Abstract:
A banknote stack receiving structure is provided in front of a banknote validator for sequentially passing banknotes to the validator in a serial manner. A first drive arrangement engages one side of an exposed banknote and urges the banknote towards the validator. A restrictive drive cooperates with the first drive and a banknote must pass between opposed rollers of the drives to move to the validator. The restrictive drive roller contacts the opposite side of the exposed banknote but may also contact an overlapping banknote. The restrictive drive rotates to feed a banknote to the validator if a single banknote is present and automatically rotates in an opposite direction if overlapping banknotes are present. This automatic direction of rotation is due to slippage between banknotes and overcoming a low torque motor of the restrictive drive when a single banknote is present.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to banknote validators and in particular, relates to banknote validators that are capable of receiving a stack of banknotes and individually feeding the banknotes through the banknote validator. 
       BACKGROUND OF THE INVENTION 
       [0002]    Automated payment terminals and/or automated teller machines typically include a banknote validator which examines the banknotes and provides an assessment of the validity of the banknotes. Certain banknotes are rejected when confirmation of the validity thereof has produced a negative result. Most banknote validators are designed to receive single banknote with the user appropriately feeding a further banknotes in a serial manner. For many applications, this is sufficient, however, there are circumstances where it is desirable to have a user insert a stack of banknotes with the device then feeding the banknotes in series through the validator. 
         [0003]    Although the concept of feeding the top or bottom banknote from a banknote stack through a validator is straightforward, in actual practice, it is difficult to provide a device which avoids feeding of overlapped banknotes. As can be appreciated, the quality of the banknotes provided to the device by the user, varies considerably and this substantial variation in the quality presents further design challenges. 
         [0004]    The present invention provides a banknote restricting drive which allows a stack of banknotes to be inputted into the device and the banknotes to be serially fed through an associated validator. 
       SUMMARY OF THE INVENTION 
       [0005]    A banknote restricting drive according to the present invention comprises a banknote receiving cavity for receiving a stack of banknotes, a first drive arrangement for engaging an exposed banknote on one side of the stack of banknotes and driving the exposed banknote into a banknote validator section. A banknote restricting drive arrangement cooperates with the first drive arrangement to limit the passage of banknotes therebetween to a single thickness banknote. The banknote restricting device includes a motor providing a low torque rotating the banknote restricting drive in a reverse direction urging a banknote to the receiving cavity when two banknotes attempt to pass between the first drive arrangement and the banknote restricting drive arrangement. The first drive arrangement is driven at a higher torque and provides sufficient force on the exposed banknote such that the exposed banknote overpowers the torque of the banknote restricting drive causing the banknote restricting drive to rotate in a direction to pass the exposed banknote to the validating section. If two banknotes attempt to pass between the first drive and the restricting drive, the banknotes slip relative to each other allowing the restricting drive to automatically rotate to reject the additional banknote. 
         [0006]    According to an aspect of the invention, the first drive arrangement and the restricting drive arrangement each have a coefficient of friction with the banknote higher than a coefficient of friction between two banknotes. 
         [0007]    In yet a further aspect of the invention, the banknote receiving cavity narrows towards an engagement point of the first drive and the restricting drive arrangement. 
         [0008]    In yet a further aspect of the invention, the restricting drive arrangement is directly opposed the first drive arrangement. 
         [0009]    In yet a further aspect of the invention, the apparatus includes a sensor arrangement for detecting initial insertion of a stack of banknotes into the banknote receiving cavity and an actuator associated with the sensor arrangement that moves the first drive arrangement to a clear position allowing the insertion of the stack of banknotes into the banknote receiving cavity to a start position. The sensor arrangement senses the position of the stack of banknotes in the start and then causes the actuator to move the first drive arrangement to a banknote engaged position. 
         [0010]    In yet a further aspect of the invention, the first drive arrangement includes a lead roller movable between the clear position and the engaged position and at least one downstream roller cooperating with at least one drive roller of the banknote restricting drive arrangement. 
         [0011]    In yet a further aspect of the invention, the first drive arrangement includes two downstream rollers and said restricting drive arrangement includes two drive rollers in opposed relationship with the two downstream rollers of the first drive arrangement for separating of overlapped banknotes. 
         [0012]    In a different aspect of the invention, the two downstream rollers of the first drive arrangement and the two downstream rollers of the banknote restricting drive arrangement, each includes an outer sleeve of a material having a high coefficient of friction with a banknote. 
         [0013]    In a different aspect of the invention, the lead roller of the first drive arrangement is provided on a pivoting arm controlled by the actuator to move between the clear position and the banknote engaged position. 
         [0014]    In a preferred aspect of the invention, the pivoting arm includes a spring bias urging the arm to the banknote engaged position. 
