Electrophotographic image forming apparatus, developing apparatus, and coupling member

An electrophotographic image forming apparatus comprising:

• i) a main assembly of the apparatus including:
• i-i) a moving force applying portion,
• i-ii) a main assembly engaging portion to be driven by a motor, the main assembly engaging portion having a driving shaft and a rotational force applying portion provided on the driving shaft, and
• i-iii) an electrophotographic photosensitive drum;
• and
• ii) a cartridge mountable to the main assembly and dismountable from the main assembly without dismounting the electrophotographic photosensitive drum from the main assembly, and the cartridge including:
• ii-i) a developing roller for developing a latent image formed on the electrophotographic photosensitive drum, the developing roller being rotatable about a rotational axis thereof,
• ii-ii) a rotatable member for transmitting a rotational force to the developing roller, the rotatable member being rotatable about a rotational axis thereof,
• ii-iii) a coupling member rotatable about a rotational axis by the rotational force received from the main assembly engaging portion, the coupling member including (a) a rotational force receiving portion engageable with the rotational force applying portion to receive a rotational force from the main assembly engaging portion, and (b) a rotational force transmitting portion for transmitting the rotational force to the rotatable member, and
• ii-iv) a frame including a moving force receiving portion that receives a moving force from the moving force applying portion, the frame supporting the developing roller and the rotatable member,
• wherein, in a state that the cartridge is mounted to the main assembly, the frame is movable in a direction substantially perpendicular to an axial direction of the driving shaft from a first frame position in which the developing roller is contact with the electrophotographic photosensitive drum to a second frame position in which the developing roller is separated from the electrophotographic photosensitive drum by receiving the moving force from the moving force applying portion,
• wherein the coupling member is capable of moving between a first coupling member position in which the rotational axis of the coupling member is substantially coaxial with the rotational axis of the rotatable member and a second coupling member position in which the rotational axis of the coupling member is not coaxial with the rotational axis of the rotatable member, and
• wherein, when the frame is in the first frame position, the coupling member is in the first coupling member position and the rotational force receiving portion engages with the rotational force applying portion, and, when the frame is in the second frame position, the coupling member is in the second coupling member position and the rotational force receiving portion engages with the rotational force applying portion.