LOADING SYSTEM FOR A FREEZE DRYER

The present invention relates to a loading system for a freeze dryer or the like.

Freeze drying is a process that removes water in the form of ice from a product. In the freeze drying process, the product is frozen and, under vacuum, the ice sublimes and the vapour flows towards a condenser. Ice subsequently condensed on the condenser can be removed in a later stage. Freeze drying is particularly useful in the pharmaceutical industry, as the integrity of the products is preserved during the freeze drying process and product stability can be guaranteed over relatively long periods of time.

Freeze dryers thus typically incorporate a pressure vessel having a freeze drying chamber for receiving a plurality of containers or vials containing the product to be freeze dried. The chamber usually includes a number of shelves, each of which can be raised and lowered within the chamber. To load the shelves, the shelves are initially collapsed in the lower portion of the chamber, and the uppermost shelf is first moved into a loading position. After that shelf has been loaded, the loaded shelf is raised to enable the next shelf to be moved to the loading position. This moving sequence continues until the chamber loading has been completed. To unload the chamber, the loading sequence is reversed, with the lowermost shelf being unloaded first. Access to the chamber for loading and removal of the containers is generally through the main door of the chamber, or through an opening formed in a wall or in the main door of the chamber.

As is common with relatively small freeze dryers, the containers may be manually loaded into the chamber. The containers may be loaded into trays, which can usually accommodate a number of rows of containers, and one or more of these trays are then placed upon each shelf.

The shelves serve to transfer heat between a diathermic fluid such as alcohol, glycol, or silicone oil, and the products to be freeze-dried. During the freeze drying

process, moisture present within the products is frozen. An external refrigeration circuit cools diathermic fluid circulating within the freeze dryer shelves in order to cause heat to be transferred from the products to the diathermic fluid and thereby cause the freezing of the moisture contained within the products. After freezing, the chamber is evacuated to a pressure typically below 1 mbar, and the diathermic fluid is heated by an external heater to cause the ice within the samples to sublimate into water vapour.

The shelves of a freeze dryer are also commonly used to press stoppers into the containers. During the freeze drying process, the stoppers are loosely located on the mouths of the containers to enable the water vapour to sublimate from the samples. Upon completion of the freeze drying process, the shelves are moved relative to each other so that the upper surfaces of the stoppers of the containers located on one shelf contact the lower surface of the shelf thereabove. Continued relative movement of the shelves depresses the stoppers into the containers to form air-tight seals. This has the advantage of sealing the containers within a controlled environment.

As the stoppers are loosely located on the mouths of the containers when the containers are loaded into the chamber, this can pose a safety hazard to an operator manually loading the containers into the freeze dryer, particularly if the contents of the containers are toxic. It is therefore an aim of the present invention to provide a loading system for loading containers into a freeze dryer which reduces the exposure of an operator to the products to be freeze dried.

In a first aspect, the present invention provides a loading system for a freeze dryer or the like, comprising: a plurality of transfer frames each for receiving a batch of containers; transfer frame transportation means moveable between a first loading position at which a loaded transfer frame is moved on to the transportation means, and a second, chamber loading position;

a moveable bridge plate beatable between a shelf of the freeze dryer and the chamber loading position to receive a first loaded transfer frame from the transportation means; means for releasably connecting the first transfer frame to a second transfer frame when the transportation means, bearing the second transfer frame, is returned to the chamber loading position; and means for moving the connected first and second transfer frames on to the shelf of the freeze dryer.

In a second aspect, the present invention provides a loading system for a freeze dryer or the like, comprising: a transfer frame for receiving a batch of containers; transfer frame transportation means for bearing a loaded transfer frame, and being moveable between a first loading position at which a loaded transfer frame is moved on to the transportation means, and a second, chamber loading position; and means carried by the transportation means for releasably engaging a loaded transfer frame, and for moving the engaged transfer frame from the loading position on to the transportation means, and subsequently between the transportation means and a shelf of the freeze dryer.

