Abstract:
A machine for making composite filter mouthpieces for cigarettes or the like has a conveyor serving to transport a series of upright tubes of paper or the like past a vertically movable plunger which serves to introduce into successive tubes alternating plugs or wads of filter material and batches of flowable granular and/or pulverulent filter material. If the extent to which the plunger descends into a registering tube is outside of a predetermined range, the tube contains an excessive quantity or less than the required quantity of filter material. This is detected by one or more sensors which causes or cause ejection of the respective tube from the path for acceptable filter mouthpieces. A compensating device cooperates with the plunger to allow for proper confinement of flowable filter material against rattling between a pair of filter plugs if the quantity of such flowable filter material in a tube is below an optimum value.

Description:
CROSS-REFERENCE TO RELATED CASES  
         [0001]    The present application claims the priority of commonly owned copending German patent application Serial No. 101 05 012.7 filed Jan. 29, 2001. The disclosure of the above-referenced German priority application, as well as that of each US and foreign patent and patent application identified in the specification of the present application, is incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    The present invention relates to improvements in machines or apparatus for making filter mouthpieces (hereinafter also called filter plugs) for tobacco smoke. More particularly, the invention relates to improvements in machines for making composite filter mouthpieces which can be utilized with advantage in filter cigarettes, cigars, cigarillos, papirossy and analogous rod-shaped smokers&#39; products. Still more particularly, the invention relates to improvements in machines for manipulating component parts of composite filter mouthpieces in or on their way into filter rod making machines.  
           [0003]    Machines of the character to which the present invention pertains are disclosed, for example, in published German patent application No. 17 82 364 which corresponds to British patent No. 1 243 977 and to U.S. Pat. No. 3,603,058 granted Sep. 7, 1971 to Schubert for “METHOD AND APPARATUS FOR THE PRODUCTION OF COMPOSITE FILTER TIPS”. These publications disclose machines for the making of filter mouthpieces which contain at least one supply of flowable (such as granular) filter material for tobacco smoke. Such machines were known as “Bernhard” and were distributed by the assignee of the present application. The so-called multisegment filter mouthpieces which are turned out by the “Bernhard” machine contain at least two different filter materials or filter segments for tobacco smoke. Such materials can include cellulose acetate, paper, tow, granulates, sintered elements, hollow cylinders or chambers, capsules, plugs, wads or the like. In many instances, two or more different filter materials for tobacco smoke are confined in a tubular envelope of paper or the like.  
           [0004]    As a rule, or in many instances, the filter rod making machine which turns out filter rod sections or mouthpieces for attachment to plain cigarettes, cigarillos, cigars or other rod-shaped smokers&#39; products is set up to produce filter mouthpieces of twice, four or six times unit length, and such mouthpieces are subdivided into shorter mouthpieces in the filter tipping machine, i.e., in the machine wherein the filter mouthpieces are united with plain cigarettes or the like by socalled tipping paper. For example, the “Bernhard” machine which is disclosed in U.S. Pat. No. 3,603,058 to Schubert turns out filter mouthpieces of twice unit length. This machine employs reciprocable plungers or pushers which serve to introduce plugs or wads of filter material into prefabricated tubular envelopes or into tubes which are obtained by converting strips of paper or other draping material into tubular envelopes for filter material. The plungers are movable along stationary cam faces which cause or permit the plungers to penetrate into or to be withdrawn or expelled from the tubular envelopes.  
           [0005]    The aforementioned U.S. patent to Schubert as well as the commonly owned U.S. patent application Ser. No. (Attorney Docket: 31976-177336) (corresponding to German patent applications Nos. 101 05 010.0 and 101 05 011.9) disclose methods of and apparatus for making composite or compound filter plugs for tobacco smoke which can be utilized in conjunction with the method and machine of the present invention.  
           [0006]    A drawback of presently known filter mouthpiece making methods and machines is that they are apt to turn out a relatively high percentage of defective filter mouthpieces. This is attributable, at least to a certain extent, to the fact that the instrumentalities which are utilized to introduce metered quantities of filter material (such as granulate) into tubular envelopes of future filter mouthpieces are likely to deliver quantities which vary within a certain range. If a pre-selected optimum quantity of granular filter material is confined between two wads or plugs of filter material, the thus confined granular material cannot generate a rattling noise which is undesirable to the smoker and is indicative of a lower-quality filter mouthpiece because tobacco smoke can readily bypass (and is thus unaffected by) the granulae. Thus, there exists an urgent need for filter rod making machines which can deliver uniform quantities of flowable (such as granular and/or pulverulent) filter material for tobacco smoke and/or which can compensate for the delivery of less than optimal quantities of granular or other flowable filter material for tobacco smoke.  
