Patent Publication Number: US-10768573-B2

Title: Process cartridge and electrophotographic image forming apparatus

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an electrophotographic image forming apparatus, and a process cartridge detachably mounted in the electrophotographic image forming apparatus. 
     2. Description of the Related Art 
     Referring to  FIG. 1 , an electrophotographic image forming apparatus  1  such as a laser printer or a multifunctional all-in-one laser printer usually uses a process cartridge  2  as an image processing apparatus.  FIG. 1  is used as a schematic view, and is only used to show that the process cartridge  2  can be mounted along a Y direction to a cartridge containing chamber of a main assembly of the electrophotographic image forming apparatus  1  or taken out in an opposite direction. The process cartridge  2  is usually mounted or taken out by using a slide groove on a pair of vertical walls in the cartridge containing chamber of the electrophotographic image forming apparatus  1 . As shown in  FIG. 1 , a right vertical wall is provided with a rotation force driving head  12 , and a guide plate  11  that is parallel to the vertical wall and that is spaced from the vertical wall. The guide plate is used to guide a connection member in a patent document with the publication number of CN101583910B and the invention title of Rotational Force Transmission Part. One end of the connection member is hingedly connected to one end of a photosensitive drum by using a spherical hinge. The connection member is a driving force receiving member, which has a shaft portion and a head portion. A pair of engaging teeth is disposed on the head portion. When the process cartridge is inserted into the cartridge containing chamber generally in the Y direction, that is, a direction that is perpendicular to the X direction in  FIG. 1 , the driving force receiving member rotates around the spherical hinge and sags due to the effect of gravity. An angle is formed between the axis of the connection member and the axis of the photosensitive drum. When the connection member touches the guide plate  11 , the driving force receiving member is lifted and is engaged with a rotational force driving member or driving head  12 , so as to drive the process cartridge to work. That is, the function of the guide plate  11  is to guide the connection member to change the foregoing angle, so that the connection member is engaged with the rotational force driving head; and when the process cartridge  2  is taken out of the cartridge containing chamber, the guide plate  11  guides disengagement between the connection member and the rotational force driving head. This driving connection structure has the following defect: firstly, the spherical hinge structure is easily detached, and secondly, when the process cartridge is not mounted into the cartridge containing chamber, the connection member is like a part hanging on the cartridge containing chamber side, and can be easily damaged, leading to loss of the function or unstable work of the connection member. 
     To avoid the foregoing defect of spherical hinge connection, a lot of patent documents disclose a connection scheme that a driving force receiving member, namely, a connection member can generate relative displacement in an axis direction relative to a photosensitive drum; that is, the driving force receiving member and the photosensitive drum are set to be coaxial, and can perform relative movement in the axial direction; when moving to a first position, the driving force receiving member is engaged with the rotational force driving member or driving head  12 , and when moving to a second position, the driving force receiving member is disengaged from the rotational force driving member  12 . However, this connection structure is relatively complex and the process of placing a process cartridge into a cartridge containing chamber for connection and taking it out for disconnection are not smooth enough. 
     The foregoing two existing technical solutions have one thing in common, that is, when the rotational force driving head is not engaged with the driving force receiving member, by means of inward retraction of the driving force receiving member towards the process cartridge or by means of inclination of the driving force receiving member towards one side, projection points of engaging teeth of the driving force receiving member on the axis of the photosensitive drum get away from the rotational force driving head; after the process cartridge enters the cartridge containing chamber or in the entering process, the driving force receiving member extends out or eliminates inclination, so that the projection points of the engaging teeth on the axis of the photosensitive drum achieve the length needed for engagement with the rotational force driving head. 
     SUMMARY OF THE INVENTION 
     A principal object of the present invention is to provide a process cartridge, and an electrophotographic image forming apparatus to which the process cartridge is detachably mountable, capable of solving the above described problems of the conventional process cartridges. 
     Another object of the present invention is to provide a process cartridge capable of smoothly rotating a photosensitive drum by being mounted in an alternative way to a main assembly provided with no mechanism for moving a main assembly side coupling member, in its axial line direction, for transmitting a rotational force to the photosensitive drum. 
     A further object of the present invention is to provide a process cartridge demountable in an alternative way from a main assembly of an electrophotographic image forming apparatus provided with a driving head in a direction perpendicular to an axial line of the driving shaft. 
