Abstract:
Apparatus for transporting rod-shaped tobacco smoke filters, which contain and/or carry particles of charcoal and/or other particulate tobacco smoke filtering and/or flavoring material, wherein a sender directs a series of successive filters lengthwise into a pneumatic conduit extending toward or into a receiving station. A section of the conduit ahead of the receiving station is provided with openings communicating with a collecting chamber. A duct which extends along the section of the conduit is provided with orifices serving to direct jets of a pressurized gaseous fluid into the openings to thus expel loose particles and/or particles adhering to the external surfaces of filters into the collecting chamber. The latter discharges collected particles by gravity flow.

Description:
CROSS-REFERENCED TO RELATED CASES 
     This application claims the priority of German patent application Serial No. 199 13 421.9 filed Mar. 25, 1999. The disclosure of the above-referenced German patent application, as well as that of each U.S. and foreign patent and patent application mentioned in the specification of the present application, is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to improvements in methods of and apparatus for transferring rod-shaped commodities which serve to filter tobacco smoke and carry and/or contain pulverulent, granular or otherwise configurated and/or dimensioned ingredients, e.g., particles of charcoal embedded in rod-like fillers of acetate fibers, crepe or the like. More specifically, the invention relates to improvements in methods of and in apparatus for transporting tobacco smoke filtering rods or plugs, which carry confined and/or adherent solid particles, or compel loose particles to advance, along an elongated path from a sender of a file of successive rods to a receiving station. 
     It is customary to advance a file of successive rod-like filters, normally filters of multiple unit length, along an elongated path which is defined by an elongated pneumatic conveyor in the form of a conduit. If the filters contain and/or carry solid particles, such as granules of charcoal, a certain percentage of solid particles becomes separated from the filters; this results in highly undesirable contamination of the conduit and/or of the parts at the receiving station. Stray particles of charcoal or the like are particularly undesirable at the receiving station because the operation of parts at such station is likely to be adversely affected to a progressively increasing degree unless the apparatus is equipped with suitable means for intercepting stray particles and/or those particles which are likely to become separated from the filters. Attempts to intercept, collect and evacuate solid particles from the path for successive filter rods of a file of such commodities are disclosed, for example, in commonly owned British specification No. 1 410 473 published Oct. 15, 1975 and in U.S. Pat. No. 5,556,236 granted Sep. 17, 1996. The means for admitting granules of charcoal and/or other solid particles can include so-called AC machines (distributed by the assignee of the present application) which sprinkle solid particles onto a running tow of filter material (e.g., acetate fibers). 
     OBJECTS OF THE INVENTION 
     An object of the invention is to provide a novel and improved apparatus which can gather and evacuate stray solid particles and/or readily separable solid particles from the path for filter rods for tobacco smoke with a degree of efficiency and reliability exceeding that of heretofore known apparatus. 
     Another object of the invention is to provide a novel and improved apparatus whose operation is not affected by the rate of delivery of filter rods from a sender to a receiving station. 
     A further object of the invention is to provide an apparatus which can reliably intercept, gather and dispose of stray solid particles ahead of the station which receives successive filter rods of a file of such commodities and which accommodates devices likely to be adversely affected by stray particles of charcoal or the like. 
     An additional object of the invention is to provide an apparatus which can intercept and evacuate high percentages of or all solid particles from the path for filter rods of unit or multiple unit length without affecting the quality (such as the configuration) of filter rods. 
     Still another object of the invention is to provide a novel and improved method of evacuating solid particles (such as granules of charcoal or dust of charcoal and/or other solid additives which enhance the filtering action of the filter rods and/or the flavor of tobacco smoke) from the path for advancement of a series of successive filter rods from a sender (e.g., a filter rod making machine) to a receiving station, e.g., a station which gathers filter rods preparatory to admission into the magazine of a filter tipping machine. 
     SUMMARY OF THE INVENTION 
     The invention is embodied in an apparatus for transporting tobacco smoke filtering rods (e.g., filter rod sections of twice, four times or six times unit length), which carry solid particles (such as fragments of charcoal) along an elongated path extending from a sender to a receiving station. The improved apparatus comprises a pneumatic conveyor which defines at least a portion of the elongated path and includes a section provided with openings serving to establish communication between the aforementioned portion of the path and a collecting chamber, and means for propelling (by way of the openings) at least some of the solid particles which become separated from the filtering rods not later than in the aforementioned portion of the path. 
