APPARATUS FOR HANDLING SHEETS

Abstract: Apparatus is described for handling sheets, such as bank notes or other value sheets. An inserted note is transported to an intermediate position in which the note can either be rejected or encashed without affecting notes already stored on a temporary storage drum (154) or the note can be stored on the temporary storage drum from the intermediate position. The intermediate position may be in an output path of the apparatus and the note reversed on to the drum, the intermediate position may be a partially stored position of the note on the drum, from which the note can be discharged without discharging any additional notes already stored on the drum. A selectable transmission coupling (176) is used to rotate the drum from a common drive source (408) in one direction for storing successive notes as a bundle, and in a reverse direction of discharging the bundle. Guides are described for controlling movement of the sheets, and an actuator is described for avoiding the effect of vibration.

Description: APPARATUS FOR HANDLING SHEETS The invention relates to apparatus for handling sheets such as banknotes, and in one aspect to a short-term or temporary storage device, or "escrow" device, for use in such apparatus. Such an escrow device is suitable for storing banknotes at an intermediate stage in the processing of the banknotes, after which the banknotes can be returned to the user, or encashed by the apparatus. For example, an escrow device can be used in the banknote reading apparatus of an automatic vending machine or an automatic currency exchange machine, for temporarily storing introduced banknotes until a desired service is requested by the user or, if a cancellation request is received, until the previously introduced banknotes are returned. Reference is made to the accompanying Figs 1-3 of the drawings which illustrate a known banknote handling system including an escrow. This system was produced by Landis _. Gyr, and was used in Europe from 1982 under the product references BSN 30/32/34. A similar system was also used in the United States from 1987. In Fig. 1, the system consists of three separate units, namely a validator unit 310, an escrow and piston stacker unit 312, and a vault 314. The route of a banknote in the system is shown schematically in Fig. 1, and detail of the transportation mechanism for the escrow/stacker unit 312 is shown in Figs. 2 and 3. Referring to Fig. 1, a note introduced into the validator unit 310 is guided along the path shown by the broken line 316, and around a drum (not shown) at which stage the note is sensed by sensors 318. Depending on whether the note is found to be acceptable, the note is routed by a switch 320 either to a single note reject slot 322 if unacceptable, or downwardly into the escrow/stacker unit 312 if acceptable. Referring to Figs. 2 and 3, the escrow consists of a rotatable drum 324 around which notes are stored as a temporary stack. A set of parallel, endless belts 326 (only one belt 326 is visible in the drawings) extends around a major portion of the circumference of the drum 324, leaving clear an entry/exit area 328 through which notes are introduced to, or discharged from, the drum 324. Notes are guided on to the drum 324, and are selectively guided around the drum 324, or are selectively discharged from the drum 324, by means of a first set of selectors 330 and a second set of selectors 332 (only one selector 330, 332 from each set is visible in Figs. 2 and 3) . Each selector 330, 332 includes a finger 334, and is pivotally movable between an activated position in which the finger 334 is pushed against the surface of the drum 324 (see Fig. 2) , and a non-activated position in which the finger 334 is spaced from the surface of the drum 324 (see Fig. 3) . The surface of the drum 324 is formed with annular recesses in which the fingers 334 are received when they are pushed against the drum, such that the ends of the fingers 334 sit below the outermost surface of the drum on which the notes are stored. The selectors 330 and 332 are operated together by a common actuator linkage (not shown) which moves the selectors 330 and 332 in unison between the activated and non-activated positions. A drive unit (not shown) drives the drum 324 through the belts 326, and is operable to rotate the drum in either a forward direction (anti-clockwise in the drawings) , or a reverse direction (clockwise in the drawings) . In use, when a note arrives from the validator unit 310, the drum 324 is driven in the forward direction, and the selectors 330 and 332 are set to the non-activated position. The note is guided towards the drum 324 by belts 336 and 338, and is directed to the left under the fingers 334 of the first selectors 330 and on to the surface of the rotating drum, such that the note is stored between the drum 324 and the belts 326. Each successive individual note from the validator unit 310 is fed to the drum 324 in a similar manner such that each new note is laid on top of notes already stored on the drum as the new note meets the existing notes at the entry/exit area 328, whereby the notes are accumulating as a stack. If, for any reason, the stack of notes accumulated on the drum 324 has to be returned to the user, the selectors 330 and 332 are set in the activated position and the drum 324 is rotated in the reverse direction. The stack of notes is lifted off the surface of the drum 324 as the leading edge of the stack engages and rides up the fingers 334 of the first selectors 330, and the stack is directed by guides (not shown) and belts 340 and 326 to a stack exit slot 342. When the stack of notes accumulated on the drum is to be encashed, the selectors 330 and 332 are set in the activated position, and the drum 324 is rotated in the forward direction. The stack of notes is lifted off the surface of the drum 324 as the leading edge of the stack engages and rides up the fingers 334 of the second selectors 332, and the stack is directed by guides (not shown) and belts 326 and 338 towards a stacking position under a piston 344. When the stack reaches that position, the piston 344 is operated to push the stack downwardly into the vault 314. Reference is also made to US Patent No. 4822018 (Hain) which describes a cash dispenser including a sheet stacking mechanism for accumulating currency notes into a stack before the notes are delivered to a customer. In that system, a stacking cylinder is rotated continuously, and notes have to be fed to the cylinder at certain synchronised time points so that the notes will reach the cylinder at an appropriate moment to be stacked in alignment with notes already stored on the cylinder. A moveable guide has to be controlled by a stepping motor to lift the stack off the cylinder when the cylinder is operated in a reverse direction of rotation. Reference is also made to EP-A-0575711 and EP-A- 0591485 The present invention relates generally to apparatus including an escrow, or temporary or short term storage device, for sheets such as value sheets, (eg. banknotes or sheets treated as having a value) . In some designs, the escrow may comprise a rotatable drum or cylindrical means around which one or more sheets are stored as a temporary stack, and endless belt means extending around a major portion of the circumference of the drum. However, other general aspects of the invention are not limited to this. One potential problem with known arrangements concerns mis-alignment of the sheet which can occur in the exit/entrance region of a drum-type escrow when a new sheet is being introduced to a bundle of sheets already held around the drum. This can occur because the sheets are not held fast against the drum in this region by the endless belts. For example, referring to Fig. 3, when the drum is rotated with the guide fingers in their lifted position, the leading edges of the sheets on the drum can fan out, resulting in misalignment with new sheet being introduced. Such misalignment will be repeated for each new sheet added. If the misalignment is so great that the sheets cover all of the surface of the drum instead of being aligned in a stack covering only a part of the surface of the drum, it will be impossible to discharge the stack from the drum normally, because a clear area is always required to permit the guide fingers to fit in the recesses of the drum in order to lift the sheets from the drum. In EP-A-0575711, a spring biased guide finger is used to press the sheets against the surface of the drum as a new sheet is added. However, in some cases, friction between the guide finger and the outermost note may itself cause misalignment of the note as it passes under the spring finger, and might even damage the note if the apparatus is being used at high speed. Furthermore, the arrangement relies on the stack to displace the guide finger as the stack approaches the exit/entry region, and this could also cause some misalignment. Bearing the above problems in mind, in one aspect, the present invention includes a movable guide in the exit/entry region of a drum-type escrow, an electrical actuator for moving the guide towards and away from the surface of the drum, and control means for controlling the electrical actuator to position the guide so that it is spaced from the drum surface by an amount dependent on the number of sheets held around the drum. With this arrangement, the guide can be positioned at an appropriate spacing from the surface of the drum to prevent the sheets from fanning out and causing misalignment. For example, the guide could be positioned at a spacing of about 0.1 - 0.2 mm when one sheet is present on the drum, the spacing being incremented by 0.1 - 0.2 mm each time that a new note is added to the stack held on the drum. Alternatively, the guide could be moved when a multiple of sheets has been added. For example, the guide could be set in a first position when the number of sheets is between 0 to 5, a second position when the number of sheets is between 6 and 10, and so on. It will be appreciated that the guide does not have to press constantly on the sheets in the same way that a spring biased guide would. Instead, the guide is positioned to leave a clearance which is suitable for the size of the stack of sheets which has been assembled. In this way, the drum can accommodate a stack of large thickness with very little, if any, misalignment, and with virtually no risk of damage to the sheets, even if the drum is being rotated rapidly. Also, by using an electrical actuator to control the position of the guide, there is no additional pressure placed on the stack which might otherwise hinder movement of the stack or be a cause of misalignment. The number of sheets on the stack could be sensed directly, for example using a tactile sensor. However, it is preferred that the control circuit maintains a count of the number of sheets which are caused to be introduced to the drum, and sets the position of the guide accordingly. Preferably, the guide is also used as the means by which sheets are