Patent Publication Number: US-9851684-B2

Title: Engaging mechanism for movable panel in image forming apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2016-036537 filed Feb. 28, 2016. 
     BACKGROUND 
     Technical Field 
     The present invention relates to an image forming apparatus. 
     SUMMARY 
     According to an aspect of the present invention, there is provided an image forming apparatus including: an open/close member supported so as to be movable between an open position at which an inside of an apparatus body is exposed and a closed position at which the inside of the apparatus body is covered; an engaged portion provided on one of the apparatus body and the open/close member; an engaging member having an engaging portion that is engageable with the engaged portion and a lever portion that contacts the engaged portion to guide the engaging portion to the engaged portion when the open/close member is moved from the open position to the closed position, the engaging member being provided on the other of the apparatus body and the open/close member and being rotatable forward and in reverse; and an urging member that urges the engaging member, an urging direction of the urging member being changeable between two urging directions including a fixing direction in which the engaging member is drawn into the engaged portion and a releasing direction in which the engaging member is moved away from the engaged portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       An exemplary embodiment of the present invention will be described in detail based on the following figures, wherein: 
         FIG. 1  is a schematic sectional view illustrating the internal configuration of an image forming apparatus  1 ; 
         FIG. 2  is a perspective view illustrating a state in which an open/close member  100  of the image forming apparatus  1  is at a closed position and engaged with an apparatus body with internal constituent members omitted; 
         FIG. 3  is a perspective view illustrating a state in which the open/close member  100  of the image forming apparatus  1  is positioned at an open position with internal constituent members omitted; 
         FIG. 4A  is a partial perspective view illustrating a state in which an engaging member  120  is engaged with an engaged portion  140  of the apparatus body; 
         FIGS. 4B and 4C  are each a partial perspective view illustrating the state of engagement between the engaging member  120  and the engaged portion  140 ; 
         FIGS. 5A and 5B  are each a perspective view of a support member  110 ; 
         FIGS. 5C and 5D  are each a perspective view of the engaging member  120 ; 
         FIGS. 5E and 5F  are each a perspective view of the engaged portion  140 ; 
         FIG. 6A  is a schematic sectional view illustrating the engaging member  120  at an initial position; 
         FIG. 6B  is a schematic sectional view illustrating the engaging member  120  at a drawn position; 
         FIGS. 7A to 7D  are each a schematic view illustrating a process in which the engaging member  120  is engaged with the engaged portion  140  when the open/close member  100  is moved from the open position to the closed position; 
         FIGS. 8A to 8G  are each a schematic view illustrating a process in which the engaging member  120  is engaged with the engaged portion  140  when the open/close member  100  is moved from the open position to the closed position with the engaging member  120  rotated in a fixing direction; and 
         FIGS. 9A and 9B  are each a partial perspective view illustrating the state of engagement between an engaging member  120 A and an engaged portion  140 A according to a modification. 
     
    
    
     DETAILED DESCRIPTION 
     An exemplary embodiment and a specific example of the present invention will be described in detail below with reference to the drawings. The present invention is not limited to the following exemplary embodiment and specific example. 
     It should be noted that, in the following description of the drawings, the drawings are schematic and the ratio of dimensions etc. may be different from the actual value, and that members other than those required to describe the present invention may not be illustrated as appropriate for ease of understanding. 
     In the drawings, in order to facilitate understanding of the following description, the front-rear direction is defined as the X-axis direction, the left-right direction is defined as the Y-axis direction, and the up-down direction is defined as the Z-axis direction. 
     (1) Overall Configuration and Operation of Image Forming Apparatus 
       FIG. 1  is a schematic vertical sectional view illustrating the internal configuration of an image forming apparatus  1  according to an exemplary embodiment. 
     The overall configuration and operation of the image forming apparatus  1  will be described below with reference to the drawing. 
     The image forming apparatus  1  includes a control device  10 , a paper transport device  20 , a photosensitive unit  30 , a developing device  40 , a toner cartridge  50 , an exposure device  60 , a transfer device  70 , and a fixing device  80 . 
     An open/close member  100  is rotatably supported on the front surface of the image forming apparatus  1 . The open/close member  100  is opened forward (−X direction) to expose the inside of the image forming apparatus  1  for replacement of consumables etc. 