In a third aspect, the present invention provides a freeze dryer comprising a chamber containing a plurality of shelves, a transfer table for bearing a transfer frame receiving a plurality of containers, and being moveable along rails mounted on the freeze dryer between a first loading position at which a loaded transfer frame is moved on to the table, and a second, chamber loading position from which the loaded transfer frame is moved on to a shelf of the freeze dryer.

Preferred features of the present invention will now be described with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a freeze dryer and a system for loading containers into the freeze dryer;

Figure 2 is a front view of a freeze dryer of Figure 1 , with the front wall partially removed to show the freeze drying chamber, and illustrating loading and unloading transfer stages for containers;

Figure 3 is a top view of the freeze dryer of Figure 1 , with the top wall and front wall partially removed to show an intermediate plate in a deployed position and illustrating various positions of a transport table used to transport containers between the freeze dryer and the transfer stages;

Figure 4 is a close-up of part of Figure 1 to illustrate the transfer loading stage and the transport table in more detail;

Figure 5 is a close-up of part of Figure 2 to illustrate the transfer loading stage in more detail;

Figure 6 is a cross-sectional view of part of the freeze dryer of Figure 1 with the transport table, bearing an empty transfer frame, located opposite to the slot of the freeze dryer and with the intermediate plate in a stowed position;

Figure 7 is a similar view to Figure 6, with the intermediate plate in a deployed position and with loaded transfer frames located on the intermediate plate and the transport table;

Figure 8 is a similar view to Figure 6, and illustrates an example of a mechanism for moving the loaded transfer frames into the freeze dryer, the mechanism being shown in a stowed position;

Figure 9 is a similar view to Figure 8, and illustrates the moving mechanism in a deployed position and with the loaded transfer frames located within the freeze dryer;

Figure 10 is a close-up of part of Figure 8 to illustrate the moving mechanism in more detail;

Figure 11 is a perspective view of a first embodiment of a transfer frame; and

Figure 12 is a perspective view of a second embodiment of a transfer frame.

With reference first to Figures 1 to 5, a freeze dryer 10 comprises a chamber 12 having a slot 14 formed in the front wall 16 of the chamber 12 to enable containers or vials to be loaded into and unloaded from the chamber 12. The slot 14 is selectively opened and closed by a slot door 18 moveable relative to the chamber 12 by a slot door moving mechanism 19. The chamber 12 includes a number of shelves 20, each of which can be raised and lowered within the chamber 12 using a shelf location mechanism.

A system for loading and unloading the chamber 12 is formed from several modules. For pharmaceutical applications the modules will be required to operate in a clean environment such as a clean room or within an isolator cabinet. The loading system enables semi-automated or automated transfer into the freeze dryer 10 of containers received from a filling machine, and semi-automated transfer of those containers from the freeze dryer for subsequent conveyance to labelling and/or capping machines.

The loading system comprises a loading transfer stage 22 for receiving containers containing products to be freeze dried. An in-feed conveyor 24 collects the containers output from a filling machine (not shown), and conveys the containers to an in-feed star wheel or transfer turn table 26. The in-feed conveyor 24 and in-feed star wheel or transfer turn table 26 are mounted on a supporting frame (not

shown) located on, and preferably attached to, the floor 27, and are driven by at least one drive mechanism (e.g. gear box or drive motor) 28. Appropriate guiding ensures a smooth transfer of containers between the in-feed conveyor 24 and the in-feed star wheel or transfer turn table 26.

The in-feed star wheel or transfer turn table 26 serves to position the containers received from the in-feed conveyor 24 on to a linear pusher conveyor 30. The pusher conveyor 30 is mounted on a supporting frame 31 , and is driven by a motor (for example, an AC, DC or servo motor). The speed of the pusher conveyor 30 can be synchronised with the rotational speed of the in-feed star wheel or transfer turn table 26 to ensure a smooth transfer of containers between the in-feed star wheel or transfer turn table 26 and the pusher conveyor 30. Control of the starting, acceleration, deceleration and stopping of the conveyors 24, 30 and the in-feed star wheel or transfer turn table 26 can be used to convey the required number of containers on to the pusher conveyor 30 and to control the pitch of those containers.

