Patent ID: 8874004
Filing Date: 2014-10-28
Classification: F16D,G03G

Abstract:
1. A developing device usable with an electrophotographic image forming apparatus, said apparatus including a driving shaft rotatable by a motor and having a rotating force applying portion, and a movable member, said developing device being mountable to the movable member, and said developing device being movable in a direction substantially perpendicular to an axial direction of the driving shaft in response to movement of the movable member in one direction with said developing device mounted to the movable member, wherein said driving shaft is not movable in a direction perpendicular to an axis thereof, said developing device comprising: i) a frame ii) a developing roller, provided in said frame, for developing an electrostatic latent image formed on an electrophotographic photosensitive drum, said developing roller being rotatable about an axis, wherein said developing roller is contacted to and separated from said electrophotographic photosensitive member drum in response to movement of the movable member; and iii) a coupling member for transmitting a rotating force to said developing roller, said coupling member including a rotating force receiving portion engageable with the rotating force applying portion to receive a rotating force from the driving shaft, and a rotating force transmitting portion for transmitting the rotating force received through said rotating force receiving portion to said developing roller, iv) a cylindrical member movably supporting one end portion of said coupling member inside of said cylindrical member so that said coupling member is capable of taking (a) a rotational force transmitting angular position for transmitting the rotational force for rotating said developing roller to said developing roller, (b) a pre-engagement angular position which is taken before said coupling member is engaged with the rotating force applying portion and in which said coupling member is inclined away from the rotational force transmitting angular position, and (c) a disengaging angular position which is taken for said coupling member to disengage from the driving shaft and in which said coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to the pre-engagement angular position, said cylindrical member being configured to transmit the rotational force from said coupling member to said developing roller, wherein said frame includes (i) a supporting portion configured to support said cylindrical member rotatably and (ii) a regulation portion capable of regulating said coupling member at a pre-engagement angular position, wherein said supporting portion encompasses said regulating portion as seen along a rotational axis of said cylindrical member, wherein in response to a movement of said developing device when the movable member moves in the one direction, said coupling member moves from the pre-engagement angular position to the rotational force transmitting angular position, and when the movable member makes a further movement in the one direction, in response to the further movement said coupling member is moved from the rotational force transmitting angular position to the disengaging angular position to disengage said coupling member from the driving shaft, and wherein, when said coupling member moves from the pre-engagement angular position to the rotational force transmitting angular position in response to the movement of said developing device, said developing roller is contacted to said electrophotographic photosensitive member in a state that said developing roller is rotated through engagement between said coupling member and the rotating force applying portion.