Sheet feeding apparatus and image forming apparatus

An image forming apparatus having a main frame body having an image forming portion configured to form an image, the image forming apparatus comprising:

• a sheet feeding apparatus configured to be detachably attached to a lower part of the main frame body with respect to a vertical direction and to feed a sheet, the sheet feeding apparatus including:
• a frame body;
• a sheet cassette in which a sheet is stacked, the sheet cassette being accommodated in the frame body;
• a heating unit configured to heat the sheet stacked in the sheet cassette, the heating unit being attachable to the frame body at a position above the sheet cassette in the vertical direction;
• and
• a locking member provided on an upper part of the frame body, the locking member being configured to be movable between a locking position where the frame body is locked to the main frame body so that the frame body is not displaceable against the main frame body and a releasing position where locking of the frame body is released so that the frame body is displaceable against the main frame body,
• wherein, in a process of attaching the heating unit to an attaching position of the frame body, the locking member is configured to restrict a movement of the heating unit to the attaching position by interfering with the heating unit when the locking member is located at the releasing position and to allow a movement of the heating unit to the attaching position when the locking member is located at the locking position.

A sheet feeding apparatus configured to be detachably attached under an optional sheet feeding apparatus that is attached to a lower part of an image forming apparatus with respect to a vertical direction and to feed a sheet to the image forming apparatus, the sheet feeding apparatus comprising:

• a frame body;
• a sheet cassette in which a sheet is stacked, the sheet cassette being accommodated in the frame body;
• a heating unit that is attachable to the frame body at a position above the sheet cassette in the vertical direction;
• and
• a locking member provided on an upper part of the frame body, the locking member being configured to be movable between a locking position where the frame body is locked to the optional sheet feeding apparatus so that the frame body is not displaceable against the optional sheet feeding apparatus and a releasing position where locking of the frame body is released so that the frame body is displaceable against the optional sheet feeding apparatus,
• wherein in a process of attaching the heating unit to an attaching position of the frame body, the locking member is configured to restrict a movement of the heating unit to the attaching position when the locking member is located at the releasing position and to allow a movement of the heating unit to the attaching position when the locking member is located at the locking position.