Patent Publication Number: US-8540143-B2

Title: Cassette for automated teller machine

Description:
TECHNICAL FIELD 
     The present invention relates to a cassette for an automatic teller machine (ATM) and, more particularly, to a cassette for an ATM, which is capable of returning a paper medium disposed at an entrance of the cassette into the cassette, during separation of the cassette from a cassette receiving portion. 
     BACKGROUND ART 
     Generally, an automatic teller machine (ATM) refers to an automated apparatus providing fundamental monetary services, such as payment and withdrawal of cash and check, using a card or a bankbook regardless of time and places without a bank teller. Recently, use of the ATM is not limited to banking facilities such as banks but expanded to convenience stores, department stores, and other public places. 
     The ATM may be classified into a cash dispenser, a cash receiver, and a cash dispenser and receiver. In these days, the ATM is used for not only payment and withdrawal of cash but also payment and withdrawal of check, bankbook arrangement, fee payment by giro, ticketing, and the like. 
     Inside the ATM, a transfer path is formed for transfer of a paper medium such as cash, checks, tickets, merchandise coupons, and the like. In addition, the ATM may include a cassette receiving portion to removably receive a cassette. The cassette is adapted to receive a paper medium to be dispensed to a customer or a paper medium received from a customer. Therefore, by transferring the cassette, the paper medium may be conveniently transferred to the outside of the ATM. Also, the paper medium in the ATM may be conveniently changed by replacing the cassette. 
     When the cassette is connected to the cassette receiving portion, an end of the transfer path is disposed at an entrance. Therefore, the paper medium in the cassette may be introduced to the end of the transfer path through the entrance and dispensed to a dispenser portion through the transfer path. In addition, the paper medium transferred along the transfer path may be stored in the cassette through the entrance. 
     However, when the cassette used for dispensing the paper medium is separated, the paper medium may remain at the entrance of the cassette being separated. Therefore, the paper medium may be partially exposed through the entrance of the cassette separated from the cassette receiving portion. Furthermore, when the cassette is connected again to the cassette receiving portion, the paper medium remaining at the entrance may cause a jam. 
     DISCLOSURE OF INVENTION 
     Technical Goals 
     An aspect of the present invention provides a cassette of an automatic teller machine (ATM), the cassette capable of returning a paper medium abnormally disposed at an entrance of the cassette at the time of separating the cassette into the cassette in advance, thereby increasing security and reliability in use of the cassette, and also capable of preventing a jam of the paper medium disposed at the entrance at the time of connecting the cassette. 
     Another aspect of the present invention provides a cassette of an ATM, the cassette capable of easily returning a paper medium disposed at an entrance using a moving force of a shutter that opens and closes the entrance during connection and separation of the cassette, and simplifying a structure for returning of the paper medium. 
     Technical Solutions 
     According to an aspect of the present invention, there is provided a cassette for an automatic teller machine (ATM), the cassette removably connected to a cassette receiving portion formed at a main body of the ATM. 
     The cassette may include a cassette body connected and separated with respect to the cassette receiving portion and configured to receive a paper medium, including an entrance disposed at one side for entry of the paper medium, a shutter movably formed at the cassette body to open and close the entrance according to connection and separation of the cassette body with respect to the cassette receiving portion, a first medium support portion movably formed in the cassette body to push the paper medium toward the entrance, a second medium support portion movably formed at the entrance so that the paper medium is disposed between the first medium support portion and the second medium support portion, a connection portion connected to each of opposite ends of the second medium support portion and movably connected at opposite lateral sides of the cassette body, and a medium return gear portion rotatably formed at each of the opposite lateral sides of the cassette body so as to be connected to a connection portion gear connected to the connection portion and to a shutter gear formed at the shutter, the medium return gear portion configured to forcibly move the connection portion in a first direction away from the entrance by a moving force of the shutter when the entrance is closed. 
     That is, when the cassette is separated, the second medium support portion may be forcibly moved in the first direction using the moving force of the shutter moving in the direction for closing the entrance. Accordingly, the paper medium disposed at the entrance may be return into the cassette body by the second medium support portion. Therefore, the paper medium may be prevented from being abnormally disposed at the entrance of the cassette separated from the cassette receiving portion. 
     The opposite ends of the second medium support portion may include connection holes or connection grooves in which connection projections formed at the portion portion are movably inserted. The connection holes or the connection grooves may extend in a movement direction of the second medium support portion to be longer than a movement distance of the second medium support portion. The second medium support portion and the cassette body may include a return spring to provide an elastic force in a second direction toward an initial position of the second medium support portion. 
