Method of assembling developing cartridge

A method of assembling a developing cartridge, the developing cartridge including:

• a casing configured to accommodate developing agent and having a through-hole extending in a first direction;
• a shaft extending in the first direction through the through-hole and movable in the first direction relative to the casing;
• a first cam positioned at one end portion of the shaft in the first direction, the first cam being movable together with the shaft in the first direction relative to the casing;
• a second cam positioned at another end portion of the shaft in the first direction, the second cam being movable together with the shaft in the first direction relative to the casing;
• and
• a resiliently urging member attached to the another end portion of the shaft and positioned between the casing and the second cam, the resiliently urging member being configured to expand and compress in the first direction,
• the method comprising steps of:
• (a) attaching the first cam to the one end portion of the shaft;
• (b) inserting the shaft to which the first cam is attached in the through-hole after the step (a);
• and
• (c) after the step (b), attaching the resiliently urging member to the another end portion of the shaft in a state where the first cam is in contact with a jig in a direction from the one end portion toward the another end portion of the shaft in the first direction.