Abstract:
An apparatus for recovering pharmaceutical product from blister packs and a method for doing same is provided. Pharmaceutical product blister pack cards, which are unsuitable for sale, are straightened, if necessary, and stacked in a magazine. Individual blister cards are indexed from the magazine stack onto an operations chain conveyor at a loading station by a finger indexing subsystem. The chain conveyor carries the blister card to a cutting station where the back face of the card receives a peripheral cut at the location of each blister pocket and inside the wall of the pocket. The chain conveyor then carries the blister card to a punching station where each product on the card is forced through the back face of the card utilizing moving the respective cut section of the card back, thereby discharging the product into a collection bin. The emptied blister card is moved to a discharge region where it is separated from the chain conveyor. The operation of the entire machine is driven and timed from a single central drive motor. The number of moving parts in the machine is minimized.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an apparatus used for the rupturing of pharmaceutical product packages and the recovery of the product from the package waste. It also relates to the process of pharmaceutical product recovery from its packages. Specifically, the invention relates to a machine for recovering pharmaceutical product from blister packs without damage to that product, and relates to the process carried out in the operation of such a machine. 
     Pharmaceutical product, such as pills, gel caps, caplets and capsules, sold over the counter, are often packaged in individual pockets on cards. These are known as blister packs and allow the consumer to access one product unit at a time by rupturing an individual pocket. This packaging structure has now found very wide use in the marketplace as it protects the adjacent product from contamination until used, and also allows for a readily discernable count of remaining product vs. product taken. 
     Blister packaging of pharmaceutical product is presently being provided by automated packaging machinery, including automated filling devices. With increased production rates, increased production line speeds and new product shapes, sizes and coatings, &#34;miss fills&#34; and other blister packaging failures often occur. In some manufacturing lines, as much as 10 to 15 percent of the blister packages of pharmaceutical product are unsuitable for market. The pharmaceutical manufacturers are, therefore, desirous of recovering the miss-packaged product, in good condition for repackaging. 
     Recovery of this product was originally done by hand. Recently, a number of manufacturers have introduced machines which rupture the unsuitable blister packages and separate the product from the packaging. These manufacturers have included: Sepha Products, Newtownards, N. Ireland; Service Industries Midwest, Inc., Rolling Meadows, Ill.; RBP Maschinevertrieb GmbH, Monschau, Germany; and Roni/Craggs, Inc., Baltimore, Md. 
     Each manufacturer&#39;s design for its product recovery machine has differed, as has the respective machine&#39;s method of operation. However, each product recovery machine&#39;s design has addressed the same generic blister pack design. A typical, generic, pharmaceutical blister package is a rectangular card having a plurality of regularly spaced plastic product pockets extending upwardly from the card and forming a rectangular product matrix on the card. The card is usually serrated in a cross-hatched fashion to form a plurality of breakaway &#34;cardettes&#34; (i.e. card subsections) each carrying but a single product pocket. 
     These blister cards are typically made by sandwiching a foil backer material to a preformed plastic sheet carrying the desired plurality of preformed product pockets. Child resistant packages have a paper layer added to the outside of the foil which must be removed before the consumer can open the blister pack. Typically, after the individual product pockets have been loaded with individual product units, the foil backer material, which forms the back surface of the card, is heat sealed with the plastic sheet, either with or without the use of a bonding agent. The foil-to-plastic bond may or may not be mechanically knurled. Following the bonding, the cross-hatched serrations are cut into the flat card surface allowing a space of from about 0.05 inches to about 0.25 inches &#34;margin&#34; between the product pocket wall and a serration. In the instance where the &#34;cardettes&#34; are rectangular, this margin is not uniform about the &#34;cardette&#34; but is equal for opposing edges of the &#34;cardette&#34;. 
     The plastic sheet is made of poly vinyl chloride (&#34;PVC&#34;) or other approved material and can vary in thickness from 0.004 inches to 0.010 inches, depending upon the size of the product pocket and the size, weight and strength of a product unit. The foil backer material is typically aluminum foil sheet of about 0.002 inches thickness. This foil is ruptured by the consumer who presses against the product pocket, distorting it and thereby pushing product unit through the foil to release it from the pocket. 
     When the serrations are cut in a card, the lateral serrations can be die cut first, and the longitudinal serrations can be die cut secondly, or the serrations can all be cut at once. A card is then fed &#34;longitudinally&#34; along the product flow path. With the lateral dimension of a blister pack card being shorter than the longitudinal dimension, a card is stiffer laterally than longitudinally, and will tend to curl along its longitudinal length. 