         [0015]    In yet a further aspect of the invention, the apparatus includes a trailing edge sensor at a discharged position of the banknote restricting drive for sensing the passing of a trailing edge of a banknote from the downstream rollers. The trailing edge sensor temporarily controls the first drive arrangement and temporarily controls the first drive arrangement when the passing of a trailing edge of a banknote is sensed by the trailing edge sensor. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    Preferred embodiments of the invention are shown in the drawings, wherein: 
           [0017]      FIG. 1  is a perspective view of the validator with a banknote stacked receiving arrangement; 
           [0018]      FIG. 2  is a sectional view of the validator with a banknote stacked receiving arrangement; 
           [0019]      FIG. 3  is a partial schematic showing the banknote stacked receiving arrangement; 
           [0020]      FIG. 4  is a partial perspective view showing certain drive rollers of the banknote stacked receiving arrangement; 
           [0021]      FIG. 5  is a partial schematic view showing a drive train arrangement connecting the validator and the banknote stacked receiving arrangement; 
           [0022]      FIG. 6  is a schematic view similar to  FIG. 5  with a secondary banknote being held in the banknote receiving arrangement; 
           [0023]      FIG. 7  is a schematic view similar to  FIG. 5  showing the rejection of a banknote; 
           [0024]      FIG. 8  is a schematic view of two drive rollers rotating to pass a single banknote; 
           [0025]      FIG. 9  shows the two rollers of  FIG. 8  with one roller rotating in the opposite direction as a second banknote is attempting to be fed through the device; 
           [0026]      FIG. 10  illustrates a torque adjustment structure; and 
           [0027]      FIG. 11  illustrates a rotation sensor. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0028]    The validator  100  is designed to have a user insert a stack of banknotes indicated as  104  in the banknote receiving cavity  102 . The banknotes are fed from the top of the stack  104  individually through the validator where various sensors  130  determine the validity of the individual banknotes. 
         [0029]    Adjacent the banknote receiving cavity  102  is a first drive arrangement  106  which includes the drive rollers  114  and  116 . These drive rollers are interconnected by a drive train as shown in  FIGS. 5 through 7 . 
         [0030]    The first drive roller  114  as shown in  FIG. 3  is connected on the pivoting lever arm  132  allowing movement of the roller between the engaged position of  FIG. 3  to a disengaged position where the periphery of roller  114  is generally adjacent the upper surface of the banknote receiving cavity  102 . A sensing arrangement  122  is provided immediately downstream of roller  114 . In this case, a light emitter is provided to one side of the cavity and a receiver is provided to the opposite side of the cavity. The insertion of the stack of banknotes into the receiving cavity interrupts this signal and the lever arm  132  is moved by the actuator  134  via the linkage  138  to position the roller  114  in a clear position. 
         [0031]    A second sensor arrangement  124  is provided immediately in front of the first drive roller  116  and the restricting drive roller  118 . Once the stack of banknotes are sensed in this position, the actuator  134  releases the lever arm  132  such that the drive wheel  114  engages the upper banknote due to a spring bias on the lever arm  132 . Other arrangements can also be used. 
         [0032]    Before considering the precise mechanism for providing the series of individual banknotes being fed to the validating section  131 , it may be helpful to consider how the individual banknotes are separated from the stack. Basically the first drive rollers  114  and  116  contact the upper most banknote and when driven, these rollers advance the banknote into the pressure gap defined by roller  118  being in contact with roller  116 . In the preferred structure as shown in  FIG. 4 , the rollers  116  and  118  are two pairs of rollers. 
         [0033]    Roller  118  is driven by motor  8 , however, this is a variable torque motor having a relatively low torque. Drive wheel  118  is urged by motor  8  to rotate in a clockwise direction. Therefore any underlying banknote will be driven to return to the cavity  102 . The torque of the low torque motor  8  is adjusted such that the torque is overcome by the force of drive wheel  116  in contact with the drive wheel  118  if a banknote is not present. 
         [0034]    In this situation, motor  6  drives drive wheel  116  and it will overpower the torque being applied to drive wheel  118  by motor  8  such that drive wheel  116  and  118  rotate to allow feeding of a banknote therebetween. The motor  8  is designed to withstand the prolonged stalls of the motor that occur when a single banknote passes through the rollers. A high resistance DC brush roller works satisfactorily. If a single banknote is presented to the nip between rollers  116  and  118 , roller  118  will continue to rotate in a counterclockwise direction with the intermediate banknote providing the component for transferring the force between roller  116  and  118 . Basically the coefficient of friction of roller  116  to a banknote and the coefficient of friction between the banknote and roller  118  are relatively high and overcome the torque being applied by motor  8 . If two banknotes are presented to the gap between roller  116  and  118 , roller  118  will rotate in the opposite direction. Basically the coefficient of friction between the two banknotes is much lower and therefore drive roller  118  will rotate clockwise and thereby return the lower banknote to the banknote cavity. Thus if two or more banknotes are provided to the gap, roller  118  will rotate clockwise and will reject these banknotes. Once a single banknote is in the gap, roller  118  will then automatically rotate counterclockwise. This particular arrangement has proven effective for limiting the passage of the banknotes between rollers  116  and  118  to banknotes in series. Preferably the motor  108  includes a torque adjustment arrangement to ensure that the torque being applied to roller  118  is low enough to be overcome by roller  116  under changing conditions. 
