The invention relates to a door arrangement to provide user access to a goods from a machine for dispensing or vending stored items, typically high value retail, pharmaceutical, or industrial goods, in a secure and accountable manner.

A goods dispensing machine may be based on carousel type conveyor mechanisms, in which stored items are located in a train of modules, typically an endless train, of boxes or compartments or shelved compartments fixed to a rotating drive mechanism whereby the stored items are driven to an access point located at a convenient position where the contents of the compartment can be removed. The term 'carousel mechanism', includes like arrangements such as paternoster systems.

A goods dispensing machine may also be based on an array of statically located modular carriers, in which stored items are located on carriers which are retrieved by a transfer system to a convenient access point located at a convenient position where the contents of the compartment can be dispensed.

In this specification reference to 'dispensing' includes like operations such as vending and retailing, unless the context is otherwise.

Prior art systems may be used to vend or retrieve items. In some applications only one item is stored in each compartment or carrier, so that when that compartment or carrier is moved to the access point only the intended item is available for removal. In other applications the compartment or carrier may be sub-divided with internal shelving or dividers to give multiple sub- compartments. In this specification reference to compartment may also comprise reference to a sub-compartment.

It may be necessary in a retail / vending environment, and advantageous in a dispensing application, that stored items are retrieved individually via the access point. A problem arises whereby the access point or access door exposes more than one sub-compartment, and it would be preferable that only the appropriate sub-compartment(s) be revealed. Use of sub-compartments is desirable since storage density can be increased for items which are smaller than the compartment or carrier module.

US-A-6450598 discloses a paternoster type storage and retrieval system having a pair of horizontally movable doors to define an access opening of variable position and size across the width of the paternoster platforms. An outer vertically movable security door is also disclosed, which additionally permits the access opening to be vertically defined in one direction.

The present invention provides an access door system that can be automatically actuated to reveal the entire compartment or carrier, or a single sub-compartment or multiple sub-compartments of a storage system, in particular in a goods dispensing, retailing or vending system. Typically such storage systems include, but are not limited to, carousel /paternoster based systems and carrier based systems. According to the invention there is provided an access door system of a carousel based or carrier based dispensing apparatus, said system comprising multiple individually actuated inner doors, acting in concert with each other and the movement of a carousel or carrier in order to selectively reveal a compartment of the carousel or carrier, said inner doors operating behind an outer closure adapted to reveal the compartment and to allow access to the compartment.

The compartment may be a sub-compartment and is revealed via a see- through outer door, thus permitting the user to confirm that the product to be dispensed is correct prior to opening said see-through outer door. The see- through door is preferably as large as a single compartment or carrier module, and the inner doors restrict access to a smaller sub-compartment which may be selected. The see-through outer door enables a 'confirm purchase' step in a retail environment, thus giving confidence to the customer that the right product has been selected before payment is made.

In a non-vending environment, the see-through door allows the recipient to confirm that the correct product has been selected, thus helping to maintain better inventory control. The see-through outer door may be of any suitable material, such as toughened or armoured glass, or a suitable clear plastics material.

The inner access door system is made from a plurality of moving doors, preferably actuated by electric motor. The doors and the compartment or carrier can preferably be moved to allow any sub-compartment space in any compartment or carrier to be revealed whilst blocking access to the other sub- compartments.

In the invention a compartment or sub-compartment in a carousel / paternoster based system may be presented at the access point by indexing the compartment of interest in the direction of travel of the conveyor mechanism. Similarly a carrier or sub-compartment in a carrier based system may be presented at the access point by the transfer mechanism. Thus a compartment or carrier may have several stopping points between index positions defined by the compartment or carrier module to permit different sub-compartments within the compartment or carrier to be revealed via the see-through outer door.

Compartments of a carousel system or carriers of a carrier based system may be sub-divided in a plurality of common sized sub-compartments or so that there are different sizes of sub-compartment in the same compartment or carrier. All compartments or carriers may be sub-divided in the same way or they may be sub-divided into different ways. Some compartments or carriers may not be sub-divided.

