Patent Publication Number: US-8122893-B2

Title: Machine for manufacturing pouches of cohesionless material

Description:
This application is the national phase of international application PCT/IB2007/003607 filed Nov. 19, 2007 which designated the U.S. and that international application was published under PCT Article 21(2) in English. This application claims priority to Italian Patent application number BO2006A000791, filed Nov. 22, 2006, which is incorporated by reference herein. 
     TECHNICAL FIELD 
     The present invention relates to a machine for manufacturing individual bags or sachets of cohesionless material, and in particular, pouches of nasal snuff, or of moist snuff (also known as snus) for oral use. 
     Reference is made explicitly to tobacco in the course of the following specification, albeit no limitation in scope is implied, as the cohesionless material might consist similarly, for example, in powdered pharmaceutical or confectionery products treated with moisturizing agents. 
     BACKGROUND ART 
     The prior art embraces machines of the type in question, which comprise a dispensing disc rotatable intermittently about a vertical axis and furnished with a ring of cavities, each containing a quantity or portion of tobacco that will correspond to the contents of a single pouch. 
     The portions are released into the single cavities at a filling station by a hopper containing a supply of powdered tobacco, en masse, treated with flavouring and moisturizing agents. 
     Downstream of the filling station, the machine comprises skimming means that serve to remove any excess tobacco from each of the cavities. 
     With the disc in rotation, the cavities are carried beyond the skimming means and toward a transfer station where the single portion of tobacco contained in each cavity is ejected. 
     Installed at this same station are pneumatic ejection means comprising a nozzle positioned above the dispensing disc. At each pause in the movement of the disc, a portion of tobacco is forced by the nozzle from the relative cavity into a duct, of which the mouth lies beneath the disc and in alignment with the nozzle, and directed toward a station where the single pouches are formed. 
     The forming station comprises a tubular element, placed at the outlet of the duct and functioning as a mandrel over which to fashion a tubular envelope of paper wrapping material. 
     The material in question consists in a continuous web decoiled from a roll and fed in a direction parallel to the axis of the tubular element, which is wrapped progressively around the element and sealed longitudinally. 
     Beyond the tubular element, the machine is equipped with transverse sealing means of which the operation is synchronized with the transfer of the tobacco portions, in such a way that each successive portion will be sealed in a relative segment of the continuous tubular envelope of wrapping material delimited by two successive transverse seals. 
     The successive tubular segments of wrapping material, formed as pouches containing respective portions of tobacco, are separated into discrete units through the action of cutting means positioned downstream of the transverse sealing means. 
     A conventional machine of the type outlined above, while dependable, is nonetheless limited in terms of operating speed and unable to match the tempo of other units, connected directly downstream, by which given numbers of the single pouches are assembled in packs for distribution. 
     Above certain operating speeds, in effect, and especially when handling tobacco with a high moisture content, there is no guarantee with machines of the type described above that the quantities of tobacco supplied to the form-fill-and-seal station will be portioned accurately and repeatably over time. 
     This is due to the fact that a correct transfer of the single portions of tobacco is conditional on each cavity remaining in the transfer station for a given minimum period of time, sufficient for the pneumatic means to remove the contents of the selfsame cavity completely. 
     The object of the present invention is to provide a machine for manufacturing single pouches of smokeless tobacco that will be unaffected by the drawbacks mentioned above in connection with machines of the prior art, and able to combine a high production tempo with an accurate and constantly repeatable transfer of tobacco portions into successive pouches. 
     DISCLOSURE OF THE INVENTION 
     The stated object is realized, according to the present invention, in a machine for manufacturing pouches of cohesionless material, as characterized in one or more of the claims appended. 
    
    
     