         OBJECTS OF THE INVENTION  
         [0007]    An object of the present invention is to provide a novel and improved method of making filter mouthpieces which are not likely to be “noisy” even though they contain one or more supplies or batches of flowable filter material for tobacco smoke in quantities which depart from optimum or intended quantities.  
           [0008]    Another object of the invention is to provide a novel and improved method of compensating for departures of supplies of flowable filter material in a series of successive filter mouthpieces from an optimum quantity.  
           [0009]    A further object of the invention is to provide a novel and improved method of converting a noise generating semifinished filter mouthpiece into a non-rattling mouthpiece.  
           [0010]    An additional object of the invention is to provide a novel and improved non-rattling filter mouthpiece which can be mass produced in filter rod making machines constituting relatively simple and inexpensive modifications of conventional filter rod making machines.  
           [0011]    Still another object of the invention is to provide a method and a machine which constitute improvements over and further developments of methods and machines disclosed in the aforediscussed U.S. Pat. No. 3,603,058 to Schubert and in the aforementioned copending U.S. patent application No. (Attorney Docket: 31976-177336).  
           [0012]    A further object of this invention is to provide a novel and improved method of and a novel and improved machine for segregating defective or potentially defective filter mouthpieces from satisfactory mouthpieces.  
           [0013]    Another object of the invention is to provide novel and improved constituents for use in filter mouthpiece making machines.  
           [0014]    An additional object of the invention is to provide a novel and improved filter mouthpiece making machine.  
           [0015]    Still another object of the invention is to provide a machine for making and for simultaneously monitoring the condition and/or quality of developing filter mouthpieces for tobacco smoke as well as for comparing the thus ascertained condition with a range of acceptable conditions.  
           [0016]    A further object of the invention is to provide a novel and improved distribution of sensors in a filter mouthpiece making machine, i.e., in a machine which supplies filter mouthpieces to a filter tipping machine.  
           [0017]    Another object of the invention is to provide a novel and improved combination of parts for use in a machine for the making of filter mouthpieces for rod-shaped smokers&#39; products.  
         SUMMARY OF THE INVENTION  
         [0018]    One feature of the present invention resides in the provision of a novel and improved combination of parts in a machine which is designed to make filter mouthpieces for attachment to rod-shaped smokers&#39; products in a so-called tipping machine which is designed to turn out filter cigarettes, cigars, cigarillos or the like. The combination comprises a mobile transfer device which is set up to introduce filter material for tobacco smoke (e.g., plugs or wads of sintered filter material, compacted fibrous material or the like) into sections of wrapping material (e.g., into tubes arranged to receive two or more different filter materials) and includes a pusher or plunger which is reciprocable into and from one end of the tube occupying a predetermined portion of a predetermined path for a succession of discrete tubes, guide means for the transfer device (such guide means can include a rail or track which is arranged to maintain the plunger in a predetermined position while in alignment with the tube occupying the predetermined portion of its path), and novel and improved compensating means between the transfer device and the guide means. The compensating means can include one or more elastic components (i.e., it can consist at least in part of a resilient material) which enables or enable the compensating means to cause a longer than normal or longer than anticipated movement of the transfer device when the quantity of filter material in the tube occupying the predetermined portion of its path is less than required, or which enables or enable the compensating means to permit a shorter than normal or anticipated movement of the transfer device when the quantity of filter material in the tube occupying the predetermined portion of the path exceeds the required (such as optimum) quantity.  
           [0019]    The guide means can comprise a groove for a portion of the transfer device or for a portion of the compensating means.  
           [0020]    The mobile plunger or pusher of the transfer device can be received in a tubular guide member of the compensating means, and such tubular guide member can include a follower received in the groove of the guide means. The combination including such tubular guide member can further comprise means (such as a stop at one end of the plunger) for limiting the extent of movability of the plunger in at least one direction, preferably deeper into the section of wrapping material in the predetermined portion of the path for the sections.  
           [0021]    The compensating means can comprise at least one spring, e.g., a helical spring or a spiral.  
           [0022]    The means for moving the transfer device (such as the aforementioned plunger) can comprise a motor, e.g., a stepping motor.  
