GB2487726A

GB2487726A - Stacking bank notes in a cassette for an ATM

Info

Publication number: GB2487726A
Application number: GB1101455.2A
Authority: GB
Inventors: Robert Wright
Original assignee: Cash Dynamics LLP
Current assignee: Cash Dynamics LLP
Priority date: 2011-01-28
Filing date: 2011-01-28
Publication date: 2012-08-08
Also published as: GB201101455D0

Abstract

A device for stacking sheet documents 31 such as bank notes onto a stack 32 extending along a stacking axis 34 in a container 21 such as a cassette for an ATM comprises a sheet document input 7, 8b, 9b spaced apart from the top of the stack 32 in a direction parallel to the stacking axis 34; and at least one stacking member 15b to which the sheet documents 31 are fed from the sheet document input 7, 8b, 9b along a feeding direction, the stacking member 15b being closer to the top of the stack 32 in the direction parallel to the stacking axis 34 than the sheet document input 7, 8b, 9b, such that a first portion of the sheet document passing the stacking member 15b is bent by the stacking member 15b from the feeding direction to a direction parallel to the stack 32 and is thereby positioned on the stack 32. The trailing edge of a document 31 flicks down onto the stack 32 as it is released from the sheet document input 7, 8b, 9b. The stacking member 15b may float on the stack 32 to accommodate growth of the stack and the container 21 and/or input may be moved by a drive system 2, 3, 4 to maintain the input above the top of the stack 32. A removable liner 25 (fig. 3) may be inserted in cassette 21 whilst it is filled with the stack 32 of bank notes 31.

Description

I

SHEET DOCUMENT STACKING

This invention relates to a device and method for stacking sheet documents in a cassette.

There are many instances where cassettes are used to store sheet documents. They are used particularly in cash handling applications. For example, the banknotes dispensed by an automatic teller machine (ATM) are loaded into secure cassettes at a cash handling site, transported to the ATM and the cassette is installed in the ATM so that the banknotes can be dispensed.

At the cash handling site, banknotes are typically sorted and counted by specialised banknote processing equipment, which discards any counterfeit or damaged banknotes and sorts the good, useable banknotes into separate pockets depending on their denomination. The banknotes are withdrawn from the pockets and placed into the cassettes manually. The process is therefore is labour intensive due to the requirement to load the cassettes manually.

Furthermore, despite the fact that the banknote processing is carefully audited and scrutinised by camera, an opportunity for pilfering exists.

Previous attempts to automate the loading of the cassettes by machine have not been particularly fruitful. It is generally difficult to form a neat stack of banknotes (as can easily be done by hand) with standard sheet document processing equipment due to the problems of operating within the confined environment of the cassette itself. Transfer of the banknotes from the pockets of the sorting equipment to the cassettes using robotic arms has been considered, but it is not cost-effective to purchase, set-up, and maintain the robotic arms, and so the manual method prevails.

In accordance with a first aspect of the invention, there is provided a device for stacking sheet documents onto a stack extending along a stacking axis in a container, the device comprising a sheet document input spaced apart from the top of the stack in a direction parallel to the stacking axis; and at least one stacking member to which the sheet documents are fed from the sheet document input along a feeding direction, the or each stacking member being closer to the top of the stack in the direction parallel to the stacking axis than the sheet document input, wherein a first portion of the sheet document passing the or each stacking member is bent by the or each stacking member from the feeding direction to a direction parallel to the stack and is thereby positioned on the stack.

By arranging the stacking members closer to the top of the stack in the direction parallel to the stacking axis than the sheet document input, the feeding direction is naturally inclined towards the stack. Thus, as the sheet documents pass the stacking members and are positioned on the stack, they are bent as a result of diverting into the direction parallel to the stack. This bend causes the trailing edge of the sheet documents to flick downwards rapidly onto the stack, thereby clearing the path for the next document and overcoming the problem of forming a neat stack of sheet documents within a is cassette.

