Image forming apparatus and sheet feeding apparatus

An image forming apparatus comprising:

• an apparatus body comprising an image forming unit configured to form an image on a sheet;
• a unit detachably attached to the apparatus body;
• a roller member provided in the unit and configured to come into contact with a sheet;
• a roller shaft supporting the roller member provided in the apparatus body and configured to be coupled with and decoupled from the roller member by being moved in a rotation axial direction of the roller member;
• a sheet stacking portion on which sheets are stacked;
• and
• a sheet feed roller configured to feed a sheet stacked on the sheet stacking portion, and
• a restriction member provided in the apparatus body and movable to a first position and a second position, the first position being a position where the restriction member restricts the unit attached to the apparatus body from being detached in a detaching direction intersecting with the rotation axial direction, the second position being a position where the restriction member does not restrict the unit attached to the apparatus body from being detached in the detaching direction,
• wherein the restriction member comprises an engaging portion configured to engage with the roller shaft and is configured to move the roller shaft by the engaging portion so that the roller shaft is decoupled from the roller member along with a move of the restriction member from the first position to the second position, and
• wherein the roller member is arranged to be in contact with the sheet feed roller to form a nip portion between the sheet feed roller and the roller member and is configured to separate the sheet in contact with the sheet feed roller from sheets other than the sheet in contact with the sheet feed roller by exerting a frictional force on the sheets at the nip portion.