The multiple inner doors may be provided in a single plane, or in multiple adjacent planes. For example a pair of doors may reciprocate across an opening so as to provide complete closure, or to provide an access space of selected width and position. Each door may reciprocate across the full width of the opening in the direction of reciprocation. Another door or pair of doors may be provided in front of or behind the first pair and having typically, but not exclusively, orthogonal directions of reciprocation. The maximum opening defined by the inner doors preferably comprises the module defined by the carrier or compartment of the dispensing apparatus.

The moving doors may move to various positions so as to define an opening of selected size and position. The stop positions may be fixed and determined by sensors or latches or they may be infinitely variable and determined by a position feedback arrangement. Thus a compartment or carrier may be wholly revealed by full retraction of the doors, or may be partially revealed by selected movement of one or more doors. The invention permits a compartment or carrier to be sub-divided into smaller sub-compartments according to the size of items to be dispensed. This provides for better utilisation of a storage /retrieval conveyor system having successive compartments of fixed size. The moving doors may open to reveal the entire internal space within a compartment or carrier but leave one or more edges obstructed or covered. This allows a user to gain access to the entire compartment or carrier but not reach past the edge of the selected compartment or carrier or remove the compartment or carrier through it.

The compartment or carrier may comprise or contain a box-like pod, within which are placed items to be retrieved. The inner doors may be positioned to allow the user to gain access to the box-like pod but not remove it, or the doors may be positioned to enable the box-like pod to be removed through it. The box-like pod may be an open fronted box facing the access point. It may have features that display a particular item favourably so it may need to be replaced if the item stored changes. The box-like pod may also be replaced for the purpose of quick restocking.

The moving doors may open beyond the edges of the compartment or carrier to provide access to fully remove the entire compartment or carrier from the system for the purpose of maintenance or quick substitution of a sub-divided compartment or carrier with a full stocked replacement.

Each door has a profile on the leading edge that moves across the access point. The profile on any door may be linear or non-linear. A linear profile may be perpendicular to the direction of reciprocation of the door or may be at an angle. A non-linear profile may be for aesthetic reasons. The edge profiles preferably meet to define a complete closure.

In one embodiment the profile of a closing edge of one or more doors may be non-linear to provide increased access, for example for finger access, to a specific compartment, carrier or sub-compartment to make removal of a product easier. Such a feature may be useful where storage density is high, and sub-compartments are small.

The doors may be actuated by one or more mechanisms. The mechanisms may include, but are not limited to, chains, belts, linkages, racks and pinions, ropes or a lever.

The mechanisms may be activated by one or more actuators or manually. The actuators may include, but are not limited to, electric motors, pneumatic pistons or motors or solenoids.

The actuators are preferably controlled by a control system. The control system may consist of, but is not limited to, a PC, a PLC, a microcontroller or PIC processor. Other items in the control system may include, but are not limited to, frequency inverters for AC motor control, stepper motor controllers, encoders for position and speed feedback, relays and sensors. The control system may also include a software programme that will receive instructions about which compartment or carrier and sub-compartment to access and will send instructions or signals to activate the actuators. The control system can rely upon any conventional technology and forms no part of the present invention. The doors can be constructed in a number of ways including, but not limited to, solid panels, multiple slats or bars placed in a row, or semi flexible material such as spring steel.

Guides may be used to control the path of movement of the doors. The paths may be linear or curved. Curved paths will enable the doors to retract around the side of the storage system to limit the dimensions of the system at the access point.

Preferably a curved door is constructed from parallel standard pitch chains with link attachments, and individual slots suspended between the chains. Running the chains around the periphery of the dispensing machine enables a slim profile door arrangement to be achieved, as the entire door or doors can be articulated to the back of the dispensing machine. The arrangement permits almost the entire width of the machine to be available for dispensing, and avoids the width restriction imposed by roller shutter and like systems where opening width is restricted by the largest diameter of the or each roller, in use.

Preferably an outer security door is provided. The outer door may lie in a plane parallel to the plane of the inner doors and see-through door, and immediately adjacent thereto. By providing a single outer security door for the access point that covers the plurality of moving inner doors, the risk of theft and vandalism is reduced. The see-through door prevents the user from reaching the inner doors or the compartment of the conveyor or the transfer mechanism of the carrier array while they are moving and is thus a safety feature. This allows the inner doors or the compartments or carriers to be freely moved to their required positions to provide access to the selected compartment or carrier or sub-compartment. Once the inner doors or compartment or carrier are in position they can be rendered immobile and the outer security door can be opened for viewing through the see-through door. The inner doors or the compartments or carriers can be made immobile by means of a safety function such as, but not limited to, a sensor, a switch, an actuator or a mechanical interlock.

