the gap G opposite that section (or those sections) 38 which 
travels (or travel) below the unit 25. The needles 46 extend into the gap 
G beyond one of the first and second surfaces. 
FIG. 4 shows a portion of the testing conveyor 31, certain other details of 
the pneumatic testing unit which includes the conveyor 31, and means for 
automatically adjusting the position of the carrier 44 relative to the 
conveyor 24 when the quantity of air or another testing fluid passing 
through the perforations of the wrappers of filter plugs F' of successive 
filter cigarettes Z of unit length deviates from an optimum quantity. The 
conveyor 31 has flutes which are parallel to its axis and each of which is 
defined by two concave sockets 57 in the outer end faces of two aligned 
projections 58. The projections 58 have suction ports 59 which extend 
radially inwardly and attract the respective filter cigarettes Z of unit 
length during travel between the conveyors 28 and 32. Each pair of suction 
ports 59 communicate with a blind bore which is machined into the body of 
the conveyor 32 and communicates with the arcuate groove of a stationary 
valve plate (not shown) which is adjacent to one end face of the conveyor 
32. The groove of such valve plate is connected to the intake of a fan or 
the like which constitutes a suction generating device. The groove is long 
enough to attract the cigarettes Z during transport from the transfer 
station between the conveyors 28, 31 to the transfer station between the 
conveyors 31, 32. 
The testing unit which includes the conveyor 31 further comprises two 
additional stationary valve plates 62a, 62b which are respectively 
adjacent to and bear against the left-hand and right-hand end faces of the 
conveyor 31 and respectively include arcuate grooves 61a, 61b connected 
with conduits 64a, 64b. The conduits 64a, 64b communicate with a source 67 
of compressed air or another suitable gaseous testing fluid by way of a 
conduit 67a which contains a shutoff valve 68 and a preferably adjustable 
flow restrictor 69. If the flow restrictor 69 is not adjustable, the valve 
68 is preferably adjustable so that it can regulate the pressure of 
testing fluid which flows from the source 67 into the conduits 64a, 64b. 
A filter cigarette Z of unit length which is received in a flute (sockets 
57) of the conveyor 31 is biased against a flange 31A of the conveyor 31 
by a helical spring 66 which surrounds a nipple 63 abutting against the 
other end face of such cigarette. The nipple 63 is reciprocable in a 
second flange 31B of the conveyor 31. The flange 31A has bores 31D, one 
for each flute, which establish communication between the groove 61a of 
the valve plate 62a and the plain cigarettes of the respective filter 
cigarettes Z during travel toward, past and beyond the testing station of 
FIG. 4. The nipples 63 have axial bores 65 which establish communication 
betweeen the groove 61b and the right-hand end of the respective filter 
cigarette Z during travel past the testing station. The testing station 
extends between the grooves 61a and 61b. Each nipple 63 is retracted by a 
suitable stationary cam (not shown) before th coresponding flute reaches 
the transfer station between the conveyors 28, 31 so that the conveyor 28 
can deliver a filter cigarette Z into the oncoming flute of the conveyor 
31. The cam thereupon allows the spring 66 to expand and to move the end 
face of the plain cigarette T of the respective filter cigarette Z into 
abutment with the flange 31A whereby the interior of the wrapper of such 
filter cigarette communicates with the respective bore 31D. The nipple 63 
is retracted against the opposition of its spring 66 before the filter 
cigarette Z reaches the transfer station between the conveyors 31, 32 so 
that the tested filter cigarette Z can be accepted by the oncoming flute 
of the conveyor 32. Cams which are suitable for controlling the movements 
of nipples 63 under and against the action of associated springs 66 are 
known from the art of testing apparatus for cigarettes or the like. 
Reference may be had to commonly owned U.S. Pat. No. 3,555,883 granted 
Jan. 19, 1971 to Heitmann. 