     Therefore, when the connection portion is moved in the first direction, the connection projections may be caught in the connection holes or connection grooves, thereby moving the second medium support portion in the first direction. When the connection portion is moved in the second direction, the connection projections are released. Therefore, the second medium support portion may be moved in the second direction by the return spring. 
     The cassette may further include a locking portion disposed at each of the opposite lateral sides of the cassette body, respectively, to restrict movement of the second medium support portion until the first medium support portion is operated when the connection portion is moved in the second direction. That is, although the connection portion is moved in the second direction by the medium return gear portion, the second medium support portion may be maintained in a state of being prevented from moving by the locking portion until the first medium support portion is operated. Therefore, when the cassette is connected, the paper medium may be stably supported by the first medium support portion and the second medium support portion. 
     Here, the opposite ends of the second medium support portion may include a locking hole or locking recess. The locking portion may include a locking projection movably formed at the cassette body to be inserted in the locking hole or locking recess when the second medium support portion is moved in the first direction and separated from the locking hole or locking recess when the second medium support portion is moved in the second direction, and an elastic member disposed between the locking projection and the cassette body to elastically support the locking projection. 
     Therefore, only when the first medium support portion applies a pressure greater than an elastic force of the elastic member to the paper medium, the locking state of the second medium support portion may be overcome. Next, the second medium support portion may return to an initial position by the elastic force of the return spring. 
     The shutter gear may be extended by a predetermined length at each of the opposite lateral sides of the shutter to move the connection portion by a predetermined distance in the first direction at the beginning of closing the entrance or to move the connection portion by a predetermined distance in the second direction right before the entrance is fully opened. That is, the shutter gear may extend along the movement direction of the shutter at the opposite lateral sides of the shutter corresponding to the medium return gear portion. The shutter gear may be extended by a predetermine length so that the second medium support portion is moved at a particular point of time. The particular point of time may include at the beginning of closing the entrance and right before the entrance is fully opened. At the particular point of time, returning of the paper medium by the second medium support portion may be more efficiently performed. Also, the paper medium may be more stably supported by the second medium support portion and the first medium support portion. 
     The shutter may include a first stopper disposed at each opposite sides to the opposite lateral sides of the shutter and extended in a movement direction of the shutter. The medium return gear portion may include a second stopper disposed at one side of the medium return gear portion to be brought into contact with the first stopper in a sliding manner so as to restrict rotation of the medium return gear portion when the shutter gear and the medium return gear portion are not connected. Therefore, the medium return gear portion may be rotated only when connected to the shutter gear but may be stopped by the first stopper and the second stopper in the other states. 
     The opposite lateral sides of the cassette body may each include a pressed portion pressed by a predetermined depth by interference with an interference portion formed at the cassette receiving portion when the cassette is connected. The pressed portion may include a pressed portion gear disposed at one side of the pressed portion to restrict rotation of the medium return gear portion through connection with the medium return gear portion. Connection between the medium return gear portion and the pressed portion gear may be released when the pressed portion is pressed by the predetermined depth. The pressed portion may be interfered with the interference portion before the medium return gear portion and the shutter gear are connected when the cassette is connected, and interference between the pressed portion and the interference portion may be released after the medium return gear portion and the shutter gear are connected when the cassette is separated. 
     Therefore, since the restricted state of the pressed portion gear and the medium return gear portion is released only when the cassette is connected in the cassette receiving portion including the interference portion, undesired opening of the entrance may be prevented. Accordingly, security and stability of the cassette may be increased. 
     The second medium support portion may include a support portion body movably disposed in the cassette body, opposite ends of which are extended along the opposite lateral sides of the cassette body, a plurality of support projections protruded from the support portion body toward the entrance and brought into contact with the paper medium when the connection portion is returned in the first direction, and a rubber pad removably connected by enclosing an outer circumference of the support projections to increase a contact force between the support projections and the paper medium. Accordingly, since a contact force between the second medium support portion and the paper medium is increased by the rubber pad, returning efficiency of the paper medium by the second medium support portion may be increased. 
     The rubber pad may include an upper fitting portion formed in a ring shape to be fit with an upper fixing recess formed at an upper portion of each of the support projection, a lower fitting portion formed in a ring shape to be fit with a lower fixing recess of each of the support projections, and a contact portion connected to the upper fitting portion and the lower fitting portion and disposed at a contact surface of the support projections contacting the paper medium. Therefore, the rubber pad may be simply connected and separated by the support projection. Accordingly, cost and time for maintenance of the rubber pad may be reduced. 