lifted from the surface of the drum during a discharge operation. Preferably, the escrow is of the type in which the drum is rotated in a first direction when sheets are introduced to the drum, and in a second direction to discharge the sheets. It will be appreciated that the guide does not have to be maintained in the set position during all operating cycles of the unit. For example, in a preferred embodiment, the guide is linked to another routing gate for routing sheets upstream of the escrow, and is moved according to the position of the routing gate. The advantageous feature of the above first aspect of the invention is that the control circuit is operable to set the position of the guide at least when the leading edge of sheets on the drum approach or are positioned in the entry/exit region. Another potential problem with known designs of drum-escrow concerns the effect of vibration on the guide or guides associated with the drum for controlling the introduction and discharge of sheets. For example, EP-A-0575711 illustrates a guide which is spring biased against the drum surface. GB-A-2209518 illustrates a guide which is spring biased to follow the surface of a control cam. Thus, in these arrangements, a spring provides a "return" force. The problem with such designs is that they can be vulnerable to external vibration, for example, if the unit is used at a train station, a bus station, an underground train station, or adjacent to or facing a busy road. One technique for overcoming this problem is to use a powerful spring so that the guide is held more strongly against vibration. However, if the guide is "passive" and is operated merely by contact with a sheet, this will increase the fric ional resistance between the sheet and the guide, and hence increase the likelihood of jamming or damaging the sheet; if the guide is activated by an actuator, then a stronger spring requires a more powerful actuator to move it. Another technique for overcoming the problem of vibration is to balance the guide using carefully placed weights. However, this can be very complicated, and results in the weight of the guide being increased undesirably. Bearing the above problem in mind, in a second aspect, the invention provides a guide for a drum-type escrow, the guide being driven between a first position for lifting sheets from the surface of the drum, and a second position in which it is spaced from the drum, by means of an electric motor which supplies the driving force for moving the guide towards and away from the drum. Such an arrangement is not vulnerable to vibration in the same way as the prior arrangements discussed above, because it does not have to rely on a spring to provide a "return" force " . Instead, the driving force for moving the guide in either direction, ie. towards or away from the drum, is derived directly from the electric motor. Preferably, the electric motor is a reversible stepper motor, as this allows simple control for advancing the motor by a predetermined amount, thereby enabling reliable positioning of the guide. However, any reversible electric motor may be used as desired. Preferably, the guide is pivoted for movement between the first and second positions. In one embodiment, the guide is coupled to the motor by means of a pin which slides in a slot as the motor turns, and, thereby moves the guide. Preferably, the slot is in a wheel turned by the motor, and defines a spiral shape, such that, as the motor turns, the pin is guided radially inwardly or outwardly in the spiral slot, depending on the direction of rotation. The spiral may extend through any suitable angle; in the preferred embodiment the angular distance between the radially inner and radially outer ends of the slot is about 300°. The angle does not have to be less than 360°, but this does enable the position of the guide to be detected simply by sensing the angular position of the wheel. Alternatively, the guide may be coupled to the motor by other means, such as gears, for example, a toothed rack, or a worm gear. A further aspect of the invention relates to controlling the movement of notes in an apparatus which includes a drum escrow or short term storage device. A note received from an input region, for example, an entry slot, is transported to sensor means for sensing the note, for example, to determine its authenticity and/or its denomination, and the note is then transported towards an intermediate position from which the note can either be stored on the escrow, or can be rejected or encashed without the need to reject or encash any other notes already stored on the escrow. The note is preferably held at the intermediate position until the output of the sensing means has been processed, whereupon the apparatus can determine how to treat the note. Preferably, the intermediate position is downstream of the sensor means. In a first particularly preferred embodiment, the apparatus includes separate input and output paths for notes, and the intermediate position is a position of the note in the output path, ie. the note is forwarded automatically from the input path to the output path, from which the note can be withdrawn for storage on the drum escrow. The output path may thus be regarded as including a region which is in two-way communication with the drum escrow, an inputted note being introduced from the input path to an intermediate position in this region of the output path. Preferably, in order to reduce the space required for the apparatus, the input and output paths are arranged side by side, for example, one on top of the other, and the note is turned through about 180° as it is transported from the end of the input path to the output path. The intermediate position of the note in the output path may conveniently be a position in which the note is disposed under a note encasher device, such as a note stacker piston, so that the note can be encashed immediately if desired. Preferably a routing device is provided for directing a note from the input path to the output path when the sheet is advanced towards the routing device from the input path, and for directing the sheet from the output path to the drum escrow when the sheet is moved in the reverse direction from the intermediate position back towards the routing device. The routing device may comprise a movable guide which is controlled by an electro-mechanical actuator (such as a solenoid or an electric motor) , and which is movable between a position for guiding a sheet from the input path to the output path, and a second position (or range of positions) for guiding a sheet from the output path to the escrow when the sheet is reversed back towards the guide. Alternatively, the routing gate may be "passive", ie. not driven by an actuator. For example, the guide may be biased towards the second position, but be movable to the first position by contact with a sheet. Preferably, the drum is driven by the same motor as the transport system, and a selectable transmission coupling used to drive the drum escrow selectively. This is particularly suitable inthe above embodiment because, at relevant times, the direction of movement of the note or notes in the output path is dependent on whether the notes are being transported to, or from, the drum escrow. The advantage of using a selectable transmission coupling to drive the drum in this way is that, once engaged, the coupling enables synchronism to be maintained between the transportation system and the drum. This is particularly important for timing the movement of the drum so that notes are superimposed neatly in register, one on top of another, on the drum. Such synchronism can be difficult to achieve if independent drive motors are used for the transportation system and for the drum, because there will always be an unpredictable delay in the start-up time of a motor when activated, which will depend on the load the motor has to drive. In a second particularly preferred embodiment, the intermediate position is a position in which the note is wound partially on to the drum escrow, the tail end of the note remaining free of the drum and separated from any notes already accumulated on the drum. From that position, the drum can either be rotated a little further to store the note fully on the drum, or the drum can be rotated in reverse direction to discharge the note from the drum without discharging any of the notes previously accumulated on the drum. This embodiment has an advantage over the embodiment described above in that it takes very little time to store the note fully on the drum from the intermediate position, this operation being generally the most frequent operation, and this reduces the time that a customer will have to wait before he can insert a following note. However, the mechanism and control unit for putting this embodiment into practice are generally more complex than those required for the previous embodiment. In order to discharge an accumulated stack from the drum, an electro-mechanically operated guide is preferred, rather than a passive guide, as the electro-mechanically operated guide has the advantage that it can be controlled to move the guide completely clear of the drum during other operations which do not use the guide. If a passive guide were used, when a new note was moved to the intermediate position, the guide would have to remain in contact with the face of the uppermost note of the previously accumulated stack. This could cause a problem because a passive guide is generally suitable for allowing notes to pass under the guide in only one direction of rotation of the drum; in the present embodiment, the drum might be rotated either direction from the intermediate position, the result being that the passive guide would be prone to jamming against the notes on the drum if the drum was rotated in the discharge direction. Such a problem would be dependent on the physical condition of each note, but in practice the apparatus should ideally be able to handle even worn or slightly holed notes without substantial risk of jamming. Depending on the design of the transportation paths for the notes, this embodiment may be suitable for use with two selectable transmission couplings (or a single selectable transmission coupling with a selectable direction inverter) for driving the drum from the main motor for the transportation system. This is because, if separate input and output paths are used, the driving source might conveniently operate in only one direction. In a closely related aspect to the second of the above embodiments, the invention also relates to controlling the drum escrow to only partially move a note into engagement with the drum so that, if desired, the individual note can be discharged from the drum by reversing the direction if rotation of the drum (through just less than one revolution) , without having to discharge any notes which were stored previously on the drum. In general, the tail end of the note will remain clear of the drum, and clear of the notes previously accumulated, and the drum will be