Abstract:
A sheet medium processing device comprising a stacking mechanism mounted on a frame, a first switching mechanism and a retractable paper baffle adjacent to the medium exit of the stacking mechanism; the stacking mechanism comprises a lower ticket stacking assembly, an upper ticket stacking assembly capable of moving parallelly above the lower ticket stacking assembly and a parallel movement confining mechanism, wherein the upper ticket stacking assembly and the lower ticket stacking assembly are both belt-conveyor mechanisms, and the belt of the upper ticket stacking assembly has a tendency of tightly pressing against the belt of the lower ticket stacking assembly. The first switching mechanism simultaneously controls the reciprocation of the paper baffle and the parallel movement of the upper ticket stacking assembly, enabling the stacking mechanism to be selectively provided with a transport state and a stacking state. The sheet medium processing device utilizes the elasticity of the belts of the stacking mechanism to adjust and limit the vertical-direction state of multiple stacked sheet mediums, thereby achieving reliable transportation.

Description:
This application is the national phase of PCT Application No. PCT/CN2012/070217 filed Jan. 11, 2012, which in turn claims the priority of Chinese patent application with application No. 201110004944.2, titled as “sheet medium processing device”, and filed on Jan. 11, 2011, and all disclosed contents thereof should be incorporated herein by reference. 
     TECHNICAL FIELD OF THE INVENTION 
     The present invention relates to a sheet medium processing device. 
     BACKGROUND OF THE INVENTION 
     Common sheet mediums include train tickets, plane tickets, checks, and cashes etc., and automatic processing including stacking, distributing and recycling etc., needs to be performed for sheet mediums in more and more industries and fields with the popularization of automatic services. 
     For example, a cash dispenser mechanism in the financial system is able to stack, transport and recycle cashes, and a ticket issuing device in the railway system is able to stack, transport and recycle ticket paper. Traditional sheet medium processing devices have problems of complicated structures, multiple components, and high costs etc. 
     To solve these problems, Chinese patent application with application No. 200810027225.0 discloses a sheet medium processing device. The device comprises: a frame; an input passage mounted on the frame; a hub component, mounted on the frame, located at the exit of the input passage and configured to transport sheet mediums to a stacking and arranging assembly; the stacking and arranging assembly comprising a support plate configured to stack and receive the sheet mediums, limiting side plates set at two sides of the support plate and configured to align the sheet mediums, and a unidirectional rotational baffle set in a transport passage of the sheet mediums; a transport assembly, connected with the support plate and configured to drive the support plate to deliver the sheet mediums. 
     The solution has the following disadvantages: when bent, the stacked sheet mediums are aligned irregularly in the vertical direction due to the lack of a pressing device above the support plate. When the support plate carries the sheet mediums, and outputs the sheet mediums from the device, the output position is blocked easily. Therefore, the device, which requires high medium flatness, can be hardly adapted to different types of mediums. 
     SUMMARY OF THE INVENTION 
     The purpose of the present invention is to provide a sheet medium processing device with simple structure and high medium adaptability as well as functions including stacking, aligning, transporting and recycling etc. 
     Therefore, the present invention provides a sheet medium processing device, comprising a stacking mechanism, a first switching mechanism and a retractable paper baffle adjacent to the medium exit of the stacking mechanism, which are mounted on a frame, wherein the stacking mechanism comprises a lower ticket stacking assembly, an upper ticket stacking assembly capable of moving parallelly above the lower ticket stacking assembly and a parallel movement confining mechanism configured to limit the moving trajectory of the upper ticket stacking assembly, wherein the upper ticket stacking assembly and the lower ticket stacking assembly respectively comprise a bracket, a belt, and at least two belt pulleys mounted on the bracket to support the belt, wherein a passage for transporting mediums or a space for stacking mediums is formed between the belt of the upper ticket stacking assembly and the belt of the lower ticket stacking assembly. The upper ticket stacking assembly has a tendency of moving towards the lower ticket stacking assembly by gravity, wherein the first switching mechanism simultaneously controls the reciprocation of the paper baffle and the parallel movement of the upper ticket stacking assembly, enabling the stacking mechanism to be selectively in a transport state and a stacking state. 
     Further, the stacking mechanism further comprises: a first elastic element configured to enable the upper ticket stacking assembly to have the tendency of moving towards the lower ticket stacking assembly. 
     Further, the first switching mechanism comprises: a push plate hinged on the frame by a hinge shaft to rotate around the hinge shaft, and having an initial position and a lifting position; a cam, provided below the push plate and configured to rotate the push plate from the initial position to the lifting position; a third elastic element, configured to have the push plate being in a tendency of maintaining at the initial position, wherein the push plate has a second edge abutted against the periphery of the cam and a third edge for pushing the upper ticket stacking assembly away from the lower ticket stacking assembly when the push plate is at the lifting position. 
     Further, the first switching mechanism further comprises: a swinging bracket comprising a left side wall and a right side wall which are pivoted on the frame, and a connection wall extended transversely between the left side wall and the right side wall, wherein the paper baffle is provided on the connection wall; and a second elastic element configured to have the paper baffle on the swinging bracket being in a tendency of stretching out, wherein the push plate further has a first edge pushing the paper baffle on the swinging bracket to retract when the push plate is at the initial position. 
