Process and apparatus for multiple testing of wrappers of cigarettes or the like

The wrappers of filter cigarettes wherein wrapper portions surrounding the filter mouthpieces have holes for admission of atmospheric air into the column of tobacco smoke are tested during sidewise movement at the periphery of a rotary drum. A first testing device establishes a first pressure differential between the interior and exterior of successive wrappers, and a second testing device establishes a second pressure differential between the interior and exterior of those wrapper portions which surround tobacco as well as a different third pressure differential between those wrapper portions which surround the filter material. An evaluating circuit has two electropneumatic transducers which furnish first and second signals respectively denoting the pressure differential between the interior and exterior of successive wrappers and the pressure differential between the interior and exterior of successive wrapper portions which surround tobacco. A subtracting circuit furnishes third signals which denote the difference between the first and second signals. The first and third signals are compared with reference signals which respectively denote maximum permissible permeability of wrappers and minimum acceptable permeability of successive wrapper portions surrounding the filter material. Cigarettes wherein the permeability of wrappers is outside of the range between the maximum permissible and minimum acceptable permeability are segregated from acceptable cigarettes.

BACKGROUND OF THE INVENTION 
The present invention relates to a process and apparatus for testing the 
wrappers of rod-shaped articles (including plain or filter-tipped 
cigarettes, cigars, cigarillos and cheroots as well as filter rod 
sections) which constitute or form part of smokers' products. More 
particularly, the invention relates to a process and apparatus for 
ascertaining the permeability of wrappers of rod-shaped articles 
(hereinafter referred to as cigarettes or filter cigarettes) of the type 
wherein each wrapper includes a portion of predetermined permeability so 
that it allows cool atmospheric air to enter the column of tobacco smoke 
flowing into the smoker's mouth. 
It is already known to provide the wrappers of cigarettes with holes or 
perforations which admit cool atmospheric air into the column of tobacco 
smoke. The perforated portions of wrappers constitute the so-called 
climatic zones which are normally adjacent to unlighted ends of the 
cigarettes. For example, the wrapper of a filter cigarette will be 
provided with perforations in that portion which surrounds or is closely 
adjacent to the mouthpiece; this insures that cool atmospheric air will 
flow into the column of tobacco smoke regardless of the length of 
non-combusted portion of the tobacco-containing part of the smokers' 
product. Devices which can be used to perforate selected portions of 
wrappers of filter cigarettes or the like are disclosed in commonly owned 
copending applications Ser. Nos. 834,645 filed Sept. 19, 1977 by Heitmann 
et al., 841,108 filed Oct. 11, 1977 by Wahle et al., and 864,441 filed 
Dec. 27, 1977 by Luders et al. 
Many manufacturers of smokers' products demand that the machines which 
produce cigarettes, cigarillos or cigars be equipped with perforating 
devices so as to allow a predetermined quantity of atmospheric air to mix 
with tobacco smoke which flows toward the mouth. The admixture of 
atmospheric air to smoke is considered to be desirable because it is 
believed to reduce the health hazards involved in smoking of tobacco by 
controlling the amount of nicotine and condensates in the smoke. The 
packages for cigarettes or other smokers' products must bear information 
indicating the nicotine content, the tar content and the percentage of 
certain other ingredients, and the manufacturer is responsible for the 
accuracy of such information. One of the factors which influence the 
quantity of nicotine and condensates in the column of tobacco smoke is the 
quantity of admitted atmospheric air; therefore, it is important to insure 
that the quantity of admitted air will invariably equal or perhaps even 
slightly exceed a predetermined minimum acceptable value. Consequently, it 
is necessary to ascertain whether or not the combined cross-sectional area 
of perforations in the wrappers suffices to guarantee the admission of 
minimum required quantity of atmospheric air. Furthermore, it is desirable 
to ascertain the permeability of a finished wrapper (i.e., of the tubular 
wrapper of a filter cigarette or the like) because this is the only 
reliable mode of determining the permeability of perforated wrapper 
portions. For example, certain perforations can be clogged by particles of 
tobacco or filter material so that, even if the permeability of wrapping 
material ahead of the wrapping station is clearly adequate, the 
permeability of perforated portion of the finished wrapper will be too 
low. 
Automatic testing of wrappers of cigarettes or the like for the presence of 
open seams, holes, frayed ends and/or other defects is known for nearly 
two decades. The first successful automatic testing apparatus is disclosed 
in commonly owned U.S. Pat. No. 3,408,858 to Heinz Kaeding. As a rule, one 
establishes a pressure differential between the interior and exterior of 
the wrapper. The pressure differential decreases when the wrapper is 
defective, e.g., due to the presence of a partly open seam. This is 
detected by a transducer which furnishes signals to a signal comparing 
stage (e.g., a threshold circuit) whch actuates an ejector when the 
intensity or another characteristic of the signal is indicative of a 
defective wrapper. The ejector segregates each defective article from 
satisfactory articles, for example, by directing streams of compressed air 
against the ends or sides of articles having unsatisfactory wrappers. 
Presently known testing apparatus are sufficiently accurate to effect the 
segregation of cigarettes or analogous rod-shaped articles having wrappers 
which are defective because their permeability exceeds the acceptable 
permeability by a value corresponding to that which is attributable to the 
presence of a hole with a diameter of approximately one millimeter. 
Deviations which are less pronounced cannot be ascertained with a 
requisite degree of accuracy and reproducibility because the results of 
tests are influenced by unavoidable factors such as unequal sealing of 
wrapper ends on successive articles during testing, deviation of density 
of the tobacco filler from an optimum value, wear upon moving parts of the 
testing apparatus, clogging of narrow passages in such apparatus by 
tobacco dust or other foreign matter and/or others. On the other hand, the 
increased permeability of intentionally perforated portions of wrappers of 
filter cigarettes or the like is less pronounced than that permeability 
which is attributable to the presence of a hole with a diameter of one 
millimeter. Moreover, it is desirable to insure that the permeability of 
intentionally perforated portions of the wrappers should not deviate from 
(above or below) optimum permeability by more than two percent. 