           [0023]    The improved combination can further comprise one or more sensors or other suitable means for monitoring the extent of movability of the plunger. For example, the monitoring means can include a power sensor, a contact sensor and/or a distance sensor.  
           [0024]    In accordance with one presently preferred embodiment, the compensating means can consist of or include an elastic synthetic plastic material, e.g., a rubber foam which at least partially fills one or more chambers in the transfer device and/or in the guide means.  
           [0025]    Another feature of the present invention resides in the provision of a machine for making filter mouthpieces for attachment to smokers&#39; products. The machine comprises a mobile device (e.g., a plunger) for introduction of filter material into at least one section of a wrapping material (e.g., into one of a series of tubes being advanced in upright position along a predetermined path), and a control element which constitutes a means for facilitating only indirect movements of the mobile device. Such apparatus can further comprise a compensating element between the mobile device and the control element.  
           [0026]    An additional feature of the present invention resides in the provision of a machine for making filter mouthpieces for smoke which is generated by products of the tobacco processing industry. The machine comprises at least one mobile transfer device (such as a reciprocable plunger) which serves to introduce quantities of tobacco smoke filtering material into tubular receptacles (such as open-ended cylindrical sleeves or tubes of paper or the like), guide means for the transfer device, and means for compensating for departures of quantities of filter material from predetermined or preselected or acceptable quantities.  
           [0027]    Still another feature of the instant invention resides in the provision of a machine for making composite filter plugs for attachment to rod-shaped smokers&#39; products. The machine comprises means for advancing a succession of tubular receptacles for filter material for tobacco smoke in a predetermined direction along a predetermined path, adjustable means (such as a plunger) for introducing discrete quantities of filter material into successive receptacles in the path, means for monitoring the quantities of filter material, and means for adjusting the introducing means when the monitored quantities depart from a predetermined value.  
           [0028]    The introducing means can be set up for movement relative to successive receptacles in a predetermined portion of the aforementioned path, and the extent of movement of such introducing means is indicative of the quantity of filter material introduced into the receptacle which is then located in the predetermined portion of the path. The monitoring means can include means for ascertaining the extent of movement of the introducing means. This machine can further comprise means for removing from the predetermined path those receptacles wherein the quantity of filter material in the receptacle occupying the predetermined portion of the path causes the introducing means to move through a distance outside of a predetermined range of (acceptable) distances.  
           [0029]    The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved filter mouthpiece making machine itself, however, both as to its construction and the modes of assembling, installing and operating the same, together with numerous additional important and advantageous features and attributes thereof, will be best understood upon perusal of the following detailed description of certain presently preferred specific embodiments with reference to the accompanying drawing.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0030]    [0030]FIG. 1 is a fragmentary schematic partly developed and partly sectional view of certain parts of a filter mouthpiece making machine including an apparatus which embodies one form of the present invention;  
         [0031]    [0031]FIG. 2 is a view of a detail of the structure which is shown in FIG. 1;  
         [0032]    [0032]FIG. 3 illustrates the structure of FIG. 2 but with one of the parts in a different axial position;  
         [0033]    [0033]FIG. 4 is a view similar to that in the upper part of FIG. 1 but showing certain parts of a different machine; and  
         [0034]    [0034]FIG. 5 is a view similar to that of FIG. 4 but showing a portion of a third machine.  
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0035]    The upper and lower portions of FIG. 1 show certain parts of a filter mouthpiece making machine and the central portion of this Figure illustrates a series of filter mouthpieces during different stages of finish starting at a and ending at i. A filter mouthpiece which undergoes a series of treatments (namely which goes through different stages of filling with filter material for tobacco smoke) includes a section of wrapping material here shown as a cylindrical sleeve or tube  11  made of paper or any other suitable material and being convertible (fillable) into a tubular envelope  37  of the finished filter mouthpiece. A central portion of the sleeve  11  contains a plug or wad  19  of a first filter material which is located in a predetermined axial position of the sleeve by a lower pusher or plunger  18  that enters the sleeve from below at b.  