     A rear cover  1   b  is rotatably supported on the rear surface of the image forming apparatus  1 . The rear cover  1   b  is opened to expose the inside of the image forming apparatus  1  for an internal check for a paper jam etc. 
     An upper cover  1   c , which also serves as an ejection tray for ejection and storage of paper on which an image has been recorded, is formed on the upper surface (Z direction) of the image forming apparatus  1 . 
     The control device  10  includes an image forming apparatus control section  11 , a controller section  12 , an exposure control section  13 , a power source device  14 , and so forth. The image forming apparatus control section  11  controls operation of the image forming apparatus  1 . The controller section  12  prepares image data according to a printing process request. The exposure control section  13  controls lighting of a light source of the exposure device  60 . The power source device  14  applies a voltage to a charging roller  32 , a developing roller  42 , a transfer roller  72 , and so forth to be discussed later, and supplies power to the exposure device  60 . 
     The controller section  12  converts image data input from an image reading device (not illustrated) and printing information input from an external information transmission device (such as a personal computer, for example) into image information for latent image formation, and outputs a drive signal to the exposure control section  13  at a timing set in advance. 
     The paper transport device  20  is provided at the bottom portion of the image forming apparatus  1 . The paper transport device  20  includes a paper cassette  21 . A large number of sheets of paper P, which serve as a recording medium, are loaded on the upper surface of the paper cassette  21 . The paper P, the position of which in the width direction is determined by restriction plates (not illustrated), is drawn rearward (X direction) from above, one sheet at a time, by a paper drawing portion  22 , and thereafter transported to a contact portion of a registration roller pair  23 . 
     The photosensitive unit  30  is provided above the paper transport device  20 , and includes a photosensitive drum  31  provided in a unit housing  35  and rotationally driven. The charging roller  32 , the developing device  40 , the transfer roller  72 , and a cleaning blade  34  are disposed along the rotational direction of the photosensitive drum  31 . A cleaning roller  33  is disposed to face and contact the charging roller  32  to clean the surface of the charging roller  32 . 
     The developing device  40  includes a developing housing  41  that stores a developer inside. The developing roller  42  and a pair of augers  44  and  45  are disposed in the developing housing  41 . The developing roller  42  is disposed to face the photosensitive drum  31 . The augers  44  and  45  are provided obliquely below and on the back side of the developing roller  42  to agitate and transport the developer toward the developing roller  42 . A layer restriction roller  46  is disposed in proximity to the developing roller  42  to restrict the layer thickness of the developer. 
     The photosensitive unit  30  and the developing device  40  are constituted integrally as a process cartridge  90 . The process cartridge  90  is removably mounted to the body of the image forming apparatus  1 . As illustrated in  FIG. 1 , the process cartridge  90  may be replaced by opening and closing the open/close member  100  which is provided on the body of the image forming apparatus  1  so as to be openable and closable in the case where the photosensitive drum  31  reaches its end of life or the like. 
     The toner cartridge  50  is removably mounted to an end portion of the process cartridge  90  on the side opposite to an end portion to which the photosensitive unit  30  is mounted. The toner cartridge  50  may be mounted to and removed from the process cartridge  90  with the process cartridge  90  mounted to the body of the image forming apparatus  1 . 
     The exposure device  60  includes a laser beam output unit  61  that is usable as a light source, and a rotary multi-faceted mirror (polygon mirror)  62  that deflects a laser beam LB from the laser beam output unit  61 , and scans a surface of the photosensitive drum  31  with the laser beam LB which has been modulated in accordance with image data to be formed. 
     The surface of the photosensitive drum  31  which is rotatable is charged by the charging roller  32 . An electrostatic latent image is formed on the surface of the photosensitive drum  31  by the exposure device  60 . The electrostatic latent image formed on the photosensitive drum  31  is developed as a toner image by the developing roller  42 . 
     The transfer device  70  is composed of the rear cover  1   b  and the transfer roller  72 . The rear cover  1   b  supports the transfer roller  72  so that the transfer roller  72  comes into and out of contact with the photosensitive drum  31 . The transfer roller  72  forms a nip together with the photosensitive drum  31 . A transfer voltage is applied to the transfer roller  72  from the power source device  14  which is controlled by the image forming apparatus control section  11 . The toner image on the photosensitive drum  31  is transferred to the paper P which passes between the photosensitive drum  31  and the transfer roller  72 . 