Each filter plug F' which travels toward, past and beyond the testing 
station between the grooves 61a, 6b of FIG. 4 is provided with at least 
one circumferentially extending row of holes or perforations because such 
filter plug has advanced all the way through the gap G between the 
conveyor 24 and perforating unit 25 of FIGS. 1 to 3. The arrangement is 
preferably such that the nipples 63 bear against the exposed end faces of 
the filter plugs F' and the flange 31A abuts against the exposed end faces 
of the corresponding plain cigarettes T. 
A flow restrictor 70 in the conduit 64b insures that the testing unit is 
most sensitive in regions P, i.e., in regions where the wrappers of filter 
plugs F' are provided with perforations. 
The conduits 64a, 64b are connected with the input of a suitable transducer 
71 (e.g., an electropneumatic diaphragm transducer) whose output transmits 
a first signal which is indicative of the quantity of testing fluid 
flowing through the perforations of the wrapper of the filter plug F' 
which advances between the grooves 61a, 61b of the stationary valve plates 
62a, 62b. The transducer 71 may be a capacitive transducer similar to or 
identical with those disclosed in the commonly owned U.S. Pat. No. 
3,412,856 to Esenwein. 
The output of the transducer 71 transmits discrete first signals (one for 
each tested filter cigarette Z of unit length) to the input of an 
integrating circuit 72 whose output transmits a signal which is indicative 
of the average quantity of testing fluid flowing through a predetermined 
number of successive filter plugs F'. In other words, each signal at the 
output of the integrating circuit 72 is indicative of the permeability 
(caused by the needle-like perforating elements 46) of a group of 
successive filter plug wrappers. Such output signals are transmitted to 
one input of a signal comparing stage 73 another input of which receives 
reference signals from an adjustable potentiometer 74 or another suitable 
source of reference signals. The reference signals are indicative of the 
desired permeability of the wrappers of filter plugs F', and the output of 
the stage 73 transmits a (third) signal when the intensity or another 
characteristic of the selected reference signal deviates from the same 
characteristic of a signal which is transmitted by the output of the 
integrating circuit 72. The output of the signal comparing stage 73 
transmits signals to a control circuit 76 for a reversible electric motor 
77 which can adjust the angular position of the shaft 49 for the eccentric 
51 of FIGS. 2 and 3 (clockwise or anticlockwise) by way of a suitable 
step-down transmission 78. The parts 72-74 together constitute an 
evaluating circuit 79 which changes the size of holes in successive filter 
plug wrappers in dependency on changes in the permeability of filter plug 
wrappers which advance past the testing station of FIG. 4. 
The circuit 79 is desirable and advantageous because it insures automatic 
adjustment of the position of perforating elements 46 relative to the 
housing 25a, 25b and conveyor 24 whenever the quantity of air which can 
escape from the filter plugs F' deviates from an optimum quantity. 
It is clear that the testing unit of FIG. 4 can operate with air or another 
testing fluid which is maintained at subatmospheric pressure. In certain 
respects, a testing unit which operates with suction is even more 
satisfactory than a testing unit which operates with pressurized testing 
fluid (see the source 67 of FIG. 4) because it establishes conditions 
which more closely resemble the conditions prevailing when a filter 
cigarette Z is lighted and the smoker draws tobacco smoke through the 
respective filter plug F'. If the manufacturer wishes to change the 
quantity of air which is to enter the filter plugs F' of cigarettes Z, the 
potentiometer 74 is adjusted so that it transmits a reference signal of 
different intensity. 
The operation of the apparatus including the conveyor 24 and perforating 
unit 25 is as follows: 
The flutes 22a of the wrapping conveyor 22 deliver filter cigarettes 39 of 
double unit length to the rolling conveyor 24 in such a way that each 
oncoming cigarette 39 is attracted to the intakes of suction ports 41 
behind the adjacent rib 37. A cigarette 39 which has advanced from the 
three to the twelve o'clock position of the conveyor 24 shown in FIG. 2 is 
engaged by the surfaces 56a, 56b and is caused to roll about its own axis 
during travel through the gap G between the surfaces 56a, 56b and the 
respective surface section or facet 38 (as mentioned above, the width of 
the gap G is less than the diameter of a cigarette 39). During such 
rolling of the cigarette, the needles 46 provide the wrapper of the 
respective filter plug F with two annuli of perforations whose diameters 
depend on the angular position of the shaft 49, i.e., on the distance 
between the tips of the conical needles 46 and the adjacent section 38. 
