Cartridge and electrophotographic image forming apparatus

1. A cartridge comprising:

a casing;

developer contained within the casing;

a photosensitive drum rotatable about an axis thereof;

a drum flange provided at one end portion of the photosensitive drum, the drum flange being configured to transmit a driving force to the photosensitive drum, the drum flange being rotatable together with the photosensitive drum about the axis of photosensitive drum, and the drum flange including a hollow interior portion elongated along the axis of the photosensitive drum;

a coupling member operatively connected to the drum flange, the coupling member being configured to transmit the driving force to the drum flange, the coupling member being coaxially rotatable with the drum flange, the coupling member including (i) at least one projection for receiving the driving force, the at least one projection being provided at an end portion of the coupling member, and (ii) a shaft portion elongated along an axis of the coupling member, the coupling member being movable with respect to the drum flange in a direction of the axis of the photosensitive drum, with the at least one projection and the shaft portion being movable with the coupling member in the direction of the axis of the photosensitive drum; and

a coil spring urging the coupling member in a direction away from an interior of the casing along the axis of the photosensitive drum,

wherein the drum flange has an opening at one end and is closed at another end, and the opening leads to the hollow interior portion,

wherein an end portion of the coil spring contacts an interior surface of the closed end of the drum flange, and

wherein the drum flange includes a housing and a cover member attached to the housing, with the closed end of the drum flange being a part of the cover member.

2. The cartridge of claim 1 , wherein the cover member includes a claw portion that engages with the housing.

3. The cartridge of claim 2 , wherein a part of the claw portion enters an engaging hole of the housing.

4. The cartridge of claim 1 , wherein the drum flange is provided with a gear portion on an outer surface thereof.

5. The cartridge of claim 4 , wherein the closed end of the drum flange includes an engaging portion that engages the end portion of the coil spring.

6. The cartridge of claim 5 , wherein the engaging portion includes a projection surrounded by the end portion of the coil spring.

7. The cartridge of claim 5 , wherein the coil spring is compressed between the coupling member and the closed end of the drum flange.

8. The cartridge of claim 1 , further comprising a developing roller,

wherein the drum flange is operatively connected to the developing roller.

9. The cartridge of claim 1 , wherein the end portion of the coupling member includes a recessed surface, and the at least one projection projects from a surface adjacent to the recessed surface.

10. The cartridge of claim 1 , wherein the end portion of the coupling member includes an inclined surface, and a maximum distance from the axis of the coupling member to the inclined surface along a line perpendicular to the axis of the coupling member decreases as a distance along the axis of the coupling member from the shaft portion increases.

11. A cartridge comprising:

a casing;

developer contained within the casing;

a rotatable member rotatably supported in the casing to permit rotation about an axis thereof;

a cylindrical member rotatably supported in the casing to permit rotation about an axis thereof, the cylindrical member including a hollow interior portion elongated along the axis of the cylindrical member, the cylindrical member being operatively connected to the rotatable member to transmit a rotational driving force to the rotatable member;

a coupling member operatively connected to the cylindrical member, the coupling member being configured to transmit the rotational driving force to the cylindrical member, the coupling member being coaxially rotatable with the cylindrical member, the coupling member including (i) at least one projection for receiving the rotational driving force, the at least one projection being provided at an end portion of the coupling member, and (ii) a shaft portion elongated along an axis of the coupling member, the coupling member being movable with respect to the cylindrical member in a direction of the axis of the cylindrical member, with the at least one projection and the shaft portion being movable with the coupling member in the direction of the axis of the cylindrical member; and

a coil spring urging the coupling member in a direction away from an interior of the casing along the axis of the cylindrical member,

wherein the cylindrical member has an opening at one end portion and is closed at another end, and the opening leads to the hollow interior portion,

wherein an end portion of the coil spring contacts an interior surface of the closed end of the cylindrical member, and

wherein the cylindrical member includes a housing and a cover member attached to the housing, with the closed end of the cylindrical member being a part of the cover member.

12. The cartridge of claim 11 , wherein the cover member includes a claw portion that engages with the housing.

13. The cartridge of claim 12 , wherein a part of the claw portion enters an engaging hole of the housing.

14. The cartridge of claim 11 , wherein the cylindrical member is provided with a gear portion on an outer surface thereof.

15. The cartridge of claim 11 , wherein the rotatable member is a photosensitive drum, and

wherein the cylindrical member is provided at an end of the rotatable member with the axis of the cylindrical member being coaxial with the axis of the rotatable member.

16. The cartridge of claim 11 , further comprising a developing roller,

wherein the cylindrical member is operatively connected to the developing roller.

17. The cartridge of claim 11 , wherein the axis of the rotatable member is coaxial with the axis of the cylindrical member.

18. The cartridge of claim 11 , wherein the cylindrical member includes an interior surface at least a part of which is configured to prevent the coupling member from inclining with respect to the axis of the cylindrical member.

19. The cartridge of claim 11 , wherein the rotatable member is a developing roller.

20. The cartridge of claim 11 , wherein the end portion of the coupling member includes a recessed surface, and the at least one projection projects from a surface adjacent to the recessed surface.