Abstract:
A device for reversing the direction of motion of a paper sheet has a passage for guiding the paper sheet inside and includes a plurality of rollers each having a specified function. A first roller serves as a driver roller, its rotation causing the paper sheet to be transported into and out of the passage. A second roller is for contacting and rotating with the first roller and thereby transporting the paper sheet in the first direction into the passage. A third roller is disposed on the opposite side of the first roller from the second roller and serves to transport the paper sheet in the second direction out of the passage by contacting and rotating with the first roller. A fourth roller is another driver roller and is disposed in the passage. It allows the front edge of the paper sheet to pass by when it is transported in the first direction by means of the first and second rollers. When the paper sheet has passed between the first and second rollers and its back edge has been disengaged from them, a guiding member pushes and guides the back edge of the paper sheet towards the third roller and the four roller rotates so as to transport the paper sheet in the second direction out of the device.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This invention relates to a device for reversing the direction of motion of a paper sheet and more particularly to such a device capable of dependably reversing the direction of transportation of a paper sheet, independent of its material quality or shape.  
           [0002]    Such devices for reversing the direction of motion of a paper sheet are recently coming to be used frequently in apparatus such as copiers, printers and facsimile machines. FIG. 1 shows an example of prior art paper reversing device  1  of this kind, disclosed in Japanese Patent Publication Tokkai 8-67390, provided with a passage  15  extending vertically between a pair of guide plates  14   a  and  14   b  for guiding a paper sheet vertically upward and downward. An upper driver roller  11 , adapted to rotate in the counter-clockwise direction by means of a motor (not shown), is disposed at one end position (“the start position”)  15   a  of the passage  15 . A paper-supplying follower roller  12  is pressed against the upper driver roller  11 , and a paper-discharging follower roller  13  is pressed against the upper driver roller  11  from the opposite side, sandwiching the upper driver roller  11  with the paper-supplying follower roller  12 . These two follower rollers  12  and  13  are adapted to rotate by following the motion of the upper driver roller  11 . The combination of these three rollers (the upper driver roller  11 , the paper-supplying follower roller  12  and the paper-discharging follower roller  13 ) is sometimes referred to as “the tri-roller.” 
           [0003]    At a position inside the passage  15  vertically below the tri-roller, there is provided another driver roller (“the lower driver roller  16 ”) adapted to be rotated in the clockwise direction by means of another motor (not shown), and another follower roller  18  is disposed opposite thereto. The rotary shaft of this follower roller  18  is supported by a solenoid  17  such that the follower roller  18  is movable horizontally (to the left and the right with reference to FIG. 1) by this solenoid  17 . When the follower roller  18  is moved by the solenoid  17  to the left, a gap appears between the follower roller  18  and the lower driver roller  16  for passing a paper sheet therethrough. When the solenoid  17  moves the follower roller  18  to the right, the follower roller  18  is pressed against the lower driver roller  16  and rotates therewith.  
           [0004]    The front edge of a paper sheet  2  transported to the paper reversing device  1  is brought to the start position  15   a  of the passage  15  so as to be clamped between the upper driver roller  11  and the paper-supplying follower roller  12  and guided vertically downward through the passage  15 . At this moment, the lower driver roller  16  is not activated and the follower roller  18  is retracted to the left by the solenoid  17 , leaving a gap so as to allow the paper sheet  2  to pass therethrough.  
           [0005]    After the front edge of the paper sheet  2  passes through the gap between the lower driver roller  16  and the follower roller  18 , the follower roller  18  is moved to the right by the solenoid  17  such that the paper sheet  2  becomes clamped therebetween. Since the lower driver roller  16  is not driven yet, however, it is caused to rotate in the counterclockwise direction by the downward motion of the paper sheet  2  (while the follower roller  18  is thereby caused to rotate in the clockwise direction). In other words, the paper sheet  2  continues to be transported downward inside the passage  15 .  
