Deblistering Press and Distensible Carriage

Field of the Invention

The field of the invention is deblistering presses for the removal of sealed contents from blister packs. Further, the field of the invention is deblistering press carriages.

Background of the Invention

A common method of packaging pharmaceutical products such as tablets and capsules is a blister pack. In such a pack individual tablets or groups of tablets are sealed within blister pans of a tray, typically by a layer of plastic or metallic foil, to create individual "blisters". This provides a blister-like enclosure within which the product may be protectively sealed. The blister pans are typically arranged in rows within the tray, and commonly in a two-dimensional array.

Blister packs are convenient for patients to use. The patient may separately retrieve the sealed product from within each individual blister by pressing a digit against the outer surface of the blister pan, such that the tablet is forced against the covering foil, rupturing the foil and causing the product to be ejected. Further the manner of display of the product within the pack enables date information to be printed on the foil associated with each blister. Also the patient may conveniently inspect the number of products used and remaining.

The process of recovering a product from the blister pan of a blister pack is commonly referred to as "deblistering". In retail pharmacies deblistering is commonplace, for example, to enable repackaging of the product, often with other products in custom blister packs that are designed to accommodate a plurality of products within each blister. Within pharmacies deblistering is commonly carried out by hand, which is a time consuming process.

A known deblistering device that is used in the retrieval of products from blister packs in pharmacies is a small, automatic hammer, which functions as a selective press to

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punch individual (or small numbers of) products from a blister pack in a series of punching operations. In use a blister pack is placed foil side down on a platen beneath a hammer that punches the outside of each blister pan to rupture the product out of the pack one at a time, with the product passing through an aligned hole in the platen. However, this operation can lead to considerable attrition through product breakage. Further, this operation is time consuming, since each product (or small number of products) is punched out sequentially. In operation either the blister pack should be moved with respect of a single platen hole, or a dedicated multi-hole platen must be provided corresponding with each design of pack. An automatic hammer type of deblistering device is disclosed in US20060277870.

Due to in the faults loading of trays with products during the manufacturing of blister packs pharmaceutical manufacturers often require to recover products from large numbers of blister packs. Deblistering devices suitable for high volume deblistering use are commercially available. However, such devices are in many cases expensive, mechanically complex, sizable and suffer attrition through damage to the retrieved product. Further, when swapping between different designs of blister packs the currently available large-scale deblistering devices require careful alteration to conform to the layout of blister pans on each pack. The alteration is time consuming and increases operational complexity.

A design of commercially available deblistering device uses a press mechanism, with a punching plate on which are arrayed a plurality of protruding punches. Such deblistering press require the fitting of dedicated components corresponding with each different layout of blister pans, e.g. the punching plate and a platen.

US5509773 to Gemel Precision Tool Co. Inc. discloses a deblistering device in which a blister pack is punched with a punch plate having an array of punches, and in which ejected products are received into apertures of a platen having an array of receiving apertures. The array of punches and array of apertures require to be complementary to the arrangement of blisters on a blister pack, and thus a dedicated punch plate and platen are required for each design of blister pack, which would require to be changed to enable different designs of pack to be deblistered.

WO2005028315 to Sepha Limited discloses a device for deblistering single blister packs in which the blister pans of the blister tray are received in complementary holes of a pack holding means. A complementary array of punches attached to a punch plate is driven through the holes to punch the blister pans, rupture the foil covering of each blister and eject the products. Such a device requires complementary designs of pack holding means and punch plate dedicated to each design of blister pack, which would require to be changed to enable different designs of pack to be deblistered.

A disadvantage of prior art deblistering presses concerns punch size. Different sizes of blister pans are used on the trays of different designs of blister pack, even when the layout of blister pans is the same. Reasons for this include different shapes and sizes of product, as well as the design choices of blister pack manufacturers. However, punches that are mismatched with respect to blister pan size can lead to breakage or failed ejection of the sealed product, in particular if the punch is much smaller than the blister pan. A reason for breakage by punching with a mismatched size of punch is due to localised regions of high pressure being applied to the sealed product. For optimised operation the dimensions of the striking surface of each punch should be optimised with respect to blister pan size, and in particular the punch should advantageously be approximately of the same size as the blister pan being punched. However, using an optimised punch for each blister pack would require changing the punch plate when swapping between blister packs with different sizes of blister pan, even if the blister pan layout pattern on the tray remained the same. This would further increase inconvenience in use of the deblistering device and lead to a requirement for a particularly large number of interchangeable punch plates.