halted at the intermediate position until it is desired either to discharge the note, or to advance the note completely on to the drum. In another general aspect, the invention relates to a temporary storage device. Such a device may be operable to receive sheets fed successively to the device for storage thereat, and selectively to return the sheets accumulated together in a bundle. Additionally, the device may be operable selectively to return the most recently fed sheet individually without having to return any previously stored sheets accumulated at the storage device. For this purpose, the storage device is operable to store a sheet only partially in an accumulated condition with existing sheets, such that the partially stored sheet can be discharged easily from the remainder of the bundle. In another aspect, the invention relates to a device for routing sheets between first, second and third transportation paths, and for this purpose a movable guide is used. The guide may be movable between three operating positions. In a closely related aspect, the invention also relates to an apparatus wherein a note is transported from an input region to an intermediate position and, in order to move the note from the intermediate position to an escrow, the direction of movement of the note is reversed. In another aspect, the invention relates to a movable guide for guiding sheets (such as banknotes) on the surface of the drum. One preferred independent feature is that the guide is resiliently biased towards a normal position relative to the drum in which a lifting end of the guide sits below or flush with the surface of the drum on which notes are accumulated. During rotation of the drum in a first, stacking direction, the leading edges of notes held by the belt means on the drum bear against the guide from the rear, and automatically displace the guide outwardly against the bias to allow the notes to pass under the guide. Once the tail edges of the notes have cleared the guide, the guide springs back to its normal position. On rotating the drum in the opposite, discharge direction, the leading edges of the notes on the drum bear against the guide from the front, and are separated from the drum by riding over the lifting end of the guide. The guide thus functions as an automatic direction-responsive guide for separating notes from the drum when the drum is rotated in one direction only. The guide may comprise one or more fingers extending generally tangentially towards the drum. The guide may be pivotably movable between its normal position and the displaced position. One or more recesses or clearances may be provided in or on the drum to enable the lifting end of the guide to be received below the level of the outermost surface of the drum. On rotation of the drum in the first direction, if the guide is displaced by notes already stored on the drum, the spring bias action of the guide will press the notes against the surface of the drum to ensure that the notes do not fan out as they leave contact temporarily with the belt means. A guide as discussed above is referred to herein as passive, as it does not require an electro¬ mechanical actuator to control its position. This can result in significant space and cost savings for the apparatus, as well as reducing the complexity of the electronic control system. A sensor switch may be coupled to the guide to provide an indication of whether the guide is in its normal position, which means that any notes on the drum are clear of the guide, and that the drum can be reversed immediately if desired to discharge the notes, or whether the fingers are in a displaced position, which means that at least some of the notes are not clear of the guide, and that the drum is not in a condition in which it can be reversed immediately to discharge the notes. In the latter condition, the drum has to be rotated anticlockwise, for example in small angular steps, until the notes are clear of the guide, allowing the guide to return to the normal position against the drum, before the drum can be reversed to discharge the stack of notes. As a first example, if the stack is to be discharged from the drum immediately after the last note has been wound on to the drum, a control unit can reverse the direction of rotation of the drum immediately upon the sensor switch indicating that the fingers have returned to the normal position. This can avoid unnecessary rotation of the drum, and can increase the responsiveness of the apparatus (by decreasing the apparent time to discharge the stack) . As a second example, if the stack of notes has become misaligned for any reason, such that one or more of the notes is out of register with the proper position of the stack, the sensor switch can be used to identify a suitable rotational position of the drum from which the stack can be discharged. In both of these examples, the basic control operation performed by the control unit can be the same: namely, to continue rotation of the drum in one direction until the switch indicates that the stack is clear of the fingers, and then to reverse the rotation of the drum, for example, through a complete revolution, to discharge the stack. In a closely related aspect, the invention also relates to a tactile sensor for sensing the presence of notes at a certain position on the drum. One or more movable elements extend towards the drum, and are displaceable from a normal position by contact with notes on the drum, at least when the drum is rotated in one direction. The one or more movable elements are coupled to a sensor switch to provide an output signal indicative of the position of the one or more elements, and hence detect the presence of notes on the drum at that position. Referring to the discussion above, the elements can be used to detect whether or not the drum is in a condition in which it can be reversed to discharge notes from the drum. Another aspect of the invention relates to a drive mechanism for rotating the drum. Preferably, a common drive source is used to drive the drum and a transportation system for feeding notes to the drum and for taking notes away from the drum, and the transportation system is operable selectively without rotation of the drum. Such an arrangement can be achieved by using one or more selectable transmission couplings for controlling the operation of the drum. The or each coupling may be coupled directly to the drive source, or it may be coupled to drive the drum from a moving part of the transportation system. In one embodiment in which the direction of rotation of the drive source is reversed between an operation to feed notes to the drum, and an operation to transport notes away from the drum, only a single selectable transmission coupling is required to drive the drum, since the direction of rotation will be reversed automatically by the drive source when the notes are discharged from the drum. In an alternative embodiment in which the direction of rotation of the drive source is not reversed between an operation to feed notes to the drum, and an operation to transport notes away from the drum, then two selectable transmission couplings may be required, adapted to provide a respective driving force in the two opposite directions of rotation for the drum. Alternatively, a single selectable transmission coupling may be used in combination with a selectable inverter gearbox mechanism for selectively reversing the direction of the driving force obtained by means of the single coupling. The or each selectable transmission coupling may comprise a relatively simple clutch mechanism for bringing a belt or roller of transportation system selectively into engagement with a belt or roller for driving the drum. Preferably, the drum is driven through the belt means. It will be appreciated that the above aspects may be used independently of each other, or certain of the aspects may be combined to yield further advantageous results . Further objects, features and advantages of the invention will become apparent from the following description of preferred embodiments of the invention, which is given by way of non-limiting example, with reference to the accompanying drawings in which like parts are designated by like reference numerals. BRIEF DESCRIPTION OF THE DRAWINGS Figs. 1-3 illustrate a known prior art apparatus (described hereinbefore) , Fig. 4 is a schematic sectional view through an apparatus including an escrow, Figs. 5-8 are partial sectional views illustrating the routing of a note in the apparatus of Fig. 4, and the operation of the escrow, Figs. 9-11 are schematic sectional views illustrating a modified switching arrangement; Fig. 12 is a schematic sectional view through a second modified embodiment including an escrow, Fig. 13 is a plan view of the switching device of the embodiment shown in Fig. 12, Figs. 14-17 are partial sectional views illustrating the routing of a note in the apparatus of Fig. 9, and the operation of the escrow, Fig. 18 is a schematic sectional view through a third modified embodiment, Fig. 19 is a schematic view illustrating a fourth embodiment; and Figs. 20-23 are schematic sectional views illustrating a modified form of switching device for use with the embodiment of Fig. 12. Referring to Figs. 4-8 an integrated system includes an escrow, for validating, accumulating, rejecting and encashing banknotes. The system is self-contained within a case 100 which sits on top of a separable storage vault (not shown) for storing banknotes encashed by the system. Referring to Fig. 4, the system consists of an input section 102 which accepts individual notes introduced by a customer and senses each note to determine whether the note is authentic and, if so, its denomination. The system also includes an escrow 104 for accumulating valid notes introduced by the customer, and an output section 106 for returning notes to a customer as necessary, and for encashing notes on completion of a transaction. The input and output sections 102 and 106, and the escrow 104 are coupled by a routing section 108 for controlling the routing of the notes between the various parts of the system. A control unit (not shown) controls the operation of the input section 102, the output section 106 and the escrow 104. The input section 102 includes a first optical sensor 110 for sensing an upper face of an introduced banknote, and a second optical sensor 112 downstream of the first sensor 110, for sensing the lower face of the note. In the drawings, the thickness of the note is exaggerated for the sake of clarity. The note is inserted through an entry slot 114 and is transported past the first sensor 110 by means of first and second (upper and lower) sets of moving endless belts, 116 and 118 respectively. The note is similarly transported past the second sensor 112 and towards the routing section 108 by third and fourth (upper and lower) sets of endless belts, 120 and 122 respectively. The first and third sets of (upper) belts 116 and 120 are guided around respective sets of pulleys which include a common upper pulley