     Effects of Invention 
     A cassette for an automatic teller machine (ATM) according to an embodiment of the present invention returns a paper medium disposed at an entrance into a cassette body by a moving force of a shutter that opens and closes the entrance during separation of the cassette. Therefore, during separation of the cassette, exposure of the paper medium out of the cassette through the entrance may be overcome. In addition, a jam caused by the paper medium disposed at the entrance may be prevented. Accordingly, security and reliability in connection and separation of the cassette may be increased. 
     In addition, the cassette for the ATM according to the embodiment of the present invention has a simple structure in which a medium return gear portion is connected to a shutter gear formed at the shutter and to a connection portion gear of a connection portion connected to a second medium support portion. Therefore, the structure may be applied to various types of cassette and reduce an installation space. 
     The cassette according to the embodiment of the present invention is structured to drive the second medium support portion by the moving force of the shutter that opens and closes the entrance. Therefore, a dedicated power source is not necessary. Consequently, a structure for transmitting and controlling power may be omitted. 
     Furthermore, the cassette according to an embodiment of the present invention may control an operation time and operation distance simply by switching the medium return gear portion, the shutter gear, and the connection portion gear. Accordingly, the cassette may be conveniently designed according to design conditions and circumstances. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram illustrating an automatic teller machine (ATM) according to an embodiment of the present invention. 
         FIG. 2  is a perspective view illustrating a cassette receiving portion of the ATM shown in  FIG. 1 . 
         FIG. 3  is a perspective view illustrating a cassette of the ATM shown in  FIG. 1 . 
         FIGS. 4 and 5  are state views illustrating operation of a shutter during connection and separation of the cassette. 
         FIGS. 6 through 13  are state views illustrating operation of a second medium support portion, a connection portion, and a medium return gear portion during connection and separation of a cassette, according to an embodiment of the present invention. 
         FIG. 14  is a perspective view illustrating main parts of the cassette shown in  FIGS. 6 through 13 . 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures. 
       FIG. 1  is a diagram illustrating an automatic teller machine (ATM)  100  according to an embodiment of the present invention. 
     Referring to  FIG. 1 , the ATM  100  may include a main body  110  and a cassette  120 . For a convenient explanation, the ATM  100  will be described as functioning as only a dispenser of a paper medium P. However, the embodiment is also applicable to an ATM  100  performing a receiving function or a receiving and dispensing function of a paper medium P. The paper medium P may include banknotes, checks, merchandise coupons, bills, coupons, and the like. However, hereinafter, the paper medium P will be described as banknotes. 
     The main body  110  may include a medium transfer portion  111 , a carriage  112 , a rotor  113 , dispenser portions  114 ,  115 , and  116 , a reject box  117 , and a reject transfer portion  118 . 
     The medium transfer portion  111  may transfer the paper medium P supplied from the cassette  120  and temporarily stack the paper medium P in the carriage  112 . The carriage  112  may dispense the paper medium P transferred by the medium transfer portion  111  through the dispenser portions  114 ,  115 , and  116  in a bundle. The rotor  113  may be rotated along with the carriage  112  so that the carriage  112  is moved to any one of the dispenser portions  114 ,  115 , and  116 . The reject box  117  may store a paper medium including at least two sheets or a skewed paper medium. By the reject transfer portion  118 , the paper medium including at least two sheets or the skewed paper medium may be guided directly to the reject box  117 , without passing through the carriage  112  and the rotor  113 . 
       FIG. 2  is a perspective view illustrating a cassette receiving portion  122  of the ATM  100  shown in  FIG. 1 .  FIG. 3  is a perspective view illustrating the cassette  120  of the ATM  100  shown in  FIG. 1 .  FIGS. 4 and 5  are state views illustrating operation of a shutter  40  during connection and separation of the cassette  120 . 
     Referring to  FIGS. 1 to 3 , the cassette  120  may be connected in an arrowed direction A and separated in an arrowed direction B with respect to the cassette receiving portion  122  disposed at the main body  110 . The cassette receiving portion  122  may be disposed at a lower portion of the main body  110 . The cassette receiving portion  122  may include a plurality of receiving spaces for receiving a plurality of cassettes  120 . The cassette receiving portion  122  may include a medium separation portion  122   a  to separate the paper medium P received in the cassette  120  into individual sheets and transfer the separated paper medium P to the medium transfer portion  111 . 