The see-through door may be opened and closed by an actuated means or manually, or opened by an actuated means or manually but closed by a non actuated means such as, but not limited to, a counterbalance or spring. This reduces the risk of injury to the user from movement of this door.

The see-through door and/or inner doors provides a security function. By providing a barrier across the access point unauthorised access is prevented. The see-through door can be locked by a suitable device which may be, but not limited to, a latch, a pin, a solenoid or an electromechanical mechanism to provide a higher level of security against unauthorised access.

It is important to allow the user to confirm that the contents of the selected sub-compartment are the intended item. To enable this, the compartment, carrier or sub-compartment space is visible through the see-through door before it opens or is released to be opened. The see-through outer door may be a clear panel such as glass or may comprise a window in a door frame, or may itself comprise an outer security door.

The see-through door may comprise a material which is switchable between opaque and clear conditions, such as an electrically switchable smart glass or plastic of any suitable configuration. In a preferred embodiment opening of the inner doors automatically activates a light to enable better inspection of the selected compartment. The light may alternatively activate in response to an opaque door changing to a clear state, and vice versa.

The present invention will now be described by way of an example only of an application to a carousel based storage /retrieval system with reference to the accompanying schematic drawings.

Figure 1 shows storage compartment 1 sub-divided in one particular pattern into smaller sub-compartments, one of which is identified as 2. The storage compartment is typically but not exclusively 300 mm high x 300 mm wide x 100 mm deep. A series of such compartments are provided in an endless sequence, and some compartments may be divided differently, or not at all.

Figure 2 shows four independently actuated doors 3, 4, 5 and 6, all in the fully open position. Figure 3 shows the four doors 3, 4, 5 and 6, as shown in Figure 2 moved together to individual positions to provide a restricted aperture. The doors are in reciprocating pairs, and arranged in two immediately adjacent planes. Either pair of doors can be brought together to close the aperture. Figure 4 shows the four doors 3, 4, 5 and 6, closed together as in Figure 3, with the compartment 1 shown in Figure 1 , in position behind them. Access is restricted to the sub-compartment 2. It will be readily understood that the doors 3, 4, 5 and 6 may also be positioned to restrict access to any other of the sub-compartments of Figure 1 , or several of them.

Figure 5 shows four independently actuated doors 3, 4, 5 and 6, in the fully open position behind an outer see-through door 7 which is shown in the fully closed position. The door is of for example of 4 mm or 6 mm laminated glass. Figure 6 shows the four doors 3, 4, 5 and 6, moved together to individual positions to provide a restricted aperture, behind the outer door 7 which is shown in the closed position. The outer door 7 can be hinged or sliding, and have more than one leaf.

Figure 7 shows the four doors 3, 4, 5 and 6, partially closed together as shown in Figure 6, with the compartment 1 shown in Figure 1 , in position behind them. Access is limited to the sub-compartment space 2. The outer door 7 is moved partially downward to reveal the compartment space 2.

Figure 8 shows an alternative arrangement where three independently actuated doors 3, 4, and 5, are in the fully open position, with a fixed edge 8, behind the outer door 7 which is shown in the closed position.

Figure 9 shows the three independently actuated doors 3, 4, and 5, shown in Figure 8, moved together to individual positions, which combined with the fixed edge 8, provide a restricted aperture. The outer door 7 is shown in the closed position.