A loading pusher pushes a row of containers from the pusher conveyor 30 on to a substantially horizontal loading table 32. With reference also to Figure 4, which illustrates the loading table 32 in more detail, the loading pusher preferably comprises a pusher bar 33a and an actuating mechanism 33b connected to the pusher bar 33a for moving the pusher bar 33a forwards to push a row of containers on to the loading table 32, and for subsequently retracting the pusher bar 33a to enable another row of containers to be accumulated on the pusher conveyor 30. Guide members 34 are provided on the sides of the loading table 32 to prevent containers from falling from the loading table 32 as they are pushed by the pusher bar 33a, and to prevent containers from falling from the end of the pusher conveyor 30.

The loading table 32 is mounted on the supporting frame 31. A mechanism may be provided on the supporting frame 31 for adjusting the vertical position of the loading table 32 to ensure a smooth transfer of containers from the pusher

conveyor 30 on to the loading table 32. For cold shelf loading, the pusher bar 33a may be provided with a mechanism for actuating a safety bar that prevents containers from falling as they are pushed on to the loading table 32. The movement of the in-feed star wheel or transfer turn table 26 and pusher conveyor 30 can be controlled so that each row of containers pushed on to the loading table 32 is laterally displaced from the previous row by an amount equal to one half of the container width. This can enable close packing of the rows of containers located on the loading table 32.

A rectangular container transfer frame 36 for receiving a batch of containers is placed on the loading table 32. If the modules are located in an isolator cabinet, this can be done by an operator located outside the isolator cabinet. The isolator cabinet may be provided with gloves, rather like a glove box, adjacent the transfer stage to enable the operator to manually locate the transfer frame 36 on the loading table 32. Alternatively, the transfer frame 36 may be mechanically lowered on to, or otherwise mechanically placed on, the loading table 32.

With reference to Figures 4 and 5, when the transfer frame 36 is initially mounted on the loading table 32, the transfer frame 36 is positioned on two moveable frame guiding plates 38 each located on or adjacent a respective side of the loading table 32. The frame guiding plates 38 are moveable relative to the loading table 32 between raised and lowered positions. In the raised position (as shown in Figures 4 and 5), the frame guiding plates 38 are positioned at an acute angle θ relative to the loading table 32 to raise the left (as illustrated) side wall 40 of the transfer frame 36 relative to the right (as illustrated) side wall 42 by an amount sufficient to enable containers to be pushed beneath the side wall 40. In the lowered position, the upper surfaces of the frame guiding plates 38 are substantially level with, or below, the upper surface of the loading table 32.

The transfer frame 36 is illustrated in more detail in Figure 11. In this embodiment, the side walls 40, 42 of the transfer frame 36 are both connected to side walls 41 , 43 to define an open rectangular frame 36 for surrounding a batch of containers.

With the transfer frame 36 located in the raised position illustrated in Figures 4 and 5, a first row of containers is pushed by the pusher bar 33a from the pusher conveyor 30 on to the loading table 32. The pusher bar 33a continues to push the row of containers until that row is positioned beneath the transfer frame 36 and so that, when the transfer frame 36 is lowered, the row of containers is surrounded by the transfer frame 36. The row of containers may be pushed by the pusher bar 33a so that the first row of containers in a batch of containers is located adjacent the right (as illustrated) side wall 42, that is, in the position illustrated by arrow 44 in Figure 5, with the second row of containers in that batch being pushed adjacent to that first row. Alternatively, the first row of containers may be pushed by the pusher bar 33a so that the first row is located adjacent the left (as illustrated) side wall 40, that is, in the position illustrated by arrow 46 in Figure 5, with the second row of containers being pushed to that same position, and in doing so pushing the first row of containers towards side wall 42. As another alternative, the batch of containers may be pushed, row by row, on to the loading table 32 with relatively short strokes. Once the batch of containers has been accumulated on the loading table 32, the whole batch is pushed in a single stroke beneath the transfer frame 36.