OBJECTS AND SUMMARY OF THE INVENTION 
An object of the invention is to provide a novel and improved process for 
ascertaining, with a high degree of accuracy, the permeability of wrappers 
of rod-shaped articles which constitute or form part of smokers' products 
and wherein predetermined portions of the wrappers must exhibit a 
predetermined permeability. 
Another object of the invention is to provide a process which insures the 
detection of all articles whose wrappers exhibit excessive permeability 
(for example, due to the presence of large holes or open seams) as well as 
the detection of all articles wherein the permeability of intentionally 
perforated wrapper portions deviates, even very slightly, from an optimum 
value. 
A further object of the invention is to provide a novel and improved 
process for multiple or repeated testing of wrappers of cigarettes or the 
like. 
An additional object of the invention is to provide a process which allows 
for multiple testing of cigarettes or analogous rod-shaped articles at the 
rate at which such articles are produced or issue from a modern high-speed 
maker, e.g., a filter cigarette making machine which turns out up to and 
in excess of 70 filter cigarettes per second. 
Still another object of the invention is to provide a novel and improved 
apparatus for the practice of the above outlined process. 
A further object of the invention is to provide a compact and relatively 
simple but highly reliable testing apparatus which can be readily 
installed in existing makers of cigarettes or the like. 
One feature of the invention resides in the provision of a process for 
testing the wrappers of cigarettes or analogous rod-shaped articles which 
constitute or form part of smokers' products. The process comprises the 
steps of moving a series of rod-shaped articles (preferably sideways) 
along a predetermined path (such path can be defined by one or more 
endless conveyors, e.g., rotary fluid drums), measuring the permeability 
of larger first portions of the wrappers of successive articles of the 
series including generating first signals (e.g., by means of a first 
electropneumatic transducer) which denote the permeability of the 
respective first wrapper portions (each such wrapper portion may 
constitute the entire wrapper of the respective article), measuring the 
permeability of smaller second portions of the wrappers of successive 
articles of the series including generating second signals (e.g., by means 
of a second electropneumatic transducer) which denote or represent the 
permeability of the respective second wrapper portions (each second 
wrapper portion forms part of the respective first wrapper portion), and 
utilizing the first and the corresponding second signals for the 
generation of third signals (e.g., by resorting to a suitable subtracting 
circuit) which denote or represent the difference between the intensities 
and/or other characteristics of the respective first and second signals 
and are indicative of permeability of the remaining parts of the first 
wrapper portions. 
For example, if the articles are filter cigarettes, the first wrapper 
portions may constitute the entire wrappers, the second wrapper portions 
may constitute the wrappers of tabacco-containing portions (plain 
cigarettes) of the filter cigarettes, and the remaining parts of the first 
wrapper portions then constitute the wrappers of filter mouthpieces of the 
respective filter cigarettes. The wrappers of filter mouthpieces (i.e., 
the remaining parts of the first wrapper portions) are preferably provided 
with one or more holes in the course of a step which precedes the last 
mentioned measuring step. The hole or holes admit atmospheric air into the 
column of tobocco smoke. 
The first mentioned measuring step may further include establishing a first 
pressure differential between the interior and exterior of successive 
first wrapper portions at a first testing station. Such pressure 
differential can be established by admitting atmospheric air into one end 
of each wrapper and by evacuating air from the space surrounding the 
respective wrapper. Alternatively, the first pressure differential can be 
established by admitting compressed testing fluid into both ends of each 
wrapper and by allowing the space around the wrapper to communicate with 
the atmosphere. The last mentioned measuring step then preferably further 
includes establishing a second pressure differential between the interior 
and exterior of successive second wrapper portions at a second testing 
station and simultaneously establishing a different third pressure 
differential between the interior and exterior of the remaining parts of 
the respective first wrapper portions. The second pressure differential 
may but need not equal or closely approximate the first pressure 
differential. As a rule, one (preferably the first mentioned) measuring 
step will precede the other measuring step. 
The pressure at the exterior or interior of the remaining parts of 
successive first wrapper portions in the course of the first mentioned 
measuring step may deviate from the pressure at the exterior or interior 
of the remaining parts of first wrapper portions in the course of the last 
mentioned measuring step. The arrangement may be such that, in the course 
of the last mentioned measuring step, the pressure at the exterior of the 
remaining part of each first wrapper portion will exceed the pressure at 
the exterior of the respective second wrapper portion and/or the pressure 
at the exterior of the remaining part of the first wrapper portion in the 
course of the first measuring step. Alternatively, the pressure in the 
interior of the remaining part of a first wrapper portion (in the course 
of the first mentioned measuring step) may deviate from the pressure in 
the interior of the remaining part in the course of the last mentioned 
measuring step; the pressure in the interior of the remaining part in the 
course of the last mentioned measuring step may exceed the pressure in the 
interior of the same remaining part in the course of the first mentioned 
measuring step. 
The third pressure differential may equal or closely approximate zero. This 
can be achieved, for example, by admitting compressed testing fluid into 
the remaining part and simultaneously admitting testing fluid or another 
fluid, at the same pressure, into the space surrounding the remaining 
part. 