     The cassette  120  may include a cassette body  130 , a shutter  140 , a first medium support portion  150 , a second medium support portion  160 , a connection portion  170 , a medium return gear portion  180 , and a locking portion  190 . 
     The cassette body  130  may be removably received in a receiving space of the cassette receiving portion  122 . The paper medium P may be received in the cassette body  130 . An entrance  132  through which the paper medium P comes in and out may be formed at a front side of the cassette body  130 . Here, when the cassette  120  is inserted in the arrowed direction A for connection to the cassette receiving portion  130 , the medium separation portion  122   a  is inserted in the entrance  132  and brought into close contact with the medium P received in the cassette body  130 . 
     The shutter  140  may be movably formed at the cassette body  130  to open and close the entrance  132 . The shutter  140  may open the entrance  132  as the cassette body  130  is received in the direction A. Since the shutter  140  is opened in advance by the cassette body  130  being received in the cassette receiving portion  122 , the medium separation portion  122   a  being inserted in the entrance  132  may not be interfered with the shutter  140 . 
     When the cassette body  130  is separated from the cassette receiving portion  122  in the direction B, the shutter  140  may be moved in a direction for closing the entrance  132 . The shutter  140  may slide along a front side and a lower side of the cassette  120 . However, the entrance  132  and the shutter  140  may be disposed in various other positions of the cassette body  130  depending on design conditions and circumstances. Also, a shape and an opening and closing system of the shutter  140  may be varied. 
     Referring to  FIGS. 2 ,  4 , and  5 , the shutter  140  may include shutter stoppers  142  and  144 . The cassette receiving portion  122  may include a shutter operation lever  124  caught by the shutter stoppers  142  and  144  when the paper medium  120  is connected in the direction A and separated in the direction B. That is, when the cassette  120  is connected to the cassette receiving portion  122  in the direction A, the shutter operation lever  124  may be caught by the shutter stoppers  142  and  144 . The shutter stoppers  142  and  144  and the shutter  140  may be relatively moved together in a direction for opening the entrance  132 . When the cassette  120  is separated from the cassette receiving portion  122  in the direction B, the shutter stoppers  142  and  144  and the shutter operation lever  124  in engagement with each other may relatively move in a direction for closing the entrance  132 . When the entrance  132  is closed by the shutter  140 , the shutter operation lever  124  may be separated from the shutter stoppers  142  and  144 . 
     The shutter operation lever  124  and the shutter stoppers  142  and  144  may be in various structures and shapes depending on the design conditions and circumstances of the cassette  120 . Hereinafter, according to the present embodiment, the shutter  140  will be described to be opened and closed with respect to the cassette  120 . However, alternatively, the cassette body  130  may be moved with respect to the main body  110  with the shutter  140  in a fixed position. 
       FIGS. 6 through 13  are state views illustrating operation of a second medium support portion  160 , a connection portion  170 , and a medium return gear portion  180  of when a cassette  120  is connected and separated, according to an embodiment of the present invention.  FIG. 14  is a perspective view illustrating main parts of the cassette  120  shown in  FIGS. 6 through 13 . In  FIGS. 6 through 13 , a cover disposed at an outside is omitted for inspection of operational states of main parts of when the cassette  120  is connected and separated. 
     Referring to  FIGS. 6 through 14 , the first medium support portion  150 , which is a member for pushing the paper medium P in the cassette body  130  toward the entrance  132 , may be movably formed in the cassette body  130 . That is, the first medium support portion  150  may support one end of the paper medium P stored in the cassette body  130 . Movement of the first medium support portion  150  may be controlled by a dedicated driving motor (not shown). In  FIGS. 6 to 13 , the paper medium P is indicated by a dotted line for clear inspection of an inner structure of the cassette  120 . 
     Referring to  FIGS. 6 through 14 , the second medium support portion  160 , which is a member for supporting the paper medium P in cooperation with the first medium support portion  150 , may be movable by a predetermined distance within the cassette body  130 . That is, the second medium support portion  160  may support an opposite end of the medium P stored in the cassette body  130 . The second medium support portion  160  may be disposed at the entrance  132  to face the first medium support portion  150 . Therefore, the paper medium P may be stably disposed between the first medium support portion  150  and the second medium support portion  160 . 
     In addition, a return spring  134  may be provided at the second medium support portion  160  and the cassette body  130  to provide an elastic force in a second direction D toward an initial position of the second medium support portion  160 . Therefore, the second medium support portion  160  may be easily returned to the initial position by the return spring  134 . 