Once the batch of containers has been accumulated on the loading table 32, the guide plates 38 are moved to the lowered position. This lowers the transfer frame 36 to surround the batch of containers, and thereby load the transfer frame 36. As illustrated in Figures 3 and 5, the loading table 32 has a buffer area 48 located between the pusher conveyor 30 and the guide members 34 so that the pusher bar 33a may continue to load one or more rows of containers from the next batch of containers on to the loading table 32 when the transfer frame 36 has been loaded.

With reference to Figure 4, a holding mechanism 50 is provided for holding the transfer frame 36 when it is mounted on the guiding plates 38. In this embodiment, the holding mechanism 50 comprises a pair of spring-loaded

members 52 located on the guiding plates 38 that engage the transfer frame 36 in a snap-fit when the transfer frame 36 is mounted on the guiding plates 38 so that, when the transfer frame 36 is lowered to surround the batch of containers, the side wall 42 does not raise. When the transfer frame 36 has been fully lowered, the holding mechanism 50 is raised or otherwise moved to release the loaded transfer frame 36. As an alternative to a mechanical holding mechanism, a pneumatic or vacuum suction mechanism may be used to releasably hold the transfer frame 36. As a further alternative, the holding mechanism 50 may be spring-loaded to release the transfer frame 36 when the transfer frame 36 is subsequently removed from the loading table 32.

Returning to Figures 1 to 4, the loading system includes a transport table 60 for transporting a batch of containers from the loading stage to the freeze dryer, and for subsequently transporting a batch of containers from the freeze dryer to an unloading stage. With reference also to Figure 6, the transport table 60 is substantially horizontal, and is connected to a substantially vertical shaft 62 which located within a sleeve 64. The shaft 62 is moveable within the sleeve 64 to adjust the vertical position of the transport table 60 for reasons discussed in more detail below. Any suitable mechanism, for example an arrangement of gears, may be provided for moving the shaft 62 relative to the sleeve 64.

The sleeve 64 is connected to a mechanism for moving the transport table 60 between the loading and unloading stages. In this embodiment, this mechanism is provided by a rail arrangement comprising a pair of vertically spaced, horizontal U-shaped rails 66 connected together by a number of spaced, connecting bars 68. At least two or more of the connecting bars 68 are attached to the freeze dryer 10 by a support frame 70 connected to and extending outwardly from the front wall 16 of the freeze dryer 10. The sleeve 64 is coupled to the rails 66 by a coupling device 71 extending about the sleeve 64. Four pairs of rotatable rollers 72 are mounted on the coupling device 71 so that each pair of rollers 72 engages a respective rail 66 to enable the coupling device 71 to be moved along the rails 66 by any suitable mechanism.

With reference now to Figures 5 and 8 to 10, the transport table 60 is provided with a mechanism for moving a transfer frame 36. In this embodiment, a gripping mechanism 74 is provided for gripping the transfer frame 36, although a pneumatic or vacuum suction mechanism may alternatively be provided for moving the transfer frame 36. The gripping mechanism 74 comprises a pair of gripper heads 76, each gripper head 76 having a downwardly depending lip or finger 78 for engaging the side wall 42 of a transfer frame 36. Each gripper head 76 is pivotally connected via connecting shoe member 79 to a respective chain 80 of linked members. A chain connector 81 is connected to the shoe member 79 for connecting the chain 80 to the shoe member 79. Each chain connector 81 extends through a respective slot 82 formed in the transport table 60, the slots 82 being substantially parallel and serving to guide the movement of the shoe members 79 over the transport table 60.