The process preferably further comprises the steps of respectively 
comparing the first and third signals with first and second reference 
signals which reference signals respectively denote the maximum 
permissible permeability of first wrapper portions and the minimum 
acceptable permeability of the respective remaining parts. The comparing 
step can be carried out by resorting to suitable threshold circuits or the 
like. Still further, the process may comprise the step or steps of 
expelling from the predetermined path those articles wherein the 
permeability of first wrapper portions exceeds the maximum permissible 
permeability and/or those articles wherein the permeability of remaining 
parts of the first wrapper portions is less than the minimum acceptable 
permeability. 
The novel features which are considered as characteristic of the invention 
are set forth in particular in the appended claims. The improved testing 
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 the assignee of the present application). The machine is 
directly coupled to a maker of plain cigarettes of unit length, e.g., to a 
machine known as GARANT (trademark) produced by the assignee of the 
present application. The maker comprises a rotary drum-shaped row forming 
conveyor 1 which is mounted in or on the frame 5 of the filter cigarette 
making machine and has peripheral flutes for continuous delivery of two 
rows of plain cigarettes of unit length. The flutes of the conveyor 1 are 
parallel to its axis, i.e., the cigarettes are transported sideways. The 
cigarettes of one row are admitted into the oddly numbered flutes and the 
cigarettes of the other row are admitted into the evenly numbered flutes 
of the conveyor 1. Furthermore, the cigarettes of one row are adjacent to 
one axial end and the cigarettes of the other row are adjacent to the 
other axial end of the conveyor 1. 
The filter cigarette making machine comprises a pair of rotary drum-shaped 
aligning conveyors 2 which are mounted in the frame 5 adjacent to the row 
forming conveyor 1 and have peripheral flutes for sidewise transport of 
plain cigarettes toward a transfer station T1. One of the conveyors 2 
receives successive plain cigarettes of one row and the other conveyor 2 
receives successive plain cigarettes of the other row. The conveyors 2 are 
driven at different speeds and/or transport the plain cigarettes of the 
respective rows through different distances so that each flute of a rotary 
drum-shaped assembly conveyor 3 which arrives at the transfer station T1 
receives a pair of coaxial plain cigarettes of unit length. The plain 
cigarettes of each pair are separated from each other by a gap having a 
width which at least equals the length of a filter rod section or 
mouthpiece of double unit length. 
The upper portion of the frame 5 supports a magazine 4 for filter rod 
sections of six times unit length. The outlet of the magazine 4 receives a 
portion of a rotary drum-shaped severing conveyor 6 having peripheral 
flutes which remove filter rod sections from the magazine 4 and transport 
them past two rotary disk-shaped knives 7 which are staggered with respect 
to each other, as considered in the axial and circumferential direction of 
the conveyor 6. The latter cooperates with the knives 7 to subdivide each 
filter rod section of six times unit length into sets of three coaxial 
filter rod sections of double unit length. The filter rod sections of each 
set are transferred into peripheral flutes of three rotary drum-shaped 
staggering conveyors 8 (only one shown) which rotate at different speeds 
and/or transport the respective filter rod sections through different 
distances to thereby stagger the sections in the circumferential direction 
of the illustrated conveyor 8. The staggering conveyors 8 deliver discrete 
filter rod sections of double unit length into successive flutes of a 
rotary drum-shaped shuffling conveyor 9 which cooperates with two 
stationary cams 9a to convert the filter rod sections into a single row 
wherein each preceding section is in exact register with the 
next-following section. Successive sections of the thus obtained row are 
delivered into successive flutes of a rotary drum-shaped accelerating 
conveyor 11 which deposits such sections into successive flutes of the 
assembly conveyor 3 at a second transfer station T2 preceding the station 
T1. Each inserted filter rod section of double unit length is positioned 
in such a way that it is flanked by two coaxial plain cigarettes of unit 
length after the respective flute of the conveyor 3 advances beyond the 
station T1. The thus obtained groups of three coaxial articles each (a 
filter rod section of double unit length and two plain cigarettes of unit 
length) are thereupon caused to move through the gap between two 
stationary condensing cams 3a which move the inner ends of the plain 
cigarettes into actual abutment with the respective ends of the coaxial 
filter rod section. The condensed groups are delivered into the flutes of 
a rotary drum-shaped transfer conveyor 12. 
The frame 5 of the filter cigarette making machine further supports a 
spindle 14' for a roll 14 of convoluted wrapping material which 
constitutes an elongated web 13 consisting of cigarette paper, artificial 
cork or the like. The web 13 is drawn off the roll 14 by two advancing 
rolls 16 at least one of which is driven by the prime mover PM of the 
filter cigarette making machine and the other of which is preferably 
biased against the one roll. Successive increments of the web 13 are 
caused to pass along the relatively sharp edge of a curling device 17 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 curling device 17 is to 
eliminate and/or equalize internal stresses in the material of the web 13. 
One side of the running web 13 is coated with a suitable adhesive by the 
rotary applicator 18a of a paster 18 which is installed in the frame 5 
downstream of the advancing rolls 16. The leader of the web 13 ahheres to 
the periphery of a rotary suction drum 19 which cooperates with a rotary 
knife 21 to subdivide the web 13 into a succession of discrete 
adhesive-coated uniting bands. Such bands are attached to successive 
groups of rod-shaped articles on the transfer conveyor 12, preferably in 
such a way that each band extends tangentially of the respective group and 
adheres to the respective filter rod section as well as to the inner end 
portions of the respective plain cigarettes. 
A second spindle 514' supports a roll 514 consisting of convoluted wrapping 
material which constitutes an elongated web 513. The leader of the web 513 
is located at a splicing station SPL which includes means for attaching 
the leader of the web 513 to the running web 13 when the diameter of the 
roll 14 is reduced to a predetermined minimum value. The device at the 
splicing station SPL may be of the type disclosed in commonly owned U.S. 