     Referring to  FIGS. 6 through 14 , the connection portion  170  may be provided at opposite lateral sides of the cassette body  130  to be movable, in connection with opposite ends of the second medium support portion  160 . The connection portion  170  may include a connection projection  172 . 
     The connection projection  172  may be movably inserted in connection holes  162   a  or connection grooves formed at the opposite ends of the second medium support portion  160 . The connection holes  162   a  or connection grooves may extend in a movement direction of the second medium support portion  160  and, furthermore, longer than a movement distance of the second medium support portion  160 . Hereinafter, for a convenient explanation of the present embodiment, the connection holes  162   a  will be described as formed at the opposite ends of the second medium support portion  160 , respectively. 
     Referring to  FIGS. 6 through 14 , the medium return gear portion  180  refers to a member for forcing the connection portion  170  in a first direction C away from the entrance  132  using a moving force of the shutter  140  at the time of closing the entrance  132 . Since the second medium support portion  160  is also forced along with the connection portion  170  in the first direction C, the paper medium P disposed at the entrance  132  may be forced into the cassette body  130 . The medium return gear portion  180  may be implemented by pinion gears rotatably formed at the opposite lateral sides of the cassette body  130 . 
     Here, a shutter gear  146  may be provided at each of opposite lateral sides of the shutter  140 . The shutter gear  146  is interactively connected to the medium return gear portion  180 . The shutter gear  146  may be implemented by a rack gear to convert a linear moving force of the shutter  140  into a rotational force of the second medium support portion  160 . The shutter gear  146  may extend along a movement direction of the shutter  140  at a position corresponding to the medium return gear portion  180 . 
     The shutter gear  146  may be formed at each of the opposite lateral sides of the shutter  140  in a predetermined length so as to move the second medium support portion  160  at a particular point of time. That is, the shutter gear  146  may move the connection portion  170  in the first direction C by a predetermined distance at the beginning of closing the entrance  132  or move the connection portion  170  in the second direction D right before the entrance  132  is fully opened. Thus, the particular point of time includes the beginning of closing the entrance  132  and right before the entrance  132  is fully opened. At the particular point of time, returning of the paper medium P by the second medium support portion  160  may be more efficiently performed. Also, the paper medium P may be more stably supported by the second medium support portion  160  and the first medium support portion  150 . 
     The connection portion  170  may include a connection portion gear  174  for interactive connection with the medium return gear portion  180 . The connection portion gear  174  may be implemented by a rack gear to convert the rotational force of the medium return gear portion  180  into the linear moving force of the second medium support portion  160 . Since the medium return gear portion  180  is connected to the connection portion gear  174  and the shutter gear  146 , simultaneously, the linear moving force of the shutter  140  may linearly move the connection portion  170  through the medium return gear portion  180 . 
     Referring to  FIGS. 6 through 13 , a first stopper  148  may be provided at each of the opposite lateral sides of the shutter  140 , being extended in the movement direction of the shutter  140 . In addition, a second stopper  182  may be provided at a lateral side of the medium return gear portion  180 . The second stopper  182  contacts the first stopper  148  in a sliding manner so as to restrict rotation of the medium return gear portion  180  at a position where the shutter gear  146  and the medium return gear portion  180  are not connected. 
     That is, at the beginning of closing the entrance  132  or right before the entrance  132  is fully opened, the medium return gear portion  180  and the shutter gear  146  are connected to each other. However, in the other states, since the medium return gear portion  180  and the shutter gear  146  are not connected, the medium return gear portion  180  may abnormally rotate in a random direction. Therefore, the first stopper  148  and the second stopper  182  may be provided to the medium return gear portion  180  and the shutter  140  to prevent the random rotation of the medium return gear portion  180  when the medium return gear portion  180  and the shutter gear  146  are not connected. 
     Referring to  FIGS. 6 to 13 , the locking portion  190  temporarily restricts the second medium support portion  160  moved in the first direction C from returning to an initial position. That is, although the second medium support portion  160  is moved in the second direction D by the medium return gear portion  180 , the locking portion  190  may temporarily restrict movement of the second medium support portion  160 . Therefore, in a state where the cassette  120  is connected to the cassette receiving portion  122 , the paper medium P may be stably supported by the first medium support portion  150  and the second medium support portion  160 . 