Therefore, in conjunction with other processing machinery (such as that described in our co-pending application PCT/GB2O1O/051613) capable of automatically removing banknotes from the output pockets of sorting equipment, we can provide an automatic mechanism for transferring banknotes from sorting equipment to cassettes for ATMs.

In one embodiment, the container is a cassette for storing sheet documents, such as a cassette for ATMs.

Typically, the sheet documents are security documents, such as banknotes.

It will be appreciated that the stacking axis is perpendicular to the stack.

Preferably, when the first portion of the sheet document has passed the or each stacking member, the trailing edge of the sheet document is released from the sheet document input such that a second portion of the sheet document between the trailing edge and the or each stacking member flicks down onto the stack.

If the sheet documents are to be fed with their long edge first then the sheet document input may be separated from the or each stacking member by a distance less than the short edge dimension of the sheet documents.

Alternatively, the sheet documents may be fed with their short edge first, in which case the receiving and stacking ends may be separated by a distance less than the long edge dimension of the sheet documents.

The sheet document input typically comprises at least one drive roller.

Preferably, the device further comprises at least one auxiliary roller, the or each auxiliary roller forming a nip with a respective one of the or each drive roller. These auxiliary rollers normally protrude through a receiving plate on which the sheet documents are received from upstream processing machinery by the device.

Normally, the at least one drive roller comprises a pair of drive rollers spaced apart along an input drive shaft.

is In a preferred embodiment, the or each stacking member is a stacking roller having a higher coefficient of friction than the or each drive roller. This ensures, when the sheet document input and the or each stacking member are separated by a distance less than the relevant edge dimension of the sheet documents, that the notes are driven under tension onto the stack. Preferably, the coefficient of friction of the stacking rollers will be selected such that the stacking rollers are capable of gripping the sheet documents to drive them onto the stack, but is not so high that they cannot slip against the sheet documents; some slippage is necessary to prevent disruption of sheet documents already placed on the stack. The coefficient of friction of the drive rollers merely needs to be high enough to drive the sheet documents along the feeding direction towards the stacking rollers.

The stacking member should be as close as possible to the top of the stack, although it can rise a short distance above it (depending on the thickness of the sheet documents) without affecting the performance of the device.

Preferably, the stacking member is in contact with the top of the stack. In one embodiment, the or each stacking member is advantageously floating on the stack such that it can move away from the stack to accommodate sheet documents being positioned on the stack.

The or each stacking member of the feeder may be urged against the stack by its own weight under gravity, or by a spring.

The or each stacking member may be suspended on a carriage, which is rotatable around a shaft on which the or each drive roller is mounted. This is one way of achieving the floating effect mentioned above.

Typically, the at least one stacking member comprises a pair of stacking rollers spaced apart along a stacking drive shaft.

In one embodiment, the feeding direction is defined by a guide extending from the sheet document input to the or each stacking member.

The guide typically comprises at least one guide belt coupling the or each drive is roller to the or each stacking member. The belts could be entrained around the drive rollers and stacking members directly, in which case they will act as driving elements themselves. However, they will normally be entrained around toothed pulleys coupled to the drive rollers and stacking members. The belts therefore can be used to provide a driving force to the stacking members, and due to the toothed pulleys there will be no slippage.

As sheet documents are added to the stack, the stack begins to occupy significant space along the stacking axis such that the distance by which the sheet document input is spaced apart from the top of the stack in the direction parallel to the stacking axis is diminished. Eventually, this will affect the performance of the stacking. Therefore, in a preferred embodiment, the device further comprises a drive system adapted to move the container and/or the sheet document input along or parallel to the stacking axis to maintain the distance by which the sheet document input is spaced apart from the top of the stack in the direction parallel to the stacking axis above a predetermined threshold.