     The product pockets are die formed into the PVC sheet while it is in a softened state. These product pocket forming die(s) is(are) tapered so that the cross sectional dimensions of the pocket are larger at its base (where it meets the plane of the sheet) than at the closed end wall of the pocket. The pocket is slightly over sized to provide a space between the wall and a product unit to be carried by that pocket. This space is reasonably uniform about the perimeter of the product and can range from 0.005 inches to 0.075 inches, but is generally in the range of 0.020 to 0.040 inches. 
     Sepha Products provides a machine which uses a set of rollers to press tablets and capsules from push-through blister packs. The packs are fed from a magazine through the roller set. The product is them separated from the packaging waste material. When child resistant blister packs are involved, having a reinforced backer pull away layer adhered to the back of the blister pack, the blister packs are fed from a magazine stack to a horse-shoe cutting station where the base of the product pocket is cut thereby converting the child resistant pack to a push through pack. The blister pack is then fed through the same roller pair as before, which removes the product from the package by forcing back the wall of the product pocket and releasing the product. The maximum capacity of this machine is about 60 blister packs per minute for straight roller burst, and about 24 blister packs per minute for the pocket cut and roller burst operation. 
     Service Industries provides a machine which contains a cutting blade structure. This cutting blade simultaneously cuts open each product pocket on a blister pack. The blisters are then cammed open outwardly from the backer card and the product drops into a collection chute. The empty package is then ejected. The maximum capacity of this machine is about 20 blister packs per minute. 
     RBP provides a machine which processes up to about 30 blister packs per minute from a magazine. It utilizes a roller system, similar to the Sepha roller system, to burst the blister packs. The RBP machine then separates the product from the package waste with a screening operation. The RBP machine does not handle child resistant blister packs. 
     Roni/Craggs provides a machine which utilizes counter rotating profile rolls to burst the blister pack pockets. Each blister cup (product pocket) is scratched on a &#34;certain spot&#34; to weaken it. The rollers then press the product units through the weakened pocket (cup) wall and the blister pack waste is then separately discarded. Again, the maximum capacity of this machine is about 30 blister packs per minute. 
     These prior machines focus on single step or &#34;fewer&#34; step operation. They incorporate certain shortcomings into their designs and/or operation, these being: limited capacity, a tendency to jam, a tendency to cut, bruise, break or otherwise injure product. 
     What is desired is to provide (1) a machine and a method of operation (process) for recovering product from pharmaceutical blister packs which has two to three times the capacity, or greater, of the previous machines. 
     What is also desired is to provide (2) such a machine which does not easily jam, and (3) which does not cut, bruise, break or injure the product. 
     What is further desired is to provide (4) such a machine which is easily changed over between various card sizes and product patterns; and (5) which does not require frequent adjustment, synchronization or timing correction. 
     SUMMARY OF THE INVENTION 
     The features of the present invention are realized in a machine for recovering product from pharmaceutical blister packs and its process of operation which yields increased capacity, enhanced product handling and reduced down time from jams and/or for adjustments. 
     The machine has a simple flow through operation implemented with a chain conveyor; is driven from a single motor source; and has three definable operating stations whose operations are indexed from the single drive source, which drive source also drives the chain conveyor. Moving parts are minimized and all movement of blister cards and of product is straight line movement. The chain conveyor path extends beyond the three operating stations to establish a change parts region up-line from the first operating station, and a blister card discharge region down-line from the third operating station. 
     The three operating stations, which are in straight line alignment with one another, are respectively, a blister card loading station, a card (backer) cutting station, and a punching/product discharge station. The central drive is coupled to the operating structure of each station so that the operation of each station is synchronized and operates in unison with the other operations of the machine. 
     The longitudinal curve which often occurs in a blister card is removed by a longitudinal rib formed along the center line of the card by a roll crimper. This straightening operation is ancillary to the three basic operating stations of the machine. It is also driven by a separate motor source. 
     The chain conveyor is built from a series of connected identically sized rectangular carrier plates. The width of these carrier plates establishing the width of the belt, and the length of these plates establishing the indexed distance of movement for the belt in the repetitive operation of the machine. Each carrier plate receives a &#34;nest plate&#34; which is the change part for the chain conveyor as it is intended to receive and hold a blister card. 
     Two sets of paired roller cams are positioned on the upper face of each carrier plate. These cams comprise a leading pair of cams, positioned one either side of the nest plate position, and a follower pair of cams likewise positioned outboard of the nest plate position and behind the leading pair with respect to the direction of travel of the carrier plate. These cam pairs operate two sets of paired indexing fingers which form a finger indexing subsystem at the card loading station. 
