Patent Publication Number: US-6334288-B1

Title: Apparatus for printing, cutting, cropping of blister packs obtained from a blister band

Description:
BACKGROUND OF THE INVENTION 
     The present invention refers to the production of automatic machines for packaging various articles into portions of a blister band, commonly called blister packs. 
     In particular, the articles are medicines, such as tablets, capsules, pills and the like. 
     DESCRIPTION OF THE PRIOR ART 
     Machines are known for producing blisters on a band of thermoformable material and subsequently fill these blisters with articles. 
     After having been filled, the blister band is driven through a station for checking if the articles are in the blisters (this checking station can De equipped with means for detecting if the articles are not damaged), through a sealing station, where a film, of aluminium is applied to the upper face of the band featuring the open blisters, and through a severing station, where the sealed blister band is cut into separate blister packs. 
     Usually, there are other additional stations before the severing station, such as station where a numeric code containing the production date and lot is anplied. 
     Downstream of the severing station, there are means forming a stack of blisters to be introduced into a corresponding container. 
     There is also a station, where off-cuts remaining after the blister packs has been cropped, are broken into small pieces and gathered for subsequent recycling. 
     A shattering device is provided for chopping the off-cuts, so as to make them smaller and to facilitate the recycling operations. 
     The shattering device must operate in areas of the blister band which do not feature blisters, so as to avoid jams, which can occur when a part of the band to form a blister pack is not complete and therefore is not cropped, but passes directly to the off-cuts chopping station. 
     Therefore, it is necessary to adjust precisely the position of this shattering device with respect to the position of blisters on the band. 
     U.S. Pat. No. 4,012,888 discloses a blister-packaging machine wherein packaging material is treated at a succession of fluid-actuated stations arranged in-line and along which the packaging material is transported. 
     This machine includes treatment means at the respective stations and means for transporting the packaging material from station to station intermittently and wherein the respective treatment means are programmed to treat the packaging material at dwell time in such intermittent transporting. 
     The transporting means grips the packaging material continuously along its opposite edges at one of the treatment stations. 
     The stations include, in sequence blister-forming, filling, sealing, and perforating stations for the packaging material, and also transporting, printing, and cut-off stations for the packaging material. 
     The most important problem of this type of machines is connected with the size change over, i.e. adapting the working means to a different size of blisters to be produced, in time as short as possible. 
     It is also important to reduce the number of operators involved in the size change over operation, maintaining reduced times. 
     Known technical solutions require long slowing down of the working means fastened to the relative bodies joined to the machine support structure, substitution of these means, adjustment of the positions and finally, locking. 
     Therefore, possible alternatives are to assign more people to the substitution or provide longer periods of time before the production activity is resumed. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide an apparatus that allows size change over in extremely short time without involving more than one person and without constructive complications. 
     In the light of what above, another object of the invention is to provide an apparatus equipped with Locking systems operated by means controlled by a suitable control unit, thus allowing to automatically lock or unlock, selectively or globally, working means to be changed or adjusted. 
     According to further object of the invention, all the substitution operations must be performed in very short periods of time, which is possible due to the fact that the apparatus is arranged to unlock and lock working means by actuators which work practically instantaneously. 
     In short, according to the objects of the invention, the operator does not have to work for hours to release the means to be changed and to tighten them again after having adjusted their position. 
     According to still further object of the invention, the adjustment of the working means positions is performed by electronic means, thus making it possible to memorise and subsequently recall parameters of the means to be adjusted. 
     The above mentioned objects are obtained in accordance with the content of the claims, by means of an apparatus for printing, scoring, cropping blister packs obtained from a blister band, and for chopping remaining off-cuts, the apparatus being mounted on an automatic machine for packaging articles into blister packs, with said machine including: 
     a station, in which a numeric code is applied to the blister band by a numbering devices operated by actuators, with first guide means for the blister band; 
     a scoring station, equipped with scoring means operated by actuators, and with second guide means for the blister band; 
     driving means for the blister band; 
     a cropping station, equipped with severing means operated by actuators, with third guide means for the blister band, and with an oscillating arm provided with picking up means for picking up the completed blister packs and sending them to a packaging device; 
     a station, in which remaining off-cuts of the blister band are chopped; and 
     a base body for supporting all said means of the above mentioned stations. 