     The restricted state of the second medium support portion  160  may be maintained until a pressure is applied to the paper medium P in the second direction D by the first medium support portion  150 . That is, the locking portion  190  may temporarily restrict the second medium support portion  160  until before the first medium support portion  150  is driven. When the first medium support portion  150  is driven, the locking portion  190  may release the restricted state of the second medium support portion  160 . 
     For example, the locking portion  190  may include locking projections  192  and elastic members  194 . Here, any of locking holes  162   b  and locking recesses in which the locking projection  192  is elastically inserted may be formed at opposite ends of the second medium support portion  160 . According to the present embodiment, the second medium support portion  160  will be described to include the locking holes  162   b  at the opposite ends. 
     The locking projections  192  may be formed movably at the opposite lateral sides of the cassette body  130  and inserted in the locking holes  162   b  of the second medium support portion  160  when the cassette  120  is separated. The locking projections  192  are movable in directions for being inserted in and separated from the locking holes  162   b . Hereinafter, a guide structure  192   a  movably supporting the locking projections  192  may be formed through the opposite lateral sides the cassette body  130 . The locking holes  162   b  are disposed to face the locking projections  192  when the cassette  120  is separated. 
     In detail, during connection and separation of the cassette  120 , when the second medium support portion  160  is moved in the first direction C, the locking projections  192  may be inserted in the locking holes  162   b , thereby restricting movement of the second medium support portion  160 . Conversely, when the second medium support portion  160  is moved in the second direction D, the locking projections  192  may be forcibly separated from the locking holes  162   b , thereby releasing the restricted state of the second medium support portion  160 . In addition, at least one of leading ends of the locking projections  192  and circumferential edges of the locking holes  162   b  may have an inclined portion (not shown) for easy insertion and separation between the locking projections  192  and the locking holes  162   b.    
     The elastic members  194  may provide a predetermined degree of elastic force to the locking projections  192  in a direction for insertion into the locking holes  162   b . That is, the elastic members  194  may elastically support the locking projections  192  in the direction for insertion into the locking holes  162   b.    
     The elastic members  194  may be provided at the locking projections  192  and the cassette body  130 . The elastic members  194  may include a spring or a rubber band. In the present embodiment, the elastic members  194  will be described as springs of which opposite ends are connected to the opposite lateral sides of the cassette body  130 . Also, a middle portion of each of the elastic members  194  may be elastically brought into close contact with each of the locking projections  192 . 
     Therefore, although the connection portion  170  is moved in the second direction D, the second medium support portion  160  is prevented from moving in the second direction D due to the elastic force of the elastic member  194 . However, when the first medium support portion  150  applies the pressure greater than the elastic force of the elastic member  194  to the paper medium P, the locking state of the second medium support portion  160  may be overcome. When the locking state is overcome by the pressure of the first medium support portion  150 , the second medium support portion  160  may return to the initial position by the elastic force of the return spring  134 . 
     Referring to  FIGS. 2 to 13 , a pressed portion  136  may be provided to each of the opposite lateral sides of the cassette body  130 . The pressed portion  136  is pressed by a predetermined depth by interference with an interference portion  126  formed at the cassette receiving portion  122  occurring when the cassette  120  is connected. The interference portion  126  may be formed in a rib shape at each of the opposite lateral sides of the cassette body  130 . The pressed portion  136  may be formed at each of the opposite lateral sides of the cassette body  130  to be elastically pressed. 
     A pressed portion gear  138  may be provided at one side of the pressed portion  136 . The pressed portion gear  138  is selectively connected with the medium return gear portion  180 . When the medium return gear portion  180  and the pressed portion gear  138  are connected, rotation of the medium return gear portion  180  may be restricted by the pressed portion gear  138 . When the pressed portion  136  is pressed by the predetermined depth by the interference with the interference portion  126 , connection between the medium return gear portion  180  and the pressed portion gear  138  may be released, accordingly allowing rotation of the medium return gear portion  180 . 
     When the cassette  120  is connected, the pressed portion  136  may be pressed by the interference portion  126  before connection between the medium return gear portion  180  and the shutter gear  146  is achieved. That is, before the medium return gear portion  180  is rotated by the shutter gear  146 , the medium return gear portion  180  becomes rotatable by the pressed portion gear  138 . In addition, when the cassette  120  is separated, interference between the pressed portion  136  and the interference portion  126  may be released after the connection between the medium return gear portion  180  and the shutter gear  146  is released. That is, when the medium return gear portion  180  is not rotated by the shutter gear  146 , rotation of the medium return gear portion  180  may be restricted by the pressed portion gear  138 . 