     Further, the paper baffle and the swinging bracket are integrated. 
     Further, the left side wall and the right side wall of the swinging bracket are provided with a pressing portion abutted against the first edge of the push plate. 
     Further, both the left side wall and the right side wall of the swinging bracket are provided with a stop portion adapted to locate a core shaft of the belt pulley of the lower ticket stacking assembly. 
     Further, the push plate is provided with an arc groove centered on the hinge shaft and the frame is provided with a locating pin located in the arc groove. 
     Further, the first switching mechanism further comprises a third driving mechanism for controlling the paper baffle independently. The third driving mechanism comprises a rack fixedly connected with the paper baffle, a gear driving the rack to move up and down, and a motor driving the gear to rotate. 
     Further, the lower ticket stacking assembly is hinged with the frame via a core shaft of the belt pulley adjacent to the medium exit, wherein the sheet medium processing device further comprises a second switching mechanism enabling the lower ticket stacking assembly to deflect around the core shaft. 
     Further, the second switching mechanism comprises: an inner gear ring fixedly connected with a bracket of the lower ticket stacking assembly and centered on the axle center of the core shaft of the belt pulley adjacent to the medium exit; a gear provided on the frame and in meshing transmission with the inner gear ring; and a driving mechanism for driving the gear to rotate. 
     Further, the deflection range of the lower ticket stacking assembly is between a medium discharge position and a medium recycling position. The medium recycling position is provided with a recycling box. 
     Further, the parallel movement confining mechanism comprises a plurality of connecting rods, wherein the plurality of connecting rods, together with the upper ticket stacking assembly and the lower ticket stacking assembly form a four-rod mechanism. 
     Further, the plurality of connecting rods are set in parallel, and the plurality of connecting rods, together with the upper ticket stacking assembly and the lower ticket stacking assembly form a four-rod mechanism. 
     In the present invention, the first switching mechanism adjusts the position relation between the upper ticket stacking assembly and the lower ticket stacking assembly of the stacking mechanism, and the position relation of the paper baffle relative to the exit or the passage for transporting mediums so as to stack, align and transport sheet mediums. When the upper ticket stacking assembly and the lower ticket stacking assembly are separated, the paper baffle is blocked at the downstream of the lower ticket stacking assembly along the medium transportation direction so that mediums transported one by one can be stacked on the lower ticket stacking assembly and aligned along the paper baffle. When the upper ticket stacking assembly is in contact with the lower ticket stacking assembly, a first belt of the upper ticket stacking assembly is tangent with a second belt of the lower ticket stacking assembly to form a sheet medium transportation passage and the paper baffle retracts at the moment. 
     During the transportation process, the belt of the upper ticket stacking assembly is tightly pressed against the lower ticket stacking assembly via the self-gravity of the upper ticket stacking assembly or the elasticity of the first elastic element so as to adjust and limit the vertical-direction state of multiple stacked sheet mediums, thereby achieving reliable transportation even if the sheet mediums are bent, and improving the adaptability of the device to mediums. In addition, different transportation directions can be formed by adjusting the rotating angle of the stacking mechanism through the second switching mechanism so as to transport sheet mediums to different destinations as required. 
     Besides purposes, features and advantages described above, the present invention also has other purposes, features and advantages. Other purposes, features and advantages of the present invention will be further described in details below as shown in drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Drawings, which form a part of the description and are provided for further understanding of the present invention, show the preferred embodiments of the present invention, and explain the principle of the present invention together with the description. In the drawings: 
         FIG. 1  is a perspective view of a sheet medium processing device according to a first embodiment of the present invention; 
         FIG. 2  is an axonometric drawing of a stacking mechanism of the sheet medium processing device shown in  FIG. 1 ; 
         FIG. 3  is a longitudinal profile view of a stacking mechanism shown in  FIG. 1 ; 
         FIG. 4   a  is a lateral view of a sheet medium processing device in a transport state according to the first embodiment of the present invention; 
         FIG. 4   b  is an axonometric drawing of a sheet medium processing device in a transport state according to the first embodiment of the present invention; 
         FIG. 5   a  is a lateral view of a sheet medium processing device in a stacking state according to the first embodiment of the present invention; 
         FIG. 5   b  is an axonometric drawing of a sheet medium processing device in a stacking state according to the first embodiment of the present invention; 
         FIG. 6  is a lateral view of a sheet medium processing device in a transport state according to a second embodiment of the present invention; 
         FIG. 7  is a perspective view of a sheet medium processing device according to a third embodiment of the present invention; 
         FIG. 8  is a schematic view of a partial structure of the sheet medium processing device shown in  FIG. 7 ; 
         FIG. 9  is a schematic view of a sheet medium processing device in a transport state according to the third embodiment of the present invention; 
         FIG. 10  is a schematic view of a sheet medium processing device in a recycling state according to the third embodiment of the present invention; and 
         FIG. 11  is a schematic view of a partial structure of a sheet medium processing device according to a fourth embodiment of the present invention. 
     