     The claimed apparatus is characterised in that said stations are equipped with clamping means for each said numbering devices, scoring members, severing means, and with motorised releasing elements acting on said clamping means as to release said numbering device, cutting members and severing means and to allow the substitution and automatic adjustment thereof by adjustment means in relation to the size of blister packs to be obtained. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The characteristics of the invention will be pointed out in the following, with particular reference to the enclosed drawings, in which: 
     FIG. 1 shows a schematic lateral view of the apparatus being the subject of the present invention; 
     FIG. 2 shows a particular of the apparatus of FIG. 1, along the plane II—II, with some parts in section view; 
     FIG. 3 shows a detail of the particular shown in FIG. 2; 
     FIG. 4 shows a particular of the apparatus along the plane IV—IV of the FIG. 1, with some parts in section view; 
     FIG. 5 shows partially the particular of the FIG. 4, along the plane V—V of the FIG. 4, with some parts in section view; 
     FIG. 6 shows schematic view of a particular of the apparatus along the plane VI—VI of the FIG. 1, with some carts in section view; 
     FIGS. 7 and 8 show schematic views, lateral and plan, respectively, of a part of the apparatus without working means acting on the blister band; 
     FIGS. 9 a  and  9   b  show a component of the apparatus in two characteristic conditions of its functioning; 
     FIG. 9 c  shows a component of the apparatus, similar to the one shown in FIGS. 9 a  and  9   b , in a version characterised by some variations; 
     FIG. 10 shows a particular type of connection between the working means acting on the blister band and relative actuators; 
     FIG. 11 shows a schematic section view of another particular of the subject apparatus, corresponding to an additional station of the apparatus; 
     FIGS. 12 and 13 show further particulars of the additional station of the FIG. 11; 
     FIG. 14 shows a schematic view of an additional device of the subject apparatus; 
     FIG. 15 shows a functional scheme of a control and check system for the adjustment devices mounted on the apparatus, like the ones shown in the FIGS. 7,  8  and  12 . 
    
    
     PREFERRED MODE OF CARRYING OUT THE INVENTION 
     With reference to the enclosed figures, the subject apparatus to be mounted on an automatic machine for packaging articles into blister packs, is aimed at printing, scoring, cropping of blister packs  3  obtainer from the blister band  2  and, subsequently, chopping the remaining off-cuts. 
     This apparatus, as seen in FIG. 1, is provided with a series of stations mounted on a support base body  1 . In a first working station A, a numeric code is applied to the band. The numeric code applying station is equipped with numbering devices  20 . A subsequent scoring station B is equipped with scoring members  20 , and a cropping station C is equipped with severing means  30 . Finally, a station D is provided for shattering the remaining off-cuts of the band. 
     According to the embodiment described and illustrated, the base body  1  is parallelepiped and its longer sides are parallel and inclined with respect to a horizontal plane. 
     The base body  1 , supported by the packaging machine, is inclined with respect to a horizontal plane, because has been found that this is the best arrangement for its operation, also in relation to the surrounding devices, with which the apparatus co-operates. 
     Moreover, inclined arrangement allows the device conform extremely easily to the essential hygiene norms, since the inclined sides do not facilitate the gathering of dirt and they are easier to clean. 
     Also the liquids used for cleaning, running on the inclined sides, are eliminated more easily. 
     Obviously, all this has been described in the following, without any modification of the real arrangement of the base body, with its sides inclined. 
     In the station A, the numbers and/or symbols identifying the articles, the production lot, possibly series, etc. are applied. 
     The identifying code is applied by a stationary die  11  and a movable punch  12 , through which the blister band  2  is made to pass stepwise. 
     The blister band  2  is driven by means  81  formed by a recessed roller, motorised by not shown means. 
     Guiding means  7  for the blister band  2  are situated in the region of the inlet of the station A. 
     In the station B, longitudinal and/or transversal score lines, allowing to separate small parts of the band, each containing one or more articles, are made on the blister band  2 . 
     These score lines are made by a die  21  and a punch  22  equipped with blades, not shown, between which the blister band  2  is made to pass. 
     Guiding means  8  for the blister band  2  are situated in the region of the outlet of the station B. 
     According to the invention, there are adjustment means  110  for automatic change or the longitudinal position of the dies  11 ,  21 , which displace along with the relative punches  12 ,  22  with respect to the band, movement direction F. 
     The station C is provided with a die  31  and a severing punch  32 . 