Each chain 80 is wound around a first sprocket 83 connected to the transport table 60 and around a second sprocket 84 connected to the sleeve 64 or coupling device 71 , each sprocket 83, 84 having teeth for engaging the chain 80 of linked members. Rotation of the sprockets 83, 84 moves the gripper heads 76 over the transport table 60 between a retracted position (illustrated in Figure 8) in which the gripper heads 76 are spaced from a transfer frame 36 located on the transport table 60, and a fully deployed position (illustrated in Figure 9) in which the gripper head 76 is located within the freeze dryer 10. As illustrated in Figure 9, as the chains 80 are unwound, the chain 80 remains located beneath the transfer table 60.

In the retracted position, which is illustrated in more detail in Figure 10, the gripper head 76 is angled so that the finger 78 is vertically positioned above the side wall 42 of a transfer frame 36 located on the transport table 60. When the gripper head 76 is moved towards a transfer frame 36, the leading bottom edge 86 of the gripper head 76 contacts a curved portion 88 of the side wall 42 of the transfer frame 36, so that with continued motion of the gripper head 76 towards the

transfer frame 36, the gripper head 76 rotates (anticlockwise as illustrated) so that the side wall 42 is gripped by the finger 78 of the gripper head 76. As an alternative, the gripper head 76 may be actuated by a pneumatic or electrical circuit.

Figures 1 to 3 and 5 illustrate the transport table 60 docked at the loading stage 22. In this position, the upper surface of the transport table 60 is vertically aligned with the upper surface of the loading table 32. The gripping mechanism 74 is then actuated to move each gripper head 76 towards the loaded transfer frame 36 located on the loading table 32 until the side wall 42 of the transfer frame 36 has been gripped. The gripping mechanism 74 is then actuated in reverse, by reversing the rotation of the sprockets 83, 84, to pull the transfer frame 36, and the batch of containers surrounded by the transfer frame 36, fully on to the transport table 60. With reference to Figure 5, a snapping mechanism 89 (similar to the snapping mechanism 50) may also be provided on the transport table 60 for releasably engaging the transfer frame 36 located on the transport table 60.

Once the loaded transfer frame 36 has been pulled on to the transport table 60, the frame guiding plates 38 may be raised to enable the operator to mount a second transfer frame on to the frame guiding plates 38. The loading pusher may then be actuated to push the rows of containers which have accumulated in the buffer area 48 of the loading table 32 between the frame guiding plates 38 so that a second batch of containers may be rapidly accumulated beneath the second transfer frame.

Before the transport table 60 is moved to a chamber loading position illustrated in Figure 3, the shaft 62 is moved relative to the sleeve 64 to raise the transport table 60 to an elevated position. The transport table 60 is then moved along the U-shaped rails 66 towards the chamber loading position. With reference to Figure 3, depending on the shape and size of the freeze dryer shelf 20, the loading system may have more than one chamber loading position. In this example, the loading system has three chamber loading positions horizontally aligned

side-by-side relative to the front wall 16 of the freeze dryer 10, to enable a "columns" of batches of containers to be loaded on to a shelf 20 of the freeze dryer 10 from each chamber loading position.

With reference now to Figures 1 , 6 and 7, the loading system includes an intermediate bridge plate 100 that enables a loaded transfer frame to be transferred between the transport table 60 and a shelf 20 of the freeze dryer 10. The bridge plate 100 comprises first and second hinged bridge plate portions 102, 104. Depending on the size of the bridge plate 102, guide members 106 or 108 may be provided on the lower surface of the first bridge plate portion 102, at least one of which may be rotatable relative to that bridge plate portion 102. The second bridge plate portion 104 is connected to a pair of arms 110 pivotally mounted to the lower part of the freeze dryer. As illustrated in Figures 1 and 3, pairs of slots 111 are formed in the bridge plate portions 102, 104 so that, when the transport table 60 is docked at one of the chamber loading positions, the slots 111 are aligned with the slots 82 of the transport table 60.