    
    
     
       
         
               
             
               
               
               
               
             
           
               
                   
               
               
                 Explanation of reference numerals 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                  1 
                 stacking mechanism 
                  2 
                 first switching mechanism 
               
               
                  5 
                 frame 
                  51 
                 entrance 
               
               
                  53 
                 exit 
                  54 
                 recycling box 
               
               
                  11 
                 upper ticket 
                  12 
                 lower ticket stacking assembly 
               
               
                   
                 stacking assembly 
               
               
                  14 
                 elastic element 
                  15 
                 first driving mechanism 
               
               
                 111 
                 first belt pulley 
                 112 
                 second belt pulley 
               
               
                 113 
                 first belt 
                 114 
                 first bracket 
               
               
                 114a 
                 first hopper chute 
                 121 
                 third belt pulley 
               
               
                 122 
                 fourth belt pulley 
                 111a 
                 core shaft of first belt pulley 
               
               
                 122a 
                 core shaft of 
                 121a 
                 core shaft of third belt pulley 
               
               
                   
                 fourth belt pulley 
               
               
                 123 
                 second belt 
                 124 
                 second bracket 
               
               
                 124a 
                 second hopper chute 
                 131 
                 first rotating shaft 
               
               
                 131a 
                 first supporting rod 
                 131b 
                 second supporting rod 
               
               
                 132c 
                 rotating shaft 
                 132a 
                 first connecting rod 
               
               
                 132b 
                 second connecting rod 
                 151 
                 first gear 
               
               
                 152 
                 second gear 
                 153 
                 toothed belt pulley 
               
               
                 154 
                 toothed belt 
                  21 
                 swinging bracket 
               
               
                  22 
                 push plate 
                  23 
                 cam 
               
               
                  24 
                 second driving mechanism 
                  25 
                 second elastic element 
               
               
                  26 
                 third elastic element 
                  27 
                 paper baffle 
               
               
                  28 
                 motor gear 
                  29 
                 rack 
               
               
                 215 
                 left side wall 
                 216 
                 right side wall 
               
               
                 211 
                 hinge portion 
                 212 
                 paper baffle portion 
               
               
                 213 
                 pressing portion 
                 214 
                 stop portion 
               
               
                 231 
                 rotating shaft 
                 232 
                 first working face 
               
               
                 233 
                 second working face 
                 225 
                 hinge shaft 
               
               
                 224 
                 limiting groove 
                  52 
                 limiting shaft 
               
               
                 221 
                 first edge 
                 222 
                 second edge 
               
               
                 223 
                 third edge 
                 M1 
                 motor 
               
               
                 M1a 
                 motor gear 
                  6 
                 second switching mechanism 
               
               
                  61 
                 inner gear 
                  61 
                 second motor 
               
               
                   
               
             
          
         
       
     