     The pressed portions  136  provided at the opposite lateral sides of the cassette  120  may be pressed by different depths by the interference portions  126 . Therefore, the restricted state between the pressed portion gear  138  and the medium return gear portion  180  is normally released only when the cassette  120  is connected to the cassette receiving portion  122  including the interference portion  126 . Accordingly, the entrance  132  of the cassette  120  may be prevented from being randomly opened. As a result, stability and security of the cassette  120  may be increased. 
     Referring to  FIGS. 6 to 14 , the second medium support portion  160  may include a support portion body  162 , a support projection  164 , and a rubber pad  166 . The support portion body  162  may be disposed in the cassette body  130  to be movable by a predetermined distance. Opposite ends of the support portion body  162  may be extended along the opposite lateral sides of the cassette body  130 . A plurality of the support projections  164  may protrude from the support portion body  162  toward the entrance  132 . A pickup roller (not shown) may be inserted in spaces formed among the support projections  164  to pick up the paper medium P present in the cassette body  130  when the cassette  120  is connected. When the connection portion  170  is moved in the first direction, the support projections  164  may be brought into close contact with the paper medium P. The rubber pad  166  may be removably connected by enclosing an outer circumference of the support projections  164 , to increase a contact force between the support projections  164  and the paper medium P. Accordingly, the contact force between the second medium support portion  160  and the paper medium P is increased by the rubber pad  166 . Therefore, a returning efficiency of the paper medium P by the second medium support portion  160  may be increased. 
     The rubber pad  166  may include an upper fitting portion  166   a  formed in a ring shape to be fit with an upper fixing recess  164   a  formed at an upper portion of the support projection  164 , a lower fitting portion  166   b  formed in a ring shape to be fit with a lower fixing recess  164   b  of the support projection  164 , and a contact portion  166   c  connected to the upper fitting portion  166   a  and the lower fitting portion  166   b  and disposed at a contact surface of the support projection  164  contacting the paper medium P. Therefore, the rubber pad  166  may be connected and separated with respect to the support projection  164  in a simple manner, rather than being bonded to the support projection  164 . Accordingly, cost and time for maintenance of the rubber pad  166  may be reduced. 
     Hereinafter, the operation of the cassette  120  of the ATM  100  structured as aforementioned according to the embodiment of the present invention will be described. 
     When the cassette  120  is connected to the cassette receiving portion  122  of the ATM  100 , the shutter operation lever  124  of the cassette receiving portion  122  is caught by the shutter stoppers  142  and  144  of the cassette  120 . That is, as shown in  FIGS. 4 and 5 , when the cassette  120  is connected, the shutter  140  may be relatively moved in a direction for opening the entrance  132  by the shutter stoppers  142  and  144  and the shutter operation lever  124 . 
     In  FIGS. 6 to 13 , operational directions of the shutter  140 , the medium return gear portion  180 , the connection portion  170 , and the second medium support portion  160  of when the cassette  120  is connected are indicated by solid-line arrows. 
     Here, the first stopper  148  formed at the shutter  140  may be slid in close contact with the second stopper  182  formed at the medium return gear portion  180  as shown in  FIGS. 6 to 9 . Therefore, since the second stopper  182  is engaged with the first stopper  148  in the rotational direction of the medium return gear portion  180 , rotation of the medium return gear portion  180  is restricted. 
     Next, the pressed portion  136  of the cassette  120  is pressed by the predetermined depth by the interference portion  126  formed at the cassette receiving portion  122 . As shown in  FIGS. 8 and 9 , when the pressed portion  136  is pressed by the predetermined depth, connection between the pressed portion gear  138  and the medium return gear portion  180  is released. Therefore, the medium return gear portion  180  may escape from the restricted state with the pressed portion gear  138 . 
     As shown in  FIGS. 10 and 11 , when the shutter  140  continuously moves in the direction for opening the entrance  132 , the first stopper  148  and the second stopper  182  are disposed at positions not to contact each other so that the medium return gear portion  180  becomes rotatable. Here, since the medium return gear portion  180  and the shutter gear  146  are connected to each other, the moving force of the shutter  140  may be transmitted to the medium return gear portion  180 . 
     That is, the linear moving force of the shutter  140  may be transmitted to the medium return gear portion  180  through the shutter gear  146  and converted into the rotational force of the medium return gear portion  180 . The rotational force of the medium return gear portion  180  may be converted into the linear moving force of the connection portion  170  through the connection portion gear  174 . Therefore, the connection portion  170  may be linearly moved in the second direction D by a predetermined distance corresponding to a length of the shutter gear  146 . 