Typically, the drive system comprises a motor coupled to the container, preferably via a lead screw or a drive belt.

in one variant, the drive system comprises a sensor adapted to generate an output signal when the distance by which the sheet document input is spaced apart from the top of the stack in the direction parallel to the stacking axis falls below the predetermined threshold, and a controller adapted to respond to the output signal by actuating the motor for a predetermined duration, whereby the io container and/or the sheet document input moves along or parallel to the stacking axis such that the distance by which the sheet document input is spaced apart from the top of the stack in the direction parallel to the stacking axis is increased.

One way in which the sensor can detect when the distance by which the sheet is document input is spaced apart from the top of the stack in the direction parallel to the stacking axis falls below the predetermined threshold is by arranging for a switch to be actuated when the carriage referred to above has rotated around the shaft on which the or each drive roller is mounted by a predetermined amount. The switch may be actuated by a cam coupled to the carriage, the cam having a profile adapted to actuate the switch at the point where the shaft on which the or each drive roller is mounted has rotated by the predetermined amount.

This variant represents a simple approach of maintaining distance by which the sheet document input is spaced apart from the top of the stack in the direction parallel to the stacking axis within acceptable limits. The predetermined duration will be chosen to increase the distance by which the sheet document input is spaced apart from the top of the stack in the direction parallel to the stacking axis by a fixed amount each time it falls below the predetermined threshold.

In an alternative approach, a sensor that provides an output signal directly representing the distance by which the sheet document input is spaced apart from the top of the stack in the direction parallel to the stacking axis could be used, the controller responding to this output signal by actuating the motor to move the cassette and/or the feeder along or parallel to the stacking axis such that the output signai from the sensor is maintained between predefined limits.

In this way, the distance by which the sheet document input is spaced apart from the top of the stack in the direction parallel to the stacking axis is maintained within the predefined limits. This alternative is a continuous adjustment process, but is more complicated to implement.

Typically, the device further comprises a support for holding the container.

The support preferably comprises a platform having a pair of retaining members with which a tab on a container liner can be engaged, thereby holding the container in position.

is If used, the liner provides smooth walls against which the stacking of sheet documents can be carried out. This can be beneficial as the interiors of containers such as ATM cassettes are often provided with protruding features that can snare sheet documents as they are fed into the cassettes. The liner is removed once the stacking process is completed.

Thus, in accordance with a second aspect of the invention, there is provided a kit comprising a device according to the first aspect of the invention and a liner having a portion adapted for insertion into a container and a portion adapted for engaging with the device.

If the width of the liner is similar to an edge dimension of the sheet documents then it provides a simple way of guiding and centralising the documents within the container.

The interior of the liner is preferably entirely smooth.

The liner advantageously comprises a hinge to enable the portion of the liner adapted for insertion into the container to rotate relative to the portion adapted for engaging with the device.

In accordance with a third aspect of the invention, there is provided a method for stacking sheet documents onto a stack extending along a stacking axis in a container, the method comprising feeding sheet documents from a sheet document input, spaced apart from the top of the stack in a direction parallel to the stacking axis, along a feeding direction, to at least one stacking member, the or each stacking member being closer to the top of the stack in the direction parallel to the stacking axis than the sheet document input, and bending a first portion of the sheet document passing the or each stacking member from the feeding direction to a direction parallel to the stack, the sheet document thereby being positioned on the stack.

Preferably, the method further comprises releasing the trailing edge of the is sheet document from the sheet document input when the first portion of the sheet document has passed the or each stacking member such that a second portion of the sheet document between the trailing edge and the or each stacking member flicks down onto the stack.

In one embodiment, the method further comprises moving the container and/or the sheet document input along or parallel to the stacking axis to maintain the distance by which the sheet document input is spaced apart from the top of the stack in the direction parallel to the stacking axis above a predetermined threshold.

