TRANSPORT SYSTEM FOR DOCUMENT VALIDATOR

Abstract: A banknote validator comprises a banknote transport path divided in multiple transport sub-systems. Each sub-system is easy to maintain because the axes of a sub-system are in reduced number, and easily removable for maintenance of the sub-system. The validator allows continuous frictional engagement of a banknote in the transport path, including between sub-systems.

Description: TRANSPORT SYSTEM FOR DOCUMENT VALIDATOR Field of the Invention The present invention pertains to systems for transporting rectangular sheets of paper, called documents hereafter, particularly inside currency validators where the document is a banknote. Description of the Background Art The U.S. Patent No. 4,958,715 discloses a transport system comprising multiple pairs of belts disposed to allow a directional change along a transport path. A problem encountered in such transport systems for validators is related to the construction of the frame of the validator. Said frame is usually made of at least one base plate, on which axes are secured perpendicularly for support of pulleys, the document- carrying belts being supported, and sometimes driven, by said pulleys. One advantage of a single base plate is to provide easy access for validator maintenance and belt replacement; however, the higher cost involved due to the larger diameters of axes that are necessary for this type of construction have led most manufacturers to prefer a frame construction comprising two parallel plates, each plate supporting one end of each axis. This type of two-plate construction allows to use thinner, cheaper rods for axes; however, maintenance is complicated because, If for example a belt has to be replaced, the operator has to completely dismantle a plate, usually the one that is closer to the belt that needs to be changed, remove the belts that are between the removed plate and the belt that has to be replaced, replace the belt and then reverse operations to finally reinstall the plate. In modern validators, processing of the document comprises several steps, comprising e.g. identifying and authenticating the document by magnetic and/or optical means, rotating the document around a plurality of axes for subsequent stacking in a predetermined orientation, sorting the document, and punching it out of the belt path into a stack. As a result, the validators are now made of a plurality of sub-parts, each of these being in charge of one of the above-mentioned functions. A single transport system carrying the document through all sub-systems is not easy to maintain; as a result, the problem of serviceability maybe solved by increasing the number of transport systems, hereafter called sub-systems, along the transport path, e.g. allocating one transport sub-system to each sub-part performing a function in the validator. This allows the use of shorter belts, being driven and supported by a smaller number of pulleys, rotating around a smaller number of axles. Summary of the Invention The present invention provides a document validator for validating documents of value, in which a document is carried along a transport path, for example for purposes of identification, authentication, rotation, sorting or stacking, said validator comprising a transport system for carrying the document along the path, said transport system comprising a plurality of belts supported by pulleys rotating around axes that are supported by two plates the position of each of the axes being determined by said plates at either side of the belts characterized in that the serviceability of the transport system is improved by said axes being easily removable from both plates. When a part of a transport sub-system has to be replaced, for example a belt that is worn out, the operator does not have to remove any plate, but only the axles that are inside a volume defined by the belt between the two plates. The present invention also discloses a system for securing axles (axes) at both ends to the plates in an easily removable manner. In a first case, the axis is made of a rod on which the pulleys are secured, bearings being provided at both ends of the rod for accommodation in corresponding housings in both plates. Such bearings allow rotation but prevent axial movement of the rod. In this type of a rotating rod, the pulleys are secured to the rod. The bearings are prevented from axial movement by circlips engaging in circular recesses in the rod, on each side of a plate. In a second case, the axis is made of a rod releasably secured by its end to both plates, for example by circlips engaging in circular recesses in the rod on each side of a plate. The rod when mounted is prevented from axial movement by said circlips, the pulleys being allowed to rotate freely around said rod by means of a bearing that is inserted into the pulley and is coaxial with the pulley and the axis. In a known manner, a typical transport system carries the document in frictional engagement between two belts systems, resilient means being provided, e.g. on the axes supporting the pulleys, to urge one system of pulleys against the corresponding one, rotating on a parallel axis. The document is pinched between the belts circulating on the respective pulleys . It has been found that dividing the transport system into a plurality of transport sub-systems, each taking over a portion of the transport path, can create document jam problems between two transport sub-systems. As the belts are driven by pulleys of a given diameter, and as the transport path in each part of the validator is made of a series of sub-paths, there are a number of critical carry-over sections between two sub-paths when the document leaves a first part of the validator to enter the next part. Such a carry¬ over section is critical because a document that would be relatively worn-out may crumple and jam between the two parts, because the front edge of the document has already been released from frictional engagement by the two cooperating belt systems of the first part and not yet been seized by the corresponding belt systems of the next part. This problem is particularly serious with pulleys of relatively large