     On the side of the die  31 , opposite to the punch, there is an oscillating arm  71  equipped with means for picking up the ready blisters  3  and sending them to a packaging device, not shown, as it is known. 
     Guiding means  9  for the blister band  2  are situated in the region of the inlet of the station D. 
     In the off-cuts chopping station D, the longitudinal stripes remaining at the outlet of the cropping station C are shattered. 
     Also the groups of closed, but not filled blisters, which are not removed from the blister band in the station C, are shattered in the station D. 
     Possible operation problems can be avoided by adjusting the off-cuts shattering means  40  in relation to the size, so that the shattering operation takes place in the area included between two transversal lines of blisters. 
     The adjusting operation is carried out by relative adjustment means  120 . 
     All the stations A,B,C,D are equipped with respective actuators  14 ,  24 ,  34 ,  44  for moving the punches  12 ,  22 ,  32  and the off-cuts shattering means  40  (FIG.  1 ). 
     On its surface turned toward the relative actuator  14 ,  24 , each of the punches  12 ,  22  features a cavity  22   a.    
     As becomes evident from the FIG. 1, a fork  24   b  is introduced into the cavity  22   a.    
     The fork  24   b  is fastened to the top of the shaft  24   a  of the respective actuator  24  and engages a cross piece  22   b  fastened to the surface of the punch  22  over the cavity  22   a.    
     This allows to connect each punch to the relative actuator by a simple introduction in the direction transversal to the station, movement, which occurs together with installation of the punch, to which the die is connected by suitable guides of known type, as will become clearer from the following description. 
     The same movement, in the opposite direction, allows to remove the punch, together with the die, from the station, by extracting the cross piece  22   b  from the fork  24   b  and extracting the fork  24   b  from the cavity  22   a.    
     According to the invention, the stations A, B, C, D are equipped with clamping means  50 ,  70  for the numbering devices  10 , cutting members  20 , severing means  30  and off-cuts shattering means  40 . 
     These clamping means are connected with the releasing motorised means  60 ,  80 ,  100  which unlock the numbering devices  10 , scoring members  20 , severing means  30  and off-cuts shattering means  40 , so as to allow the adjustment means  110  and  120  to substitute them and automatically adjust in relation to the size of blister packs to be produced. 
     The clamping means  50 ,  70  of the numeral code application station A, the scoring station B and cropping station C include outer stop means  5 , 125  (FIG. 1) and pressers  53 ,  54 ,  55  (FIGS. 9 a ,  9   b ) acting elastically, directly or not directly, as will appear in the following, on the dies  11 ,  21 ,  31 . 
     The releasing means  60 ,  80 ,  100  prevent the pressers pushing action. 
     With reference to the FIG. 7 and 8, the outer stop means of the numeral code application station A and the scoring station B include first of all a plate  5  joined, e.g. by a screw  15  seen in the FIGS. 2 and 4, to the top of the spacing bars  6   a ,  6   b ,  6   c  fastened to the base body  1 . 
     Vertical flat regions  16   a  and horizontal flat regions  16   b , made in the ends of the spacing bars  6   a ,  6   b ,  6   c  joined to the plate  5 , delimit respectively the side and the bottom of a housing S defined between this plate  5  and said tops of the bars  6   a ,  6   b ,  6   c  (FIGS. 2,  4 ,  7  and  8 ). 
     A frame  51 , slidably introduced into the housing S extending parallel to the blister band  2 , features two windows  52  (FIG.  8 ), open on the side parallel to the longitudinal edge of the blister band  2 , which remains turned towards the side opposite to the machine support structure. 
     The transversal edges of the windows, adjacent to the open side, have a step-like shape. 
     In this way plane, prismatic guides are defined for introduction therein of the dies  11 , 21 , whose transversal edges  11   a ,  21   a  are complementary to the edges  52   a  of the windows  52  (FIG. 9 a ). 
     The sections  52   b  of the edges  52   a  of the windows  52  closer to the plate  5  are thinner than the corresponding sections  11   b ,  21   b  of the edges  11   a ,  21   a  of the dies. 
     In this way, when the pressers press the frame  51  against the plate  5 , the edges  11   b ,  21   b  remain clamped between the edge  52   c  of the frame and the same plate. 
     The ends of the bars  6   a ,  6   b ,  6   c  joined to the plate, feature vertical passage flat regions  16   c  made in correspondence to the open side of the windows  52 , so as to allow the dies to be introduced into said windows. 