           [0006]    As the back edge of the paper sheet  2  passes the contact point between the upper driver roller  11  and the paper-supplying follower roller  12 , the lower driver roller  16  starts to be driven by the associated motor, rotating in the clockwise direction and thereby causing the paper sheet  2  to reverse the direction of its motion and to move in the vertically upward direction inside the passage  15 , while remaining clamped between the lower driver roller  16  and the follower roller  18 . Thus, the upwardly moving paper sheet  2  is discharged out of the passage  15  from its back end while being sandwiched between the upper driver roller  11  and the paper-discharging follower roller  13 .  
           [0007]    In summary, the paper reversing device  1  serves to supply the paper sheet  2  downward into the passage  15  from its front edge, to reverse the direction of transportation of the paper sheet  2  after the supplying is completed (when its back edge is brought inside the passage  15 ) and to discharge it out of the passage  15  from its back edge by moving it upward. Such a mode of supplying and discharging a paper sheet by means of a tri-roller as described above, that is, the mode of using a driver roller and a paper-supplying follower roller to supply a paper sheet and using the same driver roller and a paper-discharging follower roller to discharge the paper sheet is commonly referred to as the tri-roller method.  
           [0008]    A problem with the paper reversing device  1 , as described above, is that the cross-sectional size of the passage  15  is large at its start position  15   a  where a tri-roller is disposed. As a result, the space for the paper sheet to pass through is large, giving rise to the possibility that the back end of the paper sheet  2  may not dependably move from the side of the paper-supplying follower roller  12  to the side of the paper-discharging follower roller  13  when the paper sheet  2  inside the passage  15  is about to be discharged. This probability increases in particular in the case of curled paper.  
           [0009]    As explained above, furthermore, the paper sheet  2  which has been supplied into the passage  15  by means of the upper driver roller  11  and the paper-supplying follower roller  12  is guided downward through the passage  15 . This gives rise to another possibility that the paper sheet  2  may undergo a free fall as soon as the back edge of the paper sheet  2  is released from the clamping between the upper driver roller  11  and the paper-supplying follower roller  12 . This probability of free fall is particularly high if the paper sheet is thin or heavy.  
         SUMMARY OF THE INVENTION  
         [0010]    It is therefore an object of this invention in view of the problems described above to provide an improved paper reversing device capable of dependably reversing the direction of motion of a paper sheet and discharging it independently of the material quality or shape of the paper sheet.  
           [0011]    A paper reversing device embodying this invention for reversing the direction of motion of a paper sheet, with which the above and other objects of the invention can be accomplished, may be characterized as comprising a passage for guiding the paper sheet therethrough, a plurality of rollers each having a specified function and a guiding member for pressing and guiding a portion of the paper sheet in a specified direction for discharging. One of the rollers (“the first roller”) is a driver roller and its rotation causes the paper sheet to be supplied (in “the first direction”) into and discharged (in “the second direction”) out of the passage. Another roller (“the second roller” or “the paper-supplying follower roller”) is for contacting and rotating with the first roller and thereby transporting the paper sheet in the first direction into the passage. Still another roller (“the third roller” or “the paper-discharging follower roller”) is disposed on the opposite side of the first roller from the second roller such that the second and third rollers sandwich the first roller therebetween, and serves for transporting the paper sheet in the second direction out of the passage by contacting and rotating with the first roller. There is till another roller (“the fourth roller”) which is a driver roller disposed in the passage and serves to allow the front edge of the paper sheet to pass by when it is transported in the first direction by means of the first and second rollers. When the paper sheet has passed between the first and second rollers and its back edge has been disengaged therefrom, however, the guiding member functions to press and guide the back edge of the paper sheet towards the third roller and the four roller rotates so as the transport the paper sheet in the second direction and discharge it between and by means of the first and third rollers. In this manner, the direction of motion of the paper sheet inside the passage can be dependably reversed without regard to the material quality or the size of the paper sheet.  
           [0012]    If the second roller and the guiding member are coaxially disposed so as to share a shaft as their common axis of rotation, their structures can be simplified. If the guiding member is designed to have a surface configured along the outer periphery of the first roller, the paper sheet can be more dependably guided towards the third roller.  
           [0013]    The guiding member may be designed to press the paper sheet by its own weight, or by the gravitational force thereon. If the guiding member is made of an elastic material such that it pushes and guides the back edge of the paper sheet by its elastic force, the guiding of the paper sheet thereby can be effected more dependably.  