When the cigarette 39 reaches the left-hand end of the gap G, as viewed in 
FIG. 2, it is attracted to the intakes of suction ports 42 in the 
respective section 38 and is transported beyond the perforating unit 25 to 
be introduced into the oncoming flute 26A of the severing conveyor 26. The 
knife 26a severs the cigarettes 39 on the conveyor 26, and the resulting 
pairs of coaxial filter cigarettes Z of unit length are transferred onto 
the conveyor 27 of the turn-around device 29. Each flute of the testing 
conveyor 31 receives a single cigarette Z which is held between the flange 
31A and the respective nipple 63 during travel past the testing station 
between the arcuate grooves 61a, 61b. The transducer 71 transmits (first) 
signals which are indicative of the permeability of wrappers of successive 
cigarettes Z and the output of the integrating circuit 72 transmits 
signals which are indicative of the average or combined permeability of a 
predetermined number of successively tested cigarettes Z. Such signals are 
compared with the reference signal from the potentiometer 74, and the 
output of the stage 73 transmits corresponding (positive or negative) 
signals to the control circuit 76 for the reversible adjusting motor 77. 
The motor 77 causes the transmission 78 to rotate the shaft 49 clockwise 
or anticlockwise in order to move the needles 46 nearer to or away from 
the conveyor 24, depending upon the nature of signals transmitted by the 
stage 73. The needles 46 are moved nearer to the conveyor 24 if the 
average permeability of a series of successively tested cigarettes Z is 
too low, and vice versa. In other words, the needles 46 form perforations 
of larger diameter if the signal at the output of the stage 73 is a 
negative signal (insufficient permeability), and the needles 46 form 
perforations of smaller diameter if the permeability of the wrappers of 
the preceding series of cigarettes Z is too high. 
FIG. 5 shows a portion of a second filter cigarette making machine having a 
modified perforating unit 125. All such parts of the second machine which 
are identical with or clearly analogous to corresponding parts of the 
machine shown in FIGS. 1 to 4 are denoted by similar reference characters 
plug 100. 
The carrier in the housing of the perforating unit 125 of FIG. 5 comprises 
three portions 181a, 181b and 181c. The portions 181a and 181b are fixedly 
mounted in the housing of the unit 125 and constitute guide means or ways 
for the median portion 181c which is movable toward and away from the 
adjacent surface section or facet 138 of the rolling conveyor 124. The 
median portion 181c carries two needles 146 which are located behind each 
other, as considered in the axial direction of the conveyor 124. Thus, one 
of these needles can perforate that half of the filter plug of a filter 
cigarette 139 of double unit length which is nearer to the observer of 
FIG. 5 and the other needle 146 of the median portion 181c can perforate 
the other half of the filter plug. This insures that one of the 
perforations which are formed by the needles 146 is provided in the 
wrapper of the filter plug of one of two filter cigarettes of unit length 
and the other perforation is formed in the other of two filter cigarettes 
of unit length which are obtained in response to severing of a filter 
cigarette 139 on the conveyor 126. 
