Patent Publication Number: US-9415956-B2

Title: Paper feed device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2014-229542 filed Nov. 12, 2014. 
     BACKGROUND 
     Technical Field 
     The present invention relates to a paper feed device. 
     SUMMARY 
     According to an aspect of the invention, there is provided a paper feed device including a tray that holds at least one recording medium; a wall that has a portion in contact with a leading end, in a transport direction, of the at least one recording medium on the tray and is disposed so as to intersect the transport direction; and a transport member that is disposed on the downstream side, in the transport direction, of the wall and transports the at least one recording medium. The wall has an opening/closing member that is capable of being opened and closed to form an opening through which the transport member is extracted toward the tray. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiment of the present invention will be described in detail based on the following figures, wherein: 
         FIG. 1  shows the overall configuration of an image forming apparatus according to an exemplary embodiment of the present invention; 
         FIG. 2  is a perspective view of a paper feed device body according to the exemplary embodiment of the present invention; 
         FIG. 3  is a schematic diagram showing the configuration of the paper feed device body according to the exemplary embodiment of the present invention; 
         FIG. 4  is a perspective view of a tray according to the exemplary embodiment of the present invention; 
         FIGS. 5A and 5B  are perspective views of the tray according to the exemplary embodiment of the present invention, wherein  FIG. 5A  shows a state in which an opening/closing member is closed (i.e., in a normal position), and  FIG. 5B  shows a state in which the opening/closing member is open (i.e., in a replacement position); 
         FIG. 6  is a perspective view of the paper feed device body according to the exemplary embodiment of the present invention; 
         FIG. 7  is an enlarged view of a transport member and the vicinity thereof in  FIG. 6 ; 
         FIG. 8  is a diagram showing the relationship between the transport member and the opening/closing member according to the exemplary embodiment of the present invention; and 
         FIGS. 9A to 9D  are diagrams showing removal of the transport member according to the exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Next, an exemplary embodiment of the present invention will be described below with reference to the drawings. 
       FIG. 1  shows an image forming apparatus  100  according to this exemplary embodiment. The image forming apparatus  100  includes an image forming apparatus body  58 . The image forming apparatus body  58  includes an image forming section (not shown) that forms an image on the basis of an image signal inputted from an external device, such as a personal computer. A recording medium feed device  54  that feeds a recording medium to the image forming section, and a manual paper feed device  52  that is used when a recording medium is manually fed are attached to the image forming apparatus body  58 . Besides the aforementioned feed devices, there are several types of paper feed devices including: a document feed device  50  that feeds documents; a post-processing device  56  that is connected to the image forming apparatus body  58  and in which a recording medium having an image formed thereon is temporarily kept to wait for post-processing and is then fed for predetermined post-processing; and a paper feed device body  12  that feeds a recording medium, such as a slip sheet, that does not require image formation. 
       FIG. 2  is a perspective view of the paper feed device body  12  according to this exemplary embodiment. 
     There are multiple paper feed devices  10  attached to the paper feed device body  12 . In this exemplary embodiment, there are an upper paper feed device  10 A provided on the upper side and a lower paper feed device  10 B provided below the upper paper feed device  10 A. The upper paper feed device  10 A and the lower paper feed device  10 B are provided in a substantially vertical direction and each hold multiple recording media. Because the upper paper feed device  10 A and the lower paper feed device  10 B have the same configuration, they will be explained as the paper feed device  10 . 
       FIG. 3  is a schematic diagram showing the configuration of the paper feed device body  12  according to this exemplary embodiment. 
     The paper feed device  10  includes a tray  14  that holds recording media; a wall  15  standing upright, substantially perpendicular to the tray  14 , from a distal end, in the recording-medium transport direction, of the tray  14 ; a nudger roller  16  that is provided above the wall  15  and serves as a transport member; a feed roller  18  that is provided on the downstream side of the nudger roller  16  in the recording-medium transport direction and serves as a transport member; and a retard roller  20  that is provided opposite the feed roller  18  and serves as a transport member. 
     The nudger roller  16  picks up recording media on the tray  14  one-by-one and transports them into the paper feed device body  12 . The feed roller  18  transports the recording media fed by the nudger roller  16  to an even downstream side. The retard roller  20  that is in contact with the feed roller  18  separates the recording media fed by the nudger roller  16  into individual sheets. 