roller 122. Similarly, 20 the second and fourth sets of (lower) belts 118 and 122 are guided around respective sets of pulleys which include a common lower pulley roller 126. The spacing of the belts 116 in the first set, and the spacing of the belts 122 in the fourth set are each such that the belts do not substantially obstruct the faces of the note from being sensed by the two optical sensors 110 and 112. The third set of belts 120 is offset relative to the first set of belts 116 such that the two sets of belts do not interfere with each other as they pass around the pulley roller 124. Similarly, the fourth set of belts 122 is offset relative to the second set of belts 118. After passing the second optical sensor 112, the third and fourth sets of belts 120 and 122 carry the note to the routing section 108 at which the belts 120 and 122 separate. The third set of belts 120 are returned around a return pulley 128 which consists of a group of spaced apart pulley wheels mounted on a common axle, one pulley wheel for each belt 120 in the third set. The fourth set of belts 122 continues around a guide pulley 130 which also consists of a number of spaced apart pulley wheels mounted on a common axle, one pulley wheel for each belt 122 of the fourth set. At the guide pulley 130, the fourth set of belts 122 meet a fifth set of belts 132 to form upper and lower belts for transporting notes in the output section 106. The routing section 108 includes a first movable guide 134 for guiding notes to and from the output section 106. The first movable guide 134 consists of a number of guide fingers 136 which are pivoted on an axle 138 and are received in the spaces between the pulley wheels of the return pulley 128 and the guide pulley 130. Each finger 136 has a generally curved, wedge shape and includes an abutment edge 140 and a guide edge 142. The fingers 136 are biased by a spring (not shown) to a normal position (Fig. 4) in which the fingers 136 extend across the path of a note being transported by the third and fourth sets of belts 120 and 122, respectively. When the note is advanced into engagement with the fingers 136 by the movement of the belts 120 and 122, the leading edge of the note bears against the abutment edge 140 of each finger 136, causing the fingers 136 to be displaced to allow the note to pass (see Fig. 5) . The curved shape of the abutment edge 140 guides the note around the guide pulley 130, such that the note is received between the fourth and fifth sets of belts 122 and 132, respectively, and is advanced into the output section 106. Once the trailing end of the note has moved past the fingers 136 of the movable guide 134, the fingers 136 are returned to their normal position under the action of the bias spring. The note is advanced in the output section 106 until it reaches an intermediate position (see Fig. 4) at which the leading edge of the note bears against a movable sensor finger 144. The sensor finger 144 operates a switch (not shown) to send a signal to the control unit to cause the control unit to stop the belts 122 and 132. If the control unit has not yet finished processing the outputs from the two optical sensors 110 and 112 to determine whether the note is authentic and to determine its denomination, then the note is held temporarily at the intermediate position in the output section 106 until the processing is completed. If the note is found to be unacceptable, then the control unit drives the fourth and fifth sets of belts 122 and 132 to advance the note further to the left, past a one-way flap 146 and through an exit slot 148 to return the note to the customer. A sensor switch (not shown) is coupled to the one-way flap 146 to determine when the flap re-closes once the note has been fully ejected, so that the apparatus can be made ready to accept a further note through the entry slot 114. It will be appreciated that the unacceptable note can be thus ejected without interfering with notes which may already have been stored by the escrow 104, and in particular without having to eject the entire stack of (valid) notes on the escrow 104 which the customer may already have entered into the system. If the note is found to be acceptable, and the transaction completed by the customer involves only that single note, then the note can be encashed immediately by the output section 106. A note stacker piston or plunger (shown schematically at 150) positioned above the note at the intermediate position in the output section 106, can be driven to bear downwardly on the note to push the note out of the grip of the fourth and fifth sets of belts 122 and 132, and downwardly through an encash opening 152 into the vault (not shown) positioned below the case 100. It will be appreciated that this can be done without requiring the single note to be stored by, and retrieved from, the escrow 104. Alternatively, if the note is found to be acceptable, and the transaction desired by the customer may involve further notes, then the control unit drives the fourth and fifth sets of belts, 122 and 132 respectively, to "reverse" the note out of the output section 106 back to the routing section 108. Referring to Fig. 6. as the note is transported past the guide pulley 130, the guide edges 142 of the fingers 136 of the guide 134 guide the note automatically under the fingers 136 and towards the escrow 104. The escrow 104 is of a similar construction to the storage device described in EP-A-0575711, and comprises a drum 154 around which notes are stored. The drum may be for example a hollow cylinder which is supported on the drum axis by spokes. The drum could also be formed by a number of wheels mounted on an axle. The wheels may be placed in contact with each other and, in such a case, wheels may have appropriate different diameters to define the same form of recessed outer profile. Alternatively, the wheels may be spaced apart to define clearances between the wheels. The tongues 19 may then be received in the clearances when the tongues are in the position to return the notes from the drum. A set of parallel, endless escrow belts 156 extends around a major portion of the circumference of the drum leaving clear an entry/exit region 158. The escrow belts 156 are guided on a return path spaced from the drum 156 by sets of pulleys 160,162,164,166,168,172 and 174, the pulleys 160-172 being fixed, and the pulleys 174 being mounted on a movable arm 175 biased in the direction denoted by the arrow by a spring (not shown) to tension the belts 156 and to allow for expansion of the overall size of the drum as the number of stored notes increases. The escrow belts 156 are driven by means of an electrically activated clutch (shown schematically at 176) which transmits driving force from the fifth set of belts 132. A two-way electro-mechanical actuator may be used to operate the clutch 176, or the clutch may be biased in one direction (e.g. towards the disengaged position) by a spring, and an actuator used to move the clutch in the other direction (e.g. to the engaged position) . A modified clutch could also be used, based on a similar principle, in which either the fifth set of belts 132 or the pulley roller 178 could be used against the escrow belts 156, without requiring the use of an intermediate drive wheel 182. As part of both the routing section 108 and the escrow 104, a second movable guide or switch 190 guides notes being introduced to, or disengaged from, the drum 154. The switch 90 consists of a number of spaced fingers 192 having a generally V-shape and pivoted on axle 194. Each finger has an upper guide edge 196 and a lower guide edge 198 which meet at the tip 200, and each finger is biased towards a normal position (shown in Fig. 6) in which the tip 200 bears against the drum 154 and is received in a respective annular recess 202 in the surface of the drum. The clearance in the V-shape enables the fingers 192 to be movable away from the surface of the drum 154 (as explained below) without interfering with the axle on which the pulley 172 is mounted. Referring to Fig. 6, when a note is moved from the output section 108 to the escrow 104, the clutch 176 is engaged to commence rotation of the drum 156. Movement of the fifth set of belts 132 in this direction causes anti-clockwise rotation of the drum 154. As mentioned above, the note passes under the guide edges 142 of the first guide 134, and is guided by the lower guide edges 198 of the fingers 192 and by the fifth set of belts 132 and the escrow belts 156 on to the surface of the rotating drum 154, where it is received between the drum 154 and the escrow belts 156. The drum 154 is stopped when the note is stored away from the entry/exit region 158. Each note entered subsequently by the customer is processed as described above and, if valid, is transported to the escrow 104 to be stacked with the note or notes already present on the drum 154. Referring to Fig. 7, rotation of the drum is started at an appropriate time such that the leading edge of the note approaching the drum 154 will be aligned with the leading edge of each note on the drum, to form a neat stack. As the drum 154 begins to rotate, the leading edge of the stack 204 of one or more notes previously stored on the drum 154 bears against the guide edges 196 of the fingers 192, causing the fingers 192 to be displaced outwardly to permit the stack 204 to pass under the tip 200, to meet the approaching note in the entry/exit region 158. The guide edges 196 pressing against the surface of the stack 204 ensure that the notes of the stack 204 do not fan out as the stack 204 temporarily leaves contact with the escrow belts 156 while in the entry/exit region 158. The fingers 192 return to the normal position under the spring bias once the stack 204 has moved past the tips 200 of the fingers 192. In order to discharge the stack 204 from the drum 154, the direction of rotation of the drum is reversed. This is achieved by changing the direction of movement of the fifth set of belts 132. Referring to Fig. 8, as the stack of notes (moving in the clockwise direction) engages the fingers 192, the leading edge of the stack is lifted off the drum 154 by riding over the tips 200 of the fingers 192 and along the lower guide surfaces 198 of the fingers 192. Continued rotation of the drum 154 moves the stack further towards the guide pulley 130 until the stack is received between the fourth and fifth sets of belts, 122 and 132 respectively, which transport the stack 204 into the output section 106. The stack 204 can then either be returned to the customer through the exit slot 148 (for example, if the customer has requested return of the notes or the transaction has been cancelled) , or the stack 204 can be encashed by the plunger 144 (if the transaction has been completed) . A sensor switch (shown schematically at 206) is operated by the fingers 192 of the switch 190, and provides an indication of whether the fingers 192 are in the normal position, which means that any notes on the drum 154 are clear of the entry/exit area 158 and that the