     A further object of the present invention is to provide a process cartridge mountable in an alternative way to a main assembly of an electrophotographic image forming apparatus provided with a driving head in a direction substantially perpendicular to an axial line of the driving head. 
     A further object of the present invention is to provide a process cartridge mountable to and demountable from a main assembly of an electrophotographic image forming apparatus provided with a driving head in a direction substantially perpendicular to an axial line of the driving head. 
     According to the present invention, there is provided a process cartridge which can be demounted smoothly from a main assembly of an electrophotographic image forming apparatus provided with the driving head in a direction substantially perpendicular to an axis of a driving head 
     According to the present invention, there is provided a process cartridge mountable easily, in a direction substantially perpendicular to an axis of a driving head, to a main assembly of an electrophotographic image forming device provided with the driving head. 
     According to the present invention, there is provided a process cartridge which can be mounted and dismounted smoothly, in a direction substantially perpendicular to an axis of a driving head, to a main assembly of an electrophotographic image forming apparatus provided with the driving head. 
     According to the present invention, a process cartridge is mounted to a main assembly which is not provided with a mechanism for moving a main assembly side drum coupling member for transmitting a rotational force to a photosensitive drum to an axial direction, and can rotate the photosensitive drum smoothly. 
     According to the present invention, a process cartridge can be demounted in a direction substantially perpendicular to an axis of a driving head provided in a main assembly, and simultaneously, the smooth rotation of a photosensitive drum can be carried out. 
     According to the present invention, a process cartridge can be mounted in a direction substantially perpendicular to an axis of a driving head provided in a main assembly, and simultaneously, the smooth rotation of a photosensitive drum can be carried out. 
     According to the present invention, a process cartridge is mountable and dismountable in a direction substantially perpendicular to an axis of a driving head provided in a main assembly, and simultaneously, the smooth rotation of a photosensitive drum can be carried out. 
     These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings. 
     Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view illustrating an assembly relationship between an electrophotographic image forming apparatus and a process cartridge; 
         FIG. 2  is a partial enlarged view of Part A in  FIG. 1 ; 
         FIG. 3  is a perspective view of a first embodiment of a process cartridge of the present invention; 
         FIG. 4  is a structural exploded view of a driving force receiving member, an Oldham coupling, and a rotation angle limiting mechanism in the first embodiment of the process cartridge; 
         FIG. 5  is a view illustrating a relationship between a sliding plate and end walls of a process cartridge; 
         FIG. 6  is a B-B sectional view of  FIG. 5 ; 
         FIG. 7  is a structural view of a gear head of an end portion of a photosensitive drum; 
         FIG. 8  is a C-C sectional view of  FIG. 7 ; 
         FIG. 9  is a schematic view illustrating an assembly relationship between a sliding plate and a driving force receiving member; 
         FIG. 10  is a schematic view illustrating a first state of a driving force receiving member; 
         FIG. 11  is a schematic view illustrating a second state of a driving force receiving member; 
         FIG. 12  is a structural exploded view of a driving force receiving member, a Oldham coupling, and a rotation angle limiting mechanism in a second embodiment of the process cartridge of the present invention; 
         FIG. 13  is a perspective view illustrating a rotation angle limiting mechanism in the second embodiment of the process cartridge of the present invention; and 
         FIG. 14  is a structural view of a driving force receiving member in a third embodiment of the process cartridge of the present invention. 
     
    
    
     The present invention is further described below with reference to the accompanying drawings and embodiments. 
     DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS 
     In order to more clearly describe the relative position relationship and operational relationship between the parts in the embodiments, most of the drawings of the present invention show a three-dimensional coordinate system with uniform directions. This is intended to indicate that when the angles of view of the parts in the drawings are different, the parts described thereby still have a uniform coordinate directionality and are cited in the following description. In addition, taking into account the size limitation of the drawing, the same parts are not uniformly proportioned in different drawings, only to describe the present invention more clearly. 
     An electrophotographic image forming apparatus of the present invention uses a cartridge containing chamber for placing and taking a process cartridge. An opening of the cartridge containing chamber may be on a top surface of the apparatus, or on a side surface of the apparatus, and a cartridge containing chamber cover or a cartridge containing chamber door may also be disposed. However, the main characteristics are all in the structure of the process cartridge. Therefore, the implementations of only the process cartridge of the present invention are described below. The electrophotographic image forming apparatus may be a laser printer, an all-in-one (multifunction) laser printer, or the like. Details are not described again. 