     DETAILED DESCRIPTION OF THE INVENTION 
     The embodiments of the present invention will be described in detail below as shown in drawings, however the present invention may be implemented by various different ways defined and covered by the claims. In the drawings, identical components are indicated by identical reference number. 
       FIG. 1  is a perspective view of a sheet medium processing device according to the first embodiment of the present invention. As shown in  FIG. 1 , the sheet medium processing device comprises a stacking mechanism  1 , a first switching mechanism  2  and a frame  5 , wherein the stacking mechanism  1  and the first switching mechanism  2  are mounted on the frame  5 . Under the action of the first switching mechanism  2 , the stacking mechanism may be provided to be in two positions including a stacking position and a transport position, wherein the stacking mechanism  1  can neatly stack mediums transported one by one when in the stacking position; the stacking mechanism  1  may transport mediums which have been stacked neatly to the downstream when in the transport position. 
       FIG. 2  is an axonometric drawing of the stacking mechanism of the sheet medium processing device shown in  FIG. 1  and  FIG. 3  is a longitudinal profile view of the stacking mechanism shown in  FIG. 1 . An embodiment of the stacking mechanism will be explained below in combination with  FIG. 1  to  FIG. 3 . 
     The stacking mechanism  1  comprises an upper ticket stacking assembly  11 , a lower ticket stacking assembly  12 , a parallel movement confining mechanism  13 , a first elastic element  14  (shown in  FIG. 4   b ) and a first driving mechanism  15 . 
     The upper ticket stacking assembly  11  comprises a first belt pulley  111 , a second belt pulley  112 , a first belt  113  and a first bracket  114 . The first belt pulley  111  and the second belt pulley  112  are arrayed along the medium transport direction and supported by the first bracket  114 . The first belt  113  is twisted on the peripheries of the first belt pulley  111  and the second belt pulley  112  and supported by the first belt pulley  111  and the second belt pulley  112 . 
     The lower ticket stacking assembly  12  comprises a third belt pulley  121 , a fourth belt pulley  122 , a second belt  123  and a second bracket  124 . The second bracket  124  is fixedly connected with the frame  5 . The third belt pulley  121  and the fourth belt pulley  122  are arrayed along the medium transport direction and supported by the second bracket  124 . The second belt  123  is twisted on the peripheries of the third belt pulley  121  and the fourth belt pulley  122  and supported by the third belt pulley  121  and the fourth belt pulley  122 . 
     The parallel movement confining mechanism  13  comprises a first rotating shaft  131 , a first connecting rod assembly and a second connecting rod assembly (not shown in the figures). The first rotating shaft  131  is fixedly supported on the second bracket  124 . The first connecting rod assembly comprises a first connecting rod  132   a  and a second connecting rod  132   b . One end of the first connecting rod  132   a  is hinged with one end of the first rotating shaft  131  and the other end of the first connecting rod  132   a  is hinged with one end of the core shaft  111   a  of the first belt pulley  111 . One end of the second connecting rod  132   b  is hinged with one end of the core shaft  122   a  of the fourth belt pulley  122  and the other end of the second connecting rod  132   b  is hinged with one end of the core shaft  112   a  of the second belt pulley  112 . 
     The first connecting rod  132   a  and the second connecting rod  132   b  are located on the same plane. At the same time, the distance (written as L1 hereinafter) between the first rotating shaft  131  and the core shaft  111   a  of the first belt pulley  111  is equal to the distance (written as L2 hereinafter) between the core shaft  122   a  of the fourth belt pulley  122  and the core shaft  112   a  of the second belt pulley  112 , and the distance (written as L3 hereinafter) between the first rotating shaft  131  and the core shaft  122   a  of the fourth belt pulley  122  is equal to the distance (written as L4 hereinafter) between the core shaft  111   a  of the first belt pulley  111  and the core shaft  112   a  of the second belt pulley  112 , i.e. L1=L2, and L3=L4. The first rotating shaft  131 , the core shaft  111   a  of the first belt pulley  111 , the core shaft  122   a  of the fourth belt pulley  122  and the core shaft  112   a  of the second belt pulley  112  form a parallelogram. 
     The second connecting rod assembly comprises a third connecting rod and a fourth connecting rod (not shown in the figures), wherein one end of the third connecting rod is hinged with the other end of the rotating shaft  131 , and the other end of the third connected rod is hinged with the other end of the core shaft  111   a  of the first belt pulley  111 ; one end of the fourth connecting rod is hinged with the other end of the core shaft  122   a  of the fourth belt pulley  122  and the other end of the fourth connecting rod is hinged with the other end of the core shaft  112   a  of the second belt pulley  112 . 
     Thus, the upper ticket stacking assembly  11  is hinged with the lower ticket stacking assembly  12  via the first connecting rod assembly and the second connecting rod assembly and is capable of moving parallelly relative to the lower ticket stacking assembly  12  to contact or depart from the lower ticket stacking assembly  12 . When the stacking mechanism is in the transport position and the upper ticket stacking assembly  11  and the lower ticket stacking assembly  12  are in contact, the first belt  113  is tangent with the second belt  123  and a passage for transporting mediums is formed therebetween. When the stacking mechanism is in the stacking position, the upper ticket stacking assembly  11  and the lower ticket stacking assembly  12  are separated, the first belt  113  and the second belt  123  are spaced with a preset distance and a space for accommodating and stacking mediums is formed therebetween. 