Pat. No. 3,586,006 granted June 22, 1971 to Gerd-Joachim Wendt. 
Successive groups in the flutes of the transfer conveyor 12 (each such 
group carries a discrete uniting band) are delivered to a rotary 
drum-shaped wrapping conveyor 22 which cooperates with a stationary or 
mobile rolling device 23 to roll successive groups around their respective 
axes and to thus convert the respective uniting bands into tubes which 
sealingly surround the filter rod sections and the inner ends of plain 
cigarettes of the respective groups, i.e., each such group is converted 
into a filter cigarette of double unit length. The wrapping conveyor 22 
delivers successive filter cigarettes of double unit length into the 
flutes of a rotary drum-shaped heating or drying conveyor 24 which insures 
that the adhesive on each tube sets prior to transfer into the flutes of a 
rotary drum-shaped severing conveyor 26 cooperating with a rotary 
disk-shaped knife 26a which severs each filter cigarette of double unit 
length midway across the tube so that such cigarettes yield pairs of 
coaxial filter cigarettes Z (FIG. 2) of unit length (hereinafter called 
cigarettes for short). Defective cigarettes (e.g., those without a filter 
plug or tobacco-containing portion) are ejected during travel along the 
periphery of the severing conveyor 26. 
The conveyor 26 delivers pairs of cigarettes to the rotary drum-shaped 
conveyor 27 of a turn-around device 29 of the type disclosed in commonly 
owned U.S. Pat. No. 3,583,546 granted June 8, 1971 to Gerhard Koop. One 
cigarette of each pair is transferred onto a second conveyor 27a and is 
inverted through 180 degrees by one of several orbiting arms 29a. The 
other cigarettes of successive pairs are transferred into alternate flutes 
of a third rotary drum-shaped conveyor 28 of the device 29. A fourth 
conveyor 28a of the device 29 delivers inverted cigarettes into empty 
flutes of the conveyor 28 so that the inverted cigarettes are disposed 
between neighboring non-inverted cigarettes and the cigarettes form a 
single row wherein the filter mouthpieces of all cigarettes face in the 
same direction. 
The conveyor 28 delivers successive cigarettes of the single row to a 
rotary drum-shaped conveyor 31 forming part of a testing apparatus wherein 
the cigarettes are monitored to ascertain whether or not their wrappers 
are satisfactory. Cigarettes having defective wrappers are segregated from 
satisfactory cigarettes during travel with a rotary drum-shaped conveyor 
32 which is located downstream of the conveyor 31 and delivers 
satisfactory cigarettes onto the upper reach of a belt conveyor 36 trained 
over pulleys 34 (one shown). The illustrated pulley 34 cooperates with a 
rotary braking drum 33. The conveyor 36 delivers satisfactory cigarettes 
into storage, into chargers, to a pneumatic sender or directly into the 
magazine of a packing machine, not shown. 
The conveyor 32 may be associated with a device which monitors the 
tobacco-containing ends of successive cigarettes Z and generates signals 
for ejection of cigarettes having unsatisfactory tobacco-containing ends. 
Such ejection can take place at the station for ejection of cigarettes 
having defective wrappers. 
FIGS. 2 and 3 illustrate certain details of a testing apparatus which 
includes one embodiment of the conveyor 31 shown in FIG. 1. In many 
respects the testing apparatus which is used in the filter cigarette 
making machine of FIG. 1 operates (or can operate) in a manner known from 
presently used testing apparatus for rod-shaped articles which constitute 
or form part of smokers' products. The operation is based on the principle 
that one establishes a pressure differential between the interior and 
exterior of the wrapper and monitors the magnitude or extent of such 
pressure differential. The pressure can be higher in the interior of or 
around the wrapper, and the monitoring step can include measuring the rise 
of pressure at the lower-pressure side and/or measuring the drop of 
pressure at the higher-pressure side of the wrapper. As a rule, the 
testing fluid is air; however, it is clear that many other gases can be 
used with equal advantage. A suitable testing apparatus which can be used, 
with certain modifications, for the purposes of the present invention is 
disclosed in commonly owned U.S. Pat. No. 3,948,084 granted Apr. 6, 1976 
to Bob Heitmann et al. to which reference may be had for all such details 
which are not fully shown in the drawing of the present application. 
FIGS. 2 and 3 show a hollow shaft 37 which supports the components of the 
testing conveyor 31. Such components include three coaxial rotary members 
38, 39 and 41 which together constitute a drum-shaped main body portion 42 
of the conveyor. The means for transmitting torque from the prime mover PM 
to the main body portion 42 is of conventional design. The median rotary 
member 39 is flanked by two disks 44 whose peripheral portions define 
annuli of article-receiving cradles or sockets 43. Each socket 43 of the 
left-hand disk 44 of FIG. 2 is in register with a socket 43 of the 
right-hand disk 44. The conveyed articles are filter cigarettes Z of unit 
length; each such cigarette comprises a filter mouthpiece F of unit length 
and a plain cigarette T of unit length. These parts are sealingly secured 
to each other by one-half B of a convoluted uniting band which is obtained 
in response to severing of the web 13 in a manner as shown in FIG. 1. The 
rotary member 39 is formed with peripheral chambers or recesses 46 each of 
which is disposed between and aligned with two registering sockets 43. 
Still further, the rotary member 39 has an external ring 47 with an 
annulus of cradles 43A which receive the filter mouthpieces F in regions 
close to the adjacent inner ends of the plain cigarettes T. The cradles 
43A can be said to constitute partitions which divide the respective 
chambers 46 into larger first and smaller second compartments 46a and 46b. 
