Patent Publication Number: US-7588491-B2

Title: Coin processing device

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to coin processing devices for performing processing, such as identification and counting, of inserted coins, and in particular to high-speed coin processing by such coin processing devices. 
   This application claims priority from Japanese Patent Application No. 2005-372066, filed on Dec. 26, 2005, the contents of which are incorporated herein by reference. 
   2. Description of Related Art 
   Coin processing devices for performing processing, such as identification and counting, of inserted coins are known. 
   Some of such coin processing devices include a gate mechanism at an opening formed on a transfer passage along which inserted coins are transferred so that the coins are guided into the opening by opening or closing the gate. 
   One of such coin processing devices is disclosed in Japanese Unexamined Utility Model Application, First Publication No. H02-18182. 
   The above-described coin processing device will be described in detail with reference to  FIG. 4 . 
   Referring to  FIG. 4 , a coin processing device includes a transfer passage  101  along which a coin C is transferred in a direction indicated by arrow A in  FIG. 4  and a feed belt B arranged along this transfer passage  101 . 
   An opening  102  through which the coin C falls is formed at an intermediate point of this transfer passage  101 , and a gate  105  having an upper wall  103  and a lower wall  104  is provided at this opening  102 . 
   This gate  105  is rotatably supported slightly below an upstream-end periphery of the opening  102  and is tiltable toward inside of the opening  102  from a position at which an upper surface of the lower wall  104  is flush with an upper surface of the transfer passage  101 . 
   Therefore, when the gate  105  is in a closed state, the coin C transferred from upstream of the transfer passage  101  by driving the feed belt B is guided onto the upper surface of the lower wall  104  and sent to downstream of the transfer passage  101 . 
   On the other hand, in an open state of the gate  105  where a downstream-end portion of the gate  105  is tilted downward, the transferred coin C is guided between the upper wall  103  and the lower wall  104 , striking a lower surface of the upper wall  103  in some cases, into the opening  102 . 
   Provided with the upper wall  103 , the above-described gate  105  is complicated in shape and costly, though the coin C can be guided into the opening  102  reliably. 
   For coin processing devices including a gate support point adjacent to a downstream-end of an opening in order to make the devices simple in structure and less expensive, the functions of both an upper wall and a lower wall can be realized with a lower wall alone. 
   This simplified version of a gate mechanism will be described with reference to the drawings. 
   Referring to  FIGS. 5A and 5B , an opening  102  formed on a transfer passage  101  is provided with a gate  105 A that is rotatably supported by a support shaft  105   a  slightly below a downstream-end periphery of this opening  102 . 
   The gate  105 A extends upward at an oblique angle from a base thereof toward upstream of the opening  102  and includes a guide plate  107  which is formed in a curve from a position flush with an upper surface of the transfer passage  101  toward the upstream-end. The guide plate  107  includes a slit  106  extending in the transfer direction at a substantially central position in the width direction thereof. 
   Because of this slit  106 , the guide plate  107  is prevented from interfering with a feed belt B even when the gate  105 A is tilted to cause an upstream-end thereof to rise. 
   With this structure, when the gate  105 A is in a closed state, the coin C transferred along the transfer passage  101  is guided onto an upper surface of the guide plate  107  toward the downstream-end of the transfer passage  101 . 
   On the other hand, when the gate  105 A is in an open state, the transferred coin C is guided to below the guide plate  107 , striking a lower surface of the guide plate  107  in some cases, into the opening  102 . 
   In short, with the simplified gate  105 A without an upper wall, the coin C can be guided into the opening  102  in the same manner as with the above-described gate  105 . 
   In recent years, there are growing demands for increased throughput of coin processing devices. 
   One approach to enhancing the throughput of such a coin processing device is, for example, to reduce the intervals at which the coins C are transferred (hereinafter, referred to just as the transfer interval) to increase the number of coins that can be processed per unit of time. 
   In the above-described coin processing device including the gate  105 A, however, when the gate  105 A is tilted to enter the open state while the transferred coin C resides on the gate  105 A, the gate  105 A lifts the coin C, which presses up the feed belt B, possibly causing the coin to jam. 
   For this reason, a certain transfer interval d 102  and a certain transfer pitch d 101  for coins C, as indicated in  FIG. 5A , need to be secured in order to prevent the coin C from being lifted by the gate  105 A. In other words, in the known coin processing device including the gate  105 A, there is a problem in that the transfer intervals cannot be shorter than that specified in  FIG. 5A , and therefore, no further improvement in throughput by reducing the transfer intervals can be made. 