The eccentric 151 on the shaft 149 of FIG. 5 can shift the median portion 
181c of the carrier toward or away from the conveyor 124. The shaft 149 is 
turnable between two positions in one of which the needles 146 are 
withdrawn from the path of cigarettes 139 in the gap G and in the other of 
which the needles 146 perforate such cigarettes during travel below the 
perforating unit 125. The means for adjusting the shaft 149 of FIG. 5 is 
analogous to the adjusting means for the shaft 49 of FIG. 4, except that 
the motor 77 completes a predetermined number of revolutions (either 
clockwise or counterclockwise) in response to transmission of signals from 
the control circuit 76. Thus, the motor 77 merely moves the shaft 149 
between the aforementioned two positions in which the needles 146 
respectively extend into or are withdrawn from the path of movement of 
cigarettes 139 in the gap G. Each cigarette 139 which moves through the 
gap G of FIG. 5 is perforated by all needles 146a, 146b of the carrier 
portions 181a, 181b. The motor 77 for the shaft 149 is assumed to complete 
several revolutions in response to each (positive or negative) signal from 
the output of the circuit 76 because the transmission for the shaft 149 is 
a step-down transmission. 
FIG. 6 shows a mechanical perforating unit 186 which can be installed 
upstream of the paster 18 of FIG. 1, i.e., this unit is designed to 
perforate the web 13 prior to conversion of the web into uniting bands and 
prior to conversion of uniting bands into tubes surrounding the filter 
plugs of the respective filter cigarettes of double unit length. The 
perforating unit 186 can be used as a substitute for the perforating unit 
25 or 125. If the unit 25 or 125 is omitted, the conveyor 24 or 124 can be 
replaced with a conventional rotary drum-shaped conveyor having flutes 
machined into its peripheral surface to transport filter cigarettes of 
double unit length from the wrapping conveyor 22 or 122 to the severing 
conveyor 26 or 126. If desired, the conveyor 24, 124 (or the just 
mentioned simplified substitute for 24 or 124) can serve as a drying 
conveyor to promote the setting of adhesive on the convoluted uniting 
bands. 
The perforating unit 186 of FIG. 6 comprises two rotary members or rollers 
187a, 187b located at one side of the path of movement of the web 13 from 
the applicator 18a of FIG. 1 toward the suction drum 19. The rollers 187a 
and 187b are respectively provided with punching tools 188a, 188b which 
extend radially beyond the peripheral surfaces of the respective rollers 
and can remove material from the web 13 to provide the web with 
perforations or holes of predetermined diameter. The tools 188a and/or 
188b can form one or more annuli about the peripheries of the respective 
rollers 187a, 187b. 
The roller 187a cooperates with a rotary anvil or counterroller 189a which 
is located at the other side of the path of movement of the web 13 and 
whose peripheral surface is preferably hard to insure that the annular 
cutting edges of the tools 188a can provide the web 13 with holes of 
predetermined diameter without fraying of the material around the holes. 
The tools 188a are operative at all times, i.e., whenever the web 13 is in 
motion, to provide the web with a basic group of perforations, namely, 
with one group for each uniting band. The roller 187b can cooperate with a 
second rotary anvil or counterroller 189b when the testing unit of FIG. 4 
determines that the permeability of wrappers of a series of succesisve 
filter cigarettes Z of unit length is too low. The number of tools 188b is 
normally less than the number of tools 188a; for example, the roller 187 
can carry two punching tools 188b which are located diametrically opposite 
each other. 
The rollers 187a, 187b, 189a and 189b are driven by the prime mover of the 
filter cigarettes making machine in the directions indicated by arrows. 
The direction in which the web 13 is moved by the suction wheel 19 of FIG. 
1 is indicated by the arrow K. The rollers 187a, 189a, 189b rotate about 
fixed axes (see the shafts 191, 189A 189B). The shaft 187B for the roller 
187b is mounted on a pivotable support or lever 192 which is turnable on 
the shaft 191 for the roller 187a. The roller 187a is rigid with a pulley 
which drives a toothed belt 193 serving to transmit torque to the roller 
187b. 