     The conveyor preferably includes an elongated conduit and the openings can constitute slots provided in the conduit in the aforementioned portion of the path; such slots can extend at least substantially radially of the conduit. 
     The propelling means can comprise a source of pressurized gaseous fluid (e.g., compressed air) and means for directing gaseous fluid furnished by the source into the conveyor in the regions of the openings. 
     The conduit of the pneumatic conveyor can include a series of successive annular components which define the aforementioned portion of the path; the openings are then disposed between the successive annular components of the conduit and preferably constitute circumferentially complete slots. 
     The means for propelling pressurized gaseous fluid from the aforementioned source into the conveyor in the regions of the openings can comprise a pipe or duct receiving pressurized fluid from the source and extending along the aforementioned portion of the path; such duct has outlets (e.g., in the form of orifices or ports) serving to direct jets of pressurized fluid toward at least some of the openings. The duct is preferably closely adjacent to and can serve as a support for the collecting chamber and/or for the aforementioned annular components of the conduit. 
     The aforementioned portion of the path is or can be at least substantially vertical, and the conveyor is preferably arranged to convey the rods downwardly at least in the at least substantially vertical portion of the path. The particle-collecting chamber of such apparatus is or can be designed and mouted in such a way that it includes an upper portion above and a lower portion below the openings, and an outlet (such as a tubular extension of the lower portion) for collected particles. The chamber can at least partially surround the conveyor in the region of the aforementioned portion of the path. 
     Another feature of the invention resides in the provision of a method of transporting rod-shaped tobacco smoke filters, which carry solid particles along an elongated path from a sender to a receiving station. The method comprises the steps of directing into a predetermined portion of the path a plurality of jets of a pressurized gaseous fluid to thus expel from such predetermined portion of the path solid particles which are separated and/or separable from the filters, collecting the expelled particles in a chamber which is outwardly adjacent the predetermined portion of the path, and evacuating collected particles from the chamber. 
     The predetermined portion of the path is or can be at least substantially vertical, and the method can further comprise the step of conveying the filters downwardly into and through the predetermined portion of the path. 
     The evacuating step can include discharging collected particles from the chamber by gravity flow. 
     Still further, the method can comprise the step of braking successive filters downstream of the predetermined portion of the path. 
     The particles can include or constitute fragments of charcoal. 
     The method can also include the step of establishing a plurality of openings (e.g., in the form of arcuate or annular slots) for the expulsion of solid particles from the predetermined portion of the path into the chamber. 
     The pressurized fluid is or can be compressed air. 
     Still further, the method can comprise the step of changing the orientation of filters between the predetermined portion of the path and the receiving station. 
     The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and the modes of assembling and operating the same, together with numerous additional is 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 drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a partly schematic elevational view of an apparatus which embodies one form of the present invention, certain parts at the receiving station being shown in a vertical sectional view; and 
     FIG. 2 is a greatly enlarged partly sectional view of a section of the pneumatic conveyor, of the particle collecting chamber and of the means for propelling solid particles into the collecting chamber. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring first to FIG. 1, there is shown an apparatus which comprises a sender  1  of a file of successive rod-shaped filters  6 , a pneumatic conveyor including an elongated conduit  2  defining an elongated path for the file of filters  6 , and a receiving station  3  for temporary storage and/or other treatment (such as changing the orientation) of successive filters. The station  3  accommodates or follows a braking or decelerating device  4  which reduces the speed of successive filters  6  being delivered by the conduit  2 , and an accelerating device  7  which follows the braking device  4  and serves to accelerate successive filters  6  ahead of an orientation and direction changing unit including two endless belts or bands  24  (only is one shown in FIG.  1 ). 
     The apparatus of FIG. 1 can constitute a modified version of the apparatus known as FILTROMAT and distributed by the assignee of the present application. For example, the so-called FILTROMAT 3 can be set up to deliver up to and even in excess of 2500 tobacco smoke filters per minute and can manipulate acetate, crepe, charcoal and dual filters; furthermore, such apparatus are or can be equipped with automatic cleaning means and with a facility for automatic detection and removal of defective rod-shaped filters. 
     Referring again to FIG. 1, a portion of the elongated path between the braking device  4  and the accelerating device  7  is defined by an elongated arcuate guide  8  having an at least substantially U-shaped cross-sectional outline and an open upper side which is overlapped by a flexible resilient cover  9  of sheet metal or the like. An advantage of such guide is that it can change the direction of movement of successive rod-shaped filters  6  from vertically downwardly (see the upper arrow  16 ) to horizontally (see the lower arrow  16 ) within a small area and without affecting the condition (such as the shape) of successive filters. 