Typically, the container and/or sheet document is moved along or parallel to the stacking axis for a predetermined duration such that the distance by which the sheet document input is spaced apart from the top of the stack in the direction parallel to the stacking axis is increased when the distance by which the sheet document input is spaced apart from the top of the stack in the direction parallel to the stacking axis falls below the predetermined threshold.

An embodiment of the invention will now be described with reference to the accompanying drawings, in which: Figure 1 shows a perspective view of a device for stacking sheet documents in a cassette according to the invention; s Figure 2 shows a cross-sectional view of the device; Figure 3 shows a cassette and cassette liner; and Figure 4 shows a perspective view of the device and cassette together.

Figures 1 and 2 show a device for stacking sheet documents in a cassette in perspective and cross-sectional views. The device is built on an L-shaped base 1. A lift motor 2 is mounted on the L-shaped base I and coupled via a gearbox 3 (which transmits the torque developed by motor 2 through a right angle) and lead screw 4 to a platform 5.

The platform 5 acts as a support for a cassette. The platform 5 is provided with retaining members 6a, 6b, which engage with a liner for a cassette to hold the cassette in place. This is explained in detail below.

Thus, by driving the motor 2 it is possible to raise and lower the platform 5 to adjust the height of a cassette mounted on the platform 5 relative to a feeder assembly, which will be described below.

The lead screw 4 may be replaced in other embodiments by a belt drive, for example. In this case, the belt will be entrained around a pulley on the rotor of motor 2 and an auxiliary pulley and clamped to the platform 5 such that rotation of the motor 2 causes a linear vertical movement of the belt and platform 5.

The feeder assembly comprises a receiving plate 7 on which sheet documents can be fed into the feeder assembly. A pair of auxiliary rollers 8a, 8b protrudes through apertures in the receiving plate 7 to form nips with a pair of driving rollers 9a, 9b. The auxiliary rollers 8a, 8b are mounted on a shaft 10, and the driving rollers 9a, 9b are mounted on a shaft 11. The two shafts 10, 11 are coupled together by a gear mechanism (not shown) to contra-rotate at the same speed. The gear mechanism is driven by a feeder drive motor (not shown).

The shaft 11 also bears a carriage 12, which is rotatably mounted on the shaft 11. At the other end of the carriage 12, a shaft 13 is suspended, on which stacking rollers 14a, 14b are mounted. A pair of toothed belts 15a, 15b is entrained around pulleys 16a, 16b mounted on shaft 11 and pulleys 17a, 17b mounted on shaft 13. Thus, rotational motion of shaft 11 is coupled to shaft 13, and the stacking rollers 14a, 14b rotate at the same speed as driving rollers 9a, 9b.

An arm 18 couples the carriage 12 to a cam 19, the profile of which is adapted to actuate a limit switch 20 when the carriage 12 has rotated around shaft 11 by a predetermined amount.

A cassette 21 is shown in Figure 3. As can be seen, the cassette 21 has a number of features on its interior that could snare or interfere with sheet documents being loaded into the cassette. These include the edges of the aperture 22 in the base of cassette 21 and the ribs 23a, 23b, 23c, 23d on the side wall. The back wall 24 of cassette 21 is free of any such problematic features. A liner 25 is used to cover the interior walls of the cassette so that the problematic features cannot interfere with the sheet documents during loading of the cassette 21.

The liner 25 has smooth side walls and no back wall. Thus, when it is in position within the cassette 21, it is still possible for sheet documents to be stacked against the back wall 24 of the cassette 21. It is also possible to withdraw the liner 25 from the cassette 21 after it has been loaded with sheet documents. A handle 26 is provided to enable the liner 25 to be withdrawn from the cassette 21.

To insert the liner 25 into cassette 21, the liner 25 is pushed onto cassette 21 50 that a recess 27 formed in the base of the liner 25 receives the base 28 of the cassette 21. The base 28 is a friction fit in the recess 27 to prevent the cassette 21 accidentally separating from the liner 25.