diameters having to cope with documents, e.g. banknotes, of reduced dimensions. As multiple-currency validators are increasingly preferred, the size of the banknotes to be accepted can vary to a large extent. In a particular embodiment, the validator according to the present invention provides a continuous frictional engagement of the document in the- critical carry-over section between two parts of the validator. In this embodiment, one single axis supports pulleys belonging to the two different transport sub-systems. As the front edge of the document is released from frictional engagement by the belts of the first transport sub-system, it is simultaneously frictionally engaged by the belts of the next transport sub-system so that the document is prevented from any undesired change of direction departing from the transport path. Additionally advantages of the invention will be made clear in the following detailed description. Brief Description of the Drawings Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a perspective view of a first embodiment of an axis; Figure 2 is a perspective view of a second embodiment of an axis; Figure 3 is a plan view of a carry-over section according to a preferred embodiment of the invention; Figure 4 is a side view of the same carry-over section. Description of the Preferred Embodiment First Embodiment Figure 1 shows a first axis 1 around which a rod 2 can rotate once mounted between two supporting plates 3, 4. Off-center pulleys 5 are secured on the rod 2 by screws 6, which force them to rotate at the same rotating speed as the rod 2, with respect to the plates 3, 4. Shouldered bearings 7, 8 are accommodated in dedicated sections, e.g. recesses, provided at both ends of the rod 2. The bearings 7, 8 are prevented from axial movement with respect to the rod 2 by circlips 7', 8' also engaging in dedicated recesses on the rod. The circlips 7', 8' are in a form that allows easy removal with simple tooling. The bearings 7, 8 also are accommodated into corresponding, dedicated housings 20, 21 in the plates 3, 4, which prevent them, and consequently also the rod 2 and the pulleys 5, from axial movement with respect to the plates 3, 4. Figure 1 shows how the rod 2 can be mounted between the plates 3, 4 the bearings 7, 8 being thrust onto their dedicated sections on the rod 2. This embodiment is suitable for driven pulleys, in which case the rod 12 is driven by a drive motor (not shown) . Second Embodiment Figure 2 shows a second axis 1 around which a centered pulley 5 can rotate. The pulley 5 is mounted on a bearing 9, secured on a rod 10. The rod 10 is secured into holes in plates 3, 4 without any bearings of the previous embodiments. Mounting such a rod 10 on plates 3, 4 implies that the hole made in one of the plates, e.g. 4, is connected to the edge of the plate by a rod path (e.g. slot) 19 of a width which is slightly less than the diameter of the rod 10. The rod 10 is provided with a groove 12 of a diameter that is smaller than the width of the rod path 19. To mount the rod 10, it is necessary to first move the rod axially above the edge of the plate 4, introduce its groove 12 through the rod path 19, then thrust the rod 12 axially. The diameter of the end of the rod 12 being larger than the width of the rod path, the rod end cannot escape through the rod path, and circlips 7', 8' secure both ends to the plates 3, 4, preventing any axial movement of the rod 12. This embodiment is suitable for idling pulleys, which support a belt but do not drive the belt. Carry-over Section Figure 3 is a plan view of a carry-over section according to a preferred embodiment of the invention. The first transport sub-system comprises belts 13 supported by pulleys 5 rotating around an axis 1, 11 that can be either one of the embodiments hereabove described. The second transport sub-system comprises belts 14 supported by pulleys 5 rotating around the same axis 1, 11 as the first transport sub-system. Testing elements 15 belong to the part of the validator corresponding to the first transport sub¬ systems; they can be for instance magnetic sensors for detecting magnetic properties of some zones of the documents carried on the transport path. Testing elements 16 can be optical sensors for detecting optical properties of different zones of the document. The elements 16 can also be sensors of the same type as the previous ones 15, to thereby detect the same properties on the whole surface, including both sides if necessary, of the document carried on the transport path. It is clear that the document being tested and carried over by belts 13, 14 which are provided on both sides of the transport path, cannot be misdirected in any manner out of the transport path. Figure 4 is a side view of the same carry-over section as in Figure 3, showing a document 17 in frictional engagement with cooperating belts 13, 13', 14, 14' supported by pulleys 5, 5'. Resilient means 18, for example a system of springs, supported by a fixed rod of the type of figure 2, urge one of the rods, e.g. the rod 2 supporting the upper pulley 5, against the rod 2' supporting the lower pulley 5' . Additional spring means can be installed in the vicinity of pulleys 5, 5' to provide more space for the testing elements 15, 16. Alternatively, the belt path can be bent by an angle of approximatively 90 degrees around the pulley 5' to clear the way for testing elements 15, 16. As disclosed in our earlier international application WO93/21609, incorporated herein by reference, the first (13,14) and second (13',14') sets of belts on either side of the transport path may be mounted in separate sub-housings of the validator, which are hinged together to allow the validator to be opened about the document transport path by separating the first and second sets. In this embodiment, the first and second sub-housings each therefore comprise a pair of parallel plates 3, 3' and 4, 4'. A first set of plates 3, 4 may be as shown in Figure 1 or Figure 2, and the second 3', 4' is essentially a mirror image of the first reflected in a horizontal plane in Figure 1 or Figure 2, so that when hingedly closed together the edges of the plates 3, 3' and 4, 4' abut.