       SHORT DESCRIPTION OF THE DRAWINGS 
       The invention will now be described in detail, by way of example, with the aid of the accompanying drawings, in which: 
         FIG. 1  shows a machine for manufacturing single pouches of a smokeless tobacco product according to the present invention, viewed schematically in perspective and illustrated in a first possible embodiment; 
         FIG. 2  shows the machine of  FIG. 1 , viewed schematically in a side elevation; 
         FIGS. 3   a  and  3   b  show a detail of the machine as in  FIG. 1 , viewed in plan from above and illustrated respectively in a second and a third embodiment; 
         FIG. 4  shows a detail of the machine as in the second or third embodiment of  FIG. 3   a  or  3   b , viewed from the front. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION 
     With reference to the accompanying drawings, numeral  1  denotes a machine for manufacturing pouches  2  of a smokeless tobacco product. 
     The machine  1  comprises a dispensing disc  3 , furnished with a plurality of cavities  4  arranged around the periphery. 
     The disc  3  rotates intermittently about a relative axis X between a station  5  at which each of the single cavities  4  is filled with a predetermined quantity of tobacco, and a transfer station  6  at which the successive portions of tobacco are ejected from the relative cavities  4 . 
     The machine  1  further comprises a wrapping station  7  at which the portions of tobacco removed from the transfer station  6  are taken up and enclosed in respective pouches  2 , and a rectilinear duct  8  connecting the transfer station  6  with the wrapping station  7 . 
     More exactly, the rectilinear duct  8  is interposed between the cavity  4  currently occupying the transfer station  6 , and the wrapping station  7 . 
     The duct  8  thus provides interconnecting means, denoted  9 , by which the transfer station  6  is linked to the wrapping station  7 . 
     The filling station  5  comprises a hopper  10  from which portions of tobacco are fed into the cavities  4  of the disc  3 , and skimming means  11  located downstream of the hopper  10 , relative to the direction of rotation of the disc, serving to remove any excess tobacco from the cavity  4 . 
     Referring to  FIG. 1 , the transfer station  6  is equipped with a mechanical push rod  12  designed to engage the cavity  4  positioned in alignment with the selfsame push rod  12 . 
     The push rod  12  provides the machine  1  with ejector means  13 , and is composed of a plunger  12   a  reciprocated by a cam mechanism  12   b  in such a way as to slide back and forth through the cavity  4 . 
     The wrapping station  7  comprises a tubular element  14  positioned at the outlet end of the rectilinear duct  8 , around which a tubular envelope  15  of wrapping material  15   a  is formed. 
     The wrapping material  15   a  is decoiled from a roll (not illustrated) and wrapped by degrees around the tubular element  14  through the agency of suitable folding means. 
     The tubular envelope  15  is sealed longitudinally by ultrasonic welders  16  operating in close proximity to the tubular element  14 . Such welders might be of the type disclosed and claimed in publication WO2005/113218A1, for example, which is incorporated here in its entirety by reference in the interests of providing a full description. 
     Referring to  FIGS. 1 and 2 , the machine  1  also comprises sealing means  17  located beneath the tubular element  14 , of which the function is to bond the tubular envelope  15  transversely in such a manner as to form a continuous succession  101  of pouches  2 , each containing a relative portion of tobacco. 
     The transverse sealing means  17  could likewise take the form of ultrasonic welders, in which case the above noted indications relative to the longitudinal welders  16  will apply in this instance also. 
     Downstream of the transverse sealing means  17 , the machine  1  comprises a pair of transport belts  100  looped around respective pulleys  102 , positioned to take up and direct the continuous succession  101  of pouches  2  toward cutting means  18  by which the selfsame succession  101  of pouches  2  is divided up into single units. 
     In operation, with the machine  1  set in motion, the disc  3  begins rotating and directs the single cavities  4  one by one under the hopper  10 , from which each cavity  4  is filled with a given quantity of tobacco destined to provide the contents of one pouch  2 . 
     As the disc  3  rotates, the cavity  4  passes under the skimming means  11 , which will remove any excess tobacco released from the hopper  10 . 
     Once the cavity  4  occupies the transfer station  6 , the disc  3  pauses, thereby allowing the mechanical push rod  12  to engage the cavity  4  and eject the portion of tobacco contained therein. 
     The portion of tobacco is thus directed forcibly by the push rod  12  down through the rectilinear connecting duct  8  and into the tubular element  14 , which is sheathed in the tubular envelope  15  of paper wrapping material  15   a.    
     The envelope  15  of paper is sealed lengthwise by the ultrasonic welders  16 , and crosswise, at the outlet end of the tubular element  14 , by the transverse sealing means  17 . 
     The operation of the transverse sealing means  17  is intermittent, and timed to match the frequency at which successive portions of tobacco are fed into the transfer station  6 , in such a way that each portion of tobacco will be enclosed between two successive transverse seals. 
     As the welding or sealing operations proceed, a continuous succession  101  of tobacco-filled pouches  2  will emerge, connected one to the next by way of the transverse seals. 
     At a given point downstream of the transverse sealing means  17 , the single pouches  2  of the continuous succession  101  are separated one from the next by the cutting means  18 . 
     An alternative embodiment of the machine  1 , illustrated in  FIG. 3   b , might be equipped with a disc  3  presenting two rings  19  of cavities aligned on two respective circumferences, disposed concentrically in relation to the axis X of the selfsame disc. 
     In this instance the mechanical push rod  12  will generate a dual action, or in practical terms, incorporate two plungers  12   a  deployed so that each engages a respective cavity  4 , as illustrated in  FIG. 4 . 
     Alternatively, the machine could be equipped with two distinct mechanical push rods (not illustrated), one for each ring of cavities  4 . 
     A further embodiment of the machine  1 , illustrated in  FIG. 3   a , might be equipped with a disc presenting a single ring of cavities, arranged in pairs. 
     In either instance, a machine as illustrated in  FIG. 3   a  or  3   b  will split below the disc into two distinct processing lines, as discernible in  FIG. 4 . 
     The machine disclosed affords key advantages. 
     Thanks to the adoption of a mechanical push rod, the machine is able to run at considerably high operating speeds. 
     More particularly, the force applied mechanically to the portion of tobacco is impulsive in nature, so that the time the plunger needs to dwell in the cavity beneath the push rod mechanism in order to transfer the tobacco correctly is briefer than in the case of a transfer effected utilizing pneumatic means. 
     Accordingly, the time the disc must remain stationary at the transfer station to ensure a clean ejection of the portion of tobacco is significantly reduced, and the production tempo of the machine can be correspondingly increased. 
     Furthermore, the use of ultrasonic welders is instrumental in allowing the adoption of a shorter rectilinear connecting duct, and consequently enabling the mechanical push rod to transfer the entire portion of tobacco correctly to the wrapping station.