     With reference to the FIGS. 7,  8 ,  9   a ,  9   b ,  9   c , the pressers include a shaft  53 , slidably introduced into axial through hole  56  made in each of said bars  6   a ,  6   b ,  6   c  and controlled by elastic means  54  formed each by a group of Belleville washers. 
     The Belleville washers  54  are housed inside a seat  59 , with enlarged section, situated at the top of each of the bars  6   a ,  6   b ,  6   c  and act from one side on an enlarged head  55  of the stem, and from the other side resting against a shoulder  58  formed by the bottom of the seat  59  (FIGS. 9 a, b, c ). 
     Then, the shaft  53  is pushed toward the plate  5 , while the opposite end is fastened to the releasing means  60 . 
     The releasing means include a block  61  fastened to the extremity of each shaft  53  opposite to the plate  5 . 
     A cam  63  made on a stem  64  is introduced, with possibility to rotate, into a cavity  62  made in the block  61 . 
     An arm  65  is keyed on the stem  64  and articulated to a bar  66 . 
     With reference to the FIGS. 9 a  and  9   b , the longitudinal movement of the bar in the direction G, operated by known and not shown actuators, makes the cam  63  rotate and therefore, causes the head  55  move away from the corresponding run of the frame  51 , thus interrupting the clamping action of this frame on the dies  11  and  21 . 
     In this way, it is possible to remove the dies to substitute them, changing the blister pack size, or to adjust the longitudinal position of the frame  51  with respect to the blister band  2 . 
     For the automatic adjustment, the adjustment means  110 , fastened to a support case  119  made integral with the plate  5  so as to act on the frame  51 , include a threaded shank  111  screwed into a threaded longitudinal hole  112  made in said frame  51  (FIGS.  7  and  8 ). 
     A motor  113  is connected with the threaded shank  111 , which, on its turn, drives an encoder  114 . 
     In particular, the motor  113  is connected to the threaded shank  111  by toothed pulleys  115   a ,  115   b  respectively keyed onto the shaft of the motor  113  and on the threaded shank  111  and connected to each other by a toothed belt  116 . 
     The encoder  114  is linked to the threaded shank  111  by toothed pulleys  117   a   117   b , connected to each other by a toothed belt  118 . 
     As schematically shown in FIG. 15, the adjustment means  110  are connected to a check and control system, that controls and checks the position of the operative numbering devices  10  and scoring members  20 . The check and control system includes a proximity sensor  87 , detecting a zero position of the operative means to be adjusted, a signal detector  86  connected to the sensor  87  and to said encoder  114 , and a control group  89  connected to the signal detector  86  and to the motor  143 . 
     The whole is joined to a central process unit  85  suitably provided by a corresponding program. 
     Moreover, the system includes also stop switches  88   a ,  88   b  situated in correspondence to the extreme positions which can be reached by said working means  10 , 20  being adjusted, and connected to said control group 
     The automatic adjustment is selected with a switch  84  after having unlocked the plate  5 , and possibly substituted the dies  11 , 12  together with the punches  12 , 22 , by operating the motor  143  until the frame  51  reaches the proximity sensor  87  defining the zero position. 
     In this way, possible errors resulting from inevitable clearances are avoided. 
     Once the reference index of the central process unit  85  has been cleared, the frame  51  is positioned, on basis of memorized or input data, by detecting and measuring its movement in the direction H, or in the opposite direction, until it reaches the position corresponding to the size of the blister pack to be produced. 
     The two stop switches  88   a ,  88   b  prevent the moving group from going beyond the limit positions. 
     After the frame  51  has been positioned, and together with it also the dies and punches, the bar  66  is moved in the direction opposite to the direction G, and the cam  63  of the blocks  61 , fastened to the shafts  53 , is brought again to the start position, so as to lock again the frame  51  and the dies  11 , 21 . 
     With reference to the FIGS. 2 and 3, the guiding means  7  of the blister band  2  situated at the inlet of the numeral code application station include an upper surface  17 , a lower surface  18  and automatic fastening means  25 ,  26 ,  27 ,  28 ,  29 . 
     The lower surface  18 , featuring longitudinal grooves  19 , is removably fastened to the upper surface, so as to define therebetween a passage P for the blister band  2 . 