     Only the specific structure of the process cartridge of the present invention and a connection relationship with an existing structure are described below. The structure and parts that are the same as those of the existing process cartridge can be implemented by a person skilled in the art with reference to the prior art. 
     First Embodiment of a Process Cartridge 
     Referring to  FIG. 3 , a process cartridge  2  includes a cartridge body having two end walls  21  and  22  respectively in the longitudinal direction of the cartridge. The process cartridge also includes a photosensitive drum, which is rotatably supported between the two end walls  21  and  22 . The photosensitive drum is rotatable around its axis. A driving force receiving member  31  is provided at an axial end of the photosensitive drum. The driving force receiving member  31  would be coupled to the driving head  12  to receiving a driving torque for the photosensitive drum when process cartridge is mounted on the electrophotographic image forming apparatus  1 . Both the axis of the photosensitive drum and the axis of the driving force receiving member  31  are extended along X direction. It would be best that in a free state and a torque transmission state, the axis of the photosensitive drum and the axis of the driving force receiving member  31  are co-axial. By this, the driving force transfer would be very stable and smooth. A bearing plate  211  is provided adjacent to the driving force receiving member  31  to support one end of the photosensitive drum. It is preferable that the bearing plate  211  is made as an independent finished piece and is fixed to the end wall  21  so that it becomes a part of the end wall  21 . 
     Referring to  FIG. 4 , a drum gear  5  used as a shaft at one end of the photosensitive drum is a general barrel-shaped hollow cylinder. It is provided sequentially, along the X or the axial direction, with a connection end  51  that is fixedly connected to a drum cylinder, a helical gear portion  52 , and a shaft portion  53  that is supported on a bearing seat  2116  of the bearing plate  211  (referring to  FIG. 6 ). 
     The driving force receiving member  31  is provided with a driving force receiving portion that includes a pair of engaging teeth  314 , a driving force transmitting portion  311  that functions as an force outputting portion for the driving force receiving member  31 , and a shaft portion that connects the driving force receiving portion and the driving force transmitting portion and includes an engaging portion  312  and a guided portion  313 . The driving force receiving portion is also called the head portion. 
     Driving force received by the driving receiving member  31  will be transmitted to the drum gear  5  through a slide member  32  and a force transmission rod  33 . The driving force transmitting portion  311  of the driving force receiving member  31 , the slide member  32  and a right shaft end  333  of the force transmission rod  33  constitute an Oldham coupling of the present invention. Along the axial direction, i.e. the X direction, the driving force transmitting portion  311  is positioned at an outer position, so it is also called an outer coupling of the Oldham coupling; while the right shaft end  333  is positioned at an inner position, so it is also call an inner coupling of the Oldham coupling. 
     The force transmission rod  33  is provided with a left shaft end  331  that is opposing the right shaft end  333 , and a pair of force transmitting arms  332  that transfer the driving force from the Oldham coupling to the drum gear  5 . The pair of force transmitting arms  332  is configured to engage with a pair of protruding bars  54  that are disposed symmetrically at an inner wall of the drum gear  5 . 
     The shaft end  331  is seated in a shaft seat  55  provided at the inner bottom of the drum gear  5  (referring to  FIG. 7 ). Around the left shaft end  331 , a torsion spring  7  is provided to define an original position of the force transmission rod  33  in a circumferential direction at the very beginning. One end  71  of the torsion spring  7  is fixed to a spring mounting column  56  (referring to  FIG. 7 ) provided at the inner bottom of the drum gear  5 , and the other end  72  is fixed to one of the force transmitting arms  332 . 
     The force transmission rod  33  is co-axial and rotatable with respect to the drum gear  5 . It can rotate in a clockwise direction or in an anti-clockwise direction from its original position where the force transmitting arms  332  are in some distance away from the protruding bars  54  respectively to a contact position where the force transmitting arms  332  engage with the protruding bars  54  respectively. By this, the rotation angle of the force transmitting arms  332  are defined by the protruding bars  54 . This constitutes a rotation angle limiting mechanism. As the driving force receiving member  31  is connected with the force transmission rod  33 , the rotation angle of the driving force receiving member  31  is also defined by this rotation angle limiting mechanism. 