   SUMMARY OF THE INVENTION 
   An object of this invention is to provide a coin processing device that can increase the throughput by reducing the coin transfer interval without making the device complicated. 
   In order to achieve the above-described object, a coin processing device according to this invention includes. a passage along which a coin is transferred from an upstream-end toward a downstream-end thereof; an opening formed on the passage; a gate including a guide section that constitutes a part of the passage while the opening is closed and has a stepped portion formed at a portion of the guide section which is closer to the downstream-end of the passage, the gate being tilted so as to lift a portion thereof which is closer to the upstream-end of the passage in a state where the opening is closed to open the opening, and a gate mechanism for causing the coin to fall though the opening by tilting the gate. In this coin processing device, while the gate is open, the stepped portion receives a portion of the coin in the direction of the upstream. 
   According to the coin processing device of this invention, even if the gate is tilted to lift the portion thereof which is closer to the upstream-end of the passage while the portion of the coin in the direction of the upstream is on the gate, the stepped portion of the gate receives the portion of the coin in the direction of the upstream. 
   In other words, the portion of the coin in the direction of the upstream fits on the stepped portion, and therefore, the gate does not press up the coin. 
   For this reason, the transfer interval of coins can be reduced by the amount of the length of the stepped portion. 
   Consequently, the throughput of the device can be improved without making the device complicated. 
   It is preferable that the coin processing device further include: a sensor disposed so as to detect a portion of the coin which is closer to the downstream-end of the passage, the portion of the coin having passed through the gate; and a control unit for tilting the gate not earlier than a point in time when the portion of the coin which is closer to the upstream-end of the passage is receivable in the stepped portion based on a detection result by the sensor. 
   According to the coin processing device of this invention, open/close control of the gate can be performed with high accuracy based on detection by the sensor at an appropriate point in time to prevent the coin disposed at a portion of the gate mechanism which is closer to the downstream-end of the passage from being pressed up by the gate. Therefore, the transfer interval can be made as short as possible. 
   Consequently, the throughput can be further improved without compromising the reliability. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic side view of an overall structure of a coin processing device according to one embodiment of this invention. 
       FIG. 2A  is a plan view of a gate in a closed state, schematically showing a sorting unit of a coin processing device according to one embodiment of this invention. 
       FIG. 2B  is a side view of a gate in a closed state, schematically showing a sorting unit of a coin processing device according to one embodiment of this invention. 
       FIG. 3  is a side view of a gate in an open state, schematically showing a sorting unit of a coin processing device according to one embodiment of this invention. 
       FIG. 4  is a schematic cross-sectional view of a gate of a known coin processing device. 
       FIG. 5A  is a schematic plan view of a gate of a coin processing device. 
       FIG. 5B  is schematic side view of a gate of a coin processing device. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   A coin processing device according to one embodiment of this invention will be described with reference to the drawings. 
     FIG. 1  schematically shows a coin processing device  1  according to this embodiment. 
   The coin processing device  1  includes a device main body  2  and a cart  3  that is attachable to and detachable from this device main body  2 . 
   In the current description, the terms “front,” “rear,” “left,” and “right” correspond to the front (near side of an operator) of the coin processing device  1 , the rear (far side of the operator) of the coin processing device  1 , the left (left side when viewed from the operator) of the coin processing device  1 , and the right (right side when viewed from the operator) of the coin processing device  1 , respectively. 
   The device main body  2  includes, in an upper section thereof, a separating/feeding unit  5  for separating a batch of delivered coins and feeding them one by one. 
   This separating/feeding unit  5  includes a hopper  6 , a rotatable disc  7 , a coin separating unit  8 , and a coin transfer section  9 . 
   A batch of coins are delivered into the hopper  6 . 
   The rotatable disc  7  is disposed below the hopper  6  so as to form a bottom portion of the hopper  6  and can spin horizontally. 
   The coin separating unit  8  includes an opening through which only one coin can pass to deliver the coins one at a time using the centrifugal force of the rotating rotatable disc  7 . 
   The coins delivered one at a time by the coin separating unit  8  are horizontally transferred by the coin transfer section  9  on a passage  9   a  at predetermined intervals. 