     The card loading station includes a vertical standing magazine in which cards are stacked. Positioned below this magazine, to intercept its discharge, are two pairs of juxtaposed indexing fingers. The first set of juxtaposed indexing fingers is the &#34;lower&#34; indexing finger pair which id normally biased to the extended position (extended towards one another to intercept and hold a card). The second set of these indexing fingers is the &#34;upper&#34; indexing finger pair which is normally biased to the retracted position (retracted away from one another to allow a card to pass). Each indexing finger incorporates a ramp shaped caming surface on its lower face. This caming surface is operated upon by a respective carrier plate roller cam which interaction controls the operation of the fingers. 
     The card (backer, i.e. back face) cutting station has a female die fixedly positioned above the conveyor line. A cutting die is raised from below the conveyor line to operate upon a card held in a chain conveyor nest plate which is temporarily positioned at the station. The movement of the cutting die raises the card out of the nest plate and into the female die whereupon the cutting die continues its movement to cut through the back face of the card and slightly into the base of each product pocket. The cutting die is then retracted which positively draws the card downward out of the female die and back onto the nest plate. Thereafter its vertical movement is abated as the cutting die continues to retract downwardly. 
     The punching or product discharge station has a male die fixedly positioned above the conveyor line. This male punching die carries a rectangular knock out plate or individual punches depending upon the product being operated upon. The female die comprising a guide block carrying a plurality of straight punch through holes is raised from below the conveyor line to intercept a nest plate and to raise above the nest plate thereby raising the pre-cut card carried thereon into contact with the knock out plate or punches of the upper male die. This causes the plastic pockets to collapse and the product held therein to be forced downwardly forcing open the cut flap(s) in the back face of the card, thereby discharging the product through the openings in the female die to a collection point below. 
     The moving die members for both the cutting station and the punching/product discharge station are mounted on the same operating table. This table&#39;s travel and position is cam controlled. This cam is driven off the central drive of the machine. The throw of the table is adjustable. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     The features, advantages and operation of the present invention will be better understood from a reading of the following detailed description of the invention, in conjunction with the following drawings, in which like numerals refer to like elements and in which: 
     FIG. 1 is a block diagram for the process carried out by the invention in recovering pharmaceutical product from blister cards; 
     FIG. 2 is a front view of the machine assembly of the present invention; 
     FIG. 3 is a right side elevation view of the machine taken as indicated in FIG. 2; 
     FIG. 4 is a left side elevation view of that portion of the machine below the magazine and taken as indicated in FIG. 2; 
     FIG. 5 is a plan view of the machine of FIG. 2; 
     FIG. 6 is an enlarged detail view of the rib crimper; 
     FIG. 6a is a plan view of the rib crimper of FIG. 6; 
     FIG. 7 is a side elevation view of the magazine and indexing station structure, with blister cards shown in phantom; 
     FIG. 8 is a cross sectional view of the indexing station structure taken as shown in FIG. 7; 
     FIG. 9 is a plan view of a chain conveyor carrier plate with a nesting plate installed thereon; 
     FIGS. 9a and 9b are side views of the carrier plate assembly of FIG. 9 taken as shown in that figure; 
     FIG. 9c is a detail of the carrier plate to sprocket chain link up; 
     FIG. 10 is a detailed side view of the cutting station cutting plate and female die with a blister card and product shown in phantom; 
     FIG. 10a is a plan view of the female die of FIG. 10 taken as shown in that figure; 
     FIG. 10b is a plan view of the cutting plate of FIG. 10 taken as shown in the figure; 
     FIG. 10c is a partial cut away enlarged detail of the cutting plate and female die of FIG. 10; 
     FIG. 11 is a detailed side view of the knock out and female die assembly for the punching station with a blister card and product shown in phantom.; 
     FIG. 11a is a plan view of the knock out of FIG. 11 taken as shown in that figure; 
     FIG. 11b is a plan view of the female die of FIG. 11 taken as shown in that figure; 
     FIG. 12a is a plan view of a perforation knife for the cutting plate shown in FIG. 10b; and 
     FIG. 12b is side view of the knife of FIG. 12a. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The recovery of pharmaceutical product from blister pack cards may be accomplished by the process of FIG. 1. Unmarketable blister packs are received from a production line or other source. These cards may be sorted into straight cards in a flow path 11, or in bent cards in a bent card flow path 15. The straight cards are loaded 17 directly into a retention device such as a vertical standing magazine. The bent cards are straightened 19, before loading 17 into the retention device. This straightening 19 may be accomplished by forming one or more ribs in the face of the card. 
