Sheet feeding device and image forming apparatus

1. A sheet feeding device comprising:

a sheet accommodating unit that accommodates sheets, and supported by an apparatus main body in an insertable and withdrawable manner in a direction orthogonal to a feeding direction of the sheets;

a leading edge regulating unit provided fixedly to the sheet accommodating unit, configured to regulate a position on a downstream of the sheets to be accommodated in the feeding direction thereof;

a trailing edge regulating unit provided in the sheet accommodating unit, configured to regulate a position on an upstream of the sheets to be accommodated in the feeding direction;

a side edge regulating unit provided in the sheet accommodating unit, configured to regulate a position of the sheets to be accommodated in a direction orthogonal to the feeding direction thereof; and

a locking mechanism to lock the sheet accommodating unit in a locking position in the apparatus main body including a spring which push out the sheet accommodating unit, a hook portion and protrusion portion which is engaged with the hook portion to lock the sheet accommodating unit in the apparatus main body against an elastic force of the spring; and

a single insertion position limiting unit, the single insertion position limiting unit being provided only on a rear of the sheet accommodating unit in an inserting direction of the sheet accommodating unit and upstream from a center of gravity of the sheet accommodating unit in the sheet feeding direction, configured to be able to contact a frame on a rear of the apparatus main body in an inserting direction of the sheet accommodating unit to limit an insertion position of the sheet accommodating unit and a gap is formed between the single insertion position limiting unit and the frame on the rear of the apparatus main body when the locking mechanism locks the sheet accommodating unit in the locking position,

wherein after the insertion position of the sheet accommodating unit is limited by the single insertion position limiting unit while insertion of the sheet accommodating unit, the sheet accommodating unit is moved to the locking position by the elastic force of the spring,

wherein, in response to the sheet accommodating unit being inserted with an excessive force, the sheet accommodating unit rotates slightly about the single insertion position limiting unit, thus preventing damage to the side edge regulating unit and/or the trailing edge regulating unit.

2. The sheet feeding device according to claim 1 , wherein the leading edge regulating unit is a part of a box-shaped casing of the sheet accommodating unit.

3. A sheet feeding device, comprising:

a sheet accommodating unit that accommodates sheets, and supported by an apparatus main body in an insertable and withdrawable manner in a direction orthogonal to a feeding direction of the sheets;

a leading edge regulating unit provided fixedly to the sheet accommodating unit, configured to regulate a position downstream of the sheets to be accommodated in the feeding direction thereof;

a trailing edge regulating unit provided in the sheet accommodating unit, configured to regulate a position upstream of the sheets to be accommodated in the feeding direction;

a side edge regulating unit provided in the sheet accommodating unit, configured to regulate a position of the sheets to be accommodated in a direction orthogonal to the feeding direction thereof;

a locking mechanism to lock the sheet accommodating unit in a locking position in the apparatus main body including a spring which push out the sheet accommodating unit, a hook portion and protrusion portion which is engaged with the hook portion to lock the sheet accommodating unit in the apparatus main body against an elastic force of the spring;

an insertion position limiting unit provided on a rear of the sheet accommodating unit in an inserting direction of the sheet accommodating unit and upstream from a center of gravity of the sheet accommodating unit in the sheet feeding direction, configured to be able to contact a frame on a rear of the apparatus main body in an inserting direction of the sheet accommodating unit to limit an insertion position of the sheet accommodating unit and a gap is formed between the insertion position limiting unit and the frame on the rear of the apparatus main body when the locking mechanism locks the sheet accommodating unit in the locking position; and

an auxiliary insertion position limiting unit provided on the rear of the sheet accommodating unit in the inserting direction and downstream from the center of gravity of the sheet accommodating unit in the sheet feeding direction configured to be able to contact the frame on the rear of the apparatus main body in the inserting direction to limit the insertion position of the sheet accommodating unit and a leading edge portion of the auxiliary insertion position limiting unit in the inserting direction of the sheet accommodating unit is positioned upstream from a leading edge portion of the insertion position limiting unit in the inserting direction,

wherein after the insertion position of the sheet accommodating unit is limited by the insertion position limiting unit while insertion of the sheet accommodating unit, the sheet accommodating unit is moved to the locking position by the elastic force of the spring,

wherein, in response to the sheet accommodating unit being inserted with an excessive force, the sheet accommodating unit rotates slightly about the insertion position limiting unit, thus preventing damage to the side edge regulating unit and/or the trailing edge regulating unit.

4. An image forming apparatus including an image forming unit configured to form an image on a sheet fed from a sheet feeding device, the image forming apparatus comprising:

a sheet accommodating unit that accommodates sheets, and supported by an apparatus main body in an insertable and withdrawable manner in a direction orthogonal to a feeding direction of the sheets;

a leading edge regulating unit provided fixedly to the sheet accommodating unit, configured to regulate a position on a downstream in a feeding direction of the sheets to be accommodated;

a trailing edge regulating unit provided in the sheet accommodating unit, configured to regulate a position on an upstream in the feeding direction of the sheets to be accommodated;

a side edge regulating unit provided in the sheet accommodating unit, configured to regulate a position of the sheets to be accommodated in a direction orthogonal to the feeding direction thereof;

a locking mechanism to lock the sheet accommodating unit in a locking position in the apparatus main body including a spring which push out the sheet accommodating unit, a hook portion and protrusion portion which is engaged with the hook portion to lock the sheet accommodating unit in the apparatus main body against an elastic force of the spring; and

a single insertion position limiting unit, the single insertion position limiting unit being provided only on a rear of the sheet accommodating unit in an inserting direction of the sheet accommodating unit, configured to be able to contact a frame on a rear of the apparatus main body in an inserting direction of the sheet accommodating unit to limit an insertion position of the sheet accommodating unit,

wherein the single insertion position limiting unit is arranged on the rear of the sheet accommodating unit in the inserting direction thereof and upstream from a center of gravity of the sheet accommodating unit in the sheet feeding direction and a gap is formed between the single insertion position