   Furthermore, adjacent to an upstream-end of the coin transfer section  9 , the device main body  2  includes an identifying unit  11  for determining the genuine or counterfeit nature and the denomination of coins being transferred by the coin transfer section  9  and for counting these coins. 
   A reject unit (gate mechanisms)  12  for excluding rejected coins determined as not genuine based on a determination result by this identifying unit  11  is provided downstream of the identifying unit  11  in the coin transfer section  9 . 
   Furthermore, downstream of the reject unit  12  in the coin transfer section  9 , sorting units (gate mechanisms)  13   a ,  13   b , and  13   c  for sorting coins determined as genuine and acceptable based on a determination result by the identifying unit  11  are provided at a plurality of (more specifically, three) positions in that order along the transfer direction of the coin transfer section  9 . 
   All the sorting units  13   a ,  13   b , and  13   c  include, on the passage  9   a , sorting-out holes (openings)  14   a ,  14   b , and  14   c , respectively, through which the largest diameter coin (500 yen coin in Japan) can fall. 
   Of these three sorting units, the upstream two sorting units  13   a  and  13   b  include gates  15   a  and  15   b , respectively, that can open and close the sorting-out holes  14   a  and  14   b , respectively. 
   In addition, reach sensors  16   a ,  16   b , and  16   c  for detecting the arrival of a coin are provided upstream of the sorting units  13   a ,  13   b , and  13   c , respectively. 
   Passage sensors (sensors)  17   a  and  17   b  for detecting the passing of a coin are provided downstream of the sorting units  13   a  and  13   b , respectively, disposed at intermediate points of the coin transfer section  9 . 
   Similarly, the reject unit  12  includes a reject hole  14   d , a gate  15   d  that can open and close the reject hole  14   d , a reach sensor  16   d  which is closer to the upstream-end of the coin transfer section  9 , and a passage sensor  17   d  which is closer to the downstream-end of the coin transfer section  9 . 
   The reach sensors  16   a ,  16   b , and  16   d  and the passage sensors  17   a ,  17   b , and  17   d  are used to control the open/close timing of the respective gates  15   a ,  15   b , and  15   d  and also to detect whether a coin jams in the respective gates  15   a ,  15   b , and  15   d.    
   The device main body  2  further includes a detachable reject box  20  for receiving from the coin transfer section  9  those coins excluded by the reject unit  12 ; and temporary retention units  21   a ,  21   b , and  21   c  that are provided at a plurality of (more specifically, three) positions for the sorting units  13   a ,  13   b ,  13   c , respectively, to temporarily reserve coins sorted by the respective sorting units  13   a ,  13   b , and  13   c.    
   When temporarily reserved coins are to be returned, the temporary retention units  21   a ,  21   b , and  21   c  are integrally withdrawn from the device main body  2 . 
   The most upstream temporary retention unit  21   a  is disposed below the most upstream sorting unit  13   a  and, as a result of the gate  15   a  of this sorting unit  13   a  being opened, receives only coins falling through the sorting-out hole  14   a  for temporal retention. 
   The middle temporary retention unit  21   b  is disposed below the middle sorting unit  13   b  and, as a result of the gate  15   b  of this sorting unit  13   b  being opened, receives only coins falling through the sorting-out hole  14   b  for temporary retention. 
   The most downstream temporary retention unit  21   c  is disposed below the most downstream sorting unit  13   c  and receives only coins failing through the sorting-out hole  14   c  for temporal retention. 
   The cart  3  is withdrawn toward a front face  2 A of the device main body  2  by means of rolling casters  22  provided therebelow and is detached from the device main body  2  for transportation. 
   Furthermore, the cart  3  is docked on the device main body  2  from the front face  2 A side. 
   The cart  3  includes a plurality of (more specifically, three) storage boxes  24   a ,  24   b , and  24   c  arranged in line along the front/back direction. 
   These storage boxes  24   a ,  24   b , and  24   c  are provided directly below the plurality of temporary retention units  21   a ,  21   b , and  21   c , respectively, of the device main body  2 . 
   The storage boxes  24   a ,  24   b , and  24   c  receive coins as described below. 
   Only coins temporarily reserved in the temporary retention unit  21   a  are received by the storage box  24   a  to accommodate them by opening the bottom portion of the temporary retention unit  21   a.    
   Only coins temporarily reserved in the temporary retention unit  21   b  are received by the storage box  24   b  to accommodate them by opening the bottom portion of the temporary retention unit  21   b.    