     The bearing plate  211  is fixed on the end wall  21  of the cartridge body by using a fastening member, to support the photosensitive drum, as well as to enable, by using a sliding plate  4 , the force transmission rod  33 , the slide member  32 , and the driving force receiving member  31  to be limited between the drum gear  5  and the sliding plate  4  in the X direction. 
     The sliding plate  4  is provided with a pair of straight slide rails  41  and  42  that matche a pair of slide grooves  2111  and  2112  of the bearing plate  211  in a sliding manner so that it can relatively slide in an radial direction, i.e. the sliding direction. As the sliding direction here has a small angle with respect to the Y direction, we may say the sliding direction is generally the Y direction, in order to make the description more conveniently, we describe the sliding direction also the Y direction. It is understood that the sliding plate  4  may slide in another radial direction rather than the Y direction; and the same result will still be achieved. 
     The sliding plate  4  is also provided with a round hole  45  that is in clearance fit with engaging portion  312  of the driving force receiving member  31  so that when one of the sliding plate  4  and the driving force receiving member  31  moves in the Y direction, the other of the sliding plate  4  and the driving force receiving member  31  will move in the Y direction accordingly. 
     The sliding plate  4  is further provided with a pair of protrusions  43  and  44  which are positioned for matching a pair of limiting stops  2113  and  2114  of the bearing plate  211  to limit a pull-out stroke in the Y direction of the sliding plate  4  relative to the bearing plate  211 . When the protrusions  43  and  44  abut against the limiting stops  2113  and  2114 , the sliding plate  4  is located at a second position that will be described hereinafter. 
     The sliding plate  4  is further provided with an arc plate  47  that extends in a direction opposite to the X axis and is used for limiting the retraction of the sliding plate  4  relative to the bearing plate  211 . When it slides back until the arc plate  47  contact a contacted portion of the cartridge, the sliding plate  4  is back to a first position that will be described hereinafter. 
     As an elastic member of the present invention, a draw spring  6  is disposed between the sliding plate  4  and the bearing plate  211 . One end of the draw spring  6  is fixed to a hook hole  46  provided on the sliding plate  4 , and the other end is fixed to a hook hole  2115  provided on the bearing plate  211 , and a restoring force thereof forces the sliding plate  4  from the second position back to the first position. 
     As mentioned above, the driving force receiving member  31  is movable in a direction perpendicular to the axis of the drum and is also rotatable around its own axis, so in case there is some jam or clamping between the driving force receiving member and the driving head during cartridge mounting or demounting process, the driving force receiving member  31  is able to adjust its postures and/or its places with respect to the drum gear or to driving head of the printer so as to avoid such jam or clamping easily. Therefore, with these kinds of configuration, the process cartridge can be mounted to or demounted from the printer smoothly. 
     And further, as the driving force receiving member  31  moves in the direction perpendicular to the axis of the drum and rotates around its own axis compared with other parts of the process cartridge, the position(s) of the engaging teeth  314  as measured in the axis direction of the drum remains unchanged, one the other side, the position(s) of the engaging teeth  314  is changeable in the Y-Z projection plane, or viewing upon the X direction. This makes it easy for the engaging teeth change its positions when it confronts the driving head  12  during the cartridge mounting and demounting process. 
     Referring to  FIG. 5  and  FIG. 6 ,  FIG. 5  shows that the sliding plate  4  is located at the first position relative to an end wall of the cartridge body, that is, the bearing plate  211 , and the center of the round hole  45  is located on the axis of the drum gear  5 .  FIG. 6  shows a sliding matching relationship between a pair of slide rails  41  and  42  of the sliding plate  4  and a pair of slide grooves  2111  and  2112 , and the state in which the shaft portion  53  of the drum gear  5  is supported on the bearing seat  2116 . 