A risk in deblistering with such a prior art platen is that a blister pack should be misaligned with respect of the platen on which it rests and apertures in the platen through which the product is received as it is ejected from the pack. Any such misalignment can lead to breakages of the products. Consequently careful alignment of the blister pack with respect of the platen is required when the pack is loaded into the device, and a clamping means is required to hold the pack in place during at least the punching operation. However, to accept packs of different sizes, the device requires an independently adjustable clamping means, increasing manufacturing and operational complexity.

Thus a need remains in the art for a deblistering press that may conveniently be used with different blister packs, having different layouts of blisters. Further a need remains for an improved means for maintaining the alignment of a blister pack of a deblistering device during a punching operation. Yet further a need remains in the art for a deblistering press in which each punch automatically adjusts to the size of blister pans on a blister pack.

In those prior art designs of deblistering press in which all of the products are ruptured from a blister pack in a single punching action, the pack is typically placed with the foil surface against a carriage comprising a platen provided with holes in positions corresponding with the blisters of the blister pack. This design provides a resistive force distributed across the foil, excepting in the regions of the blisters, and such that the products are ejected into the apertures. However, such a design requires dedicated platen to be provided for each design of blister pack, and for the platen to be changed when different designs of blister pack are used.

A risk in deblistering with the platens of prior art deblistering presses is that a blister pack should be misaligned with respect of the platen on which it rests and apertures in the platen through which the product is received as it is ejected from the pack. Any such misalignment can lead to breakages of the products. Consequently careful alignment of the blister pack with respect of the platen is required when the pack is loaded into the device. Such alignment can be time consuming and susceptible to error.

Thus a need remains in the art for an easily adjustable product receiving carriage for use with a deblistering press.

Statement of the Invention

It is an object of the present invention to provide a press and a method of operation of a press that overcomes at least some of the above disadvantages of the prior art.

According to a first aspect of the present invention a press is provided comprising a loading carriage for receiving a blister pack, provided with at least one aperture to receive products to be pressed from a blister pack, a pin screen comprising a carrier and a plurality of pins moveable axially relative to the carrier; and an urging means for urging the pins towards the loading carriage to press the products from the blister pack.

According to a second aspect of the present invention a method of removing products from a blister pack comprising positioning the blister pack on a loading carriage provided with at least one aperture to receive products from the blister pack, providing a pin screen comprising a carrier and a plurality of pins axially moveable relative to the carrier, the pin screen being adjacent to the blister pack, urging the pins towards the loading carriage to press the products from the blister pack and through the at least one aperture of the loading carriage.

Preferably the travel of the pins is limited. Preferably the press has a pressure plate disposed adjacent to the pin screen and on an opposite side of the pin screen from the loading carriage, wherein the urging means urges the pressure plate towards the pin screen, to move the pins towards the loading carriage.

The carrier may be slidably connected to the pressure plate by means that limit the maximum separation of the carrier and pressure plate. Alternatively the pressure plate and the carrier may be integrated into a single component.

Preferably the press has a loading carriage comprising a plurality of uniformly spaced, moveable rails, having an adjustable rail pitch, between which the at least one aperture is provided. The loading carriage may be distensible, such that the rail pitch may be adjusted. The rail pitch may be modified to match a pan pitch of a blister pack. The loading carriage may be distensible, and the movement of the rails corresponds with the distension of the carriage. Alternatively the loading carriage may comprise a platen and the at least one aperture is provided by one or more holes in or through the platen.

Preferably the press is adapted to manual operation. Alternatively the press may be provided with a drive means and is adapted to driven operation. The press may be provided with a hopper for receiving a plurality of blister packs to be pressed and automatic feed means for feeding said blister packs to the press. The automatic feed means may be a belt feed mechanism or a shuttle feed mechanism.

Preferably a plurality of pins of the pin screen is urged against a blister pan of the blister pack. Preferably at least four pins are urged against each blister pan, and yet more preferably at least twelve pins are urged against each blister pan.

Preferably a pressure plate is disposed adjacent to the pin screen and on an opposite side of the pin screen from the loading carriage, wherein the pressure plate is urged towards the pin screen. Preferably a sealed product is removed from within the blister pans of the blister pack by punching pins of the pin screen against blister pans of the blister pack.

