Process cartridge, electrophotographic image forming apparatus, and electrophotographic photosensitive drum unit

A process cartridge for use with a main assembly of an electrophotographic image forming apparatus, said main assembly including a driving shaft, to be driven by a motor, having a rotational force applying portion, wherein said process cartridge is dismountable from the main assembly in a direction substantially perpendicular to an axial direction of the driving shaft, said process cartridge comprising:

• i) an electrophotographic photosensitive drum having a photosensitive layer at a peripheral surface thereof, said electrophotographic photosensitive drum being rotatable about an axis thereof;
• ii) process means actable on said electrophotographic photosensitive drum;
• iii) a coupling member engageable with said rotational force applying portion to receive a rotational force for rotating said electrophotographic photosensitive drum, said coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating said electrophotographic photosensitive drum to said electrophotographic photosensitive drum and a disengaging angular position in which said coupling member is inclined away from the axis of said electrophotographic photosensitive drum from said rotational force transmitting angular position,
• wherein when said process cartridge is dismounted from the main assembly of the electrophotographic image forming apparatus in a direction substantially perpendicular to the axis of said electrophotographic photosensitive drum, said coupling member moves from said rotational force transmitting angular position to said disengaging angular position.