A mechanism (not illustrated) is provided beneath the bridge plate 100 for rotating the bridge plate 100 from a stowed position illustrated in Figures 1 and 6, in which the bridge plate 100 is located fully external to the freeze dryer 10, to a deployed position illustrated in Figure 7 in which the bridge plate portions 102, 104 are co-planar and the bridge plate 100 extends through the slot 14 into the chamber 12 of the freeze dryer 10. A guide plate 112 is mounted within the freeze dryer 10 for guiding the guide elements 106, 108 of the first bridge plate portion 102 as the bridge plate 100 is rotated towards the deployed position to cause the first bridge plate portion 102 to rotate relative to the second bridge plate portion 104 and thereby unfold the two portions of the bridge plate 100. Raised catches 114 are located towards the rear of the guide plate 112 for engaging the guide elements 106, 108 to releasably retain the bridge plate 100 in the deployed position. As shown in Figure 3, the bridge plate 100 has a width which is substantially equal to the width of a shelf 20 of the freeze dryer 10.

With the bridge plate 100 in the deployed position, the transport table 60 is docked at a chamber loading position. The transport table 60 is first positioned, in its elevated position, opposite to the bridge plate 100. In the elevated position, the plane of the transport table 60 is vertically spaced from the plane of the bridge plate 100 by at least the height of a transfer frame 36. The transport table 60 is then lowered, by moving the shaft 62 downwards within the sleeve 64, to dock the transport table 60 in the chamber loading position, in which the transport table 60 is aligned horizontally with the bridge plate 100 and the slots 89 are aligned with slots 111 on the bridge plate 100. The bridge plate 100 and the transport table 60 may have profiled edges that mate together as the transport table 60 is lowered into location with the bridge plate 100.

The gripping mechanism 74 is then actuated to push the loaded transfer frame 36 fully on to the bridge plate 100, preferably such that the side wall 42 is substantially vertically aligned with the right hand (as illustrated) edge of the bridge plate 100, as illustrated in Figure 5. Guide elements 115 may be provided on the sides of the bridge plate portions 102, 104 to prevent a transport frame 36, or any of the containers loaded into that transfer frame 36, from falling from the bridge plate 100. Guide elements 115 also facilitate the alignment of the bridge plate 100 to the shelf 20.

In order to return the transport table 60 to the loading transfer stage 22, the gripping mechanism 74 is first actuated to release the gripper heads 76 from the transfer frame 36. For example, an electromechanical, pneumatic or mechanical release mechanism may be located on one of the gripper head 76 or connecting shoe member 79 to raise the gripper head 76 relative to the transfer frame 36 to disengage the finger 78 from the transfer frame 36.

With the gripper heads 76 released from the transfer frame 36, the gripping mechanism 74 is actuated in reverse, by reversing the rotation of the sprockets 83, 84, to pull the gripper heads 76 back to the retracted position illustrated in Figure 8. The movement of the transport table 60 to the chamber loading position is then

reversed, that is, the transport table 60 is first raised to the elevated position, the transport table 60 is then moved back along the U-shaped rails 66 towards the loading transfer stage 22, and finally the transport table 60 is lowered to dock with the loading table 32 so that the transport table 60 and the loading table 32 are again horizontally aligned. Movement of the transport table 60 may be either manual or automatic.

Once the second transfer frame has been lowered to surround the second batch of containers, the gripping mechanism 74 is actuated as described above to grip the loaded second transfer table, and then pull the loaded second transfer frame on to the transport table 60. As also described above, the transport table 60 is then moved from the loading transfer stage 22 to the same chamber loading position as before. In other words, the transport table 60 is first raised to the elevated position, and then moved along the U-shaped rails 66 before being lowered to dock with the bridge plate 100. Again, as described above, once the second transfer frame has been pulled on to the transport table 60, the frame guiding plates 38 may be raised to enable the operator to mount a third transfer frame on to the frame guiding plates 38. The loading pusher may then be actuated to push the rows of containers which have accumulated in the buffer area 48 of the loading table 32 subsequent to the lowering of the second transfer frame between the frame guiding plates 38 so that a third batch of containers may be rapidly accumulated beneath the third transfer frame.