     An entrance  51  is provided at one end of the second belt pulley  112  and the fourth belt pulley  122  adjacent to the stacking mechanism  1 , and an exit  53  is provided at one end of the first belt pulley  111  and the third belt pulley  121  adjacent to the stacking mechanism  1 . Therefore, when the stacking mechanism  1  is in the stacking position, sheet mediums enter from the entrance  51  and are stacked between the first belt  113  and the second belt  123 . When the stacking mechanism is in the transport position, the stacking mechanism  1  may discharge mediums clamped between the first belt  113  and the second belt  123  out of the sheet medium processing device via the exit  53 . 
     One end of the first elastic element  14  is connected with the upper ticket stacking assembly  11  and the other end is connected with the lower ticket stacking assembly  12  or the frame  5 . Under the action of the first elastic element  14 , the upper ticket stacking assembly  11  always has a motion tendency of pressing against the lower ticket stacking assembly  12 . 
     The first driving mechanism  15  comprises a first motor M 1  and a first transmission assembly. The first transmission assembly comprises a first gear  151 , a second gear  152 , a toothed belt pulley  153  and a toothed belt  154  (shown in  FIG. 1 ), wherein the first gear  151  is fixed at one end of the core shaft  121   a  of the third belt pulley  121 , the toothed belt pulley  153  is fixed at the other end of the core shaft  121   a  of the third belt pulley  121 , and the second gear  152  is fixed at one end of the core shaft  111   a  of the first belt pulley  111 . A motor gear M 1   a  of the first gear  151  is connected with the toothed belt pulley  153  via the toothed belt  154  (shown in  FIG. 1 ), and the first gear  151  is connected with the second gear  152  is an engaging manner. Thus, when the first motor M 1  drives the toothed belt pulley  153  to rotate, the first gear  151  drives the second gear  152  to rotate so as to drive the first belt  113  and the second belt  123  to move synchronously to transport sheet mediums. 
       FIG. 4   a  is a lateral view of a sheet medium processing device in a transport state according to the first embodiment of the present invention and  FIG. 4   b  is an axonometric drawing of a sheet medium processing device in a transport state according to the first embodiment of the present invention. An embodiment of the first switching mechanism  2  will be introduced below in combination with  FIG. 1 ,  FIG. 4   a  and  FIG. 4   b . The first switching mechanism  2  comprises a swinging bracket  21 , a push plate  22 , a cam  23 , a second driving mechanism  24 , a second elastic element  25  and a third elastic element  26 . 
     The swinging bracket  21  is located below the lower ticket stacking assembly  12 , and a left side wall  215  and a right side wall  216  of the swinging bracket  21  are hinged with the frame  5  via a hinge portion  211 . A paper baffle portion  212  is provided between the left side wall  215  and the right side wall  216  of the swinging bracket  21 . The paper baffle portion  212  is capable of stretching into the exit  53  or retracting from the exit  53  when the swinging bracket  21  swings. A pressing portion  213  for driving the swinging bracket  21  to rotate is provided on the left side wall  215  and/or the right side wall  216  of the swinging bracket  21 . A stop portion  214  oppositely matched with the core shaft  121   a  of the third belt pulley  121  of the lower ticket stacking assembly  12  is further provided on the left side wall  215  and/or the right side wall  216  of the swinging bracket  21  to limit the rotation angle of the swinging bracket  21  towards the direction of the exit  53 . 
     One end of the second elastic element  25  is connected with the swinging bracket  21  and the other end is connected with the frame  5 . Under the elasticity of the second elastic element  25 , the swinging bracket  21  always has a tendency of rotating towards the direction of the exit  53  by taking the hinge portion  211  as the circle center. Therefore, the paper baffle portion  212  always has a motion tendency of extending into the exit  53 . 
     The cam  23  is hinged with the frame  5  via the rotating shaft  231  and can rotate around the rotating shaft  231 . The periphery of the cam  23  comprises a first working face  232  and a second working face  233 , wherein the first working face  232  has a first preset distance away from the rotating shaft  231 , and the second working face  233  has a second preset distance away from the rotating shaft  231 . The first preset distance is shorter than the second preset distance. 
     The push plate  22  is hinged with the frame  5  via a hinge shaft  225  and can rotate around the hinge shaft  225 . A limiting groove  224  matched with a limiting shaft  52  on the frame  5  is provided on the surface of the push plate  22 . The limiting groove  224  is an arc groove centered on the hinge shaft  225 . The width of the limiting groove  224  is matched with the diameter of the limiting shaft  52 . The length of the limiting groove  224  is greater than the diameter of the limiting shaft  52 . The push plate  22  can rotate with a set angle along the length direction of the limiting groove  224 . 