The compartments 46a receive the major portions of plain cigarettes T and 
the compartments 46b receive portions of filter mouthpieces F of 
cigarettes Z in the respective chambers 46. The convoluted uniting bands 
or tubes B which surround the filter mouthpieces F and the adjacent inner 
end portions of plain cigarettes T have portions of desired permeability 
which is attributable to the provision of holes L adjacent to the 
right-hand side of the cradle 43A shown in FIG. 2. The manner in which the 
holes L can be formed in the material of the tubes B, either prior or 
subsequent to draping of uniting bands around the respective groups of 
coaxial articles, is disclosed, for example, in commonly owned copending 
application Ser. No. 841,108 of Wahle et al. and in commonly owned 
copending application Ser. No. 864,441 of Luders et al. Reference may be 
had to these commonly owned applications for details of the perforating 
devices which can be employed to provide the tubes B with predetermined 
portions of desired permeability. The application of Wahle et al. 
discloses that a perforating device may comprise needles, punching tools, 
spark generators and/or one or more lasers. Such device can be located 
between the roll 14 and drum 19 of FIG. 1 or adjacent to one of the 
conveyors which transport groups or rod-shaped articles, filter cigarettes 
of double unit length or filter cigarettes Z of unit length toward the 
conveyor 31. For example, a perforating device employing one or more sets 
of needles can be placed adjacent to the path of freshly formed filter 
cigarettes of double unit length on the wrapping conveyor 22 of FIG. 1. 
The testing apparatus which includes the structure of FIGS. 2 and 3 further 
comprises an arcuate sealing element or shroud 48 which is disposed 
between the disks 44 and overlies the open outer ends of several 
neighboring chambers 46. The shroud 48 is secured (preferably pivoted) to 
the frame 5, as at 48A. The concave inner side of the shroud 48 is 
preferably closely adjacent to the projections 46A between neighboring 
chambers 46 of the rotary member 39 so that the compartments 46a, 46b 
which travel along the concave side of the shroud 48 are substantially 
sealed from the surrounding atmosphere. FIG. 3 shows that the width of 
gaps between the shroud 48 and the rotary member 39 is negligible. 
The pressure of fluid in larger compartments 46a which travel along the 
concave inner side of the shroud 48 may but need not be different from the 
pressure of fluid in the associated smaller compartments 46b. The means 49 
for maintaining the pressure in compartments 46a, 46b at desired levels 
includes an annular partition or wall 51 which is provided in and divides 
the interior of the shaft 37 into two discrete spaces 52a and 52b. The 
spaces 52a, 52b are connected with the suction intake of a blower or 
another suitable source 76 of compressed gas (see FIG. 4). The cylindrical 
outer wall 37a of the shaft 37 (which is stationary) has two relatively 
long slots 53a which are parallel to the axis of the shaft 37 and each of 
which establishes communication between the space 52a and a certain number 
(including one) of channels 54a machined into the rotary member 39. Each 
channel 54a communicates with a discrete compartment 46a. The outer wall 
37a of the shaft 37 is further formed with at least one second slot 53b 
which is aligned with a slot 53a and connects the space 52b with a certain 
number (including one) of channels 54b also machined into the rotary 
member 39 and each communicating with a different compartment 46b. The 
illustrated arrangement is such that, when a compartment 46a communicates 
with the first space 52a, the aligned compartment 46b communicates with 
the space 52b. 
The rotary member 38 has a ring-shaped flange 56 with holes 57 each of 
which is in register with a socket 43 in the adjacent disk 44. The flange 
56 rotates with respect to a stationary valve plate 61 having two arcuate 
grooves 62 which communicate with successive bores 57 when the conveyor 31 
rotates about the axis of the shaft 37. Each groove 62 receives 
atmospheric air (FIG. 4) or compressed testing fluid (FIG. 5). If the 
grooves 62 receive compressed testing fluid, they are connected with a 
suitable source, e.g., with the pressure outlet of the blower 176 shown in 
FIG. 5, so that such fluid penetrates into the interior of the wrappers of 
the cigarettes Z which advance past the grooves 62. The flange 56 seals 
the left-hand ends of the wrappers of cigarettes Z save for the relatively 
small regions which register with the respective holes 57. The valve plate 
61 is biased against the outer side of the flange 56 to prevent 
uncontrolled escape of testing fluid from or uncontrolled admission of 
atmospheric air into the grooves 62. A member 5a of the frame 5 supports 
the valve plate 61 adjacent to the path of movement of the flange 56. 
The rotary member 41 has a flange 67 which carries an annulus of 
reciprocable sealing elements 66 here shown as nipples which are biased by 
helical springs 64 so that they bear against the right-hand ends of 
wrappers of cigarettes Z on the conveyor 31. Each nipple 66 is in register 
with a socket 43 in the adjacent disk 44, and each such nipple is movable 
in directions indicated by the double-headed arrow 63. A suitable 
stationary cam (not specifically shown) is mounted in the frame 5 and 
cooperates with roller followers of the nipples 66 to retract the nipples 
ahead of the transfer station between the conveyors 28, 31 and again ahead 
of the transfer station between the conveyors 31, 32 so as to allow for 
unobstructed introduction of cigarettes Z into the respective sockets 43 
and 43A. Once a cigarette Z enters the respective sockets, the cam allows 
the springs 64 to expand and to move the nipples 66 into sealing 
engagement with the adjacent ends of the wrappers of cigarettes Z; at the 
same time, the nipples 66 push the respective cigarettes Z against the 
flange 56. Alternatively, the nipples 66 can be moved by a wobble plate in 
a manner as disclosed in the aforementioned U.S. Pat. No. 3,948,084 to 
Heitmann et al. 
Each illustrated nipple 66 has an axial passage which can admit compressed 
testing fluid into the respective end of the aligned wrapper. Such 
compressed fluid is admitted by one or two arcuate grooves 69 in a second 
stationary valve plate 69 which is outwardly adjacent to the flange 67. 