     That is, the recording media held on the tray  14  are picked up by the rotation of the nudger roller  16 , are transported toward a transport path  22  by the rotation of the feed roller  18  and retard roller  20 , and are transported to the post-processing device  56 . 
       FIG. 4  shows a detailed structure of the tray  14 .  FIGS. 5A and 5B  are perspective views of the tray  14 , wherein  FIG. 5A  shows a state in which an opening/closing member  24  is closed, and  FIG. 5B  shows a state in which the opening/closing member  24  is open. Note that, because FIGS.  5 A and  5 B are presented to show the structure of the opening/closing member  24  and the vicinity thereof, the illustration of guide members  26  and  26  is omitted. 
     The tray  14  has a recess  34  in a holding surface thereof, on which the recording media are placed. The recess  34  is provided substantially in the middle of the upstream end in the recording-medium transport direction. Furthermore, the tray  14  includes an extendable tray  36  that is extendable to the upstream side in the recording-medium transport direction so that it is able to hold recording media having a large length in the recording-medium transport direction. The extendable tray  36  is accommodated in the tray  14  when the recording media are not larger than the tray  14 . 
     Furthermore, the guide members  26  and  26 , serving as recording medium guide members, that guide the recording media held by the tray  14  in the transport direction are provided on the holding surface of the tray  14 . The guide members  26  and  26  are simultaneously moved in accordance with the width, i.e., the length in a direction perpendicular to the transport direction, of the recording media while holding the middle portion of the recording media. The recording media are transported toward the transport path  22 , while being guided by the guide members  26  and  26 , with the widthwise ends thereof being aligned. 
     Furthermore, the tray  14  is provided with a detection sensor  37 , serving as a recording medium detection device, that detects the presence of the recording media on the tray  14 . When the recording media are placed on the tray  14 , the detection sensor  37  senses the presence of the recording media, and the tray  14  is moved up to a position where the recording media are transported by the nudger roller  16 . Then, transportation is started. 
     Note that the wall  15  does not necessarily have to be substantially perpendicular to the tray  14 , but may be inclined toward the retard roller  20 . 
     The wall  15  has an opening  38  substantially in the middle. The opening  38  is provided with the opening/closing member  24  that opens or closes the opening  38 . 
     The opening/closing member  24  is supported so as to be able to rotate about a shaft  40  provided at the bottom of the wall  15 . Furthermore, the opening/closing member  24  and the wall  15  are urged by an urging portion  42 , such as a return spring, and the opening/closing member  24  is urged in a direction in which the opening  38  is closed. That is, the opening/closing member  24  may be tilted from a position flush with the wall  15  toward the tray  14  against the urging force. Furthermore, the opening/closing member  24  has a semicircular notch  44  that is sized to allow a human finger to be inserted, at the upper end thereof, on a control portion side. 
     The opening/closing member  24  has projections  45   a  and  45   a , projecting toward the wall  15 , at ends adjacent to the wall  15 , and the wall  15  has recesses  45   b  and  45   b  in the surface adjacent to the tray  14 . The projections  45   a  and  45   a  are engaged with the recesses  45   b  and  45   b , preventing the opening/closing member  24  from tilting toward the other side of the wall  15  from the tray  14 . Hence, without any urging force applied from the outside, the opening/closing member  24  according to this exemplary embodiment is flush with the wall  15  and serves to align the ends of the recording media stacked on the tray  14 . 
     The opening/closing member  24  is normally at a closed position (normal position). When a transport member, such as the nudger roller  16 , the feed roller  18 , or the retard roller  20  needs to be replaced, the opening/closing member  24  is tilted toward the tray  14 , against the urging force, by a finger inserted into the notch  44  up to an open position (replacement position). Then, the transport member is replaced through the opening  38  from the tray  14  side. Thus, in an apparatus having multiple paper feed devices  10  arranged in a substantially vertical direction, it is possible to replace the transport member without needing to remove the other members (units). 
     Although this exemplary embodiment has described an example in which the notch  44  in the opening/closing member  24  has a semicircular shape that allows a human finger to be inserted therein, the shape of the notch  44  is not limited thereto as long as it allows a human finger to be inserted therein, and it may be triangular, rectangular, or circular. In addition, the positions and shapes of the projections  45   a  and  45   a  and recesses  45   b  and  45   b  for preventing tilting of the opening/closing member  24  are not limited to those described above. 