Preferably the press is adapted to manual operation. Alternatively the press may be provided with drive means and adapted to driven operation. The press may be provided with a hopper for receiving a plurality of blister packs to be pressed and automatic feed means for feeding said blister packs to the press. The automatic feed means may be a belt feed mechanism or a shuttle feed mechanism.

It is an object of the present invention to provide a product receiving carriage for use with a deblistering device that overcomes at least some of the disadvantages of the prior art.

According to a third aspect of the present invention a carriage is provided, the carriage being adapted to receive a blister pack to be pressed, and provided with at least one aperture to receive products that may be pressed from the blister pack, wherein the carriage comprises a plurality of uniformly spaced, moveable rails, having an adjustable rail pitch, and wherein the carriage is distensible to adjust the rail pitch.

The carriage according to the third aspect of the invention may be used in the first and second aspects of the invention.

Preferably the carriage is distensible, and the rail pitch is adjusted in correspondence with distension of the carriage.

Preferably the carriage has sides that support the rails, wherein the sides comprise a plurality of sections assembled in a pantograph-like arrangement, such that the sides are distensible, and the rail pitch is adjustable in correspondence with a length of the distensible sides. Preferably the rail pitch can be modified to match a pan pitch of a blister pack.

Preferably the carriage is provided with a carriage holder. The distension of the carriage may be lockable. The distension of the carriage may be locked by means that engage with the carriage holder. The locking means may comprise one or more clips that engage with the carriage holder.

Preferably the carriage or the carriage holder may be provided with a spring clamp that biases the blister pack towards the carriage. The spring clamp may be used to hold a blister pack in position on the carriage.

Preferably the carriage is adapted to manual operation. Alternatively the carriage may be provided with a drive means and is adapted to driven operation. The drive means may be operable in correspondence with a code associated with the design of a blister pack.

Preferably the carriage is provided with an edge guiding means.

Preferably the carriage is provided with a hopper for receiving a plurality of blister packs to be pressed and automatic feed means for feeding said blister packs to the press. The automatic feed means may be a belt feed mechanism or a shuttle feed mechanism.

Brief Description of the Drawings

For a better understanding of the present invention and to show more clearly how it may be carried into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:

Figures IA, IB and 1C are schematic side views of a preferred embodiment according to an aspect of the present invention.

Figures 2 A and 2B are schematic views of a preferred embodiment according to a further aspect of the present invention.

Figure 3 is a schematic side view of a further preferred embodiment according to a further aspect of the present invention.

Detailed Description of Preferred Embodiments

Referring to Figure IA of the accompanying drawings, a deblistering press 100 is illustrated according to a preferred embodiment of the present invention. The deblistering press 100 comprises a base 102 with guides 104, a carriage assembly 106, a pin screen 108, a pin carrier 110, a pressure plate 112, pin carrier hanging arms 114, a handle 116, a cam mechanism 118, a return means 120 and edge guiding means 122.

The pin screen 108 comprises a screen of parallel pins that are movably captured within holes through the pin carrier 110 such that they may freely move axially within a limited travel in a substantially axial direction. The pins may comprise a head, by means of which they may be captured within the carrier at an end.

In the position of the pin screen 108 shown in Figure IA, the pins are disengaged from a blister pack 124, and are located in their lowest positions of travel relative to the pin carrier 110 (i.e. the limit of travel closest to the carriage assembly 106).

The pin carrier 110 and pressure plate 112 are slidably engaged with the guides 104. The pin carrier 110 is slidably captured by the pin carrier hanging arms 114, by means of which it hangs from the pressure plate 112. The handle 116 and associated cam mechanism 118 are operable to lower the pressure plate 112 and captured pin carrier

110 towards the carriage assembly 106. The return means 120 biases the pressure plate 112 away from the carriage assembly 106, for example by means of a spring.

hi operation a blister pack 124 is positioned on the carriage assembly 106 with the blister pans 126 disposed towards the pin screen 108, each blister pan containing a product 130.

The method of operation of the deblistering press 100 is a two stage operation. The stages may occur in rapid succession.

An engagement stage of operation is illustrated in Figure IB, in which the pressure plate 112, captured pin carrier 110 and pin screen 108 are lowered relative to their positions in Figure 2A. The pin screen 108 engages with the arrangement of blister pans 126 on the blister pack 124, with the profile of the pin screen being in correspondence to that of the blister pack. Pins contacting the blister pans 126 remain protruding above those contacting areas of the blister pack 124 between the blister pans.