         [0036]    If the plug  19  is bonded to the internal surface of the sleeve  11  in a manner not shown in FIG. 1, the lower plunger  18  serves to hold the sleeve and the plug in a selected axial position, i.e., the axial position of the sleeve  11  is determined by the plunger  18  in that it maintains the plug  19  at a preselected level. The sleeve  11  is assumed to be borne by a suitable conveyor; for example, it can be at least partially confined in a complementary bore or hole or flute  16  of an indexible drum-shaped conveyor  12  (see FIG. 4). The conveyor  12  can operate with suction (see the suction ports  13 ) to attract the sleeve  11  to the surface surrounding the respective hole or flute  16 .  
         [0037]    The lower plunger  18  has entered the sleeve  11  at the position b shown in FIG. 1 following the position a which the sleeve assumes immediately upon entry or prior to entry into the hole or flute  16 . A renewed indexing of the conveyor  12  including the hole or flute  16  causes the sleeve  11  to assume the position c of FIG. 1 in which the sleeve receives a supply  26  of first granular and/or pulverulent filter material for tobacco smoke. The admission of the supply  26  is assumed to have taken place through one of the bores or holes or passages  14  of a first pusher  24  (see FIG. 4) or through one of the holes or bores or passages  14 ′ of a second pusher  42  which is shown in FIG. 5. Reference may be had to the aforementioned copending U.S. patent application Serial No. (Attorney Docket: 31976-177336) which was filed jointly with this application.  
         [0038]    The next step (see the sleeve  11  in the position d of FIG. 1) involves the introduction (lowering) of an upper pusher or plunger  17  which causes a second plug or wad  20  of filter material for tobacco smoke to enter the sleeve from above toward and into contact with the supply  26  above the plug  19 . The sleeve  11  at d in FIG. 1 is assumed to be properly filled, i.e., it confines the plugs  19  and  20  at the desired levels and contains an optimum quantity of flowable filter material  26  between the two plugs.  
         [0039]    The upper plunger  17  is reciprocable in a tubular duct or shaft  25  and is biased by at least one resilient element here shown as a coil spring  28  and/or another resilient element which tends to move the plunger  17  downwardly so as to compress or compact the flowable filter matrial  26  to a desired extent if the plugs  19  and  20  are maintained at an optimum distance from each other. The duct  25  has limited freedom of movement.  
         [0040]    The plunger  17  extends upwardly into the lower portion of the duct  25  and its upper end portion is provided with a radial extension or collar  31  confined in a fastener  32  borne by the frame  33  of the filter mouthpiece making machine. The fastener  32  has an internal guide groove  44  which receives the collar  31  in such a way that the latter is held at a preselected level. When the sleeve  11  is properly filled with filter materials  19 ,  20  and  26 , the upper plunger  17  is maintained in a predetermined axial position relative to the duct  25 , i.e., a stop  29  at the upper end of an elongated axial upward extension of the plunger  17  is spaced apart from the collar  31 .  
         [0041]    [0041]FIG. 2 shows the stop  29  in the same (desired or optimal) axial position relative to the collar  31  as FIG. 1. On the other hand, FIG. 3 shows the stop  29  in a (lower end) position of actual abutment with the collar  31 .  
         [0042]    [0042]FIG. 1 further shows several additional stages of making a composite filter mouthpiece. At e, the sleeve  11  is without the plug  20  and the exact quantity of flowable filter material  26  is yet to be determined. When at f, the flowable filter material  26  has an axial length which equals or approximates 5 mm and which is assumed to be the optimum height. If the axial length of the flowable filter material  26  departs from the optimum axial length by 0.5 mm (see the position g), i.e., by approximately 10%, a conventional filter mouthpiece making machine inserts the plug  20  in such a way that the the axial position of the plug  20  is proper, i.e., the inserted mass of flowable filter material  19  has room to rattle because the allotted space exceeds the required space (for such less than optimal quantity) by 0.5 mm, i.e., by more than 10%. This is undesirable because the finished composite filter mouthpiece is “noisy” as well as because the contact between the particles of flowable filter material  26  and tobacco smoke flowing into the mouth of the smoker is less satisfactory than when tobacco smoke is caused to flow through a filter mouthpiece including the plugs and the flowable filter material shown at f. The filtering action of a flowable filter material which cannot move relative to the sleeve and the adjacent plugs or wads is more satisfactory than that of the flowable filter material which can move relative to the adjacent plugs in response to shaking or analogous movements of the finished filter mouthpiece.  