drum can be reversed immediately if desired to discharge the notes, or whether the fingers 192 are in a displaced position, which means that at least some of the notes are not clear of the entry/exit area 158, and that the drum 154 is not in a condition in which it can be reversed immediately to discharge the notes. In the latter condition, the drum 154 has to be rotated anticlockwise, for example in small angular steps, until the notes are clear of the fingers 192, allowing the fingers 192 to return to the normal position against the drum 154, before the drum 154 can be reversed to discharge the stack 204 of notes. As a first example, if the stack 204 is to be discharged from the drum immediately after the last note has been wound on to the drum 154, the control unit can reverse the direction of rotation of the drum 154 immediately upon the switch 206 indicating that the fingers 192 have returned to the normal position. This can avoid unnecessary rotation of the drum, and can increase the responsiveness of the apparatus (by decreasing the apparent time to discharge the stack) . As a second example, if the stack 204 of notes has become misaligned for any reason, such that one or more of the notes is out of register with the proper position of the stack, the switch 206 can be used to find a suitable rotational position of the drum 154 from which the stack 204 can be discharged. In both of these examples, the basic control operation performed by the control unit can be the same: namely, to continue rotation of the drum 154 in the anticlockwise direction until the switch 206 indicates that the stack 204 is clear of the fingers 192, and then to reverse the rotation of the drum 154, for example, through a complete revolution. In addition to the switch 206, further sensors (not shown) , can be provided for sensing the rotational position of the drum 154, and for sensing the presence of a note approaching the drum for controlling operation of the clutch 176. The design described above enables an apparatus to be provided for processing banknotes which is substantially more compact than the previous known equivalent apparatus (discussed with reference to Figs. 1-3), and which is also considerably less expensive. Significantly, the two movable guides 134 and 190 are both passive devices, ie. they do not rely on dedicated electro-mechanical actuators to control the routing of notes, and this results in considerable space saving in the apparatus, and removes the need for dedicated electronic circuitry to control the operation of the guides 134 and 190. Furthermore, only a single drive unit (for example, an electric motor) need be provided to drive all of the belts, and the drum 154. The belts 116, 118, 120, 122, 132 are mutually arranged such that the belts all move together, and the drum 154 and the escrow belts 156 are driven selectively from the fifth set of belts 132 by means of the relatively simple clutch 176. It will be appreciated that the use of such a simple clutch arrangement is possible because the direction of movement of the fifth set of belts 132 is always in accord with the appropriate direction of rotation of the drum, ie. the fifth set of belts 132 move in one direction when notes are being transported to the escrow 104, and in an opposite direction when the notes are to be discharged from the escrow 104. It will also be appreciated that, in fact, the escrow belts 156 could be driven by a clutch coupled to any of the first, second, third, fourth and fifth sets of belts in this design, because these belts all move in unison. Referring to Fig. 4, a drive motor for the belts is shown at 90, and a second drive motor for operating the plunger 150 is shown at 92. The second driver motor operates a fork 94 which in turn extends a pantograph (not shown) to move the plunger downwardly. Although passive guides are used to route the banknotes in the above embodiment, it will be appreciated that an electromechanical actuator may be used to operate one or both of the guides 134 and 190 if desired. Figs. 9-11 illustrate a combined switch as an alternative to the passive guides 134 and 190 in the previous embodiemnt. The switch consists of a set of spaced switching members 400, which pivot around a common axle 406. Each switching member includes a first portion 402 adjacent to the pulley 130 and a second portion 404 adjacent to the drum 154. The members 400 are controlled by means of a stepper motor 408 which rotates a wheel 410 having a spiral slot 412 in which is received a sliding pin 414 of a connecting member 416. The connecting member pivots around the axle 406 and is coupled to the fingers by a pin 418 which engages through all of the switching members 400. When the motor rotates clockwise, the pin 414 is pulled radially inwardly by the spiral slot 412 causing the connecting member 416 to pivot anticlockwise, and pulling the switching members 400 towards the drum 154. Similarly, when the motor rotates anticlockwise, the pin 414 is pushed radially outwardly, causing the connecting member to pivot clockwise, and pushing the switching members 400 away from the surface of the drum 154. In use, when a note is being routed from the input path to the output path, the switching members 400 are positioned as shown in Fig. 10, in which the first portion 402 is positioned to guide the note around the pulley 130, towards the intermediate position explained previously. The first portion 402 of the switching members 400 is spaced from the outer surface of the pulley by about 0.5 mm, which is sufficient clearance to allow the note to pass without obstruction. When the note is to be transported from the intermediate position to the drum 154, the motor is operated to pivot the switching members 400 away from the drum 154, such that the first portion 402 fits behind the pulley 130. In this position the switching members guide the note towards the drum 154. Once the note has been stored around the drum 154, the switching members 400 can be moved back to the position shown in Fig. 10 so that the system is ready to receive the next inserted note, or to discharge the notes accumulated on the drum, as in the previous embodiment. The position to which the switching members 400 are moved away from the drum 154 is controlled by the control unit and depends on the number of notes which are currently stacked on the drum 154. The function of the second portion 404 is to prevent the leading edges of the notes in the stack from fanning out in the entry/exit region as the drum is rotated anticlockwise, as this could otherwise cause the misalignment of the notes on the stack. In this embodiment, the spacing is increased by about 0.1 mm for each note which is added to the stack. It will be appreciated that the stepper motor enables the position of the switching member to be set accurately, by advancing the motor in small incremental steps. If desired, the switch could instead be used as a two-position switch, the motor 408 being controlled to set the switching members either in the position shown in Fig. 10, or in the maximally lifted position illustrated in Fig. 9. Another advantage of this embodiment is that it does not rely on the use of a spring to return the switch to a predetermined position. The stepper motor provides the drive for moving the switching members in both directions of movement. Therefore, the switch is not affected by external vibrations in the same way that a spring biased switch could be. This makes the present embodiment suitable for use in environments prone to vibrations, such as at a train station, or aboard a ship. The position of the switching members 400 can easily be sensed by detecting the angular position of the wheel 410. For example, this enables the switching members 400 to detect the trailing end of the stack, in a similar manner to that described in the previous embodiment. In this embodiment, the spiral slot 412 extends through about 300 degrees. As best seen in Fig. 11, the drum 154 is hollow, and is recessed at one end to enable the stepper motor 408 to be mounted in that end, the drum rotating around the motor body. The stepper motor is mounted on a sub-chassis 430, which also supports one end 432 of the axle 434 on which the drum 154 is carried. Such an arrangement enables the motor to be accommodated easily in the compact body of the validator, without interfering with other parts of the escrow. A further modified embodiment is described with reference to Figs. 12-17. The input section 102 and the output section 106 are unchanged (and so are not shown in detail in Fig. 12) , but the designs of the escrow 104a and routing section 108a are modified. The principle of operation of the apparatus in Fig. 12 is similar to that of Fig. 4 in that an inserted banknote is transported to an intermediate position, but instead of note being transported to an intermediate position in the output section 106, the note is wound partially on the escrow drum 154 as the intermediate position. Referring to Figs. 12 and 13, the two passive movable guides 134 and 190 of the previous embodiment are replaced by a switching device 210 which comprises sixth and seventh relatively short sets of (upper and lower) endless belts, 212 and 214 respectively, which articulate with the third and fifth sets of belts, 120 and 132, and with the escrow belts 156 to define a continuous belt transportation path to and from the drum 154. The sixth set of belts 212 extend around upper pulley rollers 216 and 218, around which the third set of belts 120 and the escrow belts 156 also extend, respectively. The puller roller 218 is mounted on a fixed axle, and the pulley 216 is mounted on a movable arm 220 which is pivotable about the fixed axle of the pulley 218. As best seen in Fig. 13, the third set of belts 120 and the escrow belts 156 are offset relative to the sixth set of belts 212 so as to avoid interference between the belts around the pulley rollers 216 and 218. A guide tab 222 is pivotally mounted on the axle of the pulley 216. Similarly, the seventh set of belts 214 extend around lower pulley rollers 224 and 226, around which the fifth set of belts 132 and the escrow belts 156 also extend respectively. The pulley roller 224 is mounted on a movable arm 228 which is pivotable about the fixed axle of the pulley 226. The fifth set of belts 132 and the escrow belts 156 are offset relative to the seventh set of belts 214, in a similar manner to that shown in Fig. 13 for the sixth set of belts 212. The opposite ends of the arm 228 extend slightly beyond the pulleys 224 and 226 to provide additional guide surfaces (228a) . The switching device 210 is movable between an input position (as shown in Fig. 12) for receiving notes from the input section 102, and an output position (as shown in Fig. 14) for delivering notes to the output section 106, the position of the switching device 210 being determined by an electro-mechanical actuator (not shown) . In this embodiment, the switching device 210 is biased by a spring (not shown) towards its input position, which is