     The braking unit  4  upstream of the guide  8  comprises upstream pulleys  12   a ,  14   a  and downstream pulleys  11   a ,  13   a , a first endless belt or band  17   a  which is trained over the pulleys  11   a ,  12   a , and a second endless belt or band  18   a  trained over the pulleys  13   a ,  14   a.  The confronting vertical inner stretches or reaches of the belts  17   a ,  18   a  engage and decelerate successive filters  6  which are delivered by the pneumatic conveyor including the conduit  2 . The distances between the pulleys  11   a ,  13   a  and the associated pulleys  12   a ,  14   a  (i.e., the lengths of the confronting inner reaches of the belts  17   a ,  18   a ) are selected in such a way that these belts can reliably engage and decelerate but do not affect the shapes and/or other desirable characteristics of the oncoming filters  6 . 
     The construction of the accelerating device  7  is analogous to (and can be identical with) that of the braking device  4 , and its parts are denoted by similar reference numerals except that the characters a are replaced with characters b. The difference between the devices  4  and  7  is that the belts or bands  17   b ,  18   b  of the device  7  serve to accelerate the oncoming filters before such filters reach the endless belts  24 . The means for driving the pulleys  11   a-   14   a  at a relatively low speed comprises a prime mover  23  (e.g., an electric motor) and a transmission including a chain or toothed belt  19   a  and sprocket wheels or toothed pulleys  21   a ,  22   a  coaxial with the pulleys  11   a ,  13   a , respectively. The means for driving the pulleys is  11   b-   14   b  at a relatively high speed comprises the motor  23  (or a discrete second prime mover) and a second transmission including a chain or a toothed belt  19   b  and sprocket wheels or toothed pulleys  21   b ,  22   b  coaxial with the pulleys  11   b ,  13   b , respectively. The belts  17   a ,  18   a  serve to transmit torque from the pulleys  11   a ,  13   a  to the associated pulleys  12   a ,  14   a,  and the belts  17   b ,  18   b  serve to transmit torque from the pulleys  11   b ,  13   b  to the associated pulleys  12   b ,  14   b.  As already mentioned above, the belts  17   a ,  18   a  of the braking device  4  serve to decelerate the filters  6  descending in the conduit  2 , and the belts  17   b ,  18   b  of the device  7  serve to accelerate the filters arriving from the device  4  along the guide  8 . 
     The endless belts  24  at the receiving station  3  are trained over pairs of pulleys  26 ,  27  (only one of these pairs can be seen in FIG.  1 ). The purpose of the belts  24  is to advance successive oncoming (accelerated) filters  6  sideways (upwardly) into a magazine or reservoir (not shown), e.g., into the magazine of a filter tipping machine (such as a machine known as MAX and distributed by the assignee of the present application) wherein the filters are assembled with plain cigarettes, cigars or cigarillos to form filter-tipped smokers&#39; products. A MAX-type filter tipping machine is described, for example, in commonly owned U.S. Pat. No. 5,135,008 granted Aug. 4, 1992. 
     The pulleys  27  for the belts  24  are driven by a prime mover (not shown) through the intermediary of a transmission including an endless toothed belt or chain  29  and a toothed pulley or sprocket wheel  28 . 
     A horizontal guide  31  is provided at the receiving station  3  to steer successive accelerated filters  6  from the device  7  against a wedge-like deflector  32  serving to raise the leaders of successive filters  6  into contact with the confronting reaches of the endless belts  24  so that such belts can move the filters sideways and upwardly into the aforementioned magazine of the filter tipping machine. 
     In accordance with a feature of the present invention, a section  34  of the conduit  2  upstream of the braking device  4  (i.e., upstream of the receiving station  3 ) cooperates with a unit which serves to propel any loose solid particles  43  (see FIG. 2) which continue to adhere to the external surfaces of the filters  6  and/or which are already separated from the filters into a collecting chamber  33 . The latter can at least partially surround the section  34  and its lower portion has an outlet  42  for evacuation (e.g., by gravity flow) of collected solid particles  43  into a bin or the like, not shown. 
