Developing cartridge including first gear and second gear

1. A developing cartridge comprising:

a casing configured to accommodate therein developing agent;

a lever movable relative to the casing between a first position and a second position, the lever being positioned at an outer surface of the casing;

a first urging member configured to urge the lever toward the first position;

a first gear rotatable about a first axis extending in a first direction, the first gear being positioned at the outer surface of the casing, the first gear including:

a first gear portion having an addendum circle; and

a second gear portion positioned at a position different from a position of the first gear portion in the first direction, the second gear portion having an addendum circle greater than the addendum circle of the first gear portion;

a second gear rotatable about a second axis extending in the first direction, the second gear being positioned at the outer surface of the casing, the second gear including:

a third gear portion engageable with the first gear portion, the third gear portion having an addendum circle; and

a fourth gear portion engageable with the second gear portion, the fourth gear portion being positioned at a position different from a position of the third gear portion in the first direction, the fourth gear portion having an addendum circle smaller than the addendum circle of the third gear portion; and

a first protrusion rotatable together with the second gear, the first protrusion contacting the lever to move the lever from the first position to the second position against urging force of the first urging member in a case where the second gear rotates in a state where the second gear portion is in engagement with the fourth gear portion.

2. The developing cartridge according to claim 1 , wherein the second gear is rotatable from a first rotational position to a second rotational position and further from the second rotational position to a third rotational position,

wherein, in a case where the second gear rotates from the first rotational position to the second rotational position, the first gear portion engages with the third gear portion, and

wherein, in a case where the second gear rotates from the second rotational position to the third rotational position, the second gear portion engages with the fourth gear portion.

3. The developing cartridge according to claim 2 , further comprising a second protrusion rotatable together with the second gear, the second protrusion being positioned away from the first protrusion in a rotational direction of the second gear,

wherein, in a case where the second gear rotates from the first rotational position to the second rotational position, the second protrusion contacts the lever to move the lever from the first position to the second position against the urging force of the first urging member, and then the contact between the second protrusion and the lever is released and the first urging member urges the lever to move the lever from the second position to the first position.

4. The developing cartridge according to claim 3 , further comprising a third protrusion rotatable together with the second gear, the third protrusion being positioned away from the first protrusion and the second protrusion in the rotational direction of the second gear;

wherein, in a case where the second gear is positioned at the first rotational position, the third protrusion is in contact with the lever to position the lever at the second position against the urging force of the first urging member, and

wherein, in a case where the second gear rotates from the first rotational position to the second rotational position, the contact between the third protrusion and the lever is released and the first urging member urges the lever to move the lever from the second position to the first position, and then the second protrusion contacts the lever to move the lever from the first position to the second position against the urging force of the first urging member.

5. The developing cartridge according to any of claim 2 , further comprising a second urging member configured to hold the second gear at the third rotational position.

6. The developing cartridge according to claim 5 , wherein the second urging member is a spring.

7. The developing cartridge according to claim 6 , further comprising a cover covering at least a portion of the lever, the cover being positioned at the outer surface of the casing,

wherein the spring is a torsion spring, the torsion spring including:

a coil portion;

a first arm extending from one end of the coil portion; and

a second arm extending from another end of the coil portion,

wherein the first arm is fixed to one of the casing and the cover, and

wherein the second arm is configured to contact the second gear.

8. The developing cartridge according to claim 1 , further comprising:

an agitator configured to agitate the developing agent and rotatable about a third axis extending in the first direction, the agitator including a shaft extending in the first direction; and

an agitator gear mounted to the shaft and rotatable together with the agitator, the agitator gear being in engagement with the first gear.

9. The developing cartridge according to claim 1 , wherein the third gear portion is positioned at a portion of a circumferential periphery of the second gear and the fourth gear portion is positioned at a portion of the circumferential periphery of the second gear, and

wherein the fourth gear portion is positioned at a position different from a position of the third gear portion in a rotational direction of the second gear.

10. The developing cartridge according to claim 9 , wherein the third gear portion has a length in the rotational direction greater than a length of the fourth gear portion in the rotational direction.

11. The developing cartridge according to claim 1 , wherein the lever is swingably movable about a fourth axis extending in the first direction.

12. The developing cartridge according to claim 1 , further comprising a cover covering at least a portion of the lever, the cover being positioned at the outer surface of the casing,

wherein the lever is supported by one of the casing and the cover.

13. The developing cartridge according to claim 12 , wherein the cover includes a lever shaft extending in the first direction,

wherein the lever has a hole into which the lever shaft is inserted, and

wherein the lever is swingably movable about the lever shaft.

14. The developing cartridge according to claim 12 , wherein the cover has an opening, and

wherein at least a portion of the lever is exposed through the opening.

15. The developing cartridge according to claim 1 , further comprising a developing roller rotatable about a fifth axis extending in the first direction.

16. The developing cartridge according to claim 1 , wherein the first gear portion includes a plurality of gear teeth.

17. The developing cartridge according to claim 1 , wherein the first gear portion includes a friction member.

18. The developing cartridge according to claim 17 , wherein the friction member is a rubber.

19. The developing cartridge according to claim 1 , wherein the second gear portion includes a plurality of gear teeth.

20. The developing cartridge according to claim 1 , wherein the second gear portion includes a friction member.

21. The developing cartridge according to claim 20 , wherein the friction member is a rubber.

22. The developing cartridge according to claim 1 , wherein the third gear portion includes a plurality of gear teeth.

23. The developing cartridge according to claim 1 , wherein the third gear portion includes a friction member.

24. The developing cartridge according to claim 23 , wherein the friction member is a rubber.

25. The developing cartridge according to claim 1 , wherein the fourth gear portion includes a plurality of gear teeth.

26. The developing cartridge according to claim 1 , wherein the fourth gear portion includes a friction member.

27. The developing cartridge according to claim 26 , wherein the friction member is a rubber.

28. The developing cartridge according to claim 1 , wherein, in a state where the developing cartridge is attached to an image forming apparatus, the lever is in contact with a portion of the image forming apparatus in a case where the lever is positioned at the second position, while the lever is out of contact with the portion of the image forming apparatus in a case where the lever is positioned at the first position.

29. The developing cartridge according to claim 1 , wherein the first urging member is a spring.

30. The developing cartridge according to claim 29 , further comprising a cover covering at least a portion of the lever, the cover being positioned at the outer surface of the casing,

wherein the spring is a torsion spring, the torsion spring including:

a coil portion;

a first arm extending from one end of the coil portion; and

a second arm extending from another end of the coil portion,

wherein the first arm is fixed to one of the casing and the cover, and

wherein the second arm is in contact with the lever.