statistically the most frequently used position of the switching device, and the actuator is used when it is desired to move the switching device 210 to the output position. However, in other embodiments, the switching device 210 could instead be biased in the other direction, or a two-way electro-mechanical actuator could be used. It will be appreciated that movement of the switching device 210 causes changes in the lengths of the paths of the third and fifth sets of belts 120 and 132, respectively, and this is accommodated by providing respective tensioning pulleys 230 mounted on movable arms 232, biased by springs (not shown) in the directions shown to maintain a predetermined tension in the belts, in a similar manner to the pulley 174 for the escrow belts 156. Referring to Fig. 12, a note transported from the input section 102 by the third and fourth belts, 120 and 122 respectively, approaches the switching device 210 in its input position. The pivotable guide tab 222 is positioned clear of the path of the approaching note, which is guided by the end 228a of the lower arm 228, between the sixth and seventh sets of belts, 212 and 214 respectively, towards the drum. As in the previous embodiment, the note is received between the escrow belts 156 and the surface of the drum 154 as the drum rotates anticlockwise. However, instead of being wound fully on to the drum 154, the note is stopped at an intermediate position (shown in Fig. 12) in which the tail end of the note is retained between the sixth and seventh sets of belts, 212 and 214 respectively, of the switching device 210. The note is halted at the intermediate position until the sensor outputs in the input section 102 have been processed. If the note is determined to be acceptable, and the transaction may involve subsequent notes, then the note is loaded fully on the drum 104 by simply advancing the drum anticlockwise until the note is stored entirely between the drum 154 and the escrow belts 156. Alternatively, if the note is determined to be unacceptable, or if the single note can be encashed immediately, then the note is discharged from its intermediate position by moving the switching device 210 to the output position (see Fig. 14) , and rotating the drum 154 in the clockwise direction. Since one end of the note is already engaged by the sixth and seventh belts, 212 and 214 respectively, there is no need for a guide member at this stage to lift the note off the surface of the drum 154. In the output position, the pivotable guide flap 222 is rotated to a position to guide the note downwardly from the switching device 210, until it is received between the fourth and fifth sets of belts, 122 and 132 respectively, which transport the note into the output section 106. Fig. 15 illustrates the case in which a stack 204 of notes has already been accumulated on the drum 154, and a new note is introduced through the input section 102. The note is advanced through the switching device 210 in the same manner as described above until the note reaches the intermediate position (shown in Fig. 15) . From the intermediate position, the note can either be advanced fully on to the drum 154 to be superimposed fully on the stack 204, or the switch device 210 can be moved to the output position and the note discharged if the note is found not to be acceptable. Significantly, in the intermediate position, the tail end 204a of the stack 204 is retained captive between the escrow belts 156 and the drum 154. Consequently, if the drum 154 is rotated clockwise to discharge the partially wound note, this operation does not affect the stack 204 of previously stored notes which remain stored around the drum, ie the partially wound note can be discharged independently of the stack 204 of previously stored notes. There is thus no need for a guide member at this stage either to lift the new note from the stack 204, or to retain the remainder of the stack 204 on the surface of the drum 154. Figure 16 illustrates how the stack 204 of notes is discharged when it is desired either to return the notes to the customer, or to encash the notes. To lift the stack 204 off the surface of the drum 154, the switching device 210 comprises movable guide fingers 230 pivotable about the axle of the pulley 218. The fingers 230 are movable between an active position, in which the fingers extend to the right as shown in Fig. 16, and a retracted position as shown in phantom in Figs. 14 and 15. The fingers 230 are biased towards the retracted position by a spring (not shown) , and are moved to the active position when needed only during the stack discharge operation, by a further electromechanical actuator (not shown) . With the switching device 210 in the output position, the drum 154 is rotated clockwise to drive the stack 204 over the fingers 230 and through the switching device 210 to the output stage 106, from which the stack can either be returned to the customer or encashed, as explained hereinbefore. In this embodiment, the electro-mechanically actuated fingers 230 are preferred to passive fingers of the type used in the previous embodiment, for the sake of reliability. It will be appreciated that, in the case shown in Fig. 15, if passive finger were used as in the previous embodiment, these fingers would bear against the stack 204 under the partially wound note, and the tip of the fingers might snag on the surface of the uppermost note in the stack 204 during clockwise rotation of the drum 154, which could result in a jam. The tendency for the tip to snag against a note is dependent on the physical condition of the note, and is increased if the note is holed or has a roughened surface or roughened edges, which may be the case in practice. In contrast to the previous embodiment, each note introduced into the present embodiment is moved to the intermediate position on the drum 154 before the note has been validated. It is therefore necessary to protect the apparatus against the introduction of a long strip, or a note-on-a-string (ie a tethered note) , which might otherwise be wound through more than one revolution on the drum 154, and possibly cause a jam. The protection is afforded by the sensors in the input section 102 which can provide an immediate indication if the inserted note is longer than a predetermined maximum expected length, or has a string attached. Referring to Fig. 17, in response to such an indication, the switching device 210 is moved downwardly to the output position, with the pivotable tab 222 being angled downwardly. In this position, the inserted object 232 is routed directly around the guide pulley 130 to the output section to be returned to the customer, without being wound on to the drum 154, and thus avoiding possible jamming or defrauding of the apparatus. The driving force for moving the escrow belts 156 and rotating the drum 154 is provided from the main drive for the first, second, third, fourth and fifth sets of belts, in a similar manner to the previous embodiment. However, in contrast to the previous embodiment, these belts now move in the same direction when a note is introduced to the drum 154 as they do when the note is discharged from the drum 154; only the sixth and seventh sets of belts, 212 and 214 respectively, and the escrow belts 156 change the direction of their movement between these operations. Therefore, the apparatus employs two electro- mechanically operated clutches 176a and 176b to provide a driving force for the escrow belts 156 and for the sixth and seventh sets of belts, 212 and 214 respectively, selectively from two different pulleys or belts which move in opposite directions during the normal movement of the first, second, third, fourth and fifth sets of belts. For example, one clutch 176a may provide driving force from the fifth set of belts 132, and the other clutch may provide driving force in the opposite direction from the third set of belts 120. Alternatively, a single clutch (not shown) could be used, and the direction of the driving force controlled by a electro-mechanical inverter gearbox for selectively reversing the direction of movement. It will be appreciated the third set of belts 120 always move around the pulley 216 anticlockwise, and the fifth set of belts 132 always move around the pulley 224 anticlockwise, yet the direction of movement of the sixth and seventh sets of belts, 212 and 214 respectively, is reversible. This is accommodated by splitting the pulleys 216 and 224 into sections (Fig. 13) , the sections 216a and 224a for the sixth and seventh sets of belts 212 and 214, respectively, being of slightly larger diameter than the sections 216b and 224b for the third and fifth sets of belts 120 and 132, respectively. The split sections of the pulleys allow for contrarotation, and the larger diameter of the sections 216a and 224a for the sixth and seventh sets of belts, 212 and 214 respectively, ensures that a note driven through the switching device 210 is always driven in the direction of movement of the sixth and seventh sets of belts 212 and 214, respectively, which move in unison with the escrow belts 156 and the drum 154. The embodiment shown in Figs. 12-17 can be made just as compactly as the embodiment of Figs. 4-8, and provides an additional speed advantage in the processing of the notes. In the previous embodiment, it might typically take between 2 and 4 seconds for a note to be moved to the intermediate position in the output section, and then "reversed" on to the drum if valid. This time appears to the customer as a delay before the next note can be inserted. However, in the present embodiment, an inserted note is advanced directly to the intermediate position in which it is partially wound on the drum 156. If then takes only a very short time to rotate the drum to completely wind the note, if the note is determined to be acceptable, which results in less of a delay before the next note can be inserted. However, this increase in speed is achieved at the expense of a more complex system of transportation belts, and a larger number of electro-mechanical actuators; separate actuators have to be provided for the switching device 210 and for the fingers 230, as well as for the two clutches 176a and 176b. Figures 20-23 illustrate a modification of the design in Figs. 12-17 in which a modified, simpler form of switching device 210a is used. In modified switching device 210a, the upper pulley 216 and the lower pulley 224 are mounted at fixed positions and a pivotable guide 238 is used to route notes between the input section 102, the output section 106, and the escrow 104a. The guide 238 consists of a flap pivoted about a central axis 239. The pivotable guide 222 is omitted in this design. The guide 238 is movable between a first position (shown in Fig. 20), a second position (shown in Figs. 21 and 22) , and a third position (shown in Fig. 23) . The first position is used for routing a note arriving from the input section 102 to the escrow 104a (see Fig. 20) . The second position is used for guiding a single note discharged from the