         [0043]    In accordance with a feature of the present invention, the problems encountered by utilizing a “noisy” filter mouthpiece of the type shown at h are overcome by causing the plug  20  to descend to a level directly above the top layer of the shorter-than-desired supply  26  of flowable filter material shown at h. Thus, the wad  20  has been caused to descend to a level which is necessary to eliminate the 0.5 mm gap shown at h. It is assumed that the elimination of such gap necessitates a lowering of the stop  29  to the level of FIG. 3, i.e., to a position of actual abutment with the upper end face of the collar  31 . Such lowering of the stop  29  is caused by the coil spring  28  which reacts against the underside of the collar  31  and bears upon the end face at the upper end of the main portion of the upper plunger  17 . The axial position of the plunger  17  is determined by the guide groove  44  of the fastener  32  the level of which determines the lower end position of the plunger  17 .  
         [0044]    In accordance with a further feature of the present invention, a filter mouthpiece wherein the axial length of the column  26  of flowable filter material which is still free to rattle when the stop  29  abuts the collar  31  is less than 4.5 mm is segregated from satisfactory filter mouthpieces. Such segregation is effected by resorting to one or more sensors or monitoring means, e.g., to one or more sensors of the type shown in and about to be described hereinafter with reference to FIGS. 4 and 5.  
         [0045]    [0045]FIG. 1 further shows that the lower plunger  18  comprises a collar  131  which is received in an elongated guide groove  144  of a fastener  132  borne by a portion  133  of the machine frame. The grooves  44 ,  144  determine the directions of movement of the plungers  17 ,  18  relative to the frame of the filter mouthpiece making machine.  
         [0046]    The treatment of the sleeve  11  includes a turning through 180° in order to ensure adequate filling of the other side with flowable filter material. This is necessary because the ultimate product is to constitute a triple filter mouthpiece of double unit length or a double filter mouthpiece of three times unit length. When such filter mouthpiece is properly assembled with and is located between two tobacco-containing rod-shaped products (e.g., plain cigarettes, cigarillos or cigars) of unit length, it is severed midway between its ends to yield two filter mouthpieces of unit length each of which forms part of a filter cigarette, cigarillo or cigar of unit length. The manner of making such filter-tipped smokers&#39; products is disclosed, for example, in commonly owned U.S. Pat. No. 5,135,008 granted Aug. 4, 1992 to Oesterling et al.  
         [0047]    The manner in which a sleeve can be turned upside down upon completion of the treatment shown at f or i in FIG. 1 is shown in and described with reference to FIG. 14 in each of the commonly owned copending U.S. patent application Ser. No. (Attorney Docket: 31976-177336) to which reference may be had, if necessary. Once the inversion of a sleeve  11  (with a plug  19 , supply  26  and plug  20  therein) is completed, the (then) upwardly extending empty portion  11   a  of the inverted sleeve receives a metered quantity  26  of flowable filter material and a plug  20  in such order. This completes the making of a filter mouthpiece of double unit length which is ready to be severed midway across the plug  19  to yield two filter mouthpieces of unit length each containing one-half of a sleeve  11 , one-half of a plug  19 , a supply  26  and a plug  20 .  
         [0048]    [0048]FIG. 4 illustrates certain details of a modified machine for the making of composite filter mouthpieces. The structure which is actually shown in FIG. 4 includes several parts which are identical with or plainly analogous to some of those shown in FIG. 1 as well as certain parts having no equivalents in the machine of FIG. 1.  
         [0049]    The lower plunger,  18  of the machine shown in FIG. 4 is illustrated in an axial position in which its upper end portion is already received in the bore or hole or flute  16  of the drum-shaped indexible conveyor  12 . The latter is provided with the aforementioned suction ports  13  which hold the sleeve  11  in its bore or flute  16  during certain stages of angular movement of the conveyor  12  about its axis. These suction ports serve to transfer the sleeve  11  from a second drum-shaped indexible conveyor  10  which is shown in FIG. 5. The upper plunger  17  extends through one of the bores or holes  14  in the pusher  24  and through a tube  15  which latter extends through registering bores or holes in pushers  23 ,  24  and a bore or hole in a plate-like conveyor  22  serving to deliver filter plugs  30 . The pusher  23  contains filter plugs  20  and  30  in bores  14   a  for introduction into the second half of the partially filled sleeve  11 . Additional flowable filter materials  26  and  27  are delivered into the bores or holes  14  of the pusher  24  at a further admitting station of the filter mouthpiece making machine embodying the structure of FIG. 4.  
