Patent ID: 7092655

Claim:
A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, wherein the main assembly includes a motor, a main assembly rotatable driving member for receiving a driving force from the motor, the main assembly rotatable driving member having a twisted hole substantially coaxial with the main assembly rotatable driving member, and a main assembly grounding contact provided in the hole, wherein the hole includes three twisted inner surfaces, and wherein the main assembly grounding contact is an end portion, disposed at a rotational center of the hole, of an electroconductive main assembly grounding contact member which is urged toward the hole by a resilient force of an electroconductive spring member, said process cartridge comprising: an electrophotographic photosensitive drum; process means actable on said photosensitive drum; a projection provided at a longitudinal end of said photosensitive drum and having a plurality of engaging portions engageable with the twisted inner surfaces of the hole, the arrangement being such that when the main assembly rotatable driving member rotates with said inner surfaces of the hole and said engaging portions of said projection engaged with each other, said projection is urged inwardly of the hole with the main assembly grounding contact urged toward a cartridge grounding contact by the spring member, and a rotational driving force is transmitted from the main assembly rotatable driving member to said photosensitive drum through engagement between the hole and said projection; and said cartridge grounding contact electrically connected with said electrophotographic photosensitive drum to electrically ground said electrophotographic photosensitive drum when said process cartridge is mounted to the main assembly of the apparatus, said cartridge grounding contact being such that it is surrounded by said engaging portions so as to be electrically connectable with the main assembly grounding contact.