   Only coins temporarily reserved in the temporary retention unit  21   c  are received by the storage box  24   c  to accommodate them by opening the bottom portion of the temporary retention unit  21   c.    
   Moreover, the device main body  2  includes a control unit  26  and a display/operation unit  27 . 
   The control unit  26  controls the driving of the separating/feeding unit  5  and individually controls the gates  15   a  and  15   b  of the sorting units  13   a  and  13   b  and the gate  15   d  of the reject unit  12  based on a determination result by the identifying unit  11  and detection results by the reach sensors  16   a ,  16   b , and  16   d.    
   The display/operation unit  27  presents the operator with visual information and receives input by the operator. 
   The above-described reject unit  12  and the sorting units  13   a  and  13   b  will be described below in detail with reference to  FIGS. 2A and 2B . 
   Since the reject unit  12  and the sorting units  13   a  and  13   b  have the same structure. this embodiment is described by way of example of the sorting unit  13   a.    
   Referring to  FIGS. 2A and 2B , the coin transfer section  9  includes a feed belt B above the passage  9   a , and this feed belt B extends along a direction indicated by arrow A in  FIG. 2A , which is the transfer direction of the coin transfer section  9 . 
   Interposed between this feed belt B and the upper surface of the passage  9   a , a coin C is transferred on the passage  9   a  as the feed belt B is rotationally driven. 
   As described above, the sorting-out hole  14   a  is formed on the passage  9   a , and the gate  15   a  is tiltably disposed at this sorting-out hole  14   a.    
   Tilting of this gate  15   a  is controlled by, for example, an actuator (not shown) based on a control command from the control unit  26 . 
   More specifically, the gate  15   a  includes a shaft  31  extending in the width direction of the passage  9   a  and is supported slightly below a periphery of the sorting-out hole  14   a  which is closer to the downstream-end of the passage  9   a , and a driving source such as an actuator is connected to this shaft  31 . 
   The gate  15   a  further includes a guide plate (guide section)  32 . 
   When the gate  15   a  is in a closed state, the guide plate  32  extends upward at an oblique angle from a base  30  adjacent to the shaft  31  toward the upstream-end of the passage  9   a , and furthermore, the upper surface of the guide plate  32  extends horizontally from a point flush with the upper surface of the coin transfer section  9  toward the upstream-end of the passage  9   a , whereas the lower surface of the guide plate  32  rises in a curve whose tangential gradient becomes gradually moderate toward the upstream-end of the passage  9   a.    
   A transfer surface  32   a  that is flush with the upper surface of the passage  9   a  while the gate  15   a  is in a closed state is formed on a portion of the upper surface of this guide plate  32  which is closer to the upstream-end of the passage  9   a , and this transfer surface  32   a  constitutes the transfer passage together with the passage  9   a.    
   On the other hand, the lower surface of the guide plate  32  constitutes a guide surface  34 , substantially arc in sectional view, whose tangential gradient becomes gradually moderate from the base  30  toward an upstream edge  33  of this guide plate  32 . 
   By providing the guide surface  34  on the lower surface of the guide plate  32  in this manner, the transferred coin C, even after striking the guide surface  34  which is substantially arc in sectional view, smoothly falls into the sorting-out hole  14   a  by preventing the front end thereof from being caught. 
   Furthermore, a slit  36  slightly wider than the feed belt B is formed on the guide plate  32  at a position corresponding to the feed belt B. 
   By providing this slit  36 , the guide plate  32  does not interfere with the feed belt B even though the gate  15   a  tilts about the shaft  31  to enter an open state. 
   Referring to  FIG. 3 , a stepped portion  35  is formed at a portion of the upper surface of the guide plate  32  which is closer to the downstream-end of the passage  9   a.    
   This stepped portion  35  is formed so as to receive a portion (e.g., about one-third area at the upstream end) of the coin C in the direction of the upstream while the gate  15   a  is in an open state. 
   Even when the gate  15   a  is an open state, the guide plate  32  does not press up (i.e., toward the feed belt B) an upstream portion of the coin C by virtue of the stepped portion  35 . 
   More specifically, the above-described stepped portion  35  includes a bottom surface  35   a  which is substantially flush with the upper surface of the passage  9   a  when the gate  15   a  is in an open state and a longitudinal surface  35   b  extending substantially perpendicular to this bottom surface  35   a.    
