Abstract:
At least one solid drug form is fed into a capsule, housed inside a pocket on a first conveyor movable along an endless first path extending in a given first plane, by means of a seat on a second conveyor movable along an endless second path extending in a second plane parallel to the first plane; the seat receiving the solid form from a vibratory distributor plate, and releasing the solid form to the pocket.

Description:
[0001]     The present invention relates to a unit for feeding solid drug forms to a conveyor line of a machine for filling capsules.  
       BACKGROUND OF THE INVENTION  
       [0002]     In the drug industry, a capsule filling machine is known comprising a conveyor line, in turn comprising a chain conveyor having at least one pocket for a bottom shell of a capsule, and movable in steps to feed the pocket along an endless, substantially horizontal path through a feed station for feeding at least one solid drug form into the bottom shell.  
         [0003]     The machine also comprises a feed unit for feeding the solid drug forms successively to the feed station, and which comprises a vibrating distributor plate; a hopper for feeding the solid forms onto the distributor plate; and a conveyor belt movable in steps in a vertical plane to feed the solid forms along a substantially straight second path extending between an input station for connection to the distributor plate, and an output station defined by said feed station.  
         [0004]     Known capsule filling machines of the type described above have several drawbacks, mainly due to step operation of the chain conveyor and the conveyor belt resulting in a relatively low output rate of the machine.  
       SUMMARY OF THE INVENTION  
       [0005]     It is an object of the present invention to provide a unit for feeding solid drug forms to a conveyor line of a capsule filling machine, designed to eliminate the aforementioned drawbacks.  
         [0006]     According to the present invention, there is provided a unit for feeding solid drug forms to a conveyor line of a machine for filling capsules, the conveyor line comprising a feed station; and a first conveyor having at least one pocket for a bottom shell of a capsule, and movable to feed the pocket along an endless first path extending in a given first plane and through said feed station; the unit comprising a vibratory distributor plate; a hopper for feeding solid forms onto the plate; and a feed device comprising an input station for receiving the solid forms from the plate, and an output station defined by said feed station; and the unit being characterized in that the feed device comprises a second conveyor having at least one seat for at least one solid form, and movable to move the seat along a given endless second path extending in a second plane, parallel to the first plane, and through said input station and said feed station. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:  
         [0008]      FIG. 1  shows a schematic view in perspective, with parts removed for clarity, of a preferred embodiment of the unit according to the present invention;  
         [0009]      FIG. 2  shows a schematic plan view of the  FIG. 1  unit;  
         [0010]      FIG. 3  shows a schematic side view, with parts in section and parts removed for clarity, of the  FIG. 1  unit;  
         [0011]      FIG. 4  is similar to  FIG. 1 , and shows a variation of the  FIG. 1  unit. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0012]     With reference to  FIGS. 1 and 2 , number  1  indicates as a whole a unit for feeding solid drug forms  2  (in the example shown, tablets) to a conveyor line  3  of a machine for filling capsules (not shown), each comprising a substantially cup-shaped bottom shell  4  ( FIG. 3 ), and a cover (not shown) fitted removably to bottom shell  4 .  
         [0013]     Line  3  comprises a chain conveyor  5  looped about a number of powered sprockets  6  connected to one another by a known gear transmission (not shown) to rotate continuously about respective substantially parallel vertical axes  7 .  
         [0014]     Conveyor  5  has a number of pockets  8 , which are substantially cup-shaped with their concavities facing upwards, are equally spaced along conveyor  5  with a spacing p 1 , receive respective bottom shells  4  positioned with their concavities facing upwards, and are fed by conveyor  5  along an endless path P 1  extending in a horizontal plane S 1  ( FIG. 3 ).  
         [0015]     As shown in  FIG. 2 , unit  1  comprises, in the example shown, two feed assemblies  9  for supplying forms  2  and located along path P 1 .  
         [0016]     Each assembly  9  comprises a distributor plate  10 , in turn comprising a container  11 , which is substantially cup-shaped with its concavity facing upwards, has a substantially vertical longitudinal axis  12  parallel to axes  7 , and comprises a chute  13  coiling about and along axis  12 , and in turn comprising a bottom input portion  14  projecting inwards from a lateral wall of container  11 , and a top output portion  15  projecting outwards from the lateral wall of container  11 .  
         [0017]     Forms  2  are fed into container  11  by a hopper (not shown) located over plate  10 , which is fixed to a vibrating base  17  for so vibrating plate  10  as to feed forms  2  along chute  13 .  
         [0018]     Plate  10  also has a pneumatic blowing device  18  located upstream from the output of chute  13  in the travelling direction  19  of forms  2  along chute  13 , and which blows forms  2  off chute  13  and back into container  11 ; and a control device  20  defined, in the example shown, by a known optical sensor for detecting forms  2  issuing from chute  13 .  
         [0019]     To accurately determine the number of forms  2  issuing from chute  13 , the distance between devices  18  and  20 , measured parallel to direction  19 , is obviously controlled selectively so as to be smaller than the dimension of form  2 , also measured parallel to direction  19 .  
         [0020]     At a transfer station  21  at the output of chute  13 , forms  2  are transferred to a distributor device  22 , which is normally common to both assemblies  9 , and provides for feeding forms  2  into relative pockets  8  and therefore into relative bottom shells  4  at a feed station  23  located along path P 1 .  
         [0021]     Device  22  comprises a substantially cylindrical drum  24 , which is mounted over one of sprockets  6  (hereinafter indicated  6   a ) coaxially with relative axis  7  (hereinafter indicated  7   a ), is connected in angularly and axially fixed manner to sprocket  6 a to rotate continuously about axis  7   a,  and is bounded axially by a top surface  25  and a bottom surface  26 , both substantially perpendicular to axis  7   a.    