partially stored position (see Fig. 21) to the output section 106, and also for guiding an entire stack 204 when discharged from the escrow (see Fig. 22) to the output section 106. The third position is used for guiding a sheet 232 directly from the input section 102 to the output section 106 (see Fig. 23) if the sheet 232 is detected to be too long. It will be appreciated that with this modified design, the switching device is simpler, as the belts 212, 214, 120 and 132 do not need to articulate. The position of the guide 238 is controlled by an electro-mechanical actuator (not shown) . Fig. 18 illustrates schematically a further embodiment which is, in effect, a hybrid of the embodiment in Figs. 4 to 8, and the embodiment in Figs. 12 to 17. In Fig. 18, a note introduced through the input section 102 is routed past the passive movable guide 134 to a first intermediate position 240 in the output section 106. If the note is detected to be either too long or to have a string attached, the note is immediately returned to the customer through the exit slot, otherwise the note is immediately "reversed" from the output section 106 to a second intermediate position in which it is partially wound on the drum 154. The note is halted in the second intermediate position until the sensor outputs from the input section have been processed to identify the denomination of the note. From the second intermediate position, the note can either be wound fully on to the drum 154, or it can be returned to the output section 106 for return to the customer or for encashing. The switching fingers 230 are provided for lifting an accumulated stack from the drum 154 when the stack is to be returned to the customer or encashed. The above embodiments utilise separate input and output sections, 102 and 106 respectively, as each section can be adapted for the direction of movement of the note, for example, past the sensors in the input section. This is preferred to enable the note to be moved rapidly without risk of jamming, and it is commonly believed that such systems, although more expensive, are advantageous in this respect over bidirectional systems which use only a single entry/exit slot. Fig. 19 illustrates low-cost bidirectional system incorporating an escrow drum 154. A single entry/exit slot 250 is used, and the path of the note is shown by the broken line 252. The two sensors 110 and 112 are positioned adjacent to the entry/exit slot 250, and the stacker piston 150 is arranged downstream of the sensors 110 and 112, before the escrow drum 154. In use, a note introduced through the slot 250 is transported past the two sensors 110" and 112 to an intermediate position at which the note is held until the outputs of the sensors have been processed to determine whether the note is acceptable. The intermediate position can either be under the stacker piston 144, or it can be when the note is partially wound on the drum 154. In the former case, a passive guide can be used to discharge notes from the drum 154 on reverse rotation, but in the latter case an active guide such as the set of guide fingers 230 is preferred. Whilst specific embodiments of the invention have been described in detail, it will be appreciated that many modifications and developments may be made without departing from the scope of the invention defined in the appended claims.

Claims: CLAIMS: 1. Sheet handling apparatus comprising: a temporary storage device for sheets comprising rotatable cylindrical means around which one or more sheets can be stored, and endless belt means extending around a major portion of a circumference of the cylindrical means for holding the sheets against the cylindrical means; transportation means for transporting a sheet along a note path; and control means for operating said transportation means in a first movement direction to advance a received sheet to an intermediate position in said note path, and for selectively reversing the direction of movement of the transportation means to move said note from the intermediate position in a reverse direction to transfer the sheet to the temporary storage device. 2. Apparatus according to claim 1, wherein the note path comprises an input path from an inlet aperture, and an output path, and wherein the control means operates the transportation means to transport a sheet received in the input path to an intermediate position in the output path. 3.. Apparatus according to claim 2, wherein the transportation means transports a note from the input path substantially along a U-turn path to the intermediate position in the output path. 4. Apparatus according to claim 2 or 3 , wherein the transportation means comprises a drive motor for driving the transportation system, the apparatus -- -- 42 further comprising a selectable transmission coupling for driving the temporary storage device from the transportation means. 5. Apparatus according to claim 2, 3 or 4, wherein the output path is defined by transportation belts which, in use, when a sheet is being transferred to or discharged from the temporary storage device, move in the same sense of movement as the endless belts of the temporary storage device. 6. Apparatus according to claim 2, 3, 4 or 5, wherein the transportation means comprises a movable guide arranged between the input path, the output path and the temporary storage device, for routing a sheet advanced in the first movement direction from the input path to the output path, and for routing a sheet advanced in the reverse direction from the output path to the temporary storage device. 7. Apparatus according to claim 6, wherein the guide is operated by an electrical actuator. 8. Apparatus according to claim 7, wherein the guide moves with a second guide associated with the cylindrical means for discharging sheets from the cylindrical means. 9. Apparatus according to claim 7, wherein the first and second guides are integrally formed, and are arranged relative to each other such that, when the second guide is in a position for discharging a sheet from the cylindrical means, the first guide is in a position for guiding a sheet from the input path to the output path, and when the second guide is clear of the cylindrical means, the first guide is positioned to guide a sheet from the output path to the temporary storage device. 10. Apparatus according to claim 6, wherein the guide is biased to a predetermined position, and is operated by contact with a sheet. 11. Apparatus according to any of claims 2 to 10, wherein the intermediate position is a position in which the sheet is located adjacent to a piston operated stacker. 12. Apparatus according to any preceding claim, further comprising a sensor for sensing the presence of a sheet approaching the temporary storage device, and means for commencing rotation of the cylindrical means when a sheet is sensed. 13. A temporary storage device comprising: rotatable cylindrical means around which sheets can be stored; endless belt means extending around a major portion of a circumference of the cylindrical means for holding the sheets against the cylindrical means, the endless belt means leaving clear an entry/exit region through which sheets can be introduced to, or discharged from, the cylindrical means upon rotation of the cylindrical means; a guide movable between a first position for lifting sheets from the cylindrical means during a discharge operation, and a second position in which the guide is clear of the cylindrical means; electric motor means coupled to the guide for moving the guide, the motor providing the driving force for moving the guide towards and away from the cylindrical means. 14. A device according to claim 13, wherein the motor is coupled to the guide in such a manner that the guide can only move with movement of the motor. 15. A device according to claim 14, wherein the motor is coupled to the guide by means of a rotatable member having a slot therein in which a pin slides as the member is rotated by the motor. 16. A device according to claim 15, wherein the slot has a spiral shape. 17. Apparatus according to any of claims 13 to 16, wherein the motor is reversible. 18. Apparatus according to any of claims 13 to 17, wherein the motor is a stepper motor. 19. Apparatus according to any of claims 13 to 18, wherein the motor is positioned at least partially within the cylindrical means. 20. Apparatus for controlling the position of a guide for guiding sheets, the apparatus comprising: an electric motor; a rotable element driven by the motor and having a slot formed therein formed in a spiral shape; a pin slidable in the slot as the rotatable element is turned, the pin being coupled to the guide, whereby the pin moves the guide in one direction when the motor is rotated one sense of rotation, and the pin moves the guide in the opposite direction when the motor is rotated in the other sense of rotation. 21. Apparatus according to claim 20, wherein the guide is movable about a pivot. 22. Apparatus according to claim 20 or 21, wherein the pin mounted is on an intermediate member which is coupled to the guide. 23. Apparatus according to claim 20, 21 or 22, wherein the motor is a stepper motor. 24. A temporary storage device for sheets comprising: cylindrical means having a circumferential periphery around which one or more sheets can be stored; endless belt means extending around a major portion of a circumference of the cylindrical means for holding said one or more sheets against the cylindrical means, the endless belt means leaving clear an entry/exit region through which notes can be introduced to or discharged from the cylindrical means upon rotation of the cylindrical means; a movable guide in the entry/exit region operated by an electrical actuator for moving the guide towards and away from the surface of the drum; and control means for controlling the electrical actuator to position the guide so that it is spaced from the drum surface by an amount dependent on the number of sheets held around the cylindrical means, in order to guide sheets around the cylindrical means. 25. A device according to claim 24, wherein the guide is movable to a position for discharging sheets from the cylindrical means. 26. A device according to claim 24 or 25, wherein the control means maintains a count of the number of sheets held on the cylindrical means, and increments the count each time that a new sheet is added. 27. Sheet handling apparatus comprising: input path means for receiving sheets inputted to the apparatus; first output means for outputting a rejected sheet; second output means for outputting an accepted sheet; a temporary storage device for storing temporarily one or more sheets in the apparatus to allow processing of additional sheets, the temporary storage device comprising rotatable cylindrical means around which the sheets can be stored, and endless belt means extending around a major portion of a circumference of the cylindrical means to hold the sheets against the cylindrical means, the endless belt means leaving clear an entry/exit region to permit sheets to be introduced to, or discharged, from the cylindrical means upon rotation of the cylindrical means; and transportation means operable to transport a sheet from the input path means to an intermediate position at which the sheet can selectively be outputted by either the first output means or the second output means without outputting any additional sheet stored by the temporary storage device, or the sheet can be selectively stored by the temporary storage device. 