     The illustrated section  34  of the conduit  2  is a separately produced assembly of vertically aligned annular components  37  which are at least partially separated from is each other by openings  36  in the form of arcuate or circumferentially complete radially extending annular slots  36 . The propelling device which serves to expel loose solid particles  43  from the section  34  of the conduit  2  into the chamber  33  comprises a source  41  of pressurized gaseous fluid (e.g., compressed air), a duct  39  which serves to guide a stream of pressurized fluid upwardly and along the section  34 , and outlets  38  in the form of radial orifices provided in the duct  39  to direct jets of pressurized fluid into and across the section  34  by way of the adjacent openings or slots  36 . This results in the expulsion of loose solid particles  43  from the section  34  and into the collecting chamber  33 . The duct  39  can serve as a carrier for the annular components  37  of the section  34  and/or for the collecting chamber  33 . 
     The source  41  can include an air compressor or an accumulator (not shown). 
     The operation of the improved apparatus is as follows: 
     When the apparatus is in use, the sender  1  supplies a file of successive filters  6  into the conduit  2  wherein the filters advance lengthwise toward the receiving station  3 . During such travel, successive filters  6  advance through the section  34  of the conduit  2  before they enter the braking device  4 . The source  41  supplies pressurized pneumatic fluid into the duct  39  which causes the outlets or orifices  38  to discharge jets of pressurized fluid into the neighboring slots  36 . Such jets expel stray solid particles, as well as those solid particles which are readily separable from the descending filters  6 , from the section  34  of the conduit  2  and into the collecting chamber  33 . The particles  43  which are expelled from the section  34  impinge upon the confronting walls of the chamber  33  and descend toward and into the outlet  42 . The top portion of the chamber  33  is located above the uppermost opening  36 , and the bottom portion of the chamber (together with the outlet  42 ) is located beneath the lowermost opening  36  of the illustrated section  34 . 
     The filters  6  which descend beyond the section  34  of the conduit  2  are force-lockingly engaged and decelerated by the belts  17   a ,  18   a  of the braking device  4 . Such filters are devoid of loosely adhering solid particles  43 . Braking of the filters  6  by the device  4  results in the accumulation of a column of superimposed filters above the belts  17   a ,  18   a.  Such column rests upon and exerts a considerable downwardly oriented force upon the filter  6  which happens to be engaged and braked by the belts  17   a ,  18   a . However, and since the lengths of the confronting inner reaches of the belts  17   a ,  18   a  are selected with a view to force-lockingly engage at least a major portion of a filter  6  advancing through the braking device  4  and actually supporting a column of superimposed filters, such filter can be properly decelerated by the belts  17   a ,  18   a  without undergoing any, or any appreciable, deformation. 
     It is often sufficient to utilize a braking device wherein the length of the confronting inner reaches of the belts  17   a ,  18   a  is less (even considerably less) than or exceeds the length of a filter, depending for example upon the length and weight of the filters supplied by the sender  1 . 
     Successive filters  6  which advance downwardly beyond the braking device  4  enter and slide along the arcuate guide  8  on their way toward and into the accelerating device  7 . The confronting inner reaches of the belts  17   b ,  18   b  engage and accelerate successive filters  6  in a direction toward the deflector  32 . Such acceleration ensures that the filters  6  advancing along the guide  31  are out of contact with the neighboring (preceding and next-following) filters so that a filter which is deflected at  32  is not interfered with by the next-following filter. The belts  24  transport successive filters  6  sideways and upwardly into the aforementioned magazine or to any other selected destination. 
     An important advantage of the improved method and apparatus is that the structure which is shown in FIG. 2 (or an equivalent thereof) is capable of relieving the interior of the section  34  of the conduit  2  and the filters  6  advancing toward the braking device  4  of loose solid particles  43  when the filters descend into the section  34  at a relatively low or at a higher or much higher speed. This greatly reduces the likelihood of undesirable stoppages for the purpose of cleaning the braking device  4 , the guide  8  and/or the accelerating device  7 . 
     Another advantage of the improved method and apparatus is that the interior of the collecting chamber  33  need not be maintained at an elevated pressure because the particles  43  which are in the process of entering or have already entered this chamber can be evacuated automatically, i.e., by gravity feed. 
     A further advantage of the improved method and apparatus is that the expulsion of solid particles from the path leading from the sender  1  to the receiving station  3  can be effected in a surprisingly short portion (section  34 ) of the conduit  2 . 
     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 transporting filter rods and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the appended claims.