     Residual toner remaining on the surface of the photosensitive drum  31  is removed by the cleaning blade  34 , and recovered into the unit housing  35  which supports the photosensitive drum  31 . After that, the surface of the photosensitive drum  31  is recharged by the charging roller  32 . The residue that is not removed by the cleaning blade  34  but attached to the charging roller  32  is captured by the surface of the cleaning roller  33  which rotates in contact with the charging roller  32 , and thereafter discharged onto the photosensitive drum  31  again by way of the charging roller  32 . 
     The fixing device  80  includes a pair of a heating module  81  and a pressurizing module  82 . A press contact region between the heating module  81  and the pressurizing module  82  forms a fixing nip portion (fixing region). 
     The paper P to which the toner image has been transferred by the transfer roller  72  is transported to the fixing device  80  by way of a transport guide  74  with the toner image unfixed. When the paper P is transported to the fixing device  80 , the toner image is fixed by the pair of the heating module  81  and the pressurizing module  82  by the action of pressure bonding and heating. After the toner image is fixed, the paper P is ejected by an ejection roller pair  84  to the upper cover  1   c  on the upper surface of the image forming apparatus  1 . 
     (2) Open/Close Structure 
       FIG. 2  is a perspective view illustrating a state in which the open/close member  100  of the image forming apparatus  1  is at a closed position and engaged with the apparatus body with internal constituent members omitted.  FIG. 3  is a perspective view illustrating a state in which the open/close member  100  of the image forming apparatus  1  is positioned at an open position with internal constituent members omitted.  FIG. 4A  is a partial perspective view illustrating a state in which the engaging member  120  is engaged with the engaged portion  140  of the apparatus body.  FIGS. 4B and 4C  are each a partial perspective view illustrating the state of engagement between the engaging member  120  and the engaged portion  140 .  FIGS. 5A and 5B  are each a perspective view of a support member  110 .  FIGS. 5C  and  5 D are each a perspective view of the engaging member  120 .  FIGS. 5E and 5F  are each a perspective view of the engaged portion  140 .  FIG. 6A  is a schematic sectional view illustrating the engaging member  120  at a release position.  FIG. 6B  is a schematic sectional view illustrating the engaging member  120  at a fixing position. The open/close structure of the image forming apparatus  1  according to the exemplary embodiment will be described below with reference to the drawings. 
     (2.1) Overall Configuration of Open/Close Structure 
     In  FIGS. 1 and 3 , the open/close member  100 , which is rotatably supported on the left side of the image forming apparatus  1 , is supported so as to be movable between the open position at which the inside of the apparatus body is exposed and the closed position at which the inside of the apparatus body is covered. 
     A center of rotation  100   a  is formed at the lower end portion of the open/close member  100 . The open/close member  100  is supported on the apparatus body so as to be rotatable about the center of rotation  100   a.    
     The engaging member  120  is rotatably supported by the support member  110  on the inner surface side of the open/close member  100 . The engaged portion  140  is fixed on the apparatus body side. 
     When the open/close member  100  is rotationally moved from the open position to the closed position, the engaging member  120  is engaged with the engaged portion  140  on the apparatus body side while rotating so that the open/close member  100  closes the apparatus body. 
     To open the apparatus body, engagement between the engaging member  120  and the engaged portion  140  on the apparatus body side is canceled by performing a drawing operation on the open/close member  100  to rotationally move the open/close member  100  to the open position. 
     In the exemplary embodiment, the engaging member  120  is provided on the open/close member  100 , and the engaged portion  140  is provided on the apparatus body side. However, the present invention is not limited thereto. The engaging member  120  may be provided on the apparatus body side, and the engaged portion  140  may be provided on the open/close member  100 . 
     (2.2) Support Member 
     As illustrated in  FIGS. 5A and 5B , the support member  110  has a box shape as a whole, and has shaft receiving portions  111  that rotatably support rotary shaft portions  123  of the engaging member  120 . In addition, a hook portion  112  for attachment of one end of an urging member  130  is formed on the inner surface side of the support member  110 . 
     The support member  110  is fixed on the inner surface side of the open/close member  100 , and rotatably supports the engaging member  120 . 
     (2.3) Engaging Member 
     As illustrated in  FIGS. 5C and 5D , the engaging member  120  has an engaging portion  121  to be engaged with the engaged portion  140 , a lever portion  122  that contacts the engaged portion  140  to guide the engaging portion  121  to the engaged portion  140  when the open/close member  100  is moved from the open position to the closed position, and the rotary shaft portions  123 , and have a hook shape as a whole. 