As illustrated most clearly in Figures 6 and 7, the side wall 40 of each transfer frame 36 has a downwardly depending lip or rim 120, so that as the transport table 60 is lowered to dock with the bridge plate 100, the lip 120 of the second transfer frame is positioned over the side wall 42 of the first transfer frame 36, which is currently positioned on the bridge plate 100, to connect the two transfer frames together.

A shelf 20 of the freeze dryer 10 is raised within the chamber 12, by actuation of the shelf location mechanism, to horizontally align that shelf 20 with the bridge

plate 100. In this example, each shelf 20 has a depth such that the shelf 20 is able to accommodate two batches of containers within each "column", that is, batches of containers are arranged iη a 3 x 2 array on each shelf. Consequently, the gripping mechanism 74 is actuated to push both the first and second transfer frames from the transport table 60 and the bridge plate 100 on the shelf 20, as illustrated in Figure 9.

In the event that the depth of the shelf 20 was such that it could accommodate an additional batch of containers within each column, that is, batches of containers are arranged in a 3 x 3 array on each shelf, then the gripping mechanism 74 would push the first and second transfer frames so that the first transfer frame is positioned on the shelf 20 and the second transfer frame is positioned on the bridge plate 100 for subsequent connection to a third loaded transfer frame as the transport table 60 bearing the third loaded transfer frame is lowered to dock with the bridge plate 100. The connected first to third loaded transfer frames are then pushed by the gripping mechanism 74 so that all three loaded transfer frames are positioned on the shelf 20 of the freeze dryer 10.

Returning to the current example, with the first column of loaded transfer frames now located in the freeze dryer 10, the gripping mechanism 74 is released from the second transfer frame, and is moved back to its retracted position illustrated in Figure 8. The loading sequence described above is repeated to load the third and fourth batches of containers in the second column located immediately to the right (as illustrated) of the first and second batches of containers, and then the fifth and sixth batches of containers in the third column located immediately to the right (as illustrated) of the third and fourth batches of containers, and thereby complete the loading of the shelf 20 of the freeze dryer 10. Once this third column has been loaded, the gripping mechanism 74 is released from the sixth transfer frame, and is moved back to its retracted position. The shelf location mechanism is then actuated to raise the loaded shelf 20 away from the bridge plate 100, and to raise another shelf to dock with the bridge plate 100 to enable that shelf to be loaded.

Once all of the shelves 20, or as many of the shelves 20 as is required, have been loaded, the transfer plate 60 is moved away from its final chamber loading position, and the bridge plate 100 is rotated back to its stowed position to enable the slot door 18 to be lowered to cover the slot 14. The freeze drying process is then conducted within the freeze dryer 10. Upon completion of the freeze drying process, the shelves 20 are moved relative to each other so that the upper surfaces of the stoppers of the containers located on one shelf contact the lower surface of the shelf thereabove. Continued relative movement of the shelves depresses the stoppers into the containers to form air-tight seals.

To unload the containers from the freeze dryer 10, the slot door 18 is first raised to expose the slot 14, and the bridge plate 100 is rotated from its stowed position outside the freeze dryer 10 to the deployed position in which the first and second bridge plate portions 102, 104 are co-planar. The lowermost shelf 20 is then lowered to dock with the bridge plate 100, and the transport table 60 is moved to the third (right hand side) chamber loading position. The gripping mechanism 74 is actuated to move from its retracted position to grip the sixth transfer frame, and then is actuated in reverse to pull the connected fifth and sixth transfer frames out from the freeze dryer 10 to the positions shown in Figure 8, that is, with the fifth transfer frame located on the bridge plate 100 and the sixth transfer frame located on the transport table 60.

The transport table 60 is then raised to its elevated position to disconnect the sixth transfer frame from the fifth transfer frame, and the transport table 60 is moved along the U-shaped rails 66 to the unloading transfer stage 128 (as illustrated in Figures 1 to 3) at which the transport table 60 docks with an unloading table 130 located on a mounting frame 131 such that the transport table 60 and the unloading table 130 are substantially horizontally aligned. The gripping mechanism 74 is then actuated to push the loaded transfer frame from the transport table 60 on to the unloading table 130. The gripping mechanism 74 is released from the transfer frame, and is moved back to a retracted position. The transport table 60 is then moved back to the right hand chamber loading position

to enable the fifth transfer frame, and the batch of containers surrounded thereby, to the unloading transfer stage 128.