   This longitudinal surface  35   b  is formed to be substantially arc in plan view (as shown in  FIG. 2A ) whose diameter is slightly greater than the outer diameter of the coin C. Furthermore, the longitudinal surface  35   b  has a height substantially equal to the thickness of the coin C. 
   Although the height of the longitudinal surface  35   b  is not limited to the thickness of the coin C, it is preferable that the height of the longitudinal surface  35   b  be greater than the thickness of the coin C. 
   On a portion of the sorting unit  13   a  which is closer to the upstream-end of the coin transfer section  9 , two reach sensors  16   a  are provided to the left in the transfer direction (lower side on the drawing of  FIG. 2A ), arranged in line along the transfer direction. 
   As described above, these reach sensors  16   a  detect the coin C transferred from upstream with different timings. 
   By providing the two reach sensors  16   a  to the left of the feed belt B side by side in the transfer direction as described above, in which direction (i.e., upstream or downstream) the coin C travels at these reach sensors  16   a  can be detected. 
   As a result, the coins passing by these reach sensors  16   a  can be counted for increment or decrement. 
   On the other hand, two passage sensors  17   a  are provided on a portion of the sorting unit  13   a  which is closer to the downstream-end of the coin transfer section  9 . 
   One of these passage sensors  17   a  is provided at a substantially central position in the width direction of the coin transfer section  9 , and the other passage sensor  17   a  is provided adjacent to a raised wall  9   b  disposed to the left in the transfer direction of the coin C in the coin transfer section  9 . More specifically, these passage sensors  17   a  are arranged side by side along the width direction of the coin transfer section  9 , interposing the locus of the feed belt B therebetween. 
   These passage sensors  17   a  can sense a downstream edge in the transfer direction, that is, the front end of the coin C to detect timing with which an upstream-end portion of the coin C guided and transferred by means of the raised wall  9   b  can be positioned in the stepped portion  35 . 
   More specifically, these passage sensors  17   a  can detect that an upstream edge of a coin C with the largest diameter from among coins that are passing through the gate  15   a  for processing has reached an upstream edge, that is, the longitudinal surface  35   b  of the stepped portion  35 . 
   Furthermore, by providing two passage sensors  17   a , the transfer positions of coins C having different outer diameters can be detected. 
   The above-described reach sensors  16   a  and passage sensors  17   a  are connected to the control unit  26 . 
   The control unit  26  determines the transfer position of the coin C, the transfer direction of the coin C, and so forth based on detection results by the reach sensors  16   a  and the passage sensors  17   a  and an identification result by the above-described identifying unit  11  to control the open/close timing of the gate  15   a.    
   The operation of this embodiment will be described below. 
   First, individual coins put in the hopper  6  are delivered by the coin separating unit  8  to the coin transfer section  9  one at a time. 
   At this time, the transfer intervals of the coins C delivered one at a time need to be equal to or more than a length d 2  in the state shown in  FIGS. 2A and 2B . 
   The length d 2  indicates the distance between the upstream edge (rear end) of a coin C that has passed by the sorting unit  13   a  and the downstream edge (front end), in the transfer direction, of the subsequent coin C (a coin that has not yet passed by the sorting unit  13   a ) at the time the downstream edge (front end), in the transfer direction, of the coin C that has passed by the sorting unit  13   a  reaches the passage sensors  17   a.    
   In  FIGS. 2A and 2B , the position of the subsequent coin C indicates a position closest possible to the sorting-out hole  14   a  so long as the coin C can be sorted into the sorting-out hole  14   a  by switching the gate  15   a  of the sorting unit  13   a  from the closed state to the open state. 
   If the coin C passing by the sorting unit  13   a  is a denomination having the smallest diameter from among coins to be processed, the transfer pitch is equal to a minimum required transfer pitch d 1 . 
   Put another way, the upstream edge of the stepped portion  35 , that is, the position of the longitudinal surface  35   b  is set in accordance with the denomination having the largest diameter from among coins to be processed, and therefore, when the downstream edge (front end), in the transfer direction, of the coin C that has passed by the sorting unit  13   a  reaches the passage sensors  17   a , the gate  15   a  does not press up the coin C passing by the sorting unit  13   a  for any length of time, irrespective of the gate  15   a  of the sorting unit  13   a  being switched from the closed state to the open state. 