     An arcuate shape portion  125  and an inclined surface portion  126  are formed on the outer side of the engaging portion  121  as seen from the rotary shaft portions  123 . In addition, a hook portion  124  for attachment of the other end of the urging member  130  is formed on the inner surface side of the engaging portion  121 . 
     The engaging member  120  is urged with respect to the support member  110  by the urging member  130  with the rotary shaft portions  123  rotationally supported by the shaft receiving portions  111  of the support member  110 . As a result, the engaging member  120  is rotatably supported on the inner surface side of the open/close member  100 . 
     (2.4) Engaged Portion 
     As illustrated in  FIGS. 5E and 5F , the engaged portion  140  has an engaged surface  141  that receives the engaging portion  121  of the engaging member  120 . A notched portion  142  is provided at the middle portion of the engaged surface  141 . The urging member  130 , one end and the other end of which are fixed to the support member  110  and the engaging member  120 , respectively, is housed in the notched portion  142  when the engaging member  120  is rotated in the fixing direction. 
     The thus configured engaging member  120  is rotatably supported on the open/close member  100  via the support member  110  while being urged to be rotatable forward and in reverse, with the rotary shaft portions  123  serving as the center of rotation, by the urging member  130 , the urging direction of which is changeable between two directions, namely a fixing direction (fixing position), in which the engaging member  120  is drawn into the engaged portion  140  as illustrated in  FIG. 6A , and a releasing direction (release position), which is opposite to the fixing direction and in which the engaging member  120  is moved away from the engaged portion  140 . 
     Specifically, in the case where the hook portion  124  of the engaging member  120 , to which the other end of the urging member  130  is attached, is positioned on the engaged portion  140  side with respect to an axis C 1  that connects the hook portion  112  of the support member  110 , to which one end of the urging member  130  is attached, and the rotary shaft portions  123  of the engaging member  120  to each other, the engaging member  120  is drawn toward the fixing position by the urging force of the urging member  130 . 
     In the case where the hook portion  124  of the engaging member  120 , to which the other end of the urging member  130  is attached, is positioned on the left side with respect to the axis C 1 , the engaging member  120  is urged in the direction opposite to the fixing direction by the urging force of the urging member  130  to be returned to the release position. 
     [Modification] 
       FIGS. 9A and 9B  illustrate the state of engagement between an engaging member  120 A and an engaged portion  140 A according to a modification. 
     The engaging member  120 A has an engaging portion  121 A to be engaged with the engaged portion  140 A, a lever portion  122 A that contacts the engaged portion  140 A to guide the engaging portion  121 A to the engaged portion  140 A when the open/close member  100  is moved from the open position to the closed position, and rotary shaft portions  123 A, and have a hook shape as a whole. 
     An arcuate shape portion  125 A and an inclined surface portion  126 A are formed on the outer side of the engaging portion  121 A as seen from the rotary shaft portions  123 A. In addition, a hook portion  124 A for attachment of the other end of the urging member  130  is formed on the outer surface side of the engaging portion  121 A. 
     As illustrated in  FIGS. 9A and 9B , a support member  110 A has a box shape as a whole, and has shaft receiving portions  111 A that rotatably support the rotary shaft portions  123 A of the engaging member  120 A. In addition, a hook portion  112 A for attachment of one end of the urging member  130  is formed on the outer surface side of the support member  110 A. 
     The support member  110 A is fixed on the inner surface side of the open/close member  100 , and rotatably supports the engaging member  120 A. 
     With the support member  110 A and the engaging member  120 A according to the modification, the urging member  130  which urges the engaging member  120 A in two directions, namely the fixing direction in which the engaging member  120 A is drawn into the engaged portion  140 A and the releasing direction which is opposite to the fixing direction and in which the engaging member  120 A is moved away from the engaged portion  140 A, may be easily attached from the outer side. 
     (3) Opening/Closing Operation of Open/Close Member 
       FIGS. 7A to 7D  are each a schematic view illustrating a process in which the engaging member  120  is engaged with the engaged portion  140  when the open/close member  100  is moved from the open position to the closed position. FIGS.  8 A to  8 G are each a schematic view illustrating a process in which the engaging member  120  is engaged with the engaged portion  140  when the open/close member  100  is moved from the open position to the closed position with the engaging member  120  rotated in the fixing direction. 