     The external profile of the push plate  22  is generally in an L shape or a T shape, and comprises a first edge  221 , a second edge  222  and a third edge  223 , wherein the first edge  221  is opposite to the pressing portion  213  of the swinging bracket  21  and can contact or depart from the pressing portion  213  of the swinging bracket  21 ; the second edge  222  is lapped with the cam  23 ; the third edge  223  is opposite with the core shaft  112   a  of the second belt pulley  112  of the upper ticket stacking assembly  11  and can contact or depart from the core shaft  112   a  of the second belt pulley  112 . 
     One end of the third elastic element  26  is connected with the push plate  22  and the other end is connected with the frame  5 . Under the elasticity of the third elastic element  26 , the third edge  223  of the push plate  22  always has a motion tendency of departing from the core shaft  112   a  of the second belt pulley  112 . 
     The interaction relation between the first switching mechanism and the stacking mechanism will be explained below in combination with  FIG. 4   a ,  FIG. 4   b ,  FIG. 5   a  and  FIG. 5   b.    
     As shown in  FIG. 4   a  and  FIG. 4   b , the second driving mechanism  24  (shown in  FIG. 1 ) drives the cam  23  to rotate to a first set position. At this moment, the first working face  232  of the cam  23  is abutted against the second edge  222  of the push plate  22 , and the push plate  22  rotates around the hinge shaft  225  to the initial position under the elasticity of the third elastic element  26 . At this moment, the third edge  223  of the push plate  22  departs from the core shaft  112   a  of the second belt pulley  112  of the upper ticket stacking assembly  11 , and the first edge  221  of the push plate  22  contacts the pressing portion  213  of the swinging bracket  21  to force the swinging bracket  21  rotate around the hinge portion  211  so that the paper baffle portion  212  of the swinging bracket  21  moves out of the exit  53 . 
     At the same time, the upper ticket stacking assembly  11  presses against the lower ticket stacking assembly  12  under the action of the first elastic element  14 . Supported and limited by the parallel movement confining mechanism, the position of the upper ticket stacking assembly  11  relative to the lower ticket stacking assembly  12  is stable. At this moment, the first belt  113  of the upper ticket stacking assembly  11  is tangent with the second belt  123  of the lower ticket stacking assembly  12 , and a passage for transporting mediums is formed therebetween. Therefore, the stacking mechanism  1  can be driven to the transport position by correlative movements of the components of the first switching mechanism  2 . 
     In other variant embodiments, the paper baffle portion  212  may be shaped independently, i.e. the paper baffle portion and the swinging bracket  21  are two components. 
     As shown in  FIG. 5   a  and  FIG. 5   b , the second driving mechanism  24  drives the cam  23  to rotate to a second set position. At this moment, the second working face of the cam  23  is abutted against the second edge  222  of the push plate  22 . The second working face of the cam  23  pushes the push plate  22  to overcome the elasticity of the third elastic element  26  and rotate around the hinge shaft  225  to a lifting position. At this moment, the third edge  223  of the push plate  22  is abutted against the shaft end of the core shaft  112   a  of the second belt pulley  112  of the upper ticket stacking assembly  11  and pushes the upper ticket stacking assembly  11  to move parallelly relative to the lower ticket stacking assembly  12  so that the first belt  113  of the upper ticket stacking assembly  11  has a preset distance away from the second belt  123  of the lower ticket stacking assembly  12 , and a space for accommodating and stacking mediums is formed therebetween. 
     At the same time, since the first edge  221  of the push plate  22  is separated from the pressing portion  213  of the swinging bracket  21 , the swinging bracket  21  rotates around the hinge portion  211  under the elasticity of the second elastic element  25 . The stop portion  214  of the swinging bracket  21  is in contact and matched with the core shaft  121   a  of the third belt pulley  121  of the lower ticket stacking assembly  12 . At this moment, the paper baffle portion  212  of the swinging bracket  21  extends into the exit  53  and is located at the downstream of the stacking mechanism  1 . Therefore, the stacking mechanism  1  can be driven to the stacking position by correlative movements of all components of the first switching mechanism  2 . 
     A working process of the sheet medium processing device provided by the present invention is introduced below. 
     When mediums need to be stacked, a control device (not shown in the figures) of the sheet medium processing device controls the cam  23  of the first switching mechanism  2  to rotate to the second set position. At this moment, the cam  23  rotates to drive the push plate  22  and the swinging bracket  21  to rotate, so that there is a preset distance between the first belt  113  of the upper ticket stacking assembly  11  and the second belt  123  of the lower ticket stacking assembly  12  and a space for accommodating and stacking the mediums is formed therebetween. The first belt  113  and the second belt  123  are in a static state, and the paper baffle portion  212  of the swinging bracket  21  extends into the exit  53 . 
     The sheet mediums enter the space between the upper ticket stacking assembly  11  and the lower ticket stacking assembly  12  one by one. Since the paper baffle portion  212  of the swinging bracket  21  is located at the downstreams of the upper ticket stacking assembly  11  and the lower ticket stacking assembly  12 , the sheet mediums are blocked on the surface of the lower ticket stacking assembly  12  by the paper baffle portion  212  and aligned along the paper baffle portion  212 . 