The base of the liner 25 is joined via a hinge 29 to a tab, which enables the liner 25 to be mounted on the platform 5. A narrower portion 30a of the tab is adapted to co-operate with the retaining members 6a, 6b on platform 5 by sliding into an undercut in each of the retaining members 6a, 6b. The wider portion 30b is adapted to bear against the retaining members 6a, 6b to prevent the cassette 21 and liner 25 combination being pushed too far onto the platform 5.

io The hinge 29 enables the body of the liner 25 to rotate relative to the tab. This enables the cassette 21 to be placed on its back after stacking to reduce the possibility of the contents being accidentally tipped out. Whilst the cassette 21 is on its back, the liner 25 can be withdrawn and a lid placed on the cassette 21 to secure the stack.

Figure 4 shows the cassette 21 and liner 25 combination mounted on the platform 5 of the device shown in Figures 1 and 2. As can be seen the result is that the carriage 12 and stacking rollers 14a, 14b protrude into the cassette 21.

Sheet documents, such as banknotes, placed on the receiving plate 7 between the nip between driving rollers 9a, 9b and auxiliary rollers 8a, 8b (which act as a sheet document input) are therefore advanced underneath carriage 12 towards stacking rollers 14a, 14b. As mentioned above, in the case of ban knote processing, banknotes may be withdrawn from the output pockets of sorting machinery and transported to the receiving plate 7 using the equipment described in our co-pending patent application PCT/GB2OIO/051613.

The formation of a stack of sheet documents is best seen in Figure 2. A sheet document 31 is shown being driven through the nip between driving rollers 9a, 9b and auxiliary rollers 8a, 8b. The sheet document 31 is driven horizontally by the driving rollers 9a, 9b, but is diverted from the horizontal along a feeding path by guide belts ISa, 15b towards a stack 32 of sheet documents as it advances along the underside of the carriage 12.

The note advances substantially parallel to the guide belts 15a, 15b. The sheet document 31 eventually reaches the stacking rollers 14a, 14b. The separation between the driving rollers 14a, 14b and driving rollers 9a, 9b is less than the short edge dimension of the sheet document 31 so that the sheet document 32 is picked up by stacking rollers 14a, 14b before it is released by the nip between driving rollers ga, 9b and auxiliary roilers 8a, 8b.

The stacking rollers 14a, 14b are urged in a clockwise direction towards the stack 32 by their own weight (although, in other embodiments, a spring may be used to urge the stacking rollers 14a, 14b in this way). Thus, they drive the sheet document 31 over the stack 32 and hold the sheet document 31 in place on the stack 32. As they do this, the stacking rollers 14a, 14b bend the sheet document 31 from the feeding direction parallel to the guide belts 15a, 15b to a direction parallel to the stack 32.

The sheet document 31 is then released from the driving rollers 9a, 9b and is auxiliary rollers 8a, 8b. Due to the bend imparted by the stacking rollers 14a, 14b, the trailing edge of the sheet document 31 just released from the driving rollers 9a, 9b will flick downwards onto the stack 32. The sheet document 32 is therefore positioned neatly on the stack 32. This also clears the space between the top of the stack 32 and the driving rollers 9a, 9b for the next sheet document to be fed without risk of collision.

The driving rollers 9a, 9b are typically made of a relatively low friction material such as PTFE or Viton®. The stacking rollersl4a, 14b are typically made of a material with a higher coefficient of friction than driving rollers 9a, 9b. This ensures that the sheet document 31 is driven under tension onto the stack 32, which leads to a well-controlled and accurate placement on the stack 32. The material of stacking rollers 14a, 14b should not have a coefficient of friction that is so high that it cannot slip over sheet documents already in the stack 32 as this would otherwise disrupt such documents. We have found that nitrile

rubber is suitable.