     The upper surface  17  is removably connected to the frame  51 , by the fastening means  25 ,  26 ,  27 ,  28 ,  29  in correspondence to the inlet of the numeral code application station A. 
     The fastening means include a wall  28  protruding cantilevered from this side of the frame  51  that corresponds to the inlet of the numeral code application station A, and supporting a pin  26  near one longitudinal edge of the frame  51 . 
     The pin  26  is introduced into a receiving seat  27 , made in a coupling block  25  connected to the outer face of the upper surface  17 . 
     The seat  27  is parallel to the upper surface  17 . A cavity  17   a , extending parallel to said receiving seat  27 , is made on the side of the upper surface  17  opposite to said coupling block  25 . 
     An actuator  29 , cantilevered to the wall  28  on the side opposite to the pin  26 , acts with its stem  29   a  on the edge of the cavity  17   a , having a conical profile decreasing toward the protruding wall. 
     The actuator  29  is formed by a pneumatic cylinder, and the end of its stem  29   a  is shaped so as to have a profile complementary to the profile of the cavity  17   a.    
     After having introduced the pin  26  into the seat  27  and the end  29   b  of the shaft  29   a  into the cavity  17   a , with the horizontal translation movement of the surfaces  17  and  18 , the cylinder  29  is activated thus locking the two surfaces against the protruding wall  28 . 
     The operations performed in the opposite order allow to release and possibly substitute the guide means  7 , in relation to the size. 
     A sensor  33  detecting the presence of the blister band  3  in the passage P, is introduced in a hole  28   b  of the protruding wall  28 . 
     Likewise, the guide means (FIG. 4) of the blister band  2  at the outlet of the scoring station B include an upper surface  35 , removably connected to the frame  51 , a lower surface  36 , featuring featuring longitudinal grooves  39  and removably fastened to the upper surface for delimiting therebetween a passage P, and fastening means  37 ,  38   a ,  38   b ,  47  for removably fastening said upper surface  35  and lower surface  36  to said frame  51 . 
     The guide means  8  are situated in correspondence to the outlet of the scoring station B. 
     In this configuration, the fastening means include a flat support element  37  extending from the free surface of said upper surface  35  and featuring a plurality of seats  37   a ,  37   b ,  37   c  regularly spaced apart there along. Two pins  38   a ,  38   b , with one end fastened to the side of said frame  51  corresponding to the outlet of said scoring station B, are introduced into outermost corresponding seats  37   a ,  37   c  thus guiding the flat support element  37 . 
     An actuator  47 , formed by a pneumatic cylinder, acts with its stern  47   a  on the flat support element  37 , so as to. press it against the corresponding side of said frame  51 . 
     The stem  47   a  has a free end  47   b  of conical section, increasing outwards, which engages with a complementary conical section of the corresponding central seat  37   b  of the element  37 . 
     To improve its functionality and reduce its size, the actuator  47  is situated inside a cavity  48  made in the frame  51 , from which the stem  47   a  goes out through a through hole (FIG.  5 ). 
     Also in this case, after having situated the group composed of the lower surface  35  and upper surface  36  in such a way that the pins  28   a ,  38   b  are introduced into the outermost seats  37   a ,  37   c  and the end  47   b  of the shaft  47  is introduced into the central seat  37   b , the pneumatic cylinder  47  is activated by a combined upward and then transversal movement towards the machine support structure, thus locking the two guide means  8  against the side of the frame  51  corresponding to the outlet of the station B. 
     With reference to FIG. 9 c , the outer stop means of the cropping station C include a plate  125 , connected to the top of the spacing bars  6   d ,  6   e , and defining a window  152  having indented transversal edges  152 . 
     The side of the plate  125  opposite to the machine body is open in correspondence to the window  152 , so as to allow the introduction of the die  31  into so defined prismatic plan guides. 
     The transversal edges  31   a  of the die  31  are directly controlled by the pressers  53 , 54 , 55 , which also in this case include shafts  53  introduced inside the bars  6   d ,  6   e , as shown in FIG. 9 c.    
     Belleville washers  54 , situated on the shafts  53 , are connected on the base with the releasing means  80  which are substantially identical with the releasing means  60  described previously. 
     Suitably, the transversal edges  152   a  of the window  152  are thinner that the corresponding edges  31   a  of the die  31 , which results in a simpler construction of the locking system. 