     After a certain amount of sheet mediums are stacked, the sheet mediums stored on the surface of the lower ticket stacking assembly  12  temporarily need to be sent out once. The control device of the sheet medium processing device controls the second driving mechanism  24  to drive the cam  23  to rotate to the first set position. At this moment, the cam  23  rotates to drive the push plate  22  and the swinging bracket  21  to move. Under the action of the first elastic element  14 , the upper ticket stacking assembly  11  presses towards the lower ticket stacking assembly  12  to clamp the stacked mediums between the first belt  113  of the upper ticket stacking assembly  11  and the second belt  123  of the lower ticket stacking assembly  12 . Subsequently, the first driving mechanism  15  drives the first belt  113  and the second belt  123  to move synchronously to send out the neatly-stacked sheet mediums. 
     The sheet mediums stacked by the sheet medium processing device provided by the present invention are located between the first belt  113  and the second belt  123 . Therefore, even if the sheet mediums are bent, the vertical-direction state of multiple stacked sheet mediums can be adjusted and limited by utilizing the elasticity of the belts, thereby ensuring reliable transportation. 
       FIG. 6  is a lateral view of a sheet medium processing device in a transport state according to the second embodiment of the present invention. As shown in the figure, the difference of the present embodiment compared with the previous embodiment is that the first switching mechanism  2  in the present embodiment does not need to provide the swinging bracket  21  and the second elastic element  25 . The movements of a paper baffle  27  and the push plate  22  are controlled by independent driving mechanisms, respectively. 
     As shown in  FIG. 6 , the paper baffle  27  is provided vertical to the passage for transporting mediums, located at the exit  53  of the stacking mechanism  11  along the medium transport direction and configured to stop mediums from moving towards the exit  53  when the stacking mechanism  1  stacks the mediums. The first switching mechanism  2  further comprises a third driving mechanism, wherein the third driving mechanism comprises a third motor (not shown in the figure), a motor gear  28  and a rack  29 . The motor gear  28  is fixedly connected with a driving shaft of the third motor. The rack  29  is fixedly connected with the paper baffle  27 , and connected with the motor gear  28  in an engaging manner. Therefore, the paper baffle  27  and the rack  29  move synchronously when the rack  29  moves. 
     When the stacking mechanism  1  is in the stacking position, the motor gear  28  of the third motor rotates positively to drive the rack  29  engaged with the motor gear  28  to move upwards so that the paper baffle  27  moves upwards to block the downstream of the stacked mediums. When the stacking mechanism  1  is in the transport position, the third motor drives the motor gear  28  to rotate negatively to drive the rack  29  engaged with the motor gear to move downwards so that the paper baffle  27  moves downwards so the mediums can be sent out from the exit  53 . 
       FIG. 7  is a perspective view of a sheet medium processing device according to the third embodiment of the present invention and  FIG. 8  is a schematic view of a partial structure of the sheet medium processing device shown in  FIG. 7 . As shown in  FIG. 7  and  FIG. 8 , the difference of the present embodiment compared with the first embodiment is that the stacking mechanism  1  is hinged with the frame  5  through the core shaft  121   a  of the third belt pulley  121  and capable of rotating around the core shaft  121   a  of the third belt pulley  121 . A recycling box  54  (shown in  FIG. 9 ) is provided below the entrance  51  to recycle invalidated or forgotten sheet mediums. The sheet medium processing device further comprises a second switching mechanism  6 . The second switching mechanism  6  is configured to realizing switching of the output direction of the stacking mechanism  1  between a paper discharge direction and a recycling direction, wherein the paper discharge direction means that the stacking mechanism  1  pushes stacked mediums towards the location where the exit  53  locates, and the recycling direction means that the stacking mechanism  1  discharges the stacked mediums to the location where the recycling box  54  (shown in  FIG. 9 ) locates. 
     Specifically, the stacking mechanism  1  is hinged with the frame  5  via the core shaft  121   a  of the third belt pulley  121  of the lower ticket stacking assembly  12 . The second switching mechanism  6  comprises an inner gear  61  and a second motor  62 . The inner gear  61  is located at the outer side of the passage for transporting mediums and fixedly connected with the second bracket  124  of the lower ticket stacking assembly  12 . The circle center of the inner gear  61  is coaxial with the core shaft  121   a  of the third belt pulley of the lower ticket stacking assembly  12 . The second motor  62  is provided on the frame  5 . The motor gear of the second motor  62  is in transmission connection with the inner gear  61  via a group of transition gears. 
     Since the inner gear  61  fixedly connected with the lower ticket stacking assembly  12  is in transmission connection with the second motor  62  via a group of transition gears, when the second motor  62  drives the inner gear  61  to rotate around the center of the second motor with a set angle, the lower ticket stacking assembly  12  can rotate with a set angle by taking the core shaft  121   a  of the third belt pulley are the circle center, and when the second motor  62  stops rotating and is self-locked, the position of the lower ticket stacking assembly  12  can be kept unchanged. Thus, the relative positions of the stacking mechanism  1  and the frame  5  can be changed thought the second switching mechanism  6  so as to set the discharge direction of the stacked mediums as required. 