         [0035]    With the embodiment as shown in  FIG. 2 , movement of roller  114  to the clear position allows the banknote stack  104  to be inserted into the downwardly inclined cavity  102  to meet with the curved transition segment  103  and pass upwardly towards the drive rollers  116  and  118 . It can be seen that roller  118  basically interrupts the passage and acts as a partial stop for the stack of banknotes. Once sensors  124  senses the stack of banknotes, roller  114  is moved to the engaged position. 
         [0036]      FIG. 3  shows a further aspect of the invention where the banknote receiving cavity  102  has been provided with a series of ports  136  to allow coins, dirt, liquid, etc. to pass through the receiving cavity. 
         [0037]      FIG. 3  also illustrates a further sensing arrangement  140  that preferably senses the trailing edge of a banknote and preferably can sense a double banknote condition. As a single banknote is passed between the rollers  116  and  118 , the sensor  140  detects the trailing edge of the banknote. Once the trailing edge of the banknote has been sensed, motor  6  that drives rollers  114  and  116  is stopped. In this way, the individual banknote is fed on to the validating section  131  as the drive rollers  142 ,  144 ,  146  and  148  continue to be driven by motor  5 . After a certain period of time, motor  6  is actuated for feeding of the next banknote to the validating section. This arrangement reduces the time duration motor  108  is in a stall condition. 
         [0038]    As shown in  FIG. 5 , drive rollers  142 ,  144 ,  146  and  148  are interlinked by a gear train  150  where the motor  5  effectively drives gear  152 . In this way, the speed of rollers  142 ,  144 ,  146  and  148  are maintained in synchronization. These rollers are also synchronized with the drive rollers  114  and  116  via the gear train  154 . The gear train includes an overrunning clutch  156 . This overrunning clutch  156  allows the gear train  154  to be effectively stopped while allowing gear train  150  to continue to drive rollers  142 ,  144 ,  146  and  148 . In gear train  154 , gear  158  is effectively driven by the motor  6 . 
         [0039]    Motor  6  is run at a slightly reduced speed relative to motor  5 , however, the driver rollers  114  and  116  are kept synchronized with the drive rollers  142 ,  144 ,  146  and  148 . Any slight speed difference between the motors is accommodated by the overrunning clutch  156 . When gear  158  is effectively stopped by stopping motor  6 , drive rollers  114  and  116  are stopped. As can be appreciated, motor  6  is stopped to allow separation between the banknotes being fed in series to the validating section  131 . Motors  5  and  6  are reversible motors to allow the feeding of a banknote in the direction shown in  FIGS. 5 and 6  as well as to allow the rejection of a banknote as shown in  FIG. 7 . 
         [0040]    The principle which allows separation of the banknotes into a series of individual banknotes can be appreciated from a review of  FIGS. 8 ,  9 , and  11 . 
         [0041]    In  FIG. 8 , a single banknote  161  is shown passing between drive roller  116  and restricting drive roller  118 . Even through drive roller  118  is having a torque applied thereto by motor  108  which would cause a clockwise rotation of the roller, the roller rotates counterclockwise as it is effectively overpowered by roller  116  and the frictional engagement with the banknote  161 . When two banknotes attempt to pass between rollers  116  and  118  as shown in  FIG. 9 , the top banknote  161  is driven by roller  116  and will continue to be forced through the rollers to the validating section. The underlying banknote  163  will be urged to return to the banknote receiving cavity  102 . 
         [0042]    Basically the banknotes  161  and  163  have a low coefficient friction therebetween, and as such, roller  118  having a relatively high coefficient with banknote  163 , is automatically free to rotate clockwise by the motor  5  and the banknote  163  will be returned to the banknote receiving cavity. Therefore the lower coefficient of friction between the banknotes is effectively used to provide slippage between banknotes and the forcing of the underlying banknote to return to the cavity due to its engagement with roller  118  that is now rotating clockwise due to the slippage between the banknotes. As soon as the banknote  163  is free of the gap between the rollers  116  and  118 , roller  118  will rotate counterclockwise as shown in  FIG. 8 . 