           [0014]    The passage for the paper sheet may be preferably be designed such that the aforementioned second direction is sloped and makes a specified acute angle from the vertical direction towards the third roller. The paper sheet can then be discharged more smoothly. The angle of the slope is preferably selected to be equal to the angle made by the line which is tangent to both the first and third rollers. It is further preferable to design the passage so as to include a curved lower end part such that the paper sheet can be prevented from falling freely by its own weight inside the passage. The radius of the curvature of this curved portion may be varied according to the material characteristics of the paper sheet. This lower end part of the passage may be made detachable such that a jamming paper sheet can be removed easily. For example, the passage may be structured so as to be separable into a first passage part and a removable second passage part, connector members being provided to connect them. The passage may be formed by means of guide plates to make it openable for removing a jamming paper sheet.  
           [0015]    A paper holder member may be disposed inside the passage for serving to hold the paper sheet so as to dependably prevent the free fall of the paper sheet in the first direction inside the passage.  
           [0016]    A fifth roller may be further provided as a follower roller, disposed opposite the fourth roller for transporting the paper sheet in the second direction by contacting the fourth roller. An elastic member may be provided to support the shaft of the fifth roller to apply its biasing force on the fifth roller towards the fourth roller.  
           [0017]    The four roller may be D-shaped in cross-section, having a straight line portion and an arcuate portion, such that the paper sheet can be passed by smoothly in the first direction when it is being supplied into the passage and transported dependably in the second direction when it is being discharged.  
           [0018]    With a device thus structured according to this invention, each paper sheet is transported in the first direction by means of the first and second rollers but as soon as it passes through these rollers and its back edge is disengaged from them, the fourth roller begins to transport it oppositely in the second direction while its back edge is pressed and guided towards the third roller. Thus, the paper sheet is dependably discharged between the first and third rollers with the direction of its motion reversed. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    [0019]FIG. 1 is a schematic sectional view of a prior art paper reversing device.  
         [0020]    [0020]FIG. 2 is a schematic sectional view of a copier before a paper reversing device of this invention is installed.  
         [0021]    [0021]FIG. 3 is a schematic sectional view of the copier of FIG. 2 with a paper reversing device embodying this invention.  
         [0022]    [0022]FIG. 4 is a sectional view of a paper reversing device according to a first embodiment of this invention.  
         [0023]    [0023]FIG. 5 is a diagonal external view of the paper reversing device of FIG. 4.  
         [0024]    [0024]FIG. 6 is a diagonal external view of the guide arm and the paper-supplying follower roller of FIG. 4 according to one example.  
         [0025]    [0025]FIGS. 7A and 7B, together referred to as FIG. 7, are respectively a diagonal external view and a side view of a spring which may be used in the paper reversing device of FIG. 4.  
         [0026]    [0026]FIGS. 8A and 8B, together referred to as FIG. 8, are respectively a diagonal external view and a side view of another spring which may be used in the paper reversing device of FIG. 4.  
         [0027]    [0027]FIG. 9 is a sectional view of the paper reversing device of FIG. 4 when a paper sheet is being supplied into it.  
         [0028]    [0028]FIG. 10 is a sectional view of the paper reversing device of FIG. 4 when a paper sheet is being discharged from it.  
         [0029]    [0029]FIG. 11 is a sectional view of another paper reversing device according to a second embodiment of the invention.  
         [0030]    [0030]FIG. 12 is a sectional view of still another paper reversing device according to a third embodiment of the invention. 
