Abstract:
A unit for feeding products ( 3 ) to a blistering machine (M) includes a delivery group ( 2, 2   a , S) for selectively distributing products ( 3 ) to a station (SR), where the products ( 3 ) are introduced into respective blisters ( 40 ) of a blister band ( 4 ), moving in a forward direction (W) inside the blistering machine (M). The filling station (SR) is defined by a conveyor ( 10 ) consisting of a belt ( 11 ) provided with seas ( 110 ). Each seat ( 110 ) receives a relative product ( 3 ) distributed by the delivery group ( 2, 2   a , S) and releases the products ( 3 ) into a respective blister ( 4 ). The conveyor ( 10 ) include at least one endless belt ( 11 ), moving in step relation with the blister band ( 4 ) wound around respective pulling wheels ( 13, 14 ), with an upper portion of the belt ( 11 ) defined by an upper run ( 11   a ) extending under the delivery group ( 2, 2   a , S) in a direction parallel to the forward direction (W), defined by a lower run ( 11   b ) extending, along at least a section (O) parallel to the forward direction (W), substantially very close to and above the blister band ( 4 ) and facing the blister band ( 4 ).

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to feeding products such as tablets, pills, capsules and the like and their introduction into respective blister of a blister band usually made of plastic material or aluminum, in a blistering machine.  
         [0002]     In particular, the present invention is advantageously used in automatic blistering machines to produce blister packs containing tablets, pharmaceutical capsules, to which reference is made in the following description without losing generality.  
       BACKGROUND OF THE INVENTION  
       [0003]     Currently, in an automatic blistering machine, a continuous band of heat-weldable material, or of aluminium, is driven to move forward through different working stations in the following order: a forming station, where receptacles, or blisters, are made in the band, a station, where the products are fed and the blisters are filled with the products, a station, where the upper surface of the band is sealed, and a station, where the pieces of the band containing a predetermined number or blisters, and consequently of products, are cut, each of these pieces forming a blister pack.  
         [0004]     A unit is situated at the above feeding and filling station for feeding products and introducing them into the blisters. The above unit assures a correct filling of all the blisters, as well as the integrity of the products, so as to reduce jams and wastes of products, all this while maintaining the required high production speed.  
         [0005]     Among different proposed solutions, one particularly advantageous is described in the International Patent Application PCT Num. WO 01/42088 of the same Applicant.  
         [0006]     According to this solution, a unit for feeding products to a blister band situated below includes basically selection means which form a plurality of longitudinal channels, arranged in such a way as to define an oscillating grid and aimed at receiving products coming from the hopper situated above.  
         [0007]     The selecting means are connected to suitable oscillating means, which generate a relative oscillating movement, crosswise and/or longitudinally, between the selecting means and the blister band opposite thereto, so as to facilitate stable introduction of the products present in the longitudinal channels, falling down into the corresponding blisters formed in the band.  
         [0008]     A system of this kind requires overfeeding of products; therefore, in a fixed interval of time, the hopper must feed the selecting means with a number of products exceeding the number of blisters facing the grid in this interval of time.  
         [0009]     Then, downstream of the selecting means, the exceeding products, which are not yet introduced into the blisters, are usually conveyed, by suitable collecting means, to the feeding hopper and then re-cycled.  
         [0010]     The above described unit is functionally efficient, in particular as regards filling of blisters, which are usually sized as the products they must contain, i.e. the dimensions of the blister are slightly bigger than the dimensions of the product; the difference between the dimensions of the blister and the product facilitates the product introduction, but prevents more products from being introduced into the same blister.  
         [0011]     In some cases, an product must be introduced in a blister much bigger than it is necessary in normal situation, i.e. in order not to modify the dies in the blister forming station: in this situation, known devices of the above described type do not manage to prevent two or more products, instead of only one, from entering each blister.  
         [0012]     In other cases, blisters filling operation must be performed with bigger care with respect to the unit described in the above mentioned International Patent Application PCT Num. WO 01/42088, or other known devices, in order to protect the products integrity.  
         [0013]     This necessity is more frequent with products like tablets, which are rougher and more friable than sugarcoated pills and less sliding with respect thereto, or in situations in which aluminium band is used, less resistant to denting than the band of plastic material.  
       SUMMARY OF THE INVENTION  
       [0014]     The object of the present invention is to propose a product feeding unit, which determines stable introduction of only one product in each corresponding blister, although the dimension of the latter is bigger than the dimension of the product.  
         [0015]     Another object of the present invention is to propose a unit for feeding and introducing products into blisters, whose conformation ensures filling of the blisters by an extremely delicate operation, thus protecting the integrity of the products and/or blisters in best way.  
         [0016]     A further object of the present invention is to propose a simple unit, which can be easily adapted to different shapes, and time-matched with other means of an automatic blistering machine.  