The carriage 12 is free to rotate around the shaft 11, and so as the sheet document 31 is placed on the stack 32 and the stack 32 increases in height, the carriage 12 is forced to rotate in an anticlockwise direction to accommodate the sheet document 31. Eventually, the cam 19, which is coupled to the carriage 12, will rotate to the point where a larger radius section of the cam profiie acutates the limit switch 20. The profile of the cam is selected so that the larger radius section actuates the limit switch when the distance between the sheet document input (defined by the nip between driving rollers 9a, 9b and auxiliary rollers 8a, 8b) and the top of the stack 32 falls below a threshold value. A typical value for this distance which has been found to work reliably is 10mm. Of course different types of sheet document may require a different threshold to be set.

The limit switch 20 is coupled to a controller (not shown). The controller responds to actuation of the limit switch by driving motor 2 such that the is platform 5 is lowered by a predefined amount. This predefined amount is controlled by driving the motor 2 for a set period of time, which may be controlled by a programmable microcontroller or a simple timer circuit in the controller. We have found that a suitable distance to lower the platform 5 is 10mm. This ensures that the distance between the sheet document input and the top of the stack 32 remains within a range of 10mm to 20mm.

As the platform 5 is lowered, the cassette 21 and stack 32 are lowered too.

Since the stacking rollers 14a, 14b are urged in a clockwise direction towards the stack 32 they will rotate clockwise to bear against the stack 32 as the platform is lowered 5. This has the effect of increasing the inclination of the feeding path defined by the guide belts iSa, 15b so that the sheet documents are adequately bent as they pass the stacking rollers 14a, 14b to ensure that the flicking effect is produced for neat stacking.

As can be appreciated, the platform 5 and cassette 21 are lowered in steps as the stack of documents 32 is formed. Each step of lowering the platform 5 occurs when the distance between the sheet document input and the top of the stack 32 falls below the threshold mentioned above, and in this way a large stack 32 of sheet documents can be neatly formed within the cassette 21. The cassette 21 and liner 25 may then be removed from the device and the liner 25 withdrawn from cassette 21, which is then closed ready for onward transport, for example to an ATM.

In other embodiments, the controller may inhibit operation of the driving motor that drives the driving rollers 9a, 9b and stacking rollers 14a, 14b whilst the platform 5 is being lowered to prevent sheet documents being fed towards the stack 32 at that time. An electrical output signal may be provided for communication with upstream processing equipment to enable that to be brought to a stop at the same time.

It is also possible to provide a sensor, typically an optical sensor, in the receiving plate 7, which detects the presence of a sheet document over the receiving plate 7. This sensor will be coupled to the controller so that the controller may respond to its output such that the driving motor that drives the is driving rollers 9a, 9b and stacking rollers 14a, 14b is only actuated when a sheet document is detected.