Each of the grooves 62, 69 can be connected with a device which measures 
the pressure of testing fluid and furnishes appropriate signals indicative 
of the measured pressure. 
The grooves 69 in the valve plate 68 are necessary only in the testing 
apparatus of FIG. 5. If the apparatus is constructed in a manner as shown 
in FIG. 4, the grooves 69 are omitted and the nipples 66 can be replaced 
with nipples without axial passages for the flow of testing fluid, i.e., 
the nipples 66 then merely serve as a means for sealing the respective 
ends of the wrappers. 
In the testing apparatus of FIG. 4, the valve plate 61 has two grooves 62 
which are disposed one behind the other, as considered in the 
circumferential direction of the conveyor 31. Also, the wall 37a of the 
shaft 37 is then formed with two slots 53a (one for each groove 62) but 
with a single slot 53b (for the first groove 62). In other words, the 
apparatus of FIG. 4 is constructed in such a way that the suction intake 
of the blower 76 communicates with both compartments 46a, 46b of a chamber 
46 when the latter is located in register with the first slot 62 but that 
only the compartment 46a will communicate with the suction intake of the 
blower 76 when the respective chamber 46 travels past the second groove 
62. 
Referring to FIG. 4 in detail, the suction intake of the blower 76 is 
connected with a pipe 87 containing a pressure regulating valve 88 and a 
pressure gauge 89 and having two branches 87a and 87b. The branch 87a 
forms part of a first testing device 71a of the apparatus of FIG. 4, and 
the branch 87b forms part of a second testing device 71b. The first 
testing device 71a facilitates measurement of the permeabiity of entire 
wrappers of successive cigarettes Z during travel past the first groove 62 
of the valve plate 61, and the testing device 71b facilitates measurement 
of the permeability of predetermined (major) wrapper portions during 
travel of the respective wrappers past the second groove 62. 
The branch 87a communicates with the compartments 46a, 46b of successive 
chambers 46, and the branch 87b communicates with successive compartments 
46a. Thus, the branch 87a communicates with the first slot 53a and with 
the registering slot 53b whereas the branch 87b communicates solely with 
the second slot 53a. It will be realized that the representation of the 
apparatus of FIG. 4 is very schematic, i.e. that the branch 87a can be 
omitted if the pipe 87 communicates directly with the first slot 53a and 
with the registering slot 53b while a single branch (87b) of the pipe 87 
communicates solely with the second slot 53a. 
The first groove 62 of the valve plate 61 is connected with the discharge 
end of a pipe 82a whose inlet communicates with the atmosphere and which 
contains a preferably adjustable flow restrictor 83a and a pressure gauge 
84a of high inertia, and is further connected with the input of an 
electropneumatic transducer 91a forming part of an evaluating circuit 86. 
The high-inertia pressure gauge 84a may be of the type known as 
encapsulated spring gauge, and the transducer 91a may be of the type 
disclosed in commonly owned U.S. Pat. No. 3,412,856 to Esenwein. 
The second groove 62 of the valve plate 61 is connected to the discharge 
end of a pipe 82b whose inlet communicates with the atmosphere and which 
contains a preferably adjustable flow restrictor 83b and a pressure gauge 
84b (which is preferably identical with the pressure gauge 84a). The pipe 
82b is connected with the input of a second electropneumatic transducer 
91b in the evaluating circuit 86. 
The circuit 86 evaluates the electric signals which are furnished by the 
outputs of the transducers 91a and 91b. The output of the transducer 91a 
is connected with one input of an adjustable signal storing circuit 98a 
another input of which is connected with the proximity switch 99a of a 
pulse generator or synchronizing means 99 further having a rotary disk 99c 
provided with magnets 99b which travel past the switch 99a at the same 
rate at which successive cigarettes Z travel past the first and second 
grooves 62 of the valve plate 61. The disk 99c is driven by the prime 
mover PM of the filter cigarette making machine in synchronism with the 
conveyor 31. The output of the transducer 91b is connected with one input 
of a second adjustable signal storing circuit 98b whose other input is 
connected to the proximity switch 99a. The circuits 98a and 98b insure 
that signals furnished by the outputs of the transducers 91a and 91b are 
transmitted to additional parts of the evaluating circuit 86 at the exact 
moments when the corresponding wrappers respectively register with the 
first and second grooves 62 of the valve plate 61. 
The outputs of the signal comparing circuits 98a, 98b are connected with 
the corresponding inputs of a subtracting circuit 111. The output of the 
circuit 98b is connected directly with the corresponding input of the 
circuit 111. On the other hand, the output of the circuit 98a is connected 
with the corresponding input of the circuit 111 by an adjustable 
time-delay unit 112 which insures that the two inputs of the circuit 111 
receive, at the same time, signals generated by the transducers 91a, 91b 
during testing of one and the same wrapper. The unit 112 transports 
signals at the rate at which a wrapper advances from the first to the 
second groove 62 of the valve plate 61. To this end, the time-delay unit 
112 comprises an analog-digital converter 113 whose input is connected 
with the output of the signal storing circuit 98a and which comprises 
several outputs a, b . . . n. Each of these outputs is connected with the 
first stage of a discrete shift register 114a, 114b . . . 114n. The shift 
registers 114a-114n receive signal transporting pulses from the proximity 
switch 99a of the pulse generator 99, and the last stages of these shift 
registers are connected to the corresponding inputs (a, b . . . n) of a 
digital-analog converter 116 whose output is connected with the right-hand 
input of the subtracting circuit 111. The number of stages in the shift 
registers 114a-114n corresponds to different distances between the grooves 
62 of the valve plate 61. Only one shift register is active at any given 
time. 