         [0050]    In the embodiment of FIG. 4, a plug  30  and a metered quantity of flowable filter material  26  are introduced into a sleeve  11  in a first step, and such sleeve receives a second plug  20  and a second metered quantity of flowable filter material  27  in a second step. A sensor  43  (such as a contact sensor) is provided on or at the shoulder  31  of the hollow shaft  25  in the path of downward movement of the stop  29  (or on the stop  29 ). In the embodiment of FIG. 4, the sensor  43  is stationary relative to the hollow shaft  25 .  
         [0051]    If the stop  29  of the structure shown in FIG. 4 descends into engagement with the sensor  43 , this establishes a path for the flow of electric current for initiation of visual indication by a non-illustrated signal generating device (such as a light source and/or a source of audible signals). When the stop  29  engages the sensor  43 , the thus obtained signal or signals is or are indicative of the presence of a defective filter mouthpiece, i.e., of the fact that the quantity of at least one batch of flowable filter material insufficient and/or that the axial length of at least one filter plug or wad is below a normal or optimum or desired axial length. If the filter plugs are satisfactory, the defect consists in that the axial length of at least one batch or supply of flowable filter material in a sleeve  11  is below the desired or acceptable axial length. The signal is utilized to segregate (e.g., pneumatically expel) the corresponding defective filter mouthpiece(s) from the preceding and from the next-following (satisfactory) filter mouthpieces, i.e., the defective filter mouthpiece(s) cannot reach the filter tipping machine, e.g., a machine of the type disclosed in the aforementioned commonly owned U.S. Pat. No. 5,135,008 to Oesterling et al.  
         [0052]    [0052]FIG. 5 shows certain component parts of a further filter mouthpiece making machine which employs two additional (e.g., plate-like) pushers  41 ,  42  with bores  14   a ′ and  14 ′, respectively, disposed between the pusher  24  and the indexible drum-shaped conveyor  12 . Such additional pushers render it possible to make filter mouthpieces of the type containing four different filter materials for tobacco smoke. The upper plunger  17  is not guided in a groove (see the groove  44  in FIG. 1) but is rather guided and moved by an electric motor  36  or another suitable prime mover. The motor  35  transmits torque to a gear  35  by way of a spiral spring  40 . The gear  35  mates with a toothed rack  34  which is connected to the upper plunger  17  by way of a piezoelectric element  38 . Such connection renders it possible to utilize a force sensor or power sensor, which monitors the torque of the prime mover  36 , in addition to or in lieu of the piezoelectric element, i.e., to ascertain the force which is required to move various plugs and/or machine parts. An evaluation of such information renders it possible to draw conclusions concerning the quality of the filter mouthpieces.  
         [0053]    The function of the coil spring  28  in the machine of FIG. 5 corresponds to that of the similarly referenced coil spring in the apparatus of FIG. 4. The spring  28  of FIG. 5 bears upon a distance monitoring sensor  39  which is mounted on a shoulder  31  provided on the toothed rack  34  or on the upper plunger  17 . For example, the sensor  39  can monitor the distance of the upper side of the conveyor  22  (which delivers filter plugs  20 ) from the location of such sensor; this is indicative of the extent of movement of the upper plunger  17  in a downward direction (toward the sleeve  11 ). If a preselected or predetermined minimal distance is exceeded, the signal from the sensor  39  can be utilized to segregate the respective (presumably or actually unsatisfactory) filter mouthpiece(s) from satisfactory mouthpieces. The distance monitoring sensor  39  can constitute or employ an optical sensor, an ultrasonic sensor or a capacitive sensor.  
         [0054]    It is possible to modify the machine of FIG. 5 in such a way that the coil spring  28  (or an equivalent thereof) is omitted. Its function can be taken over by the spiral spring  40 . If the spring  40  is also omitted, the machine of FIG. 5 can employ an electronic distance monitoring device which can evaluate the distance covered by the upper plunger  17  and/or the magnitude of the force being required to move the plunger. Such force measurement can involve a determination of the torque being transmitted by the prime mover or a determination of the force being monitored by the piezoelectric element  38 . In the latter instance, the machine of FIG. 5 employs a suitable signal processing unit and an electronic control unit.  
         [0055]    A difference between the embodiments of FIGS.  1  to  4  on the one hand, and the embodiment of FIG. 5 on the other hand, is that the machines of FIGS. 1 and 4 employ a compensating means ( 25 ,  28 ,  40 ) which operates between the plunger (transfer device)  17  and the guide means  44 ,  144 . On the other hand, the machine embodying the structure of FIG. 5 employs a control element (including the motor  36 ) which constitutes a means for facilitating only indirect movements of the mobile device (plunger  17 ) for introduction of filter material into the section (sleeve)  11  of wrapping material.  