     
    
       [0031]    Throughout herein, corresponding components are indicated by the same numerals and may not be described repetitiously as they appear in different figures and/or indicate components of different devices.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0032]    The invention is described next by way of examples. FIG. 2 shows a copier  21  without a device embodying this invention. FIG. 3 shows the same copier  21  with a paper reversing device  51  according to this invention. As shown both in FIGS. 2 and 3, the copier  21  has paper cassettes  31 - 1 - 31 - 4  provided in the lower part thereof for containing respectively paper sheets  2 - 1 - 2 - 4  of specified different sizes. Above these cassettes are rollers  32 - 1 - 32 - 5  for transporting these paper sheets  2 - 1 - 2 - 4 , an image transferring drum  33  for transferring a specified image onto the paper sheets  2 - 1 - 2 - 4 , and a fixer  34  for fixing the transferred image, as well as an upper discharge opening  35  and a lower discharge opening  36  for discharging the paper sheets  2 - 1 - 2 - 4  on which an image has been fixed. A sorter  37  is further provided on a side surface for sorting the paper sheets  2 - 1 - 2 - 4  discharged through the lower discharge opening  36  in a specified sequence.  
         [0033]    Let letters A and B indicate respectively the lower and upper surfaces of paper sheets  2 - 1  in the cassette  31 - 1 . As these paper sheets  2 - 1  are pulled out of the cassette  31 - 1  and transported by means of the roller  32 - 1  and  32 - 2 , it is onto the surface A that the drum  33  transfers an image. When these paper sheets  2 - 1  are discharged into the sorter  37 , it is through the lower discharge opening  36  by means of the rollers  32 - 3  and  32 - 5  after the image is fixed thereon by means of the fixer  34 . (When they are not discharged into the sorter  37 , they are discharged through the upper discharge opening  35  by means of the roller  32 - 4 .) When they are discharged through the lower discharge opening  36 , the paper sheets  2 - 1  are piled up sequentially in the “face-up” condition with the printed surfaces facing upward. In FIG. 2, the printed surfaces of the first, second and third pages are respectively indicated as A 1 , A 2  and A 3  and their back surfaces respectively as B 1 , B 2  and B 3 . Thus, the second paper with the printed surface A 2  facing upward will be piled on top of the first page with the printed surface A 1  facing upward, and so forth. In other words, the printed paper sheets are piled up in the reverse order.  
         [0034]    Thus, it is preferable to insert a paper reversing device  51  between the lower discharge opening  36  and the sorter  37 , as shown in FIG. 3. With a paper reversing device  51  thus inserted in the copier  21 , the paper sheets  2 - 1  discharged from the lower discharge opening  36  with the printed surface A facing upward are each turned over by the paper reversing device  51  and discharged therefrom with the printed surface A facing downward. Thus, the discharged paper sheets  2 - 1  are piled up in the correct order as they are discharged from the sorter  37 , as shown in FIG. 3. The same explanation applies to printers and facsimile machines, as well as to copiers.  
         [0035]    The structure of the paper reversing device  51  according to a first embodiment of the invention is explained next with reference to FIGS. 4 and 5. As shown in FIG. 4, the paper reversing device  51  has a passage  66  formed by guide plates  65   a  and  65   b,  sloping at an angle θ from the vertical direction towards the paper-discharging follower roller  13 . According to this example, this angle θ is selected to be equal to the sloping angle of the line which is tangent to both the upper driver roller  11  and the paper-discharging follower roller  13 . In what follows, the upward and downward directions along this sloped passage  66  will be simply referred to as the upward and downward directions.  
         [0036]    The reason for thus sloping the passage  66  is to make it easier to guide a paper sheet  2  smoothly in the direction of the paper-discharging following roller  13  when it is being discharged. The passage  66  is also curved at its lower end part  66   b  for preventing the free fall (or free downward sliding) of the paper sheet  2  and also for reducing the total size of the device. The curvature of the lower end part  66   b  of the passage  66  may be made variable in order to make it suitable for different kinds of paper sheet with different material characteristics.  
         [0037]    A driver roller  11  is disposed at the top end part  66   a  of the passage  66 , sandwiched between the paper-supplying follower roller  12  and the paper-discharging follower roller  13 , that is, there is a tri-roller as shown in FIG. 1 and paper sheets are supplied and discharged by the tri-roller method.  
         [0038]    As shown in FIG. 5, the guide plate  65   a  may be opened and closed. When there is a jam, the user may open the guide plate  65   a  and remove the jammed paper remaining in the passage  66 .  