     The opening/closing operation of the open/close member  100  according to the exemplary embodiment will be described below with reference to the drawings. 
     (3.1) In Case where Engaging Member  120  is at Initial Position 
     As illustrated in  FIG. 7A , when the open/close member  100  is at the open position, the engaging member  120  is urged in the releasing direction (at the release position) by the urging force of the urging member  130 . In the case where the open/close member  100  in such a state is subjected to a closing operation, the lever portion  122  of the engaging member  120  first contacts a front surface  143  of the engaged portion  140  along with rotational movement of the open/close member  100  (see  FIG. 7B ). 
     When the closing operation on the open/close member  100  is further continued, the lever portion  122  of the engaging member  120  receives a rotational force from the front surface  143  of the engaged portion  140 , the engaging member  120  is rotated toward the engaged portion  140  from the release position, and the hook portion  124  of the engaging member  120  reaches a position on the axis C 1  (neutral position; see  FIG. 7C ). 
     When the open/close member  100  is further rotationally moved, the engaging member  120  is drawn toward the engaged surface  141  of the engaged portion  140  by the urging force of the urging member  130  into the fixing position to be engaged with the engaged portion  140 , and the open/close member  100  is positioned at the closed position (see  FIG. 7D ). 
     With the open/close structure according to the exemplary embodiment, when the lever portion  122  contacts one surface of the engaged portion  140  on the apparatus body side along with the closing operation of the open/close member  100 , the lever portion  122  is rotated toward the engaged portion  140 . When the hook portion  124  of the engaging member  120  is moved past the neutral position, the hook portion  124  is drawn toward the engaged surface  141  of the engaged portion  140  by the urging force of the urging member  130 . 
     To expose the inside of the apparatus body, the engaging member  120  is rotated away from the engaged portion  140  in the releasing direction, which is opposite to the fixing direction, by just performing a drawing operation on the open/close member  100  to rotationally move the open/close member  100  to the open position. When the hook portion  124  of the engaging member  120  is moved past the neutral position, the engaging member  120  is drawn back to the release position by the urging force of the urging member  130  to cancel engagement between the engaging member  120  and the engaged portion  140  on the apparatus body side. 
     (3.2) In Case where Engaging Member  120  is at Fixing Position 
     As illustrated in  FIG. 8A , in the case where the open/close member  100  is subjected to a closing operation from a state in which the engaging member  120  is urged in the fixing direction (at the drawn position) by the urging force of the urging member  130 , the inclined surface portion  126  of the engaging member  120  first contacts an inclined surface portion  144  of the engaged portion  140  along with rotational movement of the open/close member  100  (see  FIG. 8B ). 
     When the closing operation on the open/close member  100  is further continued, the arcuate shape portion  125  of the engaging member  120  receives a rotational force while sliding over the inclined surface portion  144  of the engaged portion  140 , the engaging member  120  is rotated in the direction opposite to the fixing direction, and the hook portion  124  of the engaging member  120  reaches a position on the axis C 1  (neutral position; see  FIG. 8C ). 
     When the open/close member  100  is further rotationally moved, the engaging member  120  is returned to the release position by the urging force of the urging member  130  (see  FIG. 8D ). 
     When the closing operation on the open/close member  100  is further continued, the lever portion  122  of the engaging member  120  contacts the front surface  143  of the engaged portion  140  (see  FIG. 8E ) to receive a rotational force from the front surface  143  of the engaged portion  140 , the engaging member  120  is rotated toward the engaged portion  140  from the release position, and the hook portion  124  of the engaging member  120  reaches a position on the axis C 1  (neutral position; see  FIG. 8F ). 
     When the open/close member  100  is rotationally moved, the engaging member  120  is drawn toward the engaged surface  141  of the engaged portion  140  by the urging force of the urging member  130  to be engaged with the engaged portion  140 , and the open/close member  100  is positioned at the closed position (see  FIG. 8G ). 
     With the open/close structure according to the exemplary embodiment, even in the case where the engaging member  120  is positioned at the fixing position, the engaging member  120  is rotated in the direction opposite to the fixing direction to be returned to the release position with the arcuate shape portion  125  of the engaging member  120  receiving a rotational force while sliding as the arcuate shape portion  125  contacts the front surface  143  of the engaged portion  140  along with the closing operation performed on the open/close member  100 . 
     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.