When the roller 187b is held in the illustrated idle or retracted position, 
the web 13 is formed with perforations during travel through the nip of 
the rollers 187a, 189a, i.e., the tools 188b are incapable of cooperating 
with the peripheral surface of the roller 189b. The means for moving the 
roller 187b between the inoperative position of FIG. 6 and an operative 
position in which the tools 188b form holes in the web 13 comprises a 
double-acting pneumatic cylinder and piston unit 194 whose piston rod 194a 
is articulately connected to the free end of the lever 192 and whose 
chambers are connected with preferably flexible conduits 194A, 194B. The 
flow of pressurized fluid (e.g., compressed air) between the chambers of 
the cylinder 194b of the unit 194 and a source 197 of compressed fluid or 
the atmosphere is regulated by a solenoid-operated valve 196 which is 
installed in the conduits 194A, 194B and whose solenoid 196a is 
energizable by a threshold circuit 198. When the conduit 194A admits 
pressurized fluid into the lower chamber of the cylinder 194b and the 
conduit 194B connects the upper chamber with the atmosphere, the lever 192 
is pivoted anticlockwise, as viewed in FIG. 6, and abuts against a stop 
195. The roller 187b is then maintained in the operative position. 
The threshold circuit 198 and the valve 196 replace the parts 76-78 of the 
adjusting means shown in FIG. 4. 
The operation: 
The tools 188a of the roller 187a perforate spaced-apart portions of the 
running web 13 so that each uniting band which is obtained in response to 
subdivision of the web 13 by the blades of the knife 21 is formed with a 
predetermined (basic) number of perforations. The unit 194 normally 
maintains the roller 187b in the idle position of FIG. 6. However, if the 
output of the signal comparing stage 73 of FIG. 4 transmits a signal which 
indicates that the average permeability of the wrappers of a series of 
successive plain cigarettes Z is too low, the threshold circuit 198 
transmits a signal which energizes the solenoid 196a and the valve 196 
admits pressurized fluid into the lower chamber of the cylinder 194b while 
permitting the conduit 194B to communicate with the atmosphere. The lever 
192 is pivoted against the stop 195 and the tools 188b of the roller 187b 
cooperate with the roller 189b to provide the web 13 with additional 
perforations. For example, the threshold circuit 198 will energize the 
solenoid 196a in response to progressing wear upon the cutting edges of 
the tools 188a and/or in response to breakage of one or more tools 188a. 
FIG. 7 shows a perforating unit 201 which can be used as a substitute for 
the perforating unit 186 of FIG. 6. The unit 201 produces sparks which 
burn holes into the material of the running web 13. The web travels 
through the relatively narrow clearance between two rotary members 202 and 
203 which are driven by the prime mover of the filter cigarette making 
machine to rotate in the directions indicated by arrows. The rotary member 
202, 203 respectively comprise hubs 204, 206 consisting of electrically 
insulating material and ring-shaped rims 207, 208 consisting of brass or 
other suitable conductive material. The rims 207, 208 are connected with a 
source 211 of high-voltage energy by way of a rotating commutator 209 and 
conventional brushes and slip rings (not specifically shown in FIG. 7). 
The commutator 209 is connected with the prime mover of the filter 
cigarette making machine by way of an infinitely variable speed 
transmission 212. The operative connection between the prime mover (which 
drives the shaft of the rotary member 203) and the transmission 212 is 
indicated by the phantom line 213; the phantom line 214 denotes the 
connection between the transmission 212 and the comutator 209. The ratio 
of the transmission 212 and hence the RPM of the commutator 209 can be 
adjusted by a servomotor 215 which is a functional equivalent of the motor 
77 shown in FIG. 4, i.e., it receives signals from the control circuit 76. 
The operation is as follows: Sparks are discharged between the rims 207, 
208 at a rate which is determined by the RPM of the commutator 209, and 
such sparks burn holes in the web portions travelling through the 
clearance between the rotary members 202 and 203. Depending on the 
construction of the rims 207, 208, these parts can cause one, two or more 
sparks to develop at the same time so that the web 13 is formed with one, 
two or more rows of perforations. The number of perforations which are 
burned into each unit length of the web 13 (i.e., into each uniting band) 
depends on the ratio of the transmission 212, i.e., on the permeability of 
wrappers of cigarettes Z which are monitored at the testing station of 
FIG. 4. 