         [0039]    As shown in FIG. 6, the paper-supplying follower roller  12  is inserted between two surfaces  61   b  and  61   c  of a guide arm  61  and its center is connected to the guide arm  61  through a shaft  67 . As shown in FIG. 4, the paper-supplying follower roller  12  and the guide arm  61  share the shaft  67  as axis of rotation at the top end part  66   a  of the passage  66  such that the device  51  can be made compact. The guide arm  61  is further provided with a surface  61   a  having the same shape as the outer periphery of the driver roller  11  and being adapted to be along this outer periphery and another surface  61   d  for pressing the paper sheets  2 . Thus, when a paper sheet  2  is being transported by means of the driver roller  11  and the paper-supplying follower roller  12 , the guide arm  61  is pushed upward around the shaft  67  by the paper sheet  2 , as shown in FIG. 9, such that its surface  61   a  follows the contour along the outer periphery of the driver roller  11 .  
         [0040]    When a paper sheet  2  is being discharged from the device  51 , as shown in FIG. 10, the guide arm  61  is pushed downward around the shaft  67  by its own weight with its surface  61   a  following the contour of the outer periphery of the driver roller  11 . As the guide arm  61  is thus being pushed downward, its surface  61   d  presses the paper sheet  2  which is being upwardly transported and thereby guides it away from the paper-supplying follower roller  12  towards the paper-discharging follower roller  13 . The guide arm  61 , thus serving to function by its own weight, or by a gravitational force thereon, may preferably be made of a material with small plastic deformation such as a metal plate, a resin material or a sponge. If the guide arm  61  is made of such a material, the pressure on the paper sheet  2  applied thereby can be made approximately uniform with only small variations. The weight of such a guide arm may be varied according to the type of the paper sheets to be used.  
         [0041]    Although a mechanism of the guide arm  61  making use of its own weight to guide the paper sheet towards the paper-discharging follower roller  13  was disclosed above, this is not intended to limit the scope of the invention. Use may be made of a guide arm provided with an elastic member such as a spring with a controllable spring constant for guiding a paper sheet from the paper-supplying follower roller  12  towards the paper-discharging follower roller  13 .  
         [0042]    With reference again to FIG. 4, there is provided along the passage  66  and below the tri-roll at the top end part  66   a  of the passage  66  a D-shaped driver roller  62  adapted to rotate in the clockwise direction by means of a motor (not shown), having its straight portion  62   a  normally contacting the guide plate  65   b  of the passage  66  when it is not being rotated by the motor. Thus, as a paper sheet  2  is downwardly transported through the passage  66  by means of the paper-supplying follower roller  12  and the driver roller  11 , its front edge passes smoothly along this straight portion  62   a  of the periphery of the D-shaped driver roller  62 . In this manner, the problem with prior art driver rollers can be largely obviated.  
         [0043]    After the back end of the paper sheet  2  is disengaged from and leaves the paper-supplying follower roller  12  and the driver roller  11 , the D-shaped driver roller  62  is activated and begins to rotate in the clockwise direction (like the lower driver roller  16  described above with reference to FIG. 1). A follower roller  18  (structured as described above with reference to FIG. 1) is thereby pressed against the arcuate portion  62   b  of the D-shaped driver roller  62 , as shown in FIG. 10, and rotated therewith. Thus, when the D-shaped driver roller  62  is activated, the paper sheet  2  is clamped between the D-shaped driver roller  62  and its follower roller  18  and transported upward inside the passage  66 . The shaft of the follower roller  18  is supported by a spring  63  adapted to apply a biasing force on the follower roller  18  in the direction of the D-shaped driver roller  62 .  
         [0044]    [0044]FIGS. 7 and 8 are referenced next to explain examples of the spring  63 . FIG. 7 shows a spring  63 - 1  according to a first example, having bent parts  63 - 1   a,  shaft-receiving parts  63 - 1   b  and a fixed planar part  63 - 1   c.  It is set such that the bent parts  63 - 1   a  contact a member  64 - 1   a  secured onto the guide plate  65   a,  that the shaft-receiving parts  63 - 1   b  support the shaft of the follower roller  18 , and that the fixed planar part  63 - 1   c  is affixed to another member  64 - 1   b  secured onto the guide plate  65   a.    