     With reference to FIG. 6, guide means  9  of the blister band  2 , situated at the inlet of the cropping station C are composed of a sliding plate  57 , featuring longitudinal grooves  58  and removably fastened to said plate  125  for delimiting therebetween a passage P for the blister band  2 , and of fastening means  57   a ,  57   b ,  126 ,  127  for removably fastening the sliding plate  57  to the plate  125 . 
     The fastening means include a pin  126  supported by the plate  125  in proximity of a longitudinal side and on the head corresponding to the area where the blister band  2  enters the cropping station C, and a protrusion  57   a , made on the surface of the sliding plate  57  turned toward the plate  125  and featuring a recess  57   b  which extends parallel to the sliding plate  57 . 
     The pin  126  is introduced into the recess  57   b . Finally, an actuator  127 , formed by a pneumatic cylinder, whose stem  127   a  acts on the sliding plate  57 , in the region or the side opposite to the protrusion  57   a  for pressing it against the corresponding face of the plate  125 . 
     The stem  127   a  has a free end  127   b  of conical section, increasing outwards, so as to engage with a complementary conical section of a corresponding seat  57   a  made in the sliding plate  57 . 
     To improve its functionality and reduce its size, the pin  1226  is situated inside a housing  125   a  made in the corresponding face of the plate  125 , into which it is introduced through a hole made on the head of the plate  125  in correspondence to the housing. 
     To receive the pin  126  in the recess  57   b , the protrusion  57   a  of the sliding plate  57 , is introduced into the housing  125   a.    
     Yet to improve the functionality and reduce the size, the cylinder  127  is situated inside a cavity  125   b  made in the face of the plate  125 , opposite to the sliding plate  57 , and the shaft  127   a  passes through a hole  125   c  made in the bottom of the cavity  125   b.    
     To mount the guide means  9  with a combined movement, beginning from below the inlet of the cropping station C, in the direction of going away from the base  1 , and then transversally to the blister band advancement direction, it is necessary to introduce the protrusion  57   a  in the housing  125  and then to introduce the pin  126  into the recess  57   b , and, contemporaneously, the end  127  of the shaft  127   a  of the cylinder  127  into the complementary seat  57   c.    
     At this point, the pneumatic cylinder  127  is activated and the sliding plate  57  is locked to the plate  125 . 
     As has been already said, also the station D of the remaining off-cuts reclaiming, in which shattering means  40  cut the off-cuts by a moveable blade  41  and a stationary counter blade  42 , is equipped with automatic clamping means  90 , shover In FIG.  11 . 
     These clamping means include stop means  91 , substantially formed by a plate  91  slidably guiding a plate  43 , which supports the stationary counter blade  42 . 
     The plate  91  is connected to the spacing bars  6   f  fastened to the body  1 , and features a window  92  with longitudinal U-grooved edges  92   a , so as to define prismatic plan guides for introduction of the support plate  43 . 
     Also in this case there are pressers  93 ,  94 ,  95  acting elastically on the support plate  43 , so as to press it against the edges of the window of the plate  91  through holes  92   b  made on the walls  92   c  situated along the edges  92   a  of the window  92  and turned toward these pressers. 
     Also the pressers of the station D, shown in FIG. 11, include stems  93 , slidably introduced inside respective axial through holes  96  made in the bars  6   f.    
     Each of the stems  93  is controlled by elastic means  94 , which push it toward the stop means  91 , and whose end opposite to the stop means is fastened to the unlocking means  100 , likewise the pressers of other stations. 
     In particular, the stem  93  features an enlarged head  95 , below which there are situated Belleville washers  94  resting on a shoulder  98 . 
     The shoulder  98  is obtained in the hole  96  by a section widening  99  situated a the top of each of the bars  6   f  and containing said head  95  and said Belleville washers  94 . 
     The unlocking means  100  of the station D are different from the unlocking means of other stations A, B and C. 
     In fact, they include, for each stem  93 , a rocker arm  101  hinged to the body  1  and whose one end acts on a disc  97 , which is integral with the end of said stem  93  opposite to the relative head  95 . 
     An actuator  102 , including a pneumatic cylinder, pushes with the relative stem  103  on the other end of the rocker arm  101 , driving the latter to oscillate, moving the stem away from the plate  91 , and releasing the support plate  43  of the stationary counter blade. 