Claims: CLAIMS : 1. A document validator for validating documents of value, in which a document (17) is carried along a transport path, for example for purposes of identification, authentication, rotation, sorting or stacking, said validator comprising a transport system for carrying the document (17) along the path, said transport system comprising a plurality of belts (13, 13', 14, 14') supported by pulleys (5, 5') rotating around axes (1, 11) that are supported by two plates (3, 4), the position of each of the axes (1, 11) being determined by said plates (3, 4) at either side of the belts (13,14), characterized in that the serviceability of the transport system is improved by said axes (1, 11) being easily removable from both plates (3, 4) . 2. A document validator according to claim 1, characterised in that at least some of said axes (1) comprise a rod (2) on which the pulleys (5) are secured, bearings (7,8) being provided at both ends of the rod (2) for locating in both plates (3,4) to allow the rod (2) to turn. 3. A document validator according to claim 1, characterised in that at least some of said axes (11) comprise a rod (10) secured to both plates (3,4) the or each pulley (5) on each said rod (5) being allowed to rotate freely around said rod (5) by means of a bearing (9) coaxial with the pulley (5) and the axis (11) . 4. A document validator according to claim 1, in which the axes comprise rods (2,10) secured to the plates (3,4) with the help of circlips (8'). 5. A document validator according to claim 1, in which said axes (1, 11) may individually be removed from said plates (3,4) without removing either of said plates. 6. A document validator according to claim 1, in which at least one of said plates (4) has a slot (19) leading from an edge thereof to a position at which a said axis (1,11) supports a said belt, said slot (19) defining a path along which said axis can be guided for insertion or removal. 7. A document validator according to claim 6, in which said slot (19) is narrower than an outer dimension of said axis (10) , and said axis (10) has a narrowed portion (12) having an outer dimension which is narrower than said slot. 8. A document validator according to claim 1, in which some of said plurality of belts (13, 13', 14, 14' ) may be removed without removing others. 9. A document validator according to claim 1, in which there are provided a first set of said belts (13, 14) and a second set of said belts (13', 14'), outer surfaces of said first set being close to those of said second set and being arranged to travel in the same direction, so as to define, between said " first and second sets, a document path. 10. A document validator according to claim 9, in which there are provided means (18) for urging one or more axles (5) supporting said first set (13, 14) towards said second set (13', 14'). 11. A document validator according to claim 9, in which said first and second sets (13, 14; 13',14') are supported in respective first and second sets of plates (3,4; 3' ,4') . 12. A document validator according to claim 11, in which said first and second sets of plates (3,4; 3' ,4' ) are articulated together to form a body which hingedly opens about said document path. 13. A banknote validator according to any preceding claim. 14. A transport system for a validator according to any preceding claim, divided into a plurality of transport sub-systems comprising belts (13,13'; 14,14') supported by pulleys (5;5') and providing continuous frictional engagement of a document (17) carried over between two consecutive sub-systems along the transport path. 15. A method of servicing a document validator comprising a plurality of belts (13, 13'; 14, 14') carried on axles (1,10) defining a transport system for carrying a document along a document path, said axles being supported by a pair of plates (3,4) one on either side of the document path, comprising maintaining both plates in alignment, and removing only selected said axles to selectively remove a subset of said belts (13,13' ,14,14' ) whilst leaving another belt or belts between said plates.

Inventors: GERLIER ANDRE, POLIDORO ROBERTO, GERLIER, ANDRE, POLIDORO, ROBERTO
Applicants: GERLIER ANDRE, MARS INC, POLIDORO ROBERTO, GERLIER, ANDRE, MARS INCORPORATED, POLIDORO, ROBERTO
Application year: 1993
Main classification: G07D9
IPC codes: B65H5, G06K9, G06K13, G06T1, G07D7, G07D9, G07F7, G07F19