     A working process for realizing recycling and processing of the sheet medium processing device according to the present embodiment will be explained below in combination with  FIG. 9  and  FIG. 10 . 
     As shown in  FIG. 9 , after sheet mediums are stacked, the stacking mechanism  1  switches from the stacking position to the transport position. In the transport position, the stacking mechanism  1  discharges the stacked mediums along the paper discharge direction first. At this moment, the second motor  62  does not rotate and is in a self-locked state. Therefore, the positions of the inner gear  61  and the lower ticket stacking assembly  12  fixedly connected with the inner gear  61  are fixed. At this moment, the stacking mechanism  1  can discharge the stacked mediums towards the location where the exit  53  locates. If the mediums are not taken away after a set period of time, the first driving mechanism  15  of the stacking mechanism  1  drives the first belt  113  and the second belt  123  to move reversely to recycle the mediums into the stacking mechanism  1 . 
     As shown in  FIG. 10 , after the stacking mechanism  1  recycles the mediums into the stacking mechanism  1 , the second motor  62  drives the inner gear  61  to rotate with a set angle in a preset direction to drive the stacking mechanism  1  to rotate synchronously with the inner gear  61  with a set angle so that the stacking mechanism  1  can discharge the stacked mediums towards the location where the recycling box  54  locates. Subsequently, the first driving mechanism  15  drives the first belt  113  and the second belt  123  to rotate reversely to send the mediums into the recycling box  54 . 
     It needs to be shown that the rotation angle of the stacking mechanism  1  may be set through the control of the second motor  62 . The rotation angle of the stacking mechanism  1  can be adjusted so that the stacking mechanism  1  can transport mediums along different directions to transport the sheet mediums to different destinations such as the recycling box or an invalidated ticket box etc. as required. 
     In addition, the first belt  113  and the second belt  123  may be two or more narrow belts in parallel. At this moment, the paper baffle  27  may be located in a gap between the two narrow belts and extend into the space for stacking mediums between the first belt  113  and the second belt  123 . 
     In addition, the parallel movement confining mechanism is not limited to a parallel four-rod mechanism as long as the parallel movement confining mechanism is able to limit the upper ticket stacking mechanism  11  to move parallelly from the lower ticket stacking mechanism  12 . 
       FIG. 11  is a schematic view of a partial structure of a sheet medium processing device according to the fourth embodiment of the present invention. As shown in  FIG. 11 , the difference of the present embodiment compared with other embodiments is that, in the parallel movement confining mechanism, the first connecting rod  132   a  and the second connecting rod  132   b  are hinged by a rotating shaft  132   c . One end of the first connecting rod  132   a  is hinged with one end of the first rotating shaft  131 , and the other end of the first connecting rod  132   a  is fixedly provided with a first supporting rod  131   a . The first supporting rod  131   a  can slide along the length direction of a first hopper chute  114   a . One end of the second connecting rod  132   b  is hinged with one end of the core shaft  111   a  of the first belt pulley  111  and the other end of the second connecting rod is fixedly provided with a second supporting rod  131   b . The second supporting rod  131   b  can slide along the length direction of a second hopper chute  124   b.    
     When the first connecting rod  132   a  or the second connecting rod  132   b  are lifted around the hinge point, the parallel movement confining mechanism pushes the upper ticket stacking assembly  11  to move parallelly relative to the lower ticket stacking assembly  12  so that the upper ticket stacking assembly  11  and the lower ticket stacking assembly  12  are separated and a space for stacking mediums is formed therebetween. 
     When the first connecting rod  132   a  or the second connecting rod  132   b  descends, the first supporting rod  131   a  moves along the length direction of the first hopper chute  114   a  and the second supporting rod  131   b  moves along the length direction of the second hopper chute  124   a , the upper ticket stacking assembly  11  contacts the lower ticket stacking assembly  12  to form a passage for transporting mediums therebetween under the action of the self-gravity of the upper ticket stacking assembly  11  or an external force. In the present embodiment, the first switching mechanism  2  may be a gear rack driving mechanism or a cam driving mechanism. 
     In other embodiments, the parallel movement confining mechanism may be a guide mechanism such as a guide groove or a guide pillar etc., so as to limit the moving trajectory of the upward parallel movement of the upper stacking assembly  11  relative to the lower ticket stacking assembly  12 . 
     Above contents only describe the preferred embodiments of the present invention and are not intended to limit the present invention; for one skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention should be included within the protection scope of the present invention.