     Referring to  FIG. 7  and  FIG. 8 ,  FIG. 7  and  FIG. 8  show the structure of the drum gear  5 . There is provided two spring mounting columns  56 , in order to achieve dynamic balance during rotation of the photosensitive drum; however, as mentioned above, only one of the two is connected with the end  71  of the torsion spring  7 . As discussed above, the protruding bars  54  mainly have two functions, one is for limiting the rotation angle of the force transmitting arms  332 , and the other is to receive the torque transmitted by the force transmitting arms  332 . The inner circle of the drum gear  5  is divided by the protruding bars  54  into two intervals. It is understood that each force transmitting arm  332  is disposed and positioned in one of the intervals, so the maximum rotation angle for any of the force transmitting arms  332  begins at the place where the force transmitting arm  332  contacts one of the protruding bars  54  and ends at the place where the force transmitting arm  332  contacts the other of the protruding bars  54 . The shaft seat  55  is formed by a cylinder hole and it is in clearance fit with the left shaft end  331 , as well as limits the force transmission rod  33  in the X direction. 
     Referring to  FIG. 9 , to solve the assembly problem when the driving force receiving member  31  is integrally manufactured, the sliding plate  4  is provided with a guiding slot  48  that extends from an edge of the sliding plate  4  to the round hole  45 . The shaft portion of the driving force receiving member  31  is provided with two portions, i.e. an engaging portion  312  that is formed by a cylinder portion and has a circular section, and a guided portion  313  that is formed by an elliptical cylinder portion and has an oval section. Viewing opposing the X direction, i.e. on a YZ projection plane, an imaginary connection line between the pair of engaging teeth  314  of the driving force receiving member  31  is perpendicular to the long axis of the elliptical cylinder portion  313  of the shaft portion thereof, so as to further avoid the clamping phenomenon. 
     It is preferable that the width of the guiding slot  48  is slightly greater than the length of the short axis of oval section of the guided portion  313  so that it is convenient for the guided portion  313  passes through the guiding slot  48  to make the engaging portion  312  align with the round hole  45 , and after the engaging portion  312  engages with the round hole  45 , the engaging portion  312  can not escape through the guiding slot  48 . More specifically, the driving force receiving member  31  may be inserted into the sliding plate  4  by aligning the long axis of the of oval section of the guided portion  313  with the guiding slot  48 , and after reaching the round hole  45 , the driving force receiving member  31  moves in the X axial direction relative to the sliding plate  4 , to make the cylinder portion  312  engage with the round hole  45  completely. 
     At the leading edge of the sliding plate  4  with respect to the cartridge mounting direction, a front end  49  having an arc-shaped edge is provided. When the sliding plate  4  is located at the first position, the front end  49  is closely contacted to a front wall of the cartridge body, that is, the bearing plate  211 , and when the sliding plate  4  is located at the second position, the front end  49  disposed away from the front wall of the cartridge body. 
     Referring to  FIG. 10  and  FIG. 11 , these partial cross section views not only show the two different state of the driving force receiving member  31 , but also the two different positions of the sliding plate  4 . In  FIG. 10 , the sliding plate  4  is in the first position, at the same time the driving force receiving member  31  are co-axial with the photosensitive drum, i.e., the driving force receiving member  31  is in a co-axial position. In  FIG. 11 , the sliding plate  4  is in the second position, at the same time, and the driving force receiving member  31  is away from the axis L 1  from the photosensitive drum such that the axis L 2  of the driving receiving member  31  is parallel with the axis L 1  of the photosensitive drum, i.e. the driving receiving member  31  is in a parallel position. 
     When the sliding plate  4  is located at the first position, the front end  49  is closely contacted to a front wall of the cartridge body, that is, the bearing plate  211 , and when the sliding plate  4  is located at the second position, the front end  49  disposed away from the front wall of the cartridge body. 
     It is understood that, if viewing upon the X direction, when the driving force receiving member  31  is in the co-axial position, it is disposed within the drum gear  5 , but when the driving receiving member  31  is in the parallel position, at lease part of the driving force receiving member  31  is disposed out of the drum gear  5  in the Y direction. This would help the demounting of the process cartridge more easily. 
     In the process of placing the process cartridge  2  into the cartridge containing chamber or taking the process cartridge  2  out of the cartridge containing chamber, when the driving force receiving member  31  receives a force in the Y or axial direction, the driving force receiving member  31  can move between the co-axial position and the parallel position, wherever it moves, its axis is always co-axial or parallel with the axis of the photosensitive drum; the movement may be translation of the driving force receiving member  31  relative to the process cartridge or translation plus rotation relative to the X direction thereof within a range limited by the rotation angle limiting mechanism, that is, a rotation angle is generated in the peripheral direction. In this way, the foregoing clamping phenomenon when the process cartridge is placed into the cartridge containing chamber or taken out of the cartridge containing chamber is avoided by means of radial movement and/or a peripheral rotation angle. 