         [0017]     The above mentioned objects are obtained, in accordance with the subject matter of the claims, by a unit for feeding products to a blistering machine, the unit including a delivery group for selectively distributing products to a station, where the products are introduced into respective blisters of a blister band, the band moving in a forward direction inside said blistering machine;  
         [0018]     the unit is characterized in that said filling station includes conveyor means consisting of a belt in which seats are made, each of said seats provided for receiving a relative product distributed by the delivery group and for releasing said products into a respective blister;  
         [0019]     said conveying means including at least one endless belt, moving in step relation with said blister band and wound around respective pulling wheels, with an upper portion of the endless belt being defined by an upper run extending below the delivery group, and with a lower portion of the endless belt being defined by a lower run extending, along at least a section parallel to said forward direction, substantially above said blister band and facing said blister band. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]     The characteristic features of the present invention will be pointed out in the following description of a preferred, but not only embodiment, with reference to the enclosed drawings, in which:  
         [0021]      FIG. 1  is a lateral schematic view of a preferred embodiment of the proposed unit;  
         [0022]      FIGS. 2, 3 ,  4 ,  5  are enlarged views of some constructive variants of a particular of the unit shown in  FIG. 1 .  
         [0023]      FIG. 6  shows the oscillating means 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]     With reference to  FIG. 1 , the reference number  1  indicates a unit for feeding products  3 , designed to be mounted in correspondence to a filling station SR of a blistering machine M.  
         [0025]     The Unit  1  is situated between a group  2  for delivering products  3 , e.g. tablets, sugarcoated pills, capsules and the like, and a blister band  4 , situated below, in which blisters  40  are formed, and moved forward, preferably continuously, in a horizontal longitudinal direction W.  
         [0026]     The distributor group  2  includes a hopper  2   a  (indicated with broken line in  FIG. 1 ), which is aimed at feeding a predetermined quantity of products  3  over means S for selecting the products  3 , preferably a vibrating grid (indicated with a broken line in  FIG. 1 ), according to the solution described and illustrated in the above mentioned International Patent Application No. WO 01/42088.  
         [0027]     The group  2  is coupled with recycling means  5 , of known type, including a brush  50 , which intercepts the products  3  in excess over the selecting means S and deviates them onto conveying means of known type, indicated with  51 , which convey the exceeding products  3  into a return channel  52 , opening into the hopper  2   a.    
         [0028]     According to  FIG. 1 , the unit  1  includes a conveying member  10 , extending endlessly, formed by a belt  11  mounted onto two turn-around wheels  13 ,  14 , the first of which being a driving wheel, and moving the belt  11  counterclockwise, shown with the arrow F in  FIG. 1 .  
         [0029]     The belt  11  defines two substantially horizontal runs of the conveyor  10 , upper  11   a  and lower  11   b,  respectively, with the upper run  11   a  situated directly beneath the distributor group  2  and with the lower run  11   b  facing said blister band  4 .  
         [0030]     In analogy with the solution described in the above mentioned International Patent application WO 01/42088 of the same applicant, in which a blister band and a grid are described as being in an oscillating motion relative to each other, the conveying belt  11  and the means S can be set in oscillating movement in relation to each other. In other words, oscillating means  20 ,  30  (see  FIG. 6 ) are provided coupled to said belt  11  mounted on the wheels  13 ,  14  and/or to said means S so as to move the belt  11  and the means S with a vibrating motion.  
         [0031]     The lower run  11   b  of the belt  11  moves in the same direction as the blister band  4  and in step relation therewith. The lower run  11   b  is so situated to skim the blister band along a substantially horizontal active section  0 , parallel to the direction W; to obtain this configuration, a third turn-around wheel  15  is provided, idle on its axis.  
         [0032]     The above wheels  13 ,  14 ,  15  are adjustable, in known way, to ensure the correct tension of the belt  11  and the position of the abovementioned runs  11   a  and  11   b  with respect to the delivery group  2  and to the blister band  4 .  
         [0033]     The belt  11  is equipped with a plurality of seats  110  arranged on the belt  11  in a plurality of parallel rows (only one of which is shown in the enclosed figures from  1  to  5  for simplicity&#39;s sake), defining a matrix of seats, which are obtained with the same geometric arrangement as the blisters  40  of the belt  4 .  
         [0034]     The seats  110  are turned toward the outside of the belt  11  and feature, made in the bottom, a through hole  111  ( FIGS. 2, 3 , and  4 ), whose function will be explained later on.  
         [0035]     The driving wheel  13  is formed by a fixed hub  130 , on which a ring-like drum  131  rotates (counterclockwise in  FIG. 1  in the direction F).  
         [0036]     The ring-like drum is engaged with the belt  11  and connected to motor means, known and shown, which operate the conveying member  10  in time relation with the above blister band  4 ; consequently, the movement of the lower run  11   b  is in agreement with the direction W of the forward movement of the band  4 , and the relative seats  110 , in the working section O, are aligned with the corresponding blisters  40 .  
         [0037]     In order to ensure the correct timing of the belt  11  and to avoids slips, gearing means  135  are provided to obtain the mutual engaging between the ring-like drum  131  and the belt  11 .  