         [0045]    The bent parts  63 - 1   a  serve to prevent the follower roller  18  supported by the shaft-receiving parts  63 - 1   b  from becoming displaced in the direction of the D-shaped driver roller  62  by a distance greater than a specified length. Since these bent parts  63 - 1   a  are provided in the direction of the elastic force of the spring  63 - 1 , as shown in FIG. 7, the position of the follower roller  18  cannot be definite because of the variation in the elastic force of the spring  63 - 1 . When a paper sheet  2  is being supplied and moving downward, a sufficient space for passing the paper sheet  2  may not be dependably secured between the follower roller  18  and the D-shaped driver roller  62 .  
         [0046]    When the paper sheet  2  is being discharged and moving upward, the pressure on the paper sheet  2  between the follower roller  18  and the D-shaped driver roller  62  may fluctuate.  
         [0047]    In view of these problems, it is preferable to use a spring  63 - 2  as shown in FIG. 8, adapted to be disposed in the device  51 , characterized also as having bent parts  63 - 2   a,  shaft-receiving parts  63 - 2   b  and a fixed planar part  63 - 2   c  but additionally wherein the bent parts  63 - 2   b  are perpendicular to the direction of the elastic force of the spring  63 - 2 . The spring  63 - 2  thus structured is set in the device  51 , as shown in FIG. 8, with its bent parts  63 - 2   a  contacting the guide plate  65   a,  its shaft-receiving parts  63 - 2   b  supporting the shaft of the follower roller  18  and its fixed planar part  63 - 2   c  secured to a member  64 - 2  affixed to the guide plate  65   a.  Thus, since the spring  63 - 2  has its bent parts  63 - 2   a  perpendicular to the direction of its elastic force and the bent parts  63 - 2   a  are pressed against the guide plate  65   a,  the position of the follower roller  18  supported by the shaft-receiving parts  63 - 2   b  can be maintained dependably without regard to the variations in the elastic force of the spring  63 - 2 . In other words, the spring  63 - 2  shown in FIG. 8 can maintain the space between the follower roller  18  and the D-shaped driver roller  62  at the time of supplying a paper sheet  2  and the compressive force on the paper sheet  2  between the follower roller  18  and the D-shaped driver roller  62  at the time of discharging the paper sheet  2  more uniformly than the spring  63 - 1  shown in FIG. 7. In summary, the spring  63 - 1  shown in FIG. 7 may be used in the device  51  but the spring  63 - 2  shown in FIG. 8 is preferred.  
         [0048]    Next, FIGS. 9 and 10 are referenced again to explain the operations of the paper reversing device  51 . FIG. 9 shows the device  51  when a paper sheet  2  is being supplied, and FIG. 10 shows the same device  51  when the paper sheet  2  has had its direction of motion reversed and is being discharged.  
         [0049]    As shown in FIG. 9, the front edge of a paper sheet  2 , as it is supplied to the device  51  from the lower discharge opening  36  shown in FIG. 3, is clamped between the upper driver roller  11  and the paper-supplying follower roller  12  to the top end part  66   a  of the passage  66  and guided downward through the passage  66 . During this operation, the guide arm  61  is pushed upward by the paper sheet  2  by using the shaft  67  as the axis of rotation, and the D-shaped driver roller  62  is not activated but remains in the condition shown in FIG. 9. Thus, the front edge of the paper sheet  2  passes directly downward along the straight portion  62   a  of the D-shaped driver roller  62  until it reaches the lower end part  66   b  of the passage  66 .  
         [0050]    As the back edge of the paper sheet  2  is disengaged from the upper driver roller  11  and the paper-supplying follower roller  12 , the device  51  terminates the paper-supplying portion of the operations and starts the operations for reversing the direction of motion of the paper sheet  2  and discharging it. For this portion of the operations, the D-shaped driver roller  62  is activated, say, by means of a motor, and starts to rotate in the clockwise direction, as shown in FIG. 10. During this time, the guide arm  61  is pushed downward due to its own weight, using the shaft  67  as the axis of rotation. The paper sheet  2  may tend to undergo a free fall motion by freely sliding downward inside the passage  66  but the lower end part  66   b  of the passage  66  is curved and serves as a stopper, preventing such a free falling motion and keeping the paper sheet  2  remaining inside the passage  66 .  