   In addition, although the subsequent coin C continues to be transferred by means of the feed belt B also while the gate  15   a  of the sorting unit  13   a  is being switched from the closed state to the open state, a positional relationship that does not cause the downstream edge (front end) of the subsequent coin C to collide with the upstream edge  33  of the guide plate  32  of the gate  15   a  is maintained, as shown in  FIG. 3 , even after the gate  15   a  of the sorting unit  13   a  has been switched from the closed state to the open state. In short, a positional relationship indicated by the transfer interval d 2  and the transfer pitch d 1  is maintained. 
   Although, in this embodiment, the sorting unit  13   a  is used as a reference of the transfer interval for convenience of description, the reject unit  12  and the sorting unit  13   b  can also be used as a reference because the reject unit  12  and the sorting unit  13   b  have the same structure as that of the sorting unit  13   a.    
   If the reject unit  12  and the sorting units  13   a  and  13   b  used as references have different sizes, the one having the largest set transfer interval is preferably used as a reference. 
   The coins C delivered to the coin transfer section  9  are determined by the identifying unit  11  as to whether they are genuine or counterfeit and as to the denomination and then counted. 
   Of the coins C transferred by the coin transfer section  9 , those determined as not genuine are diverted by the reject unit  12  into the reject box  20 . 
   On the other hand, those coins C that have not been rejected are transferred toward the sorting units  13   a  to  13   c  downstream of the reject unit  12 , and based on a determination result by the identifying unit  11 , are sorted by the sorting unit  13   a  or the sorting unit  13   b . Those coins C that have not been sorted by the sorting unit  13   a  or the sorting unit  13   b  are transferred to the sorting unit  13   c.    
   Then, the coins C fall through the sorting-out holes  14   a ,  14   b , and  14   c  of the sorting units  13   a ,  13   b , and  13   c  into the temporary retention units  21   a ,  21   b , and  21   c.    
   Sorting control in the above-described reject unit  12  and the sorting units  13   a  and  13   b  will be described below in detail by way of example of the sorting unit  13   a.    
   Since the transfer speed of coins C by the coin transfer section  9  is known, the transfer distance of coins to be sorted into the temporary retention unit  21   a  is calculated by the control unit  26  based on an elapsed time. 
   In addition, the control unit  26  determines that a coin C which is detected by the reach sensors  16   a  when a period of time reasonable to detect that coin C has passed is the coin to be sorted. 
   Furthermore, in the control unit  26 , when a coin C serving as a coin to be sorted is determined, it is further determined based on a detection result by the passage sensors  17   a  whether or not the upstream edge of the coin C, that has not been sorted, one coin downstream of the coin C in question is located downstream from the upstream edge of the stepped portion  35  formed on the gate  15   a.    
   Thereafter, as shown in  FIG. 2B , if it is determined that the upstream edge of the coin C is located downstream from the upstream edge of the stepped portion  35  and that the time is late enough to allow the upstream end of the coin C to be located in the stepped portion  35  when the gate  15   a  is switched to an open state, then the control unit  26  performs open control of the gate  15   a , and as a result of the gate  15   a  being opened, the coin C as a coin to be sorted is guided into the sorting-out hole  14   a  and reserved in the temporary retention unit  21   a.    
   At this time, even if the guide plate  32  of the gate  15   a  moves up, the downstream coin C is received in the stepped portion  35  and is transferred without pressing up the feed belt B. 
   On the other hand, if it is determined that the upstream edge of the coin C is not located downstream of the upstream edge of the stepped portion  35 , that is, the upstream end of the coin C cannot be positioned in the stepped portion  35 , the control unit  26  performs control in response to abnormalities, such as terminating transfer operation, assuming that a problem such as a transfer jam occurs. 
   Furthermore, after the coin C to be sorted has been stored into the temporary retention unit  21   a , the control unit  26  performs close control of the gate  15   a , for example, when the subsequent coin C not to be sorted is detected by the reach sensors  16   a.    
   When the gate  15   a  is switched to a closed state, the coin C passes through the gate  15   a  toward downstream of the sorting unit  13   a.    
   The above embodiment has been described by way of example of the sorting unit  13   a . Similarly, open/close control of the gate  15   d  is performed based on an identification result by the identifying unit  11  and detection results by the reach sensors  16   d  and the passage sensors  17   d  in the above-described reject unit  12 . Furthermore, open/close control of the gate  15   b  is performed based on an identification result by the identifying unit  11  and detection results by the reach sensors  16   b  and the passage sensors  17   b  in the sorting unit  13   b.    