         [0022]     Drum  24  has a number of—in the example shown, four—distribution channels  27 , which are equally spaced about axis  7   a,  are formed through drum  24  so as to open out at surfaces  25  and  26 , and are fed by drum  24  along an endless path P 2  extending about axis  7 a and through stations  21  and  23 .  
         [0023]     Each channel  27  tapers downwards, is bounded at the bottom by a substantially paraboloidal bottom wall  28 , has a top inlet  29  extending about axis  7   a,  and has a substantially circular bottom outlet  30  smaller in cross section than inlet  29  and which is advanced by drum  24  in time with a relative pocket  8 .  
         [0024]     In connection with the above, it should be pointed out that outlets  30  are equally spaced about axis  7   a  with a spacing p 2  which is a whole multiple of spacing p 1  of pockets  8 .  
         [0025]     Drum  24  also has a number of grooves  31 , which are formed in surface  25 , are equal in number to channels  27 , extend between channels  27  and about axis  7   a,  and are advanced by drum  24  along path P 2  and through stations  21  and  23 .  
         [0026]     Finally, device  22  comprises a control device  32  located along path P 2 , downstream from stations  23  in the travelling direction  33  of channels  27  along path P 2 , and which comprises, in the example shown, a known optical sensor for determining correct operation of channels  27 , i.e. the absence of forms  2  inside channels  27 , and a pneumatic blowing device for expelling forms  2  jammed inside channels  27 , in response to a signal from said optical sensor. Any forms  2  jammed inside channel  27  are expelled by feeding an air jet along an exhaust conduit (not shown) formed through drum  24  so as to form an angle of other than 90° with surfaces  25  and  26 , and to communicate with bottom outlet  30  of channel  27 .  
         [0027]     Operation of unit  1  will now be described with reference to  FIG. 2  and only one assembly  9 , bearing in mind that bottom shells  4  are only fed, in known manner, into pockets  8  spaced apart by a distance equal to spacing p 2 , bearing in mind that forms  2  are fed successively by vibration of distributor plate  10  along chute  13  to station  21 , and as of the instant in which inlet  29  of a distribution channel  27  begins travelling through transfer station  21 .  
         [0028]     As inlet  29  of the channel  27  considered travels through station  21 , pneumatic blowing device  18  is activated to prevent forms  2  reaching station  21 , and to blow them back into container  11 .  
         [0029]     When inlet  29  of the channel  27  considered is located downstream from station  21  in direction  33 , device  18  is deactivated by an electronic central control unit (not shown) to allow a given number of forms  2  to reach station  21  and fall by gravity into the groove  31  located upstream, in direction  33 , from the channel  27  considered.  
         [0030]     Once control device  20  detects the passage of a given number of forms  2  through station  21 , device  18  is reactivated by the electronic central control unit (not shown) in response to a signal from device  20 , to prevent any more forms  2  from travelling through station  21 .  
         [0031]     The forms  2  which have dropped into the groove  31  considered are fed by drum  24  in direction  33  into contact with a fixed stop member  34  located at feed station  23 , extending crosswise to path P 2 , and for arresting travel of forms  2  in direction  33 . The forms  2  considered are thus retained in station  23  by member  34 , and engage relative groove  31  in sliding manner until inlet  29  of another channel  27  reaches station  23 .  
         [0032]     At this point, the forms  2  considered drop by gravity into and along the other channel  27 , and are therefore fed into relative pocket  8  and, hence, relative bottom shell  4 . In this connection, it should be pointed out that the paraboloidal shape of bottom wall  28  of channel  27  prevents impact and/or rebound of forms  2  inside channel  27 , i.e. prevents any phenomena which might jam and/or slow down fall of forms  2  along channel  27 .  
         [0033]     Alternatively, operation of the assembly  9  considered may be controlled to deactivate device  18  as inlet  29  of a channel  27  travels through station  21 , and to reactivate device  18  in response to a signal from device  20  following the passage of a given number of forms  2  through station  21 .  
         [0034]     Using two assemblies  9 , each bottom shell  4  can be fed with more forms  2  than using only one assembly  9 , or may be fed with two different types of forms  2  housed in respective hoppers.  
         [0035]     Unit  1  therefore has various advantages, mainly due to chain conveyor  5  and drum  24  being operated continuously and so enabling a relatively high output rate of unit  1 .  
         [0036]     The  FIG. 4  variation relates to a feed unit  35  which differs from unit  1  in that: 
        the four channels  27  are divided into two pairs of channels  27 ;     the channels  27  (hereinafter indicated  27   a ) in one pair of channels  27  are movable along path P 2 , and the channels  27  (hereinafter indicated  27   b ) in the other pair of channels  27  are movable along a path P 3  coaxial with and located inwards of path P 2 ; and     the top output portions  15  of the two chutes  13 , and therefore the two transfer stations  21 , are offset radially with respect to axis  7   a,  so that one station  21  (hereinafter indicated  21   a ) is located over path P 2 , and the other station  21  (hereinafter indicated  21   b ) is located over path P 3 .        
 
         [0040]     Unit  35  is particularly advantageous when bottom shells  4  are all fed with the same type of form  2 . That is, since each distributor plate  10  only supplies two channels  27 , drum  24  of unit  35  can be rotated about axis  7   a  at a higher rotation speed than drum  24  of unit  1 .  
         [0041]     The output rate of unit  35  may obviously be further increased by forming more than two channels  27   a  and  27   b.