Figure 10 shows the three independently actuated doors 3, 4, and 5, closed together as shown in Figure 9, with the compartment 1 shown in Figure 1 , in position behind them. Access is restricted to the sub-compartment 2. It will be readily understood that the doors 3, 4, 5 and 6 may also be positioned to restrict access to any other of the sub-compartments of Figure 1 , or several of them. The outer door 7 is shown open. This alternative arrangement has fewer moving doors, but a correspondingly simpler mechanism with reduced headroom for door reciprocation. The arrangement illustrates that the carousel conveyor may run close to one edge of the aperture of a door access system. Figure 11 shows a number of compartments arranged on a carousel with access doors positioned in front of a storage compartment. The outer casing is omitted. Figure 11 shows an embodiment of the invention with four moveable doors 3, 4, 5 and 6 and one outer door 7. The doors are located in front of a carousel 9 of moveable compartments 1. Doors 3 and 4 are guided so that they move perpendicular to the direction of movement of the compartments 1 located on the carousel 9. Doors 5 and 6 are guided so that they move parallel to the movement of the compartment 1 located on the carousel 9.

The four moveable doors 3, 4, 5 and 6 are controlled by electric motors. The outer door 7 is opened by an electric motor and closed by a counterweight. The carousel 9 is controlled by an electric motor. The position of each element is co-ordinated and controlled by a computerised control system to ensure that each compartment stops at the opening as required, and that the inner doors open to reveal only the compartment or sub-compartment of interest. When the outer door 7 is closed the safety function for the machine will enable the four moveable doors 3, 4, 5 and 6 to be moved. The safety function will detect when the outer door 7 is opened and will prevent the four moveable doors 3, 4, 5 and 6 from being moved, rendering the access point safe for the user to reach into. Any appropriate interlock mechanism may be used.

The outer door 7 is made from a transparent material. This will enable the user to visually check that the item located in the exposed sub-compartment 2 is the required item. The user can confirm to the computerised control system that the item located in the exposed sub-compartment is the required item. Once this confirmation is received the computerised control will open the outer door 7 so the user can remove the item. This avoids erroneous or unwanted items being dispensed. Figure 12 shows the arrangement shown in Figure 1 1 but with the outer casing 10 in place.

In Figure 12 the moveable doors 3, 4, 5 and 6 and the outer door 7 can be seen through the access point 1 1. The moveable doors 3, 4, 5 and 6 are positioned to expose the selected sub-compartment 2. The outer door 7 is shown open. The selected sub-compartment 2 is the only sub-compartment that can be accessed. Figure 13 shows the carousel 9 with the access door system comprising doors 3, 4, 5, 6 and 7 in a different orientation.

Figure 14 shows an alternative embodiment of the invention for a vertically moving carousel where one door is constructed from a chain of slats 12 that are guided round a curved track by an upper guide 13 and a lower guide 14. The curved track guides the slats around the side of the carousel. The other doors are similar to previous examples with door 4 opposing the slated door 12 and door 5 working in an orthogonal direction to the chain of slats 12 and door 4. The outer door 7 is shown closed.

Figure 15 shows top view of the door system shown in Figure 14. The upper guide 13 is shown guiding the chain of slats 12 around the corner.

Figure 16 shows the independently actuated doors 4 and 5 and the chain of slats 12 closed together with the compartment 1 shown in Figure 1 , in position behind them. Access is restricted to the sub-compartment 2. It will be readily understood that the doors 4 and 5 and the chain of slats 12 may also be positioned to restrict access to any other of the sub-compartments of Figure 1 , or several of them. The outer door 7 is shown open. This arrangement allows the outer case of a machine to be located much closer to the carousel so the unit will occupy a smaller foot print. Figure 17 shows an alternative arrangement where three independently actuated doors 3, 4, and 5, are in the fully open position, with a fixed edge 8, behind the outer door 7 which is shown in the closed position. Doors 3 and 4 have a non-linear profiled edge with cut-outs 15. Door 5 is has a linear profiled edge.

Figure 18 shows the three independently actuated doors 3, 4, and 5, shown in Figure 8, moved together to individual positions, which combined with the fixed edge 8, provide a restricted aperture. The outer door 7 is shown in the closed position.

Figure 19 shows the three independently actuated doors 3, 4, and 5, closed together as shown in Figure 18, with the compartment 1 shown in Figure 1 , in position behind them. Access is restricted to the sub-compartment 2. The cut-outs 15 provide additional access to remove the product from the sub- compartment 2. The outer door 7 is shown open. The cut-outs may be revealed as the inner doors move to the open condition, so that when closed there is no access to the sub-compartment 2.