     The support plate  43  is moved by adjustment means  120 , shown in FIG. 12, which include a threaded shaft  121  screwed into a threaded hole  122  made in this support plate  43  and parallel to the longitudinal extension of the blister band. 
     The threaded shaft  121  is connected to a motor  123  and to rotation detecting means  124  formed by an encoder  124 . 
     The motor  123  is connected with the threaded shaft by toothed pulleys  105   a ,  105   b  respectively keyed to the shaft of the motor  123  and to the threaded shaft  121 , and linked to each other by a toothed belt  106 . 
     Also the threaded shaft  121  is connected to the encoder  124  by toothed pulleys  107   a  and  107   b , connected to each other by a toothed belt  108 . 
     Besides the counter blade  42 , the support plate  43  carries also guide means  45 , of known type, along which a blade holder  46  slides, with the movable blade  41  mounted thereon. 
     The blade holder  46  is connected to operation means  44  formed by a connecting rod  44   a —crank  44   b  assembly, joined to a rotating body  144  (FIG.  13 ), which is operated in time relation with the band advancement movement by not shown operating means. 
     As has been already said, there is a motorised recessed driving roller  81  of the blister band  2 , while in correspondence to the cropping station C there is an oscillating arm  71 . 
     These means are supported by respective pins  82 , and are kept in the respective working positions by locking/unlocking means  72 , shown in FIG.  14 . 
     The locking/unlocking means  72  include a bar  74  supported rotatingly, with possibility to slide axially and parallel to the respective pin  82 , by a support structure  4 . 
     A holding segment  73  fastened in radial direction to the end of said bar  74  corresponding to the free end of said pin  82 , carries a protrusion with a conical head  73   a  fastened to the free end of the segment and turned toward the pin  82 . 
     Two pneumatic cylinders  75 ,  76  act on the bar  74 , so as to drive it to swing and move longitudinally. 
     In particular, the pneumatic cylinders  75 ,  76  are connected to the bar  74  by respectively, a rocker arm  77  hinged to the support structure  4 , and a crank  78  fastened in radial direction to this bar  74 . 
     Operated in a suitable sequence, the two cylinders  75 ,  76  determine first the axial translatic of the bar  74 , moving the pointed protrusion  73   a  away from the pin  8  and releasing the roller  81 , or respectively, the oscillating arm  71 . 
     The cylinder  75 , by dragging the rocker arm  77 , moves the bar  74  outwards. 
     Then, the cylinder  76 , only the shaft of which is shown in the figure, acts on the crank  78  causing the rotation of the holding segment  73 , thus allowing to extract and substitute the roller  81 , and respectively, the oscillating arm  71 . 
     It is obvious how all the objects mentioned in the introductory notes have been obtained with the apparatus being the subject of the present invention. 
     In particular, the assembling of the locking systems operated by pneumatic means allows, by suitably arranged pushing means controlled by a suitable control unit, to automatically lock or unlock, selectively or globally, working means previously described. 
     With reference to the described arid illustrated example embodiment, when it is necessary to change the size of the blister packs to be produced, only one command determines unlocking the dies  11 ,  21 ,  31  in the stations A, B, C and the cutting means  40  in the station D, release of the guide means  7 ,  8 ,  9  and oscillation of the holding segments  73  of the roller  81  and the oscillating arm  71 . 
     Therefore, the operator substitutes only the numbering and cutting means by removing the dies  11 ,  21  together with the relative punches  12 ,  22 , introducing then the working means corresponding to the new size. 
     Afterwards, the adjustment means operate, so as to adjust the position of the substituted means, as well as of the shearing means  40 , on the base of the arrangement of the blisters on the blister band of the new size. 
     The roller  81  and the oscillating arm  71  are removed from the relative supporting pins  82  and substituted with the ones suitable for the new size. 
     Finally, one command determines locking of these working means, and the apparatus is ready for restoring the operating condition. 
     All these substitution operations are performed in very short periods of time, which is possible due to the fact that the apparatus is arranged to unlock and lock working means by pneumatic actuators which work practically instantaneously. 
     The operator does not have to work for hours to release the means to be changed and to tighten them again after having adjusted their position. He must only substitute the parts with the ones corresponding to the new size. 
     Since the adjustment of the working means positions is controlled by electronic means, it is possible to memorise and subsequently recall parameters related to the different dies, which can be performed manually or automatically, as it is known to the experts of the sector.