FIG. 8 shows a further perforating unit. The spark generating means of FIG. 
7 is replaced by a source of coherent radiation, preferably a CO.sub.2 
impulse laser 216. The beam of coherent radiation which is emitted by the 
laser 216 can reach the web 13 by way of apertures in a rotary disk 217 
which is indicated by broken lines. The web 13 is advanced at a constant 
speed in the direction indicated by arrow K and travels between the disk 
217 and an aluminum plate 223 having a roughened surface facing the web. 
The speed of the disk 217 (and hence the number of holes in each unit 
length of the web 13) can be changed by an infinitely variable speed 
transmission 218 which is operatively connected with the disk (the torque 
transmitting connection is indicated by the phantom line 219). The 
transmission 218 is driven by the prime mover of the filter cigarette 
making machine (the operative connection is indicated by the phantom line 
221), and the ratio of the transmission (and hence the RPM of the disk 
217) can be changed by a servomotor 222 constituting a functional 
equivalent of the motor 77 shown in FIG. 4. Thus, the signals which are 
transmitted by the control circuit 76 regulate the speed of the disk 217 
and hence the frequency at which the laser beam can impinge upon the web 
13 per unit of time. The plate 223 intercepts the beam which has 
penetrated through the material of the web 13. 
The perforating units of FIGS. 6, 7 and 8 can be used with equal advantage 
in a machine for the production of plain cigarettes, for example, in the 
aforementioned GARANT (trademark) produced by the assignee of the present 
application, or in a machine for the making of filter rod sections. In a 
cigarette maker, the web of cigarette paper normally passes through a 
conventional imprinting mechanism which is located ahead of the locus 
where the web reaches the garniture of the wrapping mechanism. The 
imprinting mechanism is used to apply printed matter to spaced-apart 
portions of the web. Such printed matter denotes the brand name of the 
cigarette, the name of the manufacturer and/or other information. The 
perforating unit of FIG. 6, 7 or 8 can be installed immediately ahead of 
or immediately behind the imprinting mechanism. The perforating unit is 
preferably set up in such a way that it forms one or more rows of holes 
extending transversely of spaced apart portions of the running cigarette 
paper web. The perforating unit is adjusted in accordance with the results 
of measurements of permeability of the wrappers of finished plain 
cigarettes. The testing unit for plain cigarettes can be installed at the 
discharge end of the cigarette maker, e.g., the row forming conveyor 1 of 
FIG. 1 can constitute a conveyor which transports plain cigarettes 
sideways through a testing station wherein the permeability of wrappers of 
plain cigarettes is monitored by a device similar or analogous to the 
testing unit of FIG. 4, and such device transmits signals to means for 
energizing the solenoid 196a of FIG. 6, for changing the ratio of the 
transmission 212 of FIG. 7 or for changing the ratio of the transmission 
218 of FIG. 8. A cigarette maker which can be combined with a perforating 
unit of the type shown in FIG. 6, 7 or 8 is shown, for example, in FIG. 7 
of the commonly owned copending application Ser. No. 766,927 filed Feb. 9, 
1977 by Heitmann et al. The row forming conveyor 1 of FIG. 1 receives 
successive plain cigarettes which form a single file wherein the 
cigarettes move axially, and the conveyor converts such single file into 
one or more rows wherein the cigarettes move sideways. 
An advantage of the improved method and apparatus is that the quantity of 
cool atmospheric air which is admixed to the column of tobacco smoke can 
be regulated and maintained at a desired level with a high degree of 
reproducibility. Furthermore, the number of rejects is reduced because the 
presence of articles whose wrappers exhibit excessive or insufficient 
permeability is detected before the articles leave the machine. Also, 
articles having wrappers of unsatisfactory permeability are not permitted 
to reach the customers. 
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 our contribution to 
the art and, therefore, such adaptations should and are intended to be 
comprehended within the meaning and range of equivalence of the claims.