Abstract:
In a device for recovering exceeding articles from a blister band on a blistering machine, the blister band is moved in a forward movement direction through a station for feeding the articles to the blisters. A displacing device is situated very close to the blister band for removing exceeding articles while a conveying device recovers the exceeding articles removed from the blister band by the use of a rotating drum. The rotating drum is hollow and has a plurality of radial separating plates defining a number of niches. The niches receive the exceeding articles removed from the blister band and a transport conveyor receives the exceeding articles present in the niches and brings the articles to the feeding station.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to automatic packaging of various articles, in particular tablets, pills, capsules and the like into blister packages. 
     More particularly, the present invention relates to a device for collecting exceeding products from a blister band in a blistering machine. 
     DESCRIPTION OF THE PRIOR ART 
     Pharmaceutical products are usually packaged into blister packs, formed by a plate with a plurality of blisters, which contain the products. 
     The plate is generally closed by a sheet of e.g. aluminium. The article is removed by breaking the sheet of aluminium. Blister packs are obtained by forming one or more rows of blisters in a continuous band, usually of plastic heat-formable material or aluminium. Then the band passes through a filling station, where one product is introduced into each blister; then the surface with the blisters openings is definitely closed by applying and welding a sheet of aluminium. 
     The sealed band so obtained is cut into parts containing a selected number of blisters, and consequently products, thus defining blister packs. 
     Known apparatuses fill the blisters of the blister band according to various techniques. 
     About this matter, the International Patent Application No. WO 00/07881 and the Italian Patent Application No. BO99A 000667 of the same Applicant, is to be considered. 
     According to this last mentioned application, the device for feeding articles to a blister band situated thereunder basically includes selecting means, which form a plurality of longitudinal channels receiving articles coming from a conventional feeding hopper situated thereabove. 
     The selecting means are joined to suitable oscillating means, which generate relative oscillating motion, crosswise and/or lengthwise, between the selecting means and the opposite blister band, so as to facilitate the introduction of products present in the longitudinal channels into the corresponding blisters formed in the band. 
     This kind of system requires excessive feeding of products; in other words, in a predetermined time interval, the hopper must feed the selecting means with an number of articles much larger than the number of blisters facing a same ideal grid in the same time interval. 
     Consequently, downstream of the selecting means, the exceeding articles, which are not introduced into the blisters, are usually conveyed to the feeding hopper by suitable collecting means, and then re-introduced in the process. 
     The collecting means usually include a deflecting brush, which is situated very close to the blister band and which makes the exceeding articles fall on a pocket conveying belt trained around a pair of pulleys and bringing the exceeding articles back into the hopper. 
     The installation and maintenance of a pocket conveying band is usually very expensive, in particular because it id necessary to obtain a correct tensioning between the two pulleys during operation. 
     Moreover, the band is usually situated on the front part of the blistering machine, beside the moving blister band, and therefore, it is not only very cumbersome but it does not allow an easy access to the machine during maintenance operations. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to propose a device for recovering exceeding articles, specially tablets, pills and the like, from a blister band in a blistering machine, which resolves the above mentioned problems, ensuring at the same time optimal collection of articles which have not entered the corresponding blisters. 
     Another object of the present invention is to propose a recovering device, which ensures high reliability and production rate with any operation condition, without affecting the operation of the whole equipment. 
     A further object of the present invention is to propose a device, which cooperates with blister bands obtained in any way, so as to make it possible the collection of any type of article with any shape or composition as well as to allow particularly rapid and easy production rate adjustments in relation to packaging cycle characteristics of the blistering machine. 
     A still further object of the present invention is to propose a recovery device, which is obtained by a simple, cheap, extremely functional and reliable technical solution, which ensures an easy and rapid installation and maintenance thereof. 
