Electrophotographic image forming apparatus, developing apparatus, and coupling member
A cartridge for an electrophotographic image forming apparatus includes a developing roller, a rotatable member for transmitting a rotational force to the developing roller, a coupling member, and a frame. The coupling member is capable of moving between a first coupling member position in which the coupling axis is substantially coaxial with the rotational axis of the rotatable member and a second coupling member position in which the coupling axis is not coaxial with the rotational axis of the rotatable member. When the frame is in a first frame position, the coupling member is in the first coupling member position and a rotational force receiving portion of the coupling member engages with a rotational force applying portion of the apparatus, 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.
1. A cartridge for an electrophotographic image forming apparatus, wherein a main assembly of the apparatus includes a moving force applying portion, a main assembly engaging portion to be driven by a motor, having a driving shaft and a rotational force applying portion provided on the driving shaft, and an electrophotographic photosensitive drum, wherein the cartridge is dismountable from the main assembly without dismounting the electrophotographic photosensitive drum from the main assembly, the cartridge comprising:
i) a developing roller for developing a latent image of the electrophotographic photosensitive drum, the developing roller being rotatable about a roller axis thereof;
ii) a rotatable member for transmitting a rotational force to the developing roller, the rotatable member being rotatable about a rotational axis thereof;
iii) a coupling member rotatable about a coupling 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
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 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 coupling axis is substantially coaxial with the rotational axis of the rotatable member and a second coupling member position in which the coupling axis 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.
2. A cartridge according to claim 1 , wherein the frame is movable between the first frame position and the second frame position by rotating.
3. A cartridge according to claim 2 , wherein the main assembly of the apparatus includes a supporting member supporting the frame and rotatable integrally with the frame such that the frame is movable between the first frame position and the second frame position.
4. A cartridge according to claim 1 , wherein the rotatable member is a gear.
5. A cartridge according to claim 1 , wherein, when the frame is in the first frame position and the coupling member is in the first coupling member position, the coupling member is capable of receiving the rotational force from the main assembly engaging portion, and, when the frame is in the second frame position and the coupling member is in the second coupling member position, the coupling member is capable of receiving the rotational force from the main assembly engaging portion.
6. A cartridge according to claim 1 , wherein the developing roller includes a shaft and an elastic portion provided on the shaft.
7. A cartridge according to claim 6 , wherein the elastic portion is a rubber portion.
8. A cartridge according to claim 1 , wherein the coupling member includes a recess that is urged by a free end of the driving shaft when the coupling member receives the rotational force from the main assembly engaging portion.
9. A cartridge according claim 8 , wherein the recess is provided with an expanding portion that expands away from the coupling axis as the distance from the developing roller along the coupling axis increases, and
wherein the expanding portion is urged to the free end of the driving shaft.
10. A cartridge according to claim 1 , further comprising an urging member for urging the coupling member.
11. A cartridge according to claim 10 , wherein the urging member includes an elastic member.
12. A cartridge according to claim 11 , wherein the elastic member is a spring.
13. A cartridge according to claim 1 , wherein, when the frame is in the second frame position and the coupling member is in the second coupling member position, the coupling axis is inclined with respect to the rotational axis of the rotatable member.
14. A cartridge according to claim 3 , wherein the supporting member includes the moving force applying portion.