     Furthermore, the upper ends of the wall  15  and opening/closing member  24  are rounded to enable smooth transportation of the recording media. Alternatively, the upper ends of the wall  15  and opening/closing member  24  may be sloped, not rounded. 
     Although this exemplary embodiment has described a configuration in which the opening/closing member  24  is opened and closed by being tilted toward the tray  14  by the urging portion  42 , the opening/closing member  24  may be opened and closed by being slid sideways or may be attached to or detached from the wall  15 . 
       FIG. 6  is a perspective view of the paper feed device  10  according to this exemplary embodiment, showing replacement of a transport member of the lower paper feed device  10 B.  FIG. 7  is an enlarged view of the transport member and the vicinity thereof in  FIG. 6 . Furthermore, FIG.  8  is a diagram showing the relationship between the opening/closing member  24  and the lengths of the respective transport members. Note that, in  FIG. 6 , for ease of explanation, the guide members  26  on the near side are illustrated with a two-dot chain line, and the detection sensors  37  are not shown. 
     The nudger roller  16  is connected to the torque limiter  17  and is supported by bearings  46  via a support shaft  16   a . The feed roller  18  is supported by bearings  48  via a support shaft  18   a . The retard roller  20  is supported by bearings  47  via a support shaft  20   a.    
     In this exemplary embodiment, it is possible to attach or detach the nudger roller  16 , the feed roller  18 , and the retard roller  20  to or from the bearings by reducing the overall length thereof by holding the ends of the support shaft  16   a , support shaft  18   a , and support shaft  20   a , respectively, with fingers. 
     The length of the opening/closing member  24  is larger than the maximum roller length, in the axial direction, of the nudger roller  16 , feed roller  18 , and retard roller  20 , and more desirably, it equals the sum of the maximum roller length, in the axial direction, of the nudger roller  16 , feed roller  18 , and retard roller  20  and the working lengths, i.e., the lengths of working spaces in which fingers hold the rollers. Because the opening  38  has a length equal to the sum of the maximum roller length, in the axial direction, of the transport members and the working lengths, attachment/detachment of the transport members is easy. Although this exemplary embodiment has described the above-described attachment/detachment method, the length should of course be such that it allows attachment/detachment to be performed even in a different roller supporting method, such as a method using a retaining ring. 
     The bearings  46  have gaps  46   a  oriented toward the bottom in the vertical direction. The nudger roller  16  is attached to or detached from the bearings  46  through the gaps  46   a . Furthermore, the bearings  47  have gaps  47   a  oriented at an upward angle relative to a direction substantially parallel to the tray  14 . The retard roller  20  is attached to or detached from the bearings  47  through the gaps  47   a . Furthermore, the bearings  48  have gaps  48   a  oriented at an angle toward the tray  14  relative to the bottom in the vertical direction. The feed roller  18  is attached to or detached from the bearings  48  through the gaps  48   a.    
       FIGS. 9A to 9D  are diagrams showing removal of the transport members. 
     First, the opening/closing member  24  is tilted toward the tray  14  against the urging force, and the nudger roller  16  is removed from the bearings  46  (see  FIGS. 9A and 9B ). 
     Next, the retard roller  20  is removed from the bearings  47  ( FIGS. 9B and 9C ). Then, the feed roller  18  is removed from the bearings  48  ( FIGS. 9C and 9D ). 
     When the transport members are attached, the above-described removal process is performed in the reverse order. 
     With the paper feed device according to this exemplary embodiment, the transport members located inside the device body may be attached or detached for maintenance without needing to remove the tray and other units. 
     Examples of the recording media explained in the above-described exemplary embodiment include documents having images thereon, besides paper to be subjected to image forming. 
     Furthermore, the paper feed device described in the above exemplary embodiment is applied to sheet feed devices and document sending devices (document feed devices), and also to image forming apparatuses, such as copiers, post-processing devices, facsimile devices, printers, etc., and manual feed trays (manual paper feed devices) of the image forming apparatuses. 
     The foregoing description of the exemplary embodiment of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiment was chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.