     Second Embodiment of a Process Cartridge 
     This embodiment is partially the same as the first embodiment of the process cartridge, and the difference is described below. Referring to  FIG. 12 , the manner of connection between the force transmission rod  33  and the drum gear  5  is making the assembled force transmission rod  33  and drum gear  5  fixed to each other by using a pin  8 ; further both the force transmission rod  33  and the hole provided on drum gear  5  to engage with the force transmission rod  33  have non-circular cross sections. That is, the force transmission rod  33  cannot move or rotate in a three-dimensional coordinate system relative to the drum gear  5 . However, a driving force receiving member  30  of this embodiment consists of a pin  303 , a shaft left end  302 , and a shaft right end  301 . The shaft left end  302  has a shaft hole for the shaft right end  301  to pass through, and after the pin  303  is mounted on a pin hole of the shaft right end  301 , the shaft right end  301  is enabled to rotate by an angle around the axis relative to the shaft left end  302 . That is, the rotation angle limiting mechanism is disposed between the shaft portion of the driving force receiving member  30  and the Oldham coupling which in this embodiment includes the shaft left end  302 , the slide member  32  and a right shaft end of the force transmission rod  33 . 
     Referring to  FIG. 13 , it can be seen that on the one hand, the pin  8  disposed in two fan-shaped grooves  3021  of the shaft left end  302  limits the movement of the shaft right end  301  in the X axial direction relative to the shaft left end  302  and on the other hand, the pin  8  and the two fan-shaped grooves together limit a rotation angle range between the shaft right end  301  and the Oldham coupling. If taking the shaft right end  301  as an independent driving force receiving member, then the rotation angle limiting mechanism is disposed between this corresponding driving force receiving member and the Oldham coupling. 
     For this embodiment, because the driving force receiving member  30  is manufactured in a split manner, before assembly, the sliding plate  4  can be mounted on the right shaft end  301  in advance. Therefore, the mounting groove  48  of the sliding plate  4  in the first embodiment may be omitted, thereby improving the anti-deformation rigidity of the sliding plate  4  made of plastics. 
     Apparently, for this embodiment, the force transmission rod  33  may be a protruding bar formed on a right side end surface of the drum gear  5 , provided that the protruding bar matches the slide member  32  to facilitate the formation of a Oldham coupling. 
     Third Embodiment of a Process Cartridge 
     Referring to  FIG. 14 , this embodiment differs from the first embodiment of the process cartridge in that the shaft portion of the driving force receiving member has only a cylinder portion  312 , but no elliptical cylinder portion at all. To solve the problem of assembly with the sliding plate  4 , the left shaft end  311  and other parts are manufactured in a split manner, and the advantage is reducing the manufacturing costs. In addition, the sliding plate  4  also uses the structure like that in the second embodiment of the process cartridge. 
     Other Implementations of the Process Cartridge 
     A draw spring  6  used as the elastic member of the present invention is not necessary, and completely can be omitted. In addition, an elastic means in other forms may also be used, provided that after the process cartridge leaves the cartridge containing chamber, the sliding plate  4  is enabled to be at the first position. 
     The torsion spring  7  is not necessarily disposed. In the state in which the torsion spring  7  is not disposed, the function of the rotation angle limiting mechanism is not lost. 
     INDUSTRIAL APPLICABILITY 
     In the process of mounting the process cartridge into the cartridge containing chamber or demounting the process cartridge from the cartridge containing chamber in the present invention, that is, in the process in which the process cartridge  2  moves in the Y direction shown in  FIG. 1  relative to the electrophotographic image forming apparatus  1  for engagement or disengagement, the position of engaging teeth of the driving force receiving member as measured in the X direction always remain unchanged. In the mounting and demounting process, once the engaging teeth are clamped or abutted dead with the rotational force driving head, the problem is resolved by making the engaging teeth rotate by an angle around the X or the axis direction, or a compound movement of translation along the Y direction at the same time. 
     Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.