         [0051]    As the arcuate portion  62   b  of the D-shaped driver roller  62  comes to contact the follower roller  18  with the paper sheet  2  in between, the paper sheet  2  reverses the direction of its downward motion and is transported upward inside the passage  66  in this clamped condition. The upwardly moving paper sheet  2  is pushed from its back edge part by the surface  61   d  of the guide arm  61  from the side of the paper-supplying follower roller  12  towards the paper-discharging follower roller  13  and discharged out of the passage  66  by means of the upper driver roller  11  and the paper-discharging follower roller  13 .  
         [0052]    [0052]FIG. 11 shows another paper reversing device  71  embodying this invention, indicating like or equivalent components by the same symbols as used in FIG. 4 for the device  51  according to the first embodiment of the invention. The device  71  according to this embodiment is characterized as further comprising a paper holding member  81  made of a resin material, Mylar or sponge disposed inside the passage  66  below the D-shaped driver roller  62 .  
         [0053]    As shown in FIG. 11, the paper holding member  81  has its upper end portion  81   a  affixed to a guide plate  82   b  and its lower end portion  81   b  remains unattached. With the paper holding member  81  thus provided, the front edge of the paper sheet  2  which is guided downward through the passage  66  pushes down the lower end portion  81   b  of the paper holding member  81  towards the guide plate  82   b  such that a space for passing the paper sheet  2  through is dependably secured between the guide plate  82   a  and the paper holding member  81 . Thus, while the paper reversing device  71  is supplying a paper sheet  2  by means of the driver roller  11  and the paper-supplying follower roller  12 , the paper sheet  2  can pass through the space between the paper holder member  81  and the guide plate  82   a.    
         [0054]    When the device  71  finishes the paper-supplying operation and the back edge of the paper sheet  2  becomes disengaged from the driver roller  11  and the paper-supplying follower roller  12 , the lower end portion  81   b  of the paper holder member  81  is pushed upward toward the guide plate  82   a  by naturally returning to its original form and the paper sheet  2  is dependably held between the paper holder member  81  and the guide plate  82   a,  prevented from falling downward freely.  
         [0055]    The passage  66  is further divided into the first passage part  66   c  formed by guide plates  82   a  and  82   b  (from the top end part  66   a  to a point above the lower end part  66   b ) and a second passage part  66   d  formed by guide plates  83   a  and  83   b  (corresponding to the curved portion of the curved lower part  66   b  shown in FIG. 4), connected together by means of connector members  84   a  and  84   b  such that the second passage part  66   d  can be disconnected and separated from the first passage part  66   d,  as separately shown in FIG. 11. In the case of a jam, the user may remove the guide plate  65   a  to remove the jamming paper sheet, as explained above with reference to FIG. 5, but the user may alternatively remove the second passage part  66   d  to remove the jamming paper sheet  2 .  
         [0056]    In other respects, the device  71  according to the second embodiment of the invention is the same and operated similarly as the device  51  according to the first embodiment described above. It also goes without saying that the device  71  may be attached not only to the copier  21  but also to an apparatus of a different kind such as a printer and a facsimile machine.  
         [0057]    [0057]FIG. 12 shows still another paper reversing device  91  embodying this invention, indicating like or equivalent components by the same symbols as used in FIG. 11 for the device  71  according to the second embodiment of the invention. The device  91  according to this embodiment is characterized wherein the second passage part  66   d  (and hence the guide plates  83   a  and  83   b ) and the connector members  84   a  and  84   b  of the device  71  according to the second embodiment are removed. This is to say that these components removed from the device  71  to form the device  91  are not indispensable because of the presence of the paper holder member  81 . The advantage of the third embodiment is that the device  91  is much more compact.  
         [0058]    In other aspects, the device  91  according to the third embodiment of the invention is the same and operated similarly as the device  71  according to the second embodiment described above. It also goes without saying that the device  91  may be attached not only to the copier  21  but also to an apparatus of a different kind such as a printer and a facsimile machine.