     The above mentioned objects are obtained by a device for recovering exceeding articles from a blister band in a blistering machine, with the blister band moving longitudinally through a station for feeding the articles, the device including: 
     displacing means, situated very close to the blister band for removing exceeding articles from the band; and 
     conveying means for recovering the exceeding articles removed from the blister band; 
     the conveying means including; 
     a rotating substantially hollow drum with a circumferential edge and an outer cylindrical surface; 
     a plurality of radial separating plates disposed along said circumferential edge to define corresponding niches for receiving said exceeding articles removed from said blister band; and 
     transport means cooperating with said drum for receiving said exceeding articles present in said niches and for bringing the articles back to said feeding station. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     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: 
     FIG. 1 is a schematic lateral general view of a preferred embodiment of the proposed device in a general operation step; 
     FIG. 2 a  is a schematic lateral view, enlarged with respect to the previous Figure, of a particularly important element of the device; 
     FIG. 2 b  is a schematic front section view, enlarged with respect to the previous Figure, of the element of the FIG. 2 a.   
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to the above described figures, the reference numeral  3  indicates a blister band forming a plurality of longitudinal rows of blisters  3   a , aimed at receiving articles  2  fed by a feeding station  101  of a blistering machine M. The blister band  3 , moved longitudinally in a forward movement direction W, is supported and guided by known means, not shown. 
     A feeding station  101 , including e.g. a feeding hopper  1 , in which the articles  2  are disposed in bulk, is situated above the blister band  3 . 
     The upper part of the hopper has an inlet portion  1   b  for the articles  2  and its lower part forms an aperture or outlet portion  1   a , through which the articles  2  go out due to gravity. 
     The articles  2 , which enter into the hopper  1  through the inlet portion  1   b , come from an upstream container (not shown) or directly from a corresponding longitudinal feeding channel  33 , situated in horizontal condition and substantially parallel to the forward movement direction W (FIG.  1 ). 
     The articles  2  delivered by the hopper  1  are inserted into the blisters  3   a  formed in the band  3  by means for selecting/sorting the articles  2 , e.g. a grid G (shown with broken line in FIG.  1 ), driven into oscillation. 
     According to FIGS. 1,  2   a  and  2   b , a device  100  for recovering exceeding articles  2  from the band  3 , i.e. articles  2  which do not enter the corresponding blisters  3   a  of the band  3 , is situated downstream of the hopper  1 , with respect to the forward movement direction W. 
     The device  100  includes substantially a brush  13 , situated very close to the blister band  3  and aimed at removing therefrom the exceeding articles  2 . 
     The brush  13  cooperates with a rotating drum  40 , situated near the brush  13 , beside the blister band  3 . 
     The drum  40 , rotating continuously in the counterclockwise direction Z, (indicated in FIG. 2 a ), on an axis Y horizontal and orthogonal to direction W of the band  3  forward movement, is hollow and forms, along its edge, a plurality of radial separating plates  41   a , which define corresponding niches  41  (FIG. 2 a ). 
     The niches  41  receive, when passing near the brush  13 , the articles  2  removed from the band  3  and falling therefrom, and release them, at the level higher than the band  3 , to the longitudinal channel  33  opening into the inlet portion  1   b  of the hopper  1 . 
     Downstream of the brush  13 , the rotating drum  40  cooperates with a stationary annulus sector or retainer section  32 , which is aimed at closing the niches  41  facing it during the drum  40  rotation, so as to prevent the articles  2 , picked up near the brush  13 , from leaving the niches due to the gravity, and at releasing the articles  2  into the longitudinal channel  33  through a suitable slide  33   a.    
     The lower part of the rotating drum  40  is supported and stabilized by at least a pair of opposite rollers  31 , rotating idly on axes parallel to the rotation axis Y of the rotating drum  40 . 
     The drum  40  is rotated continuously in direction Z by corresponding driving means  30 , acting in the region of the outer surface of the drum  40  and over it (FIG. 2 b ). The driving means  30  include, e.g. an actuator  301  with a rotor  310  is constantly in contact with the outer surface of the drum  40 , so as to rotate it by friction, (FIG. 2 b ). 
     The actuator  301  is supported by a shaft  50 , so that it can be driven, by known and not shown means, to move between a working position, in which the rotor  310  touches the outer edge surface of the drum  40  and causes rotation thereof, as shown in FIG. 2 b , and a raised rest position (not shown), in which the rotor  310  does not touch the outer edge surface of the drum  40 , thus releasing the drum  40  from any constraint, and consequently allowing it to be detached from the rollers  31  and removed, e.g. for some rapid maintenance operations of the machine M and/or the band  3  and/or the drum  40 . 