         [0043]    As can be appreciated, as soon as an additional banknote attempts to pass through the rollers, slippage between the banknotes occurs, and roller  118  will automatically rotate clockwise. This arrangement has proven particularly effective in avoiding the passing of two banknotes between rollers  116  and  118 . 
         [0044]    As shown in  FIG. 4 , rollers  116  and  118  are essentially two pairs of rollers provided across the banknote. Preferably, roller  114  is a single roller provided adjacent the center line of the banknote processing path. 
         [0045]      FIGS. 10 and 11  provide additional details regarding one embodiment for control of the variable torque motor  108 . The condition of the banknotes and particularly the amount where the banknotes and the amount of dirt on the banknotes render it difficult to provide a single setting of the motor torque that will assure separation of the banknotes. The arrangement as shown in  FIGS. 10 and 11  allow for adjustment of the motor torque through the controller  121 . 
         [0046]    As previously described, the feed roller  116  and the separating roller  118  cooperate to separate a double layer of banknotes passing between the rollers. In addition, the sensor  140  is capable of detecting a double banknote condition. As can be appreciated, if the coefficient of friction between two banknotes is high enough to overcome the torque being applied by the variable torque motor  108 , then two banknotes will be processed. 
         [0047]    With the sensor  140 , detecting a double banknote condition, this signal is provided to the controller  121  which is able to adjust the torque of motor  108  until the sensor  140  no longer detects a double banknote condition. This increase is carried out as the double banknotes are being processed and the banknotes can be returned to the stacked condition if the separation is not successful. 
         [0048]    To assist the system, the variable torque  108  includes a rotation sensor  119  associated with the separation roller  118 . The rotation sensor  119  can be quite accurate and provides feedback with respect to the direction of rotation of roller  118 . This is helpful in that when a double banknote condition is detected by  140  and the torque is being increased, the rotation sensor  119  can determine when the torque is sufficient to separate the banknotes. 
         [0049]    The rotation sensor  119  is partially shown in  FIG. 11  and includes a rotating member  123  with a series of spaced teeth  125  thereon which move past a series of infrared beams  127 . This provides fast accurate feedback with respect to rotation direction. 
         [0050]    In addition to monitoring for a double banknote condition during normal operation of the device, the arrangement is also used as part of a calibration process which is carried out periodically, for example, at power up of the device. The torque calibration process for setting the torque value is as follows: 1) With no bills in the device, feed roller  116  is driven in its normal manner. Variable torque motor  108  is set at a relatively low torque value and the rotation sensor is monitored to determine the direction of rotation of separation roller  118 . If roller  118  is not rotating, then there is no requirement to change the torque. If roller  118  is rotating in sympathy with roller  116 , then the torque is increased. The torque is increased until such time as there is no rotation of roller  118 . Once the calibration has been completed, the particular torque is then reduced to an operating level of between 70 and 80%. This particular level has been found to be effective in separating of the banknotes. This calibration arrangement takes into account the working conditions of the separating arrangement and partially reflects the surface conditions of the rollers which can deteriorate due to dirt, etc. 
         [0051]    It is also possible to operate the system in a slightly different manner. In this case, after the calibration and a determination of the torque necessary to hold roller  118  stationary when in contact with roller  116 , controller  121  adjusts the variable torque motor  108  to a setting of approximately 20 to 30 percent of the calibrated torque. With this lower torque arrangement, the rollers  116  and  118  will allow the banknote to pass therebetween, but may allow two banknotes to pass therebetween. The sensor  140  then senses a double banknote condition. Once this condition is detected, the torque on motor  108  can be increased until such time as the rotation sensor  119  detects a reverse rotation. At that point, the torque can remain until the double banknote condition has been overcome. 
         [0052]    From the above it can be appreciated that variations in operating procedures for adjusting the torque on the motor  108  are possible using the rotational sensor  119  for determining the direction of rotation of roller  118  in combination with the double banknote sensor  140 . 
         [0053]    A further feature of the validator  100  is the ability to access the first drive  106  and the banknote restricting drive  108 . Access to this is provided by the access door  180  which is pivoted at  182  to swing upwardly. A latch  184  is provided at the free edge of the lid  180 . Release of the latch  184  allows the drive rollers  114  and  116  to move upwardly with the lid. The drive gears can also move upwardly or being provided at the sides of the lid. This provides excellent access to the banknote receiving cavity for service of any of the components and/or clearing of anything lodged within the device. Similarly, the banknote validating section  131  can be accessed via the access door  186  pivoted at  188  and having the releasable latch  190 . Release of latch  180  allows the access door  186  to move into the left about the pivot point  188  to provide access to the banknote processing path. 
         [0054]    Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.