28. Apparatus according to claim 27, wherein said transportation means is operable selectively to reverse the direction of movement of the sheet when moving the sheet out of the intermediate position. 29. Apparatus according to claim 27 or 28, wherein the intermediate position is a partially stored position in which a first portion of said sheet in said intermediate position is received around said cylindrical means, and a second portion of said sheet is retained clear of said cylindrical means in said entry/exit region, such that the sheet can be discharged from the partially stored position without discharging other sheets already stored on the cylindrical means. 30. Apparatus according to claim 29, wherein said cylindrical means is rotatable in a first direction for moving said sheet to said intermediate position, and is rotatable in a second direction of rotation for discharging said sheet from said intermediate position for output by said first or second output means. 31. Apparatus according to claim 29 or 30, wherein said transportation means is operable to advance said sheet in a first direction of movement of the sheet to said intermediate position, and said transportation means is operable to move said sheet from the intermediate position selectively in said first direction of movement of the sheet, or selectively in a second direction of movement of the sheet opposite to said first direction. 32. Apparatus according to claim 29, 30 or 31, further comprising sensor means for sensing the length of the sheet, and the transportation means comprises means for moving the sheet to the intermediate position only if the length of the sheet is acceptable, the transportation means being operable to transport the sheet directly to the first output means if the length of the sheet is not acceptable. 33. Apparatus according to claim 27, further comprising output path means for guiding said sheet for output by either said first output means or said second output means, wherein said intermediate position of said sheet is a position in said output path means. 34. Apparatus according to claim 33, wherein said transportation means is operable to move said sheet in a first direction of movement of the sheet to said intermediate position in said output path, and said transportation means is selectively operable to reverse the direction of movement of said sheet to transport the sheet to said temporary storage device. 35. Apparatus according to claim 33 or 34, wherein said transportation means comprises means for guiding a sheet from the input path means substantially along a U-turn path to said intermediate position in said output means. 36. Apparatus according to claim 33, 34 or 35, wherein the cylindrical means is rotatable in a first rotation direction when a sheet is to be fed to the cylindrical means, and in a second rotation direction when one or more sheets are to be discharged from the cylindrical means. 37. Apparatus according to claim 36, further comprising drive means for driving the transportation means in first and second transportation directions of movement, and a selectable transmission coupling for selectively coupling a driving force to the cylindrical means for rotating the cylindrical means in the first rotation direction when the transportation means is driven in one transportation direction, and for rotating the cylindrical means in the second rotation direction when the transportation means is driven in the other transportation direction. 38. Apparatus for handling value sheets, comprising: input means for receiving a value sheet inputted to the apparatus; a temporary storage device for storing one or more value sheets temporarily in the apparatus to allow processing of additional value sheets; and transportation means operable to transport a value sheet from the input means to an intermediate position from which the value sheet can selectively either be ejected or encashed without removing any additional sheets stored by the temporary storage device, or can selectively be stored by the temporary storage device. 39. A temporary storage device for storing one or more sheets fed successively thereto and operable to return the sheets in an accumulated bundle, the storage device being operable selectively to return the most recently fed sheet individually from the storage device without returning any sheet fed previously and stored by the storage device. 40. A storage device according to claim 39, wherein the device comprises means operable to receive a most recently fed sheet in a particularly stored condition, from which the sheet can be discharged individually. 41. A storage device according to claim 40, comprising means for carrying one or more notes stored by the storage device, and wherein the partially stored condition is a condition in which a first portion of the sheet is carried by the carrying means or for the stored notes, and a second portion is retained clear of the carrying means. 42. A storage device according to claim 41, wherein the carrying means comprises cylindrical means having a cylindrical periphery around which notes can be stored. 43. A storage device according to claim 39, 40, 41 or 42, wherein the storage device is an escrow for storing value sheets. 44. A temporary storage device for sheets comprising: cylindrical means having a circumferential periphery around which sheets can be stored; endless belt means extending around a major portion of a circumference of the cylindrical means for holding said sheets against the cylindrical means, said endless belt means leaving clear an entry/exit region through which one or more sheets can be introduced to, or discharged from, the cylindrical means; drive means for rotating the cylindrical means in a first direction when one or more sheets are to be introduced to the cylindrical means, and in a second direction when one or more sheets are to be discharged from the cylindrical means; and control means operable to control the drive means to rotate the cylindrical means in the first direction to receive a sheet introduced to the cylindrical means, and to halt rotation of the cylindrical means in the first direction at a partially stored position in which a first portion of the sheet is received around the cylindrical means and a second portion of the note remains clear of the cylindrical means in the entry/exit area. 45. A temporary storage device according to claim 44, wherein the control means is operable selectively to control the drive means to recommence rotation of the cylindrical means in the first direction to store the sheet on the cylindrical means at a position clear of the entry/exit region. 46. A temporary storage device according to claim 44 or 45, wherein the control means is operable selectively to control the drive means to rotate the cylindrical means in the second direction of rotation to discharge the partially stored sheet from the cylindrical means without discharging any additional sheet which may already be stored around the cylindrical means. 47. Sheet handling apparatus for routing a sheet between first, second and third transportation paths, comprising guide means movable between a first position for transporting a sheet in at least one direction between the first and second paths and between the first and third paths, and a second position for transporting a sheet between the second and third paths. 48. Apparatus according to claim 47, wherein the guide means is pivotally movable between the first and second positions, and comprises a fixed end adjacent to the third path, and a mouth movable between the first and second paths. 49. Sheet handling apparatus for routing a sheet selectively between first, second and third transportation paths, comprising guide means movable between a first guide position for transporting a sheet between the first and second paths, a second guide position for transporting a sheet between the second and third paths, and a third guide position for transporting a sheet between the first and third paths. 50. Apparatus according to claim 49, wherein the guide is pivotally movable between the first, second and third positions. 51. Apparatus according to claim 50, wherein the guide comprises at least two portions extending from the pivot axis in different directions. 52. Apparatus according to claim 49, 50 or 51, wherein the guide is generally planar. 53. Apparatus according to claim 49, 50, 51 or 52, wherein the guide is pivoted about an axis located generally at the junction of the first, second and third transport paths. 54. Apparatus according to claim 49, wherein at least one of the transport paths is defined by an upper set of parallel spaced apart belts and a lower set of spaced apart belts, and the guide is received between one or more spaces between the belts of each set. 55. Banknote handling apparatus comprising apparatus defined in any preceding claim. 56. Banknote handling apparatus according to claim 55, wherein the apparatus is a banknote validator. 57. A method of controlling a rotatable intermediate sheet storage device around which sheets can be stored, comprising: rotating the storage device in a first direction to receive a sheet being fed thereto; halting rotation of the storage device in the first direction at a position in which a first portion of the sheet is received around the storage device, and a second portion of the sheet remains clear of the storage device, whereby the sheet can either be stored on the storage device with any previously stored sheets by continuing rotation of the storage device in the first direction, or the sheet can be discharged from the storage device independently of any previously stored sheets by reversing the rotation of the storage device. 58. A method of handing a value sheet in a value sheet handing apparatus, comprising transporting the sheet from an input to an intermediate position in the apparatus, selectively reversing the direction of movement of the sheet towards a temporary storage device which comprises rotable cylindrical means and endless belt means extending around a major portion of a circumference thereof, and commencing rotation of the cylindrical means as the sheet approaches the cylindrical means, such that the sheet is received between the cylindrical means and the endless belt means.

Inventors: GERLIER ANDRE, POLIDORO ROBERTO, GERLIER, ANDRE, POLIDORO, ROBERTO
Applicants: GERLIER ANDRE, MARS INC, POLIDORO ROBERTO, GERLIER, ANDRE, MARS, INCORPORATED, POLIDORO, ROBERTO
Application year: 1995
Main classification: G07D13
IPC codes: B65H29, G07D9, G07D11, G07F7, G07F19