Small scale blister packers are used for eg. clinical trials, pack development, stability trials and low volume production, and they are designed to make either a single pack or up to possibly 10,000 packs in a batch. Such packers are also preferably designed for use and relocation where required. The pressing plates are generally adapted to support a number of different pressing tools for different operations such as forming, sealing and cutting, and for different pack shapes and sizes, and at least the upper tool is secured to its pressing plate by a number of bolts, usually near the plate centre. However, the bolting takes time and effort, especially to ensure accurate alignment and levelling of the tools.

According to one aspect of the present invention, there is provided a pressing station assembly for a small-scale blister packing apparatus comprising upper and lower pressing plates, one or both of which are moveable between a rest position and a pressing position, the pressing plates securely supporting upper and lower tools respectively, wherein one or both of the tools are adapted to be secured to the or each respective pressing plate(s) using a quick release attachment means.

The quick release attachment means allows quick and simple location, securement and release of one or both of the tools. This reduces the time and skill needed to change tools. The tools include dies, platen formers,

sealers, cutters, perforators, batch coders, and tools for thermo or cold- forming, etc.

The tool(s) may be secured directly to the pressing plates.

Alternatively the tool(s) are indirectly secured to the pressing plates using tool attachment means and/or tool holding means. The or each tool attachment or tool holding means is preferably moveable between an open position for the location, conjoining or release of a tool or tool holding means therewith, and a closed position which secures the tool or tool holding means to the pressing plate(s). More preferably, the quick release means operates the movement of the tool attachment means.

The quick release attachment means could be any suitable arrangement or assembly, including a toggle joint, biased switch, ram assembly, solenoid, etc, either manually operated or automatic, which is able to secure the relevant pressing plate to the remaining station assembly under pressure. The quick release operation is preferably a single action, such that the relevant tool or tool attachment or tool holding means is readily available for replacement from the rest position. The securement action of the quick release attachment means is also preferably a single action.

Each tool must be accurately aligned and level for the proper forming, sealing, cutting, perforating, etc. of blister packs. Preferably, the pressing station assembly includes one or more guidance means to provide alignment and levelling of the moveable tool(s) when secured to the pressing plate(s).

The guidance means may also help support the secured tool(s) during pressing. The guidance means may be one or more pins, posts, etc. with complementary fitting slots, apertures, depressions, etc., in the pressing plates(s), tool holding or tool attachment means.

The, if any, pressing plate not having a quick release attachment means may only need to locate or secure simply its tool in place for pressing.

Any such secondary pressing plate, usually the lower plate, may also be independently moveable between a pressing position and a tool-changing position. Preferably, the changing position is out of alignment with the other pressing plate to provide ease of access.

According to the second aspect of the present invention, there is provided a small-scale blister packing apparatus comprising a blister roll supporting apparatus, blister roll guidance means, and a blister pack pressing station assembly as herein defined.

In the packing apparatus of the present invention, the blister roll supporting apparatus (and hence blister roll) is preferably located wholly or substantially vertically below the pressing station assembly. The packing apparatus need not therefore be significantly bigger than the size of the pressing station assembly and the housing area for the blister roll. This creates a compact apparatus compared with prior apparatus which support the blister roll away from the pressing station.

The blister roll guidance means preferably comprises one or more rollers around which the blister roll material is guided in use, thus avoiding any possibly unsmooth or rough edges which could scratch (and hence ruin) the blister roll material, usually through friction. The blister roll guidance means may include a one-way roll-feeding means to prevent the roll material rewinding when cut or otherwise unsupported.

The packing apparatus of the present invention is also preferably wholly or substantially enclosed during use except for the formed blister pack exit. This reduces or avoids dust or microbes etc. which could affect the packing apparatus and/or packs formed. The packing apparatus may be fully

or partly automatic. The upper and/or lower tools may be accessed from any side for changing, most conveniently the side having any external heating and/or air leads.

The packing apparatus of the present invention is also preferably mobile, e.g supported on one or more wheels. As the invention is intended for small scale use, mobility assists relocatability wherever the invention is needed or required.

According to a third aspect of the present invention, there is provided a method of securing one or both tools of a pressing station assembly for a small-scale blister packing apparatus to the upper and/or lower pressing plates wherein the tool(s) are secured to the pressing plate(s) using quick release attachment means.

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Fig. 1 is a front view of a small-scale blister packing apparatus of the present invention with blister roll; Figs. 2a and 2b are side views of the apparatus of Fig. 1 without blister roll with the lower holding means in pressing and tool-changing positions respectively; Fig. 3 is a diagrammatic perspective view of the upper pressing plate, tool attachment means, and tool in Fig. 1 in an open position; and Figs. 4a and 4b are schematic side views of the upper, lower and base pressing plates of the apparatus of Fig. 1 in open and closed positions respectively.

Referring to the drawings, Fig. 1 shows a small-scale blister packing apparatus. The apparatus is on casters 2 for rapid and easy movement. The apparatus comprises a pressing station assembly 4 and blister roll housing 6.

Within the housing 6 is a blister roll support means 8 supporting a blister roll 10. The blister roll 10 is located vertically beneath the pressing station assembly 4, thereby providing compaction of the overall apparatus compared with prior apparatus.

The roll material 12 is guided from its roll 10 by two guide rollers 14 which form the blister roll guidance means. The material 12 is guided to pass through the pressing station assembly 4. The rollers 14 create a simple and frictionless passage for the material 12 which avoids any edges which could damage the material 12. The upper guide roller 14 could have an aligned and shaped rubber wedge or bar engaging therewith or thereon to act as a one-way feeding means to prevent roll material therebeyond when cut or otherwise not secured rewinding back onto the main roll 10.

The pressing station assembly 4, partly shown in more detail in Fig. 3 comprises upper and lower pressing plates 16, 18. The lower plate 18 is fixed and the upper plate 16 is relatively vertically moveable between rest and pressing positions by means of four corner columns 20 connected to a ram assembly beneath the pressing station assembly 4. the ram assembly is shown in Figs. 4a and 4b and discussed below.

As shown in Figs. 2a and 2b, a lower tool holding means 22 is located on the lower plate 18, with a lower tool 23 (shown in dotted form) inserted therein. The lower tool holding means 22 is slideably mounted between a pressing position in Fig. 2a and a tool-changing position in Fig. 2b. This allows easy access to the lower tool holding means 22 when changing the lower tool 23, as well as distancing the changing operation from any heated upper tool. The lower tool 23 is generally the blister-shaping or shaped die.

The upper tool attachment means is a tool attachment block 26, centrally supported through an elongate column 28 to one end of a toggle

joint 32 acting as the quick release attachment means. The top of the column 28 is linked to a toggle handle 30 which is also pivotally secured to the upper pressing plate 16. The toggle handle 30 is adapted to move the attachment block 26 between an open position (as shown in Fig. 3) and a closed position (as shown in Fig. 1) relative to the upper pressing plate 16 through the action of the toggle joint 32.

The tool attachment block 26 has side flanges 34 over which side pieces 36 can slide. Preferably, the sides of the block 26 include one or more stops to assist positive location of the side pieces 36 on the block 26. The side pieces 36 are secured to and form part of an upper tool holding means 38, which holding means 38 holds a tool 40. The upper tool 40 is generally the forming, sealing or cutting tool.

Depending from the upper pressing plate 16 are four posts 42. The posts 42 meet the upper tool holding means 38 when the attachment block 26 is in its closed position and at or near the corners of the holding means 38.

The posts 42 thus provide support in use wholly or substantially across the whole of the holding means 38 (in combination with the support from the tool attachment block 26). This can help allow reduction in the size of the ram assembly required for the same degree of pressing, or allow for increased pressure, compared with prior small-scale blister packing apparatus (wherein one or both of the tools or tool attachment means were only supported in their centres).

The posts 42 are preferably tapered at their lower ends and there are complementary conical depressions 43 in the upper surface of the upper tool holding means 38. Thus, the posts 42 can assist and/or provide correct and accurate alignment and levelling of the holding means 38 (and hence upper tool 40) with the lower tool etc.

In use, the upper tool holding means 38 and side pieces 36 are slidingly located onto the tool attachment block 26 in its open position. The toggle handle 30 is then moved by the operator in a single action until the block 26 is raised and becomes flush with the lower surface of the pressing plate 16. Simultaneously the four corner posts 42 mate with the depressions 43 in the upper tool holding means 38. The pressing station assembly 4 is now ready for use. Reverse movement of the toggle handle 30, again as a single action moves the block 26 away from the upper pressing plate 16 and posts 42 to allow rapid removal (by simple sliding action) of the upper tool holding means 38 from the pressing assembly 4 for replacement with a similar upper tool holding means but with a different tool.

The fitting and removal of the upper tool holding means 38 is thus a very fast and simple operation taking seconds, and the new tool or tool holding means can still be accurately aligned using the tapered corner posts 42. This operation is in contrast to the requirement of prior tool holding blocks to be bolted in piace using usually four bolts, each requiring exactly the same degree of tightening to ensure the tool is level. With hot tools for thermoforming, holding the tool or tool attachment means whilst the bolts are tightened or loosened can be difficult and a lengthy operation.

Once the tools are located and secured, the blister roll material 12 is fed between the tools and the apparatus is ready for operation. The apparatus has a control panel 44. The parts of the apparatus are fully enclosed by the roll housing 6 and a pressing station assembly hood 46 (having an openable front and/or rear portion for access). The pressed material exits through a slot (not shown) in the hood 46.

Figs. 4a and 4b show the pressing operation. The columns 20 from the upper pressing plate are connected to a base pressing plate 48 within the

housing 6. The base plate 48 is moved by a ram assembly 50 beneath the lower pressing plate 18. Lowering the base plate 48 creates the pressing of the upper and lower pressing plates 16, 18 together. To increase the pressing pressure, hydraulically-operated tapering side arms 52 extend inwardly over roll bars 54 on the upper edges on the base plate 48, giving possibly a 6:1 mechanical increase in pressing pressure.

The pressing station assembly of the present invention provides a means for quick and simple release and attachment of tools (which are usually already housed, inserted or secured to their required tool attachment means). The tools are stili accurately alignable, and are fully supported across their pressing surface. The blister packing apparatus of the present invention can be fully mobile, and is significantly more compact (compared with prior apparatus). The apparatus may therefore be used, located or relocated with significantly fewer problems.