Claims

CLAIMS1. A device for stacking sheet documents onto a stack extending along a stacking axis in a container, the device comprising a sheet document input spaced apart from the top of the stack in a direction parallel to the stacking axis; and at least one stacking member to which the sheet documents are fed from the sheet document input along a feeding direction, the or each stacking member being closer to the top of the stack in the direction parallel to the stacking axis than the sheet document input, wherein a first portion of the sheet document passing the or each stacking member is bent by the or each stacking member from the feeding direction to a direction parallel to the stack and is thereby positioned on the stack.
2. A device according to claim 1, wherein when the first portion of the sheet document has passed the or each stacking member, the trailing edge of the sheet document is released from the sheet document input such that a second is portion of the sheet document between the trailing edge and the or each stacking member flicks down onto the stack.
3. A device according to any of the preceding claims, wherein the sheet document input is separated from the or each stacking member by a distance less than the short edge dimension of the sheet documents.
4. A device according to any of the preceding claims, wherein the sheet document input comprises at least one drive roller.
5. A device according to claim 4, further comprising at least one auxiliary roller, the or each auxiliary roller forming a nip with a respective one of the or each drive roller.
6. A device according to claim 4 or claim 5, wherein the at least one drive roller comprises a pair of drive rollers spaced apart along an input drive shaft.
7. A device according to any of claims 4 to 6, wherein the or each stacking member is a stacking roller having a higher coefficient of friction than the or each drive roller.
8. A device according to any of the preceding claims, wherein the or each stacking member is floating on the stack such that it can move away from the stack to accommodate sheet documents being positioned on the stack.
9. A device according to claim 8 when dependent on claim 4, wherein the or each stacking member is suspended on a carriage, which is rotatable around a shaft on which the or each drive roller is mounted.
10. A device according to any of the preceding claims, wherein the at least one stacking member comprises a pair of stacking rollers spaced apart along a stacking drive shaft.
11. A device according to any of the preceding claims, wherein the feeding direction is defined by a guide extending from the sheet document input to the is or each stacking member.
12. A device according to claim 11 when dependent on claim 4, wherein the guide comprises at least one guide belt coupling the or each drive roller to the or each stacking member.14. A device according to any of the preceding claims, further comprising a drive system adapted to move the container and/or the sheet document input along or parallel to the stacking axis to maintain the distance by which the sheet document input is spaced apart from the top of the stack in the direction parallel to the stacking axis above a predetermined threshold.15. A device according to claim 14, wherein the drive system comprises a motor coupled to the container, preferably via a lead screw or a drive belt.16. A device according to claim 14 or claim 15, wherein the drive system comprises a sensor adapted to generate an output signal when the distance by which the sheet document input is spaced apart from the top of the stack in the direction parallel to the stacking axis falls below the predetermined threshold, and a controller adapted to respond to the output signal by actuating the motor for a predetermined duration, whereby the container and/or the sheet document input moves along or parallel to the stacking axis such that the distance by which the sheet document input is spaced apart from the top of the stack in the direction parallel to the stacking axis is increased.17. A device according to any of the preceding claims, further comprising a support for holding the container.18. A device according to claim 17, wherein the support comprises a platform io having a pair of retaining members with which a tab on a container liner can be engaged, thereby holding the container in position.19. A kit comprising a device according to any of the preceding claims and a liner having a portion adapted for insertion into a container and a portion adapted for engaging with the device.is 20. A kit according to claim 19, wherein the interior of the liner is entirely smooth.21. A kit according to claim 19 or claim 20, wherein the liner comprises a hinge to enable the portion of the liner adapted for insertion into the container to rotate relative to the portion adapted for engaging with the device.22. A method for stacking sheet documents onto a stack extending along a stacking axis in a container, the method comprising feeding sheet documents from a sheet document input, spaced apart from the top of the stack in a direction parallel to the stacking axis, along a feeding direction, to at least one stacking member, the or each stacking member being closer to the top of the stack in the direction parallel to the stacking axis than the sheet document input, and bending a first portion of the sheet document passing the or each stacking member from the feeding direction to a direction parallel to the stack, the sheet document thereby being positioned on the stack.23. A method according to claim 22, further comprising releasing the trailing edge of the sheet document from the sheet document input when the first portion of the sheet document has passed the or each stacking member such that a second portion of the sheet document between the trailing edge and the or each stacking member flicks down onto the stack.24. A method according to claim 22 or claim 23, further comprising moving the container and/or the sheet document input along or parallel to the stacking axis to maintain the distance by which the sheet document input is spaced apart from the top of the stack in the direction parallel to the stacking axis above a predetermined threshold.25. A method according to claim 24, wherein the container and/or sheet document is moved along or parallel to the stacking axis for a predetermined duration such that the distance by which the sheet document input is spaced apart from the top of the stack in the direction parallel to the stacking axis is is increased when the distance by which the sheet document input is spaced apart from the top of the stack in the direction parallel to the stacking axis falls below the predetermined threshold.26. A device substantially as hereinbefore described with reference to the accompanying drawings.27. A method substantially as hereinbefore described with reference to the accompanying drawings.