Cartridge having locking portion for locking cartridge with an image forming apparatus and releasing portion to release the locking portion, and image forming apparatus having such a cartridge

An electrophotographic image forming apparatus for forming an image on a recording material, said apparatus having a main assembly to which a cartridge is detachably mountable, said apparatus comprising:

• (i) a main assembly locking portion;
• (ii) a mounting portion configured and positioned to detachably mount the cartridge, the cartridge including:
• a frame;
• a developing member configured and positioned to develop an electrostatic latent image formed on an electrophotographic photosensitive member;
• a developer accommodating portion configured and positioned to accommodate a developer to be used for developing an electrostatic latent image by the developing member;
• a cartridge locking portion configured and positioned to lock the cartridge with said main assembly locking portion provided in the main assembly of said apparatus to prevent the cartridge from disengaging from the main assembly of said apparatus when the cartridge is mounted to the main assembly of said apparatus,
• wherein the cartridge locking portion projects out of or is retracted into each one of and the other end portions of the frame in the longitudinal direction of the developing member;
• and
• a releasing member configured and positioned to release the cartridge locking portion to release the cartridge from said main assembly locking portion when the cartridge is to be removed from the main assembly of said apparatus;
• and
• (iii) feeding means for feeding the recording material.