The output of the subtracting circuit 111 is connected with one input of a 
signal comparing threshold circuit 92b another input of which receives a 
reference signal from a suitable source 94b (e.g., an adjustable 
potentiometer). The output of the threshold circuit 92b transmits a signal 
when the intensity or another characteristic of the signal which is 
transmitted by the output of the subtracting circuit 111 is less 
pronounced than the corresponding characteristic of the reference signal 
from the source 94b. 
The output of the signal storing circuit 98a is further connected with one 
input of a signal comparing threshold circuit 92a another input of which 
receives a reference signal from a source 94a. The output of the threshold 
circuit 92a transmits a signal when the intensity or another 
characteristic of the signal at the output of the circuit 98a exceeds the 
corresponding characteristic of the reference signal which is furnished by 
the source 94a. 
The outputs of the threshold circuits 92a, 92b are connected with the 
corresponding inputs of an OR-gate 97 whose output is connected to the 
first stage of an additional shift register 101. The shift register 101 
receives signal transporting pulses from the proximity switch 99a and its 
last stage is connected with the amplifier 103 of a segregating device 102 
further including a normally closed solenoid-operated valve 104 in a 
conduit 108 connecting a source 106 of compressed air or another gas with 
an ejector nozzle 107. The latter is mounted adjacent to or in the 
conveyor 32 and serves to segregate defective cigarettes Z (i.e., 
cigarettes having defective wrappers) from satisfactory cigarettes by 
expelling the cigarettes with defective wrappers from that portion of the 
cigarette path which is defined by the conveyor 32. The shift register 101 
insures that the signal which is transmitted by the output of the OR-gate 
97 is transported toward the ejecting station at the speed of movement of 
the corresponding wrapper. 
The high-inertia gauges 84a and 84b respectively furnish readings denoting 
the average permeability of several successive wrappers and several 
successive perforated wrapper portions. 
The operation: 
As soon as a chamber 46 reaches the concave inner side of the shroud 48, 
its compartments 46a, 46b are connected with the intake of the blower 76 
by the pipe 87 and its branch 87a. In other words, the entire chamber 46 
constitutes a suction chamber while the cigarette Z therein advances past 
the first testing device 71a. On the other hand, only the compartment 46a 
of a chamber 46 is connected with the intake of the blower 76 (via pipe 87 
and branch 87b) while the corresponding cigarette Z travels past the 
second testing device 71b. The (subatmospheric) pressure in the 
compartments 46a, 46b which register with the first groove 62 is the same 
as the pressure in the compartment 46a which registers with the second 
groove 62. It is presently preferred to connect successive second 
compartments 46b with the atmosphere during travel past the second groove 
62; this can be achieved by removing that portion of the shroud 48 which 
would overlie successive compartments 46b during travel past the second 
groove 62. 
The signal storing circuit 98a accepts a signal from the transducer 91a 
only when it receives a signal from the proximity switch 99a. The 
intensity of (first) signal which is transmitted by the transducer 91a is 
indicative of permeability of a first wrapper portion, namely the entire 
wrapper, of a cigarette Z which registers with the first groove 62. If the 
measured permeability of the entire wrapper exceeds a predetermined 
maximum permissible permeability (denoted by the reference signal which is 
furnished by the source 94a), e.g., because that (second) portion of the 
wrapper which forms part of the plain cigarette T has an open seam, one or 
more relatively large holes, a frayed end or a combination of such defects 
and/or because the combined cross-sectional area of holes L in the wrapper 
portion of the filter mouthpiece F (remaining part of the wrapper) is 
excessive, the output of the threshold circuit 92a transmits a signal to 
the OR-gate 97 with the result that the corresponding cigarette Z is 
ejected from the respective flute of the conveyor 32 during travel past 
the orifice of the nozzle 107. 
The output of the signal storing circuit 98a transmits each (first) signal 
from the transducer 91a to the analog-digital converter 113 of the 
time-delay unit 112. The latter delays the transmission of such signal to 
the corresponding input of the subtracting circuit 111 until the 
respective cigarette Z reaches the second groove 62 of the valve plate 61, 
i.e., until the respective cigarette enters the second testing device 71b. 
The signal which is transmitted by the output of the transducer 91b 
denotes the permeability of that (second) portion of a wrapper which forms 
part of the respective plain cigarette T, i.e., of a wrapper portion which 
forms part of the first wrapper portion (constituting the entire wrapper); 
therefore, the signal at the output of the subtracting circuit 111 denotes 
the permeability of wrapper portions (remaining parts of first wrapper 
portions) which are provided with the holes L, i.e., the permeability of 
wrapper portions forming part of the filter mouthpieces F. It can be said 
that the signal at the output of the subtracting circuit 111 denotes the 
combined cross-sectional area of holes L and hence the rate at which the 
respective wrapper can admit atmospheric air into the column of tobacco 
smoke. It has been found that signals at the output of the circuit 111 
reflect the permeability of perforated wrapper portions with a 
surprisingly high degree of accuracy. This is attributed to the fact that 
the principle of operation of testing device 71a is identical to that of 
the device 71b so that eventual errors in the course of first testing 
operation are compensated for by similar errors in the course of the 
second testing operation and the (third) signals at the output of the 
subtracting circuit 111 are truly indicative of permeability of the 
perforated wrapper portions, i.e., of remaining parts of first wrapper 
portions. 
