Sheet feeding apparatus and image forming apparatus with sheet feeding cassette and associated locking means

An image forming apparatus provided with a sheet feeding apparatus provided with a sheet feeding cassette detachably mounted on a main body of said image forming apparatus, and a feed roller for feeding a sheet stacked on said sheet feeding cassette, and an image forming portion for forming an image on the sheet fed out from said sheet feeding apparatus, said image forming apparatus comprising:

• a holding portion provided in said main body of said image forming apparatus, and having said feed roller rotatably supported on said holding portion, and detachably holding said feed roller;
• and
• a locking member movable to a lock position for restricting a detachment of said feed roller, and a lock releasing position for permitting the detachment of said feed roller, wherein when said sheet feeding cassette is mounted to the main body, said locking member is located in a position that is not pushed by said sheet feeding cassette at the lock position and is located in a position that is pushed by said sheet feeding cassette at the lock releasing position,
• wherein the locking member is pivotally moved between the lock position and the lock releasing position, and when said locking member is in the lock releasing position with said sheet feeding cassette drawn out from said main body of said image forming apparatus, said locking member is moved to the lock position by being pushed by said sheet feeding cassette in association with a mounting operation of said sheet feeding cassette.