         [0038]     According to a first preferred embodiment, shown in  FIGS. 1 and 2 , the belt  11  has a section of a constant thickness, with the seats  110 , which act as teeth, and by complementary spaces  134  made on the outer circumference of the ring-like drum  131 .  
         [0039]     According to a second embodiment, shown in  FIG. 3 , the belt  11  includes an outer layer  115 , made integral with an inner layer  116 , the latter being formed by e.g. toothed belts of known type, featuring teeth  116   a.    
         [0040]     In this case, the teeth  116   a , together with the complementary spaces (not shown) made on the outer circumference of the ring-like drum  131  define fearing means  135  with the drum  131 ; the seats  110  are dug in the thickness of the outer layer  115 , and the through hole  111  of each seat in made both layers  115 ,  116 .  
         [0041]     According to a third embodiment, shown in  FIGS. 4 and 5 , the belt  11  includes an outer layer  115 , identical to the one of the second embodiment shown in  FIG. 3 . The outer layer  115  is made integral with a semi-rigid strip  117 , in which holes  118  are made for engagement with corresponding pins (not shown) made radially on the outer circumference of the ring-like drum  131 .  
         [0042]     According to what is shown in  FIG. 1 , holding means  132  are connected to the driving wheel  13 , to prevent the products  3  from leaving the seats  110  in the semicircular section T of the belt  11 , engaged with, and touching, the drum  131  of the wheel  13 , the section T being defined between the upper run  11   a  and the lower run  11   b.    
         [0043]     The above mentioned holding means  132  are formed by suction means and include a fist ring-like chamber  132 , made in the fixed hub  130  and set in a vacuum condition by suction means, known and now shown, and set in communication with the seats  110  of the corresponding section of the belt  11  by the relative through holed  111 , which in turn communicate with the corresponding holes  131   a  made on the ring-like drum  131 .  
         [0044]     A second chamber  133  is made directly after of the fist chamber  132  on the fixed hub  130  (considering the rotation direction thereof), and has such a width as to engages only one row of seats  110 , when the latter is situated in the lower part of the ring-like drum  131  and moves after the first chamber  132  during rotation of the driving wheel  13 .  
         [0045]     The second chamber  133  is set in communication with blowing means, likewise known and not shown, to define means E for ejecting the products  3 , that is to say aimed at delivery jets of compressed air which reach the seats  110 , each time involved, through the relative holes  131   a ,  111 , so as to expel the products  3  from the seats  110 . In this way, the introduction of the products  3 , each inside a respective single blister  40  of the blister band  4 , is determined and facilitated.  
         [0046]     The operation of the unit  1  is described below.  
         [0047]     The distributor group  2  feeds the products  3  over the selecting means S, which are situated directly above the upper run  11   b  of the belt  11  to allow the products  3  to be correctly introduced into the seats  110  of the belt  11  situated below.  
         [0048]     When the products  3 , introduced each one into the relative seats  110 , reach the terminal part of the upper rum  11   a , they move forward along the joining semi-circular section, on the circumference of the ring-like drum  131 , held inside the seats  110  by the vacuum effect in the first chamber  132  and acting through the holes  111  and  131   a.    
         [0049]     When the seats  110  reach the lower position under the ring-like drum  131  and at the beginning of the lower rum  11   b , they face and are aligned with the corresponding blisters  40 , situated below, along the above mentioned working section O of the same run; in this step, the products fall delicately into the respective blisters  40 , both due to gravity, but first of all due to the push of the jet of compressed air present in the second chamber  133  and acting through the holes  111  and  131   a.    
         [0050]     Therefore, from what described above, also due to the flat arrangement along the section O of the belt  11  deviated by the wheel  15  and facing the blister band  4 , each blister  40  will be surely filled stably with only one product  3 , also if the dimensions of the blisters  40  are much bigger than the dimension of the products  3 , without any subsequent risk that the products  3  leave blisters  40 .  
         [0051]     This allows to use the same dies for blisters  40  arranged in the blister forming station without changing them each time products  3  of different dimension or shape are to be fed, since it is enough to substitute the belt  11  in order to adjust the blistering machine M.  
         [0052]     In order to protect the integrity of the products  3 , the belt  11  can also be made of a material whose hardness does not cause scratches, abrasions, tears and fragmentations of the products  3 .  
         [0053]     The length of the working section O could in some cases coincide with the length of the lower run  11   b  so as to allow maintaining the seats  110  in a facing relation with the corresponding blisters  40  for a relatively long time, so that the expulsion of the products  3  from the seats  110 , facilitated in a first moment by the above mentioned jet of air, can be completed due to the gravity in a relatively long time and this with certainty that the deposit into the relative blisters has been done.  
         [0054]     It is also to be noted that the just mentioned feature allows a considerable increase of the speed of the blistering machine M, and consequently, of the production rate.  
         [0055]     While various embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes or modifictions can be made without varying from the spirit and scope of the invention.