     Cards are drawn from the magazine singly, in sequential order 21. This may be accomplished by an indexing structure which permits one card at a time to fall from the magazine on to an awaiting conveyor structure. This conveyor structure carries 23 each card away from the magazine to a cutting station, where the travel of the conveyor is temporarily halted 25. At this cutting station a cutter assembly is raised to cut 27 into the back of the card and through the back face. This is accomplished by the cutter assembly carrying the card onto a female die containing a plurality of cavities, one for each blister pocket on said card, where the die face stops the card and the cutters puncture the back of the card thereby traveling partially into the die cavities. 
     Conveyor movement is then re-initiated 29 and the cut card is carried by the conveyor structure to a punching station where conveyor movement is again halted. At this punching station a female die containing a plurality of portals, one for each product unit to pass, is raised to meet a fixed knock out plate. This operation forces 33 the product through the back face of the card and thereafter falls through said female die portals to a collection station 35. Conveyor movement thereafter continues and the card drops off the conveyor 37 into waste collection as the conveyor begins its return. 
     This process is performed by the machine apparatus shown in FIG. 2. The apparatus has a lower portion 39, which is essentially a cart, houses the single electric drive motor 41, a Geneva type timing transmission 43, the drive belts/chains 45a, 45b for the conveyor 47 operation and the cutting station 49 and the punching station 51 operations. 
     The upper portion 53 houses a sprocket chain conveyor 47 which operates horizontally down the length of the machine. This conveyor has at least a drive sprocket 55a at a first end, which is connected to the drive chain 45a, and a follower sprocket 55b at the other end of the conveyor 47. 
     The conveyor 47 is made up of a plurality of flat rectangular carrier plates 57 linked between the two side sprocket chains 59. Each carrier plate 57 holds a nest plate 61 which in turn holds a blister card 63. 
     Blister cards 63 are held in a vertically standing magazine 65 positioned at the up line end of the machine established as the loading station 67. A finger indexing subsystem 69 loads one card at a time from the magazine 65 on to the conveyor 47, nest plate 61. 
     A card straightening assembly 71 operates ancillary to the main functions of the machine but provides a valuable and necessary function as the straightness of each card bears upon the performance of the machine. This straightening assembly 71, which contains a plurality of drive wheels and a pair of machine working wheels, imparts a bend in the back face of the card in the shape of a raised rib like crimp. 
     Cutting station 49 and the punching station 51 each utilize a stationary die and a moving die, the moving dies for each station 49, 51 are mounted to a commonly shared movable shuttle plate 73 which is guided for operation by four vertically extending guide rods 75. The shuttle plate 73 is caused to raise and lower by the operation of an eccentric cam 77 which is caused to rotate on its own shaft by the chain drive 45b. A cam follower, having a bracket and a wheel, is mounted to the bottom of the shuttle plate 73. 
     This structure can also be seen in the side view shown in FIG. 3 and FIG. 4. FIG. 3 shows a side view of the loading station 67, while FIG. 4 shows a side view of the punching station 51. Product is carried away from the punching station 51 by the chute 79 which extends from a point below the discharge of the punching station 51 to a point beyond the front face of the machine. 
     FIG. 5, the plan view of the machine, shows that the loading station 67, the cutting station 49 and the punching station 51 are evenly spaced apart and evenly spaced along the length of the machine. In fact the distance between each station is equal to the length of one &#34;index&#34; of the conveyor 47 (slightly more than the length of a carrier plate 57). 
     FIG. 6 shows a side view, from the loading end, of the rib crimper 71 which as seen in FIGS. 2 and 3 is mounted to feed the magazine 65. The crimper 71 includes a pair of guides 81, FIG. 6a, to align a card with the male and female crimping wheels 83, 85, respectively. The crimping wheels 83, 85 rotate in counter rotation to positively drive a card there through. The female wheel 85 has a groove formed in its perimeter surface, while the male wheel 83 has an annular ridge to mate with the female wheel&#39;s groove. Then a card is pulled between the two wheels 83, 85, a rib shaped ridge is crimped into the back face of the card along its longitudinal center line. This straightens a curled card and allows it to lay flat. A second drive wheel 87, FIG. 6a, positioned before the crimping wheels 83, 85, pushes each card into these crimping wheels 83, 85. 
     The structure and operation of the loading station 67 and its finger indexing subsystem 69 is seen in FIG. 7. The vertical magazine 67 can be slightly flared out at its intake end. A cross section of the conveyor, including its chain 59, a carrier plate 57, a nest plate 61 and a blister card 63 at rest at the loading station 67 is shown. 