   Open/close control of these gates  15   d  and  15   b  is the same as that by the above-described sorting unit  13   a , and hence a detailed description thereof will be omitted. 
   On the other hand, coins C that have not been sorted by the reject unit  12 , the sorting unit  13   a , or the sorting unit  13   b  are transferred to the sorting unit  13   c  disposed at a most downstream portion of the coin transfer section  9  and caused to fall through the sorting-out hole  14   c  into the temporary retention unit  21   c.    
   Also in this sorting unit  13   c , if it is determined that a problem such as a jam occurs based on a detection result by the reach sensors  16   c , control in response to abnormalities is carried out in the same manner as with the above-described sorting units  13   a  and  13   b.    
   Therefore, according to the above-described embodiment, even if the gates  15   a ,  15   b , and  15   d  are tilted to raise the upstream ends thereof while the upstream end of a coin C transferred by the coin transfer section  9  is located on the gates  15   a ,  15   b , and  15   d , the upstream end of the coin C can be positioned in the stepped portion  35  formed on the upper surface of the guide plate  32 . 
   Consequently, the gates  15   a ,  15   b , and  15   d  do not lift the coin C and therefore can prevent the coin C from pressing up the feed belt B. 
   As a result, the transfer interval d 2  and the transfer pitch d 1 , which are reduced by the amount of a length d 3  in the transfer direction of the stepped portion  35  compared with the transfer interval d 102  and the transfer pitch  101  of the known art shown in  FIG. 5A , can be employed as shown in  FIG. 2A . 
   For this reason, the coin processing capability per unit of time can be improved. 
   More specifically, assuming that, for example, the speed of the feed belt B is 60,000 mm/min, the transfer interval requires 27.92 mm, and the largest of coins C to be processed has a diameter of 25.8 mm in the known art, the transfer pitch is 53.72 mm, which results in a throughput of 1,116 coins (=60,000/53.72) per minute. According to this invention, a throughput of 1,348 coins (=60,000/44.48) per minute can be achieved without increasing the speed of the feed belt B, that is, merely by reducing the transfer interval of the coins C by the length d 3  (e.g., 9.24 mm=27.92−18.68) in the transfer direction of the stepped portion  35 . 
   It should be noted, however, that the above-described numbers of coins to be processed assume an efficiency of 100%. 
   It is advantageous if the bottom surface  35   a  is longer in the transfer direction, because the greater the length of the bottom surface  35   a  in the transfer direction, the more the transfer interval of coins C can be reduced. However, the greater the length of the bottom surface  35   a , the shorter the distance between the stepped portion  35  and the guide surface  34 , and therefore, it is preferable that the length of the bottom surface  35   a  in the transfer direction be the largest possible, so long as the robustness of the guide plate  32  is ensured and transfer operation is not adversely affected. 
   In addition, since the gates  15   a ,  15   b , and  15   d  include the guide plate  32  supported by the shaft disposed adjacent to the portions of the sorting-out holes  14   a ,  14   b , and  14   d  which are closer to the downstream-end of the coin transfer section  9 , a simple structure can be achieved without making the gates  15   a ,  15   b , and  15   d  complicated in shape. This contributes to preventing an increase in cost. 
   Furthermore, due to the passage sensors  17   a ,  17   b , and  17   d , a coin C can be detected located at a position where it is not pressed up by the gates  15   a ,  15   b , and  15   d . Therefore, the tilting of the gates  15   a ,  15   b , and  15   d  can always be controlled to prevent the coin C from being pressed up. This increases the reliability. 
   In addition, since the position of a coin C, whether before or after the gates  15   a ,  15   b , and  15   d , can be correctly detected by using the reach sensors  16   a ,  16   b , and  16   d  and the passage sensors  17   a ,  17   b , and  17   d , the open/close timing of the gates  15   a ,  15   b , and  15   d  can be controlled with high accuracy by the control unit  26 . This further increases the throughput and the reliability. 
   Although the current embodiment has been described by way of an example where the stepped portion  35  of each of the gates  15   a ,  15   b , and  15   d  is composed of a horizontal bottom surface  35   a  and a longitudinal surface  35   b  extending upward substantially perpendicular to this bottom surface  35   a , this invention is not limited to the stepped portions  35  with such a structure. 
   A stepped portion  35  with any structure is acceptable so long as the stepped portion  35  can receive an upstream end of the coin C.