     In this instance, different from the connection portion  170 , the second medium support portion  160  is temporarily restricted from moving by the locking portion  190 . Therefore, the second medium support portion  160  is not moved in the second direction D. Since the first medium support portion  150  and the second medium support portion  160  are in close contact with the paper medium P when the cassette  120  is connected, the paper medium P may be stably supported. 
     When the cassette  120  is connected to the cassette receiving portion  122  completely, the entrance  132  is fully opened and the pickup roller is disposed at the entrance  132  to pick up the paper medium P present in the cassette  120  sheet by sheet. Next, when the first medium support portion  150  moves toward the entrance  132 , the pressure of the first medium support portion  150  is applied to the second medium support portion  160  in the second direction D. Accordingly, the second medium support portion  160  may overcome a locking force of the locking portion  190 . 
     As shown in  FIGS. 12 and 13 , the second medium support portion  160  may be moved in the second direction D and disposed at the entrance  132 . The paper medium P in the cassette body  130  may also be disposed at the entrance  132 , thereby contacting the pickup roller. When the pickup roller is driven, the pickup roller may pick up the paper medium P in the cassette body  130  sheet by sheet and feed the paper medium P to the transfer portion  111  through the entrance  132 . 
     However, when the cassette  120  is separated from the cassette receiving portion  122  of the ATM  100 , the shutter  140  may be relatively moved by the shutter operation lever  124  and the shutter stoppers  142  and  144  in the direction for closing the entrance  132 . 
     In  FIGS. 6 to 13 , operational directions of the shutter  140 , the medium return gear portion  180 , the connection portion  170 , and the second portion  160  of when the cassette  120  is separated are indicated by dotted-line arrows. 
     As shown in  FIGS. 12 and 13 , when the shutter  140  is moved in the direction for closing the entrance  132 , the linear moving force of the shutter  140  may be transmitted to the medium return gear portion  180  through the shutter gear  146  and converted into the rotational force of the medium return gear portion  180 . In addition, the rotational force of the medium return gear portion  180  may be converted into the linear moving force of the connection portion  170  through the connection portion gear  174 . Accordingly, the connection portion  170  may be linearly moved by the predetermined length corresponding to the length of the shutter gear  146  in the first direction C. 
     Comparing the connection process and the separation process of the cassette  120 , the movement directions of the shutter  140 , the connection portion  170 , and the second medium support portion  160  are opposite. Also, the rotational directions of the medium return gear portion  180  are opposite. 
     As aforementioned, when the second medium support portion  160  is moved in the first direction C along with the connection portion  170 , the second medium support portion  160  is separated away from the entrance  132  as shown in  FIGS. 8 and 7 . Therefore, the paper medium P disposed at the entrance  132  may return into the cassette body  130 . 
     When the second medium support portion  160  and the connection portion  170  are moved by the predetermined distance corresponding to the length of the shutter gear  146  in the first direction C, the locking portion  190  may be caught in the locking holes  162   b  and connection between the medium return gear portion  180  and the shutter gear  146  is released. In addition, the first stopper  148  of the medium return gear portion  180  is brought into contact with the second stopper  182  of the shutter  140 . Therefore, the second medium support portion  160  and the connection portion  170  are maintained in a state of being moved by the predetermined distance in the first direction C. In addition, the medium return gear portion  180  is maintained in a state of being restricted from rotating by the first stopper  148  and the second stopper  182 . 
     As shown in  FIGS. 6 and 7 , when the cassette  120  is separated from the cassette receiving portion  122 , the shutter  140  is continuously moved in the direction for closing the entrance  132 , and the pressed portion  136  is moved to the position not interfered with the interference portion  126 , thereby returning to the initial position. Accordingly, the pressed portion gear  138  of the pressed portion  136  may be connected with the medium return gear portion  180 , thereby completely restricting rotation of the medium return gear portion  180 . Next, separation of the cassette  120  may be completed with the entrance  132  of the cassette body  130  fully closed by the shutter  140 . 
     Although a few embodiments of the present invention have been shown and described, the present invention is not limited to the described embodiments. Instead, it would be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents. 
     Industrial Applicability 
     The present invention relates to a cassette used for an automatic teller machine (ATM). The cassette may be applied to any types of ATM in which the cassette is connected and separated to receive or dispense a paper medium such as banknotes, merchandise coupons, and the like.