     Two pairs of juxtaposed fingers 89a, 89b and 91a, 91b are shown interrupting the path of blister cards 63 in the magazine stack 65 to the loading position of the nest plate 61. These finger pairs 89a, b, 91a, b are spring biased to the retracted position and the extended position, respectively. Two pairs of button type roller cams 93a, b, 95a, b are positioned on the upper face of each carrier plate 61 and interact with caming surfaces on the finger structure to cause them to move against their respective biasing. FIG. 7 shows button roller cam 93a engaging the cam surface 97a of the upper finger 89a, and button roller cam 95b engaging the cam surface 99b of the lower finger 91b. 
     FIG. 8 shows a detailed cross sectional plan view of the loading station 76 and the configuration of the finger pairs 89a, b, 91a, b. The carrier plate 57 carries the two pairs of button type roller cams 93a, 93b and 95a, 95b. The cams 95a, 95b which operate the lower fingers 89a, 89b are positioned slightly outboard and ahead (with respect to the direction of travel) of the cams 93a, 93b which operate the upper fingers 91a, 91b. Each finger pair is caused to operate against its respective spring 97. 
     Each finger of the finger pairs 89a, b and 91a, b has a wider blade portion 99 and a narrower tab portion 101. The blade portions meet the blister cards and have a tapered outer edge. Each tab portion 101 is removably mounted to a slider bar 103 which incorporates the caming surfaces 97a, 97b, 99a, 99b discussed above in connection with FIG. 8. The spring 97 biasing is mounted to operate directly on each slider bar 103 which translates to operating on the respectively mounted tab 101 of a respective finger 89a, 89b, 91a, 91b. 
     Each carrier plate 57, FIG. 9, has a cut out 105 along its opposing outside edges. Mounted to each cutout is a bracket shaped and drilled to mount into the links of the sprocket chain 59, FIG. 9c. The nest plate 61 which is carried upon the carrier plate 57 is attached by spring biased, quick release snap detentes 109 which force the nest plate against lip type catches 111. 
     The male end members which perform the cutting at the cutting station 49 are shown in FIGS. 10, 10a, 10b and 10c. The stationary female die 113, contains a plurality of truncated tapered holes of a position and size to receive the blister pocket structures 117, one each, of a blister card 63. The regular and repetitive pattern of these holes is seen in FIG. 10a. The cutting plate 119 supports the plurality of individual cutting knives 121 used for cutting through the back of a card 63. These cutting knives allow for give and misalignment with the tapered female die 115 openings 117 when the two dies are brought together. A spring loaded stripper mechanism assures that the card 63 does not move when in position to be cut and strips the blades 121 from the card 63 back face when the blades 121 are withdrawn. FIG. 10c shows a cross sectional enlargement of the mounting screws for each knife which is shaped in a U shape to produce a cut flap. The knives 121 for the machine are easily removable and exchangeable as are all of the blister card interfacing/interacting components of the machine. 
     FIG. 11, 11a and 11b show the male and female members which perform the punching operation at the punching station 51. A fixed position knock out plate 123 carries a rectangular knock out bar 125 on its surface, FIG. 1, 11a. This knock out 125 simultaneously pushes down on each blister pocket as the movable female die is raised to intercept a card 63 and push it into the knock out 125. This action forces each product unit through the flap previously cut in the back face of the card 63 and downwardly through a respective one of the passageways of ports 129 of the female die 127. It is to be understood that the size and location of these ports 129 are established to accommodate the movement of product without injury to the product itself, or the binding or jamming of product against the surfaces of the machine as illustrated in FIG. 11b. 
     Each knife 121 has a U shaped profile, FIG. 12a, and includes a base member 131 and a serration member 133 having perforation teeth. 
     The dimensions of the various elements of the invention will vary depending upon the specific blister card and specific product being handled. Therefore, the design has incorporated numerous &#34;change parts&#34; which are easily accessed without the extensive disassembly of the machine. 
     The present invention provides an improved machine over the prior art. This improvement is realized in greatly enhanced speed (capacity), increased reliability and reduced product damage and jamming, and reduced maintenance and change over time. This has been accomplished by reducing the number of moving parts, the timing requirements for synchronizing the various operations of the machine and the physical spreading out to various locations of the sequential operational steps of the machine. All movement of product is simple straight line. Additionally, the invention incorporates the opening of a blister pocket by cutting through the back face of the card where the spacing is greatest and the likelihood of damaging the product is least. The incorporation of simple direct drive conveyor positioning and the incorporation of mating die members having tapered surfaces assists in the proper alignment of elements and allows for the accurate &#34;blind&#34; cutting into the blister pocket from the back side. 
     The above described embodiment(s) are intended to be an example of the invention, which may be implemented in additional ways to those discussed above without departing from the scope and intent of the invention. It is therefore intended that the above description be read as illustrative of and not taken as limiting the invention.