         [0056]    The parts  25 ,  28  of the machines shown in FIGS. 1 and 4 or the part  40  of the machine shown in FIG. 5 can be said to constitute a compensating device or compensating means the primary purpose of which is to compensate for differences in the heights of cellulose acetate plugs or wads or segments or elements and correspondingly differently high paper segments and fleece segments as well as different fillers of granulate. For example, if the quantity of flowable filter material is insufficient, the absence of compensating means would result in such introduction of a plug  20  or  30  that the sleeve  11  would contain an empty space (as shown at h in FIG. 1) which could enable the flowable filter material  26  to rattle in the finished filter mouthpiece. The compensating means ( 25 ,  28 ) ensures that the plug  20  descends to the level shown at i in FIG. 1 so that the supply  26  of flowable filter material is held between the plugs  19  and  20  without any, or without any appreciable, freedom of movement and resultant generation of noise.  
         [0057]    The guide means or control means can be said to constitute a raising/lowering device (elevator), e.g., a ring-shaped cam which enables the transfer device (plunger  17 ) to carry out a predetermined movement or a predetermined series of movements.  
         [0058]    The solution of problems which exist in conventional filter mouthpiece making machines is particularly simple and advantageous if the compensating means includes an elastic material (such as the coil spring  28  or the spiral spring  40 ). The elastic material ensures that the guide means ( 44 ,  144  or  34 ,  35 ,  36 ) can invariably move along one and the same path. This contributes to simplicity of the guide means. The compensating means renders it possible to introduce the plunger  19  into the tube or sleeve  11  (in the portion d of the path for the sleeve) as far as is necessary to avoid the provision of room for a rattling of one or more batches of flowable (granular and/or pulverulent) filter material. The resiliency of the elastic part or parts of the compensating means is preferably adjustable or variable prior to installation in the machine.  
         [0059]    The provision of the sensor  39  or  43  (or another suitable sensor) renders it possible to ascertain the extent of axial displacement of the plunger  17  and hence the extent to which a tube or sleeve  11  (in the portion d of its predetermined path) is filled with filter material for tobacco smoke.  
         [0060]    It is also possible to replace the motor  36  of FIG. 5 with an electromagnetic power generator. To this end, at least a portion of the compensating means should consist of a metallic material. This renders it possible to establish a so-called eddy current braking function. At least a portion of the compensating means is or can be magnetizable or magnetized. It is also possible to employ pneumatically operated compensating means. Still further, it is possible to employ a gravity-operated compensating means.  
         [0061]    The sensor means which is employed in the improved machine can constitute a power sensor, a contact sensor or a distance sensor. A contact sensor or a distance sensor (the latter can constitute a contact sensor) preferably serves to ascertain the density of filter material in the sleeve  17 . This renders it possible to reliably detect and segregate defective filter mouthpieces from satisfactory mouthpieces. For example, the contact sensor (such as  43 ) can constitute an electric sensor which, when properly engaged, transmits electric current. A distance sensor can operate with light or ultrasonically or can transmit capacitive measurement signals. A power sensor ( 39 ) can constitute or employ a piezoelectric element or a torque monitoring device which can ascertain the output of a motor or another prime mover.  
         [0062]    The elastic material of the compensating means can constitute a foam which fills at least one space or chamber of the transfer device.  
         [0063]    By avoiding a direct coupling of movement of the transfer device with the control element, the extent of movement (i.e., the distance covered by the transfer device or by a part of the transfer device) can be selected independently of the forced movement imparted by the control element (such as  44 ,  36 ). It is often preferred to employ a preferably mechanical compensating means which is disposed between the transfer device and the control element. The compensating means of such machine is or can be a spring.  
         [0064]    The filter mouthpiece maker which embodies the present invention employs at least one transfer device (such device can include a pusher or plunger) which is operated in accordance with the method of the present invention. In a preferred embodiment of the invention the spring rate or spring constant of the spring  28  can be adjusted. Thus, the force with which the filter material is pushed into the receptacles is also adjustable.  
         [0065]    Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specific aspects of the above outlined contribution to the art of making filter mouthpieces for cigarettes or the like and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the appended claims.