Patent ID: 8498553

Claim:
A cartridge that is detachably mounted to a main body of an image forming apparatus and to which driving force is transferred from a driving force transfer member rotatably provided to the main body, the cartridge comprising: a rotational body that is rotatably supported to a case of the cartridge; a joint member that is coaxially arranged to an end portion of the rotational body in an axial direction of the joint member and has a first joint-side engagement part that is configured to be engaged to a rotational body-side engagement part provided to the end portion of the rotational body with a predetermined moving range in a rotational direction, and a press member that presses the joint member to a position in which the predetermined moving range is secured, wherein the joint member has a second joint-side engagement part that is configured to be engaged with a transfer-side engagement part provided to the driving force transfer member in the rotational direction with central axes of the joint member and the driving force transfer member being substantially matched, and wherein while the cartridge is mounted to the main body, when the second joint-side engagement part is contacted to a part of the driving force transfer member at a position at which the central axes of the joint member and the driving force transfer member are not matched, the joint member is rotated within the predetermined range and the second joint-side engagement part is thus moved, so that the central axes of the joint member and the driving force transfer member are substantially matched and the second joint-side engagement part is engaged with the transfer-side engagement part in the rotational direction.