     A circumferential groove  42  is made in the outer surface of the drum  40  for free engagement with a corresponding crown  30   a  of the rotor  310  of the actuator  301 , so as to prevent axial displacements of the rotating drum  40 . 
     The shape of the crown  30   a  is complementary to the shape of the groove  42 . 
     The operation of the proposed device  100  for recovering exceeding articles  2  from a blister band  3  is described in the following with reference to an intermediate operation configuration, in which the actuator  301  drives the rotating drum  40  to rotate in direction Z. 
     The brush  13  catches the exceeding articles  2 , i.e. the articles which do not enter relative blisters  3   a  during the blister band  3  forward movement in direction W, and displaces them laterally with respect to the blister band  3 . 
     Downstream of the brush  13 , the blister band  3  features longitudinal rows of blisters  3   a  each filled with an article  2 ; this means that there are no articles  2  left out of the blisters  3   a  of the blister band  3 . 
     The exceeding articles  2  removed from the blister band  3  fall, due to the gravity, into the niches  41  of the rotating drum  40 , which are near the brush  13 . 
     The continuous rotation of the drum  40  in direction Z gradually brings the niches  41  to face gradually the retainer section  32 , thus closing them from above. 
     This allows to hold the articles  2  within the niches  41  with a selected angular portion, substantially defined by the extension of the retainer section  32 . 
     Obviously, closing of the niches  41  prevents the articles  2 , picked up near the brush  13 , from going out because of gravity. 
     The continuous rotation of the drum  40  in direction Z brings the articles  2  to a height near to the level of the longitudinal channel  33 . 
     The niches  41  are gradually opened by the angular displacement of the retainer section  32  and consequently, the articles contained therein fall, due to the gravity, onto the longitudinal channel  33  through the slide  33   a . 
     Thus, the articles  2  exceeding on the band  3 , laterally displaced by the brush  13 , are conveyed on the longitudinal channel  33 , and then introduced again into the hopper  1 . 
     This is made possible by holding the articles  2  within the niches  41  of the rotating drum  40 , which are closed by the retainer section  32 , so as to prevent the articles  2  from going out due to gravity, and by releasing the articles  2  in the region of the longitudinal channel  33 , at a level higher than the band  3 . 
     The transport of the articles  2  inside the longitudinal channel  33  to the hopper  1  is facilitated by oscillating means  90 , which drive the longitudinal channel  33  into oscillation. This does not exclude a slight inclination of the longitudinal channel  33  with respect to the plane defined by the band  3 , so as to facilitate the transport of the articles  2  contained therein to the hopper  1  due to the gravity. 
     The proposed device  100  for recovering exceeding articles  2  from the blister band  3  is particularly indicated for capsules, tablets and pills of any shape. 
     The described device  100  ensures optimal recovering of the articles which do not enter corresponding blisters  3   a , avoiding any damage to both the treated articles  2  and the blister band  3 , independently from the shape and size of the articles  2  and the relative blisters  3   a.    
     In particular, the rotating drum  40  does not include a motor shaft, and consequently it does not include corresponding bearings, which allows to reduce, simplify and speed up any installation and/or maintenance procedure, thus reducing considerably their costs. 
     The necessary rotation of the drum  40  is obtained by particularly simple driving means  30 , which are mainly based on the considerable friction between the rotor  310  of the actuator and the outer surface of the drum  40 . 
     Moreover, the position of the drum  40  between the pair of opposite idle rollers  31  and the means  30  allows the drum to be disassembled and/or substituted during the blistering machine M stops, e.g. in case the type of articles  2  is changed or drum  40  maintenance operations must be performed. Moreover, it is to be pointed out that the above described device is formed by few simple elements, which is advantageous for production costs, which are thus very low. 
     It is understood that what above, has been described as a pure, not limitative example, therefore, possible variants of the invention remain within the protective scope of the present technical solution, as described above and claimed hereinafter.