The first testing device 71a establishes a first pressure differential 
between the exterior (chamber 46) and interior of successive wrappers, and 
the second testing device 71b establishes a second pressure differential 
between the exterior (compartment 46a) and interior of the wrapper portion 
which forms part of the plain cigarette T as well as a third pressure 
differential between the exterior (compartment 46b) and interior of the 
remaining part of the wrapper, namely, the wrapper portion forming part of 
the filter mouthpiece F. In the apparatus of FIG. 4, the first pressure 
differential may but need not equal the second pressure differential but 
the third pressure differential is different from the first and second 
pressure differentials. Thus, the pressure in the compartment 46b which 
registers with the first groove 62 of the valve plate 61 is different from 
the pressure in compartment 46b which registers with the second groove 62. 
The output of the subtracting circuit 111 transmits (third) signals to the 
threshold circuit 92b and the latter compares such signals with the 
reference signal from the source 94b. If the intensity of signals at the 
output of the circuit 111 is less pronounced than the intensity of 
reference signal from 94b, the permeability of perforated wrapper portion 
of the respective wrapper is less than a minimum acceptable permeability 
and the threshold circuit 92b transmits a signal to the OR-gate 97 whereby 
such signal serves to effect expulsion of the corresponding cigarette Z 
during travel past the orifice of the nozzle 107. 
It is clear that the testing apparatus of FIG. 4 can be modified in a 
number of ways without departing from the spirit of the invention. For 
example, the testing device 71a can be installed adjacent to that portion 
of the cigarette path which is defined by a first conveyor and the testing 
device 71b can be mounted adjacent to a second portion of the path which 
second portion is defined by a discrete second conveyor. Furthermore, the 
testing device 71b can be placed ahead of the testing device 71a; the 
time-delay unit 112 is then connected between the transducer 91b or signal 
storing circuit 98b and the signal storing circuit 98b or subtracting 
circuit 111. 
FIG. 5 shows a portion of a second testing apparatus wherein all such parts 
which are identical with or clearly analogous to corresponding parts of 
the apparatus of FIG. 4 are designated by similar reference characters 
plus 100. The main difference is that the testing device 171a admits 
compressed testing fluid into both ends of a wrapper between the first 
groove 62 and the first groove 69 whereas the second testing device 171b 
admits compressed testing fluid into both ends of a wrapper between the 
second grooves 62, 69 as well as into the corresponding compartment 146b. 
The evaluation of pneumatic signals by the circuit 186 is analogous to 
that by the evaluating circuit 86 except that the signals have different 
signs. Thus, the pressure at the inputs of the transducers 91a, 91b in the 
circuit 86 of FIG. 4 is below atmospheric whereas the pressure of signals 
which are transmitted to the transducers of the circuit 186 is above 
atmospheric pressure. 
The blower 176 has a pressure outlet which is connected with a pipe 177 
containing a pressure regulating valve 178 and having branches 177a, 177b 
which respectively contain preferably adjustable flow restrictors 181a, 
181b. The branch 177a admits compressed testing fluid to the first grooves 
62, 69 and the branch 177b admits compressed testing fluid to the second 
grooves 62, 69. The pipe 177 has a further branch 187b containing a 
pressure regulating valve 188b and a preferably adjustable flow restrictor 
190b and is connected with the compartments 146b of successive chambers 
during travel between the second grooves 62 and 69. 
The compartments which travel through the first testing device 171a 
communicate with the atmosphere; this can be readily achieved by the 
simple expedient of shortening the shroud 148 so that it does not overlie 
the chambers between the first grooves 62 and 69. The branch 177a is 
further connected with that transducer of the circuit 186 which 
corresponds to the transducer 91a of FIG. 4. The branch 177b is further 
connected with the other transducer of the circuit 186. The testing device 
171a facilitates measurement of the permeability of entire wrappers and 
the testing device 171b facilitates measurement of the permeability of 
wrapper portions which form part of the respective plain cigarettes T. 
The aforementioned branch 187b communicates with successive second 
compartments 146b by way of the space 52b in the shaft 37 (not shown in 
FIG. 5). The adjustment of regulating valve 188b is such that the pressure 
in the compartment 146b which moves through the second testing device 171b 
equals or closely approximates the pressure of testing fluid which is 
admitted by the branch 177b into the right-hand end of the wrapper, as 
viewed in FIG. 5. Therefore, the pressure differential between the 
interior and exterior of a perforated wrapper portion in the testing 
device 171b is zero and the testing fluid can flow only from the interior 
of the other wrapper portion into the compartment 146a which communicates 
with the atmosphere. Some testing fluid will escape through the (second) 
wrapper portion surrounding the plain cigarette T because, as a rule, the 
wrapping material (cigarette paper) exhibits at least some porosity. The 
(third) signal which is transmitted by the subtracting circuit of the 
measuring circuit 186 is again indicative of permeability of the wrapper 
portions which are provided with holes L. 
The testing apparatus of FIG. 5 can be readily converted for operation in a 
manner as described in FIG. 4 or vice versa. All that is necessary is to 
change the connections to the compartments of chambers in the testing 
conveyor, to replace the valve plate 61 and to replace the nipples 66 with 
different nipples or to seal the passages of the nipples 66. 
An important advantage of the improved process and apparatus is that 
repeated testing of successive wrappers (in such a way that one testing 
operation is influenced and the other testing operation is not influenced 
by the presence of holes L) insures a highly accurate determination of 
permeability of perforated wrapper portions and hence of the amount of 
atmospheric air which can flow into the corresponding wrappers when the 
respective cigarettes are lighted. It has been found that the improved 
process and apparatus insure that the packing machine receives only those 
cigarettes wherein the permeability of perforated wrapper portions equals 
or very closely approaches the desired permeability. Moreover, factors 
which normally affect the accuracy of testing operations are eliminated in 
view of repeated testing of each wrapper in accordance with the same 
principle; this will be readily appreciated by taking into consideration 
that the measuring circuit 86 or 186 comprises a subtracting circuit. 
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.