A punching stage of operation is illustrated in Figure 1C follows the engagement stage, in which the pressure plate 112 has been lowered further, driving down the protruding pins flush with the surrounding pins of the pin screen 108. In this position the pins of the pin screen 108 are raised to their highest position of travel relative to the pin carrier 110 (i.e. limit of travel away from the carriage assembly 106).

hi the punching stage each convex blister pan 126 is depressed or buckled, pressing the contained product against the covering region of foil, causing the foil to rupture 132, and allowing the product 130 to be ejected. The ejected products 130 may be collected by the base 102.

Advantageously the engagement of the pin screen 108 with the blister pack 124 provides stability to the pack against lateral movement. By maintaining the position of the pack during the punching stage of the deblistering operation it is possible to eliminate or reduce the occurrences of misalignment during punching, and associated attrition. Consequently, the device may operate without the need for a separate pack

clamping means. However, pack clamping means may nonetheless also be employed to provide extra stability against lateral movement.

During the punching step, the protruding pins associated with each blister pan 126 function cooperatively as a composite punch 128. Each composite 128 punch is comprised of a plurality of pins, and their number is a function of the pin density in the pin screen 108 and the area of each blister pan 126. Preferably each composite punch 128 comprises at least four pins and more preferably at least twelve.

Advantageously, when the pin screen 108 is lowered onto the blister pack 124 the size of the composite punch 128 corresponds with the size of the blister pans 126 on the blister pack 124. Sizing of the composite punch occurs automatically as a self-aligned process. The provision of such a punch provides the application of a punching force across substantially the full width of each blister pan 126, ensuring improved distribution of the punching force across the blister pan compared with the single piece punches of the prior art. This improved distribution of the punching force on a blister pan 126 reduces the risk of damage to the captured product 130 that may occur in prior art methods by eliminating or reducing the occurrence of regions of localised high pressure, which may otherwise lead to breakage of sealed products within blister pans 126.

The engagement and punching steps of operation of the device may comprise parts of a single fluid operation.

In the illustrated preferred embodiment the pressure plate 112 and pin carrier 110 are separate components whose movement is at least partially interrelated by means of the pin carrier hanging arms 114 within which the pin carrier is slidably captured. The arms 114 limit the maximum separation of the pin carrier 110 and pressure plate 112. Alternatively, the pressure plate 112 and pin carrier 110 may move independently. In a further alternative the pressure plate 112 and pin carrier 110 may be integrated into a single component.

The deblistering press of the present invention may be provided with an automatic feed mechanism, e.g. delivering blister packs from a hopper with a shuttle feed or a belt feed mechanism.

The movement of the pressure plate may be hand-operated. Alternatively the movement of the pressure plate may be controlled by other known means, such as by electrical, pneumatic or hydraulic drive means.

Although the device has illustrated with a mechanism orientated such that the pin screen acts on a blister pack from above, by means of any necessary adaptation the deblistering press may operate in other orientations. For example the blister press may be mounted such that the pin screen acts horizontally onto a blister pack.

The deblistering press may also be provided with a sorting and repackaging mechanism. The device of Figure 1C is provided with such a mechanism, comprising a shaking plate 134 having recesses 136, a release plate 138 having holes 140, a further blister pack 142 and a support 144.

The ejected products 130 fall through the base 102 (which may be absent) onto the shaking plate 134 provided with recesses 136 adapted to accept a product. The shaking plate 134 is shaken by a mechanism (not illustrated) such that each product moves around the surface of the shaking plate it falls into a recess 136.

The bottom of each recess 136 has a hole through the shaking plate 134 that is covered by the release plate 138. The release plate 138 is moveable and may be sprung loaded to remain in a position such that the bottoms of the recesses 136 are covered by the release plate.

The release plate 138 is provided with a pattern of holes 140 in correspondence with the arrangement of recesses 136 in the shaking plate 134. When the products 130 have fallen into the recesses 136, the release plate 138 may be moved, in-plane, such that the holes 140 align with the recesses 136 (as illustrated in Figure 1C), and the products 130 may drop through the release plate into the blister pans of the blister pack 142 beneath. The blister pack 142 may be supported on the support 144.

In an alternative design of sorting and repackaging mechanism the shaking plate 134 is not shaken, but is provided with a brush that sweeps products 130 around the surface of the shaking plate until the products fall into a recess 136.

Referring to Figure 2A and 2B of the accompanying drawings, a deblistering press carriage assembly 200 is illustrated.

Figure 2A illustrates the carriage assembly 200 in plan view. The carriage assembly 200 comprises a distensible carriage 202 and a frame 204. The distensible carriage

202 comprises rails 206, a fixed end 208, a moveable end 210, distensible sides 212 and fixed clamp 214. The fixed clamp 214 may be function as an edge guiding means, against which a blister pack loaded onto the carriage 202 may be abutted, to aid in alignment of the blister pack on the carriage. Alternatively an edge guiding means may be provided in place of the fixed clamp 214.

The fixed end 208 is rigidly attached to the frame 204. The rails 206 and the moveable end 210 are connected with the fixed end 208 by means of the distensible sides 212. The rails 206 and the moveable end 210 are slidably associated with the frame 212. The distensible carriage 202 can be lengthened by distension to increase the separation between the fixed 208 and moveable 210 ends.

The rail pitch (i.e. repeat distance of the rails) 213 between the rails 206 of the carriage 202 is uniform. As the carriage 202 is distended the rail pitch 213 scales in correspondence with the length of the carriage, preferably in a linear relationship.

The locking means 210 locks the carriage at a particular distension. The locking means 210 may comprise a pair of clips associated with the moveable end 210, and which engage with the frame 204.

Figure 2B illustrates a side view of a corresponding carriage assembly 200 loaded with a blister pack 224. The pack 224 engages with an edge guiding means associated with the fixed end 208. In the illustrated embodiment the edge guiding means is associated with a fixed clamp 214. A moveable clamp 216 is provided that is

associated with the moveable end 210. Alternatively separate edge guiding means and or clamps may be provided, or one or both may be omitted.

The sides of the carriage support the rails 206 and comprise an arrangement of interconnected strips assembled in the manner of a pantograph (in appearance like a continuous series of diagonal crosses). Consequently the sides may distend, and the rail pitch 213 distends in correspondence with the length of the sides.

In use with a deblistering press a blister pack 224, with a plurality of rows of blister pans 226 is placed on the distensible carriage 202. The blister pack 224 may be aligned on the distensible carriage 202 by means of abutment with the edge guiding means 122. The carriage 202 is distended until the rail pitch 213 matches the blister pan pitch 228 of the rows of blister pans 226, and the rails 206 are aligned with the portions of the blister pack 224 between the rows of blister pans 226 to provide support to the pack.

Figures IA- 1C illustrate a deblistering press 100 that is provided with a carriage assembly 106 according to the present invention. The carriage assembly 106 comprises rails 132 and edge guiding means 122. In operation pressure plate 112, pin carrier 114 and associated pin screen 108 are lowered to cause a punching operation in which a plurality of pins are forced against each blister pan 126 of a blister pack 124 to rupture a foil (not shown) on the opposed side of the blister pack and cause a sealed product 130 to be ejected. During the punching operation the carriage assembly 106 provides a reactive force on the blister pack 124 opposed to the punching operation. The product 130 is ejected between the rails 132 and may be collected in the base 102.

Advantageously, according to the present invention, an distensible carriage of the carriage assembly is provided that may conveniently be distended to match the blister pan pitch 228, such that it may be adjusted to suit different blister packs 224 with different blister pan pitches 228.

In the illustrated embodiments the distensible carriage is designed for manual distension. However, it is within the scope of the present invention that the distension

may be driven by a drive mechanism. Such a drive mechanism may be controlled by a computer, which controls the drive means to set the distension of the distensible carriage in correspondence with a code provided on the blister pack that identifies the blister pan pitch.

The carriage assembly of the present invention may be provided with an automatic feed mechanism, e.g. delivering blister packs from a hopper with a shuttle feed or a belt feed mechanism.

Figure 3 illustrates a device 300 comprising a carriage assembly 302 and a carriage assembly holder 304, suited for loading a blister pack 324 into a deblistering press. The carriage assembly 302 is provided with a spring clamp 306 that biases the blister pack 324 towards the carriage assembly. The blister pack 324 is slid under the spring clamp 306 in the direction indicated by arrow 1. The carriage assembly 302 is then slid into the carriage assembly holder 304 in the direction indicted by arrow 2. The carriage assembly holder 304 is provided with a chamfered edge 308 to aid entry of the loaded carriage assembly 302.