The sixth transfer frame is automatically raised, or manually raised by an operator, to expose the sixth batch of containers. If the modules are located within an isolator cabinet, the isolator cabinet may be provided with another pair of gloves adjacent the unloading stage to enable the operator to manually remove the transfer frame from the unloading table 130. This batch of containers is then pushed on to a rotating table 132 to produce a single row of containers which is transported away from the rotating table 132 by an out-feed conveyor 134 to a labelling and/or capping machine. The rotating table 132 and the out-feed conveyor 134 are also mounted on the supporting frame 131 located on, and preferably attached to, the floor 27, and are driven by motors located within or beneath the supporting frame 131. Appropriate guiding 136 ensures a smooth transfer of containers between the unloading table 130, the rotating table 132 and the out-feed conveyor 134 to prevent containers from toppling over or falling from

This unloading sequence is then repeated for each of the fifth to first transfer frames in turn to unload the shelf of the freeze dryer. The unloaded shelf is then lowered, and another shelf is then lowered to dock with the bridge plate 100 to enable that shelf to be unloaded. The unloading sequence is repeated as required until all of the shelves of the freeze dryer 10 have been unloaded.

In summary, a loading system for a freeze dryer or the like comprises a plurality of transfer frames each for surrounding a batch of containers to be loaded into the freeze dryer. A transport table is moveable between a table loading position at which a loaded transfer frame is moved on to the transport table, and a chamber loading position. A moveable bridge plate is positioned between a shelf of the freeze dryer and the chamber loading position to receive a first loaded transfer frame from the transport table. The transfer frames are provided with at least one connecting member to enable the first transfer frame to be connected to a second transfer frame when the transport table, bearing the second transfer frame, is

returned to the chamber loading position. The first and second transfer frames are then moved on to the shelf of the freeze dryer. Use of this system can reduce the space required to accommodate the loading system within an isolator cabinet or clean room area.

Figure 12 illustrates an alternative design for the transfer frame. In this embodiment, the transfer frame 150 comprises a base 152 connected to the side walls 41 , 42, 43. The fourth side wall 154, bearing the lip 120, is removable from the side walls 41 , 43 to enable the containers to be pushed into the base 152 of the transfer frame by the pusher rod 33. This can enable the guiding plates 38 to be omitted, with the transfer frame 150 being placed directly on to the loading table 32 to receive the batch of containers. Once the batch of containers has been loaded on to the transfer frame 150, the side wall 154 is attached to the side walls 41 , 43 to retain the batch of samples within the transfer frame 150 during movement of the transfer frame 150 between the loading transfer stage 22 and the freeze dryer 10, and to enable transfer frames to be connected together.

In the illustrated loading and unloading system, the freeze dryer 10 is both loaded and unloaded through the front wall 16 of the freeze dryer 10. As an alternative, the freeze dryer 10 may be unloaded from the opposite side of the freeze dryer 10. For example, a second slot 14 and slot door 18 may be provided on the rear wall of the freeze dryer 10 opposite to the front wall 16. The set of rails 66 may then extend around the back of the freeze dryer 10 to enable the transfer table 60 to be moved to chamber unloading positions located opposite to the chamber loading positions to enable the transfer frames 36; 150 to be unloaded from the freeze dryer 10 through the second slot 14. In this case, the transfer table 60 would be lowered when a transfer frame 36; 150 is pulled on to the transfer table 60 from a shelf 20 of the freeze dryer 10 to enable that transfer frame 36; 150 to be disconnected from another transfer frame 36; 150.

Each feature disclosed in this specification (which term includes the claims) and/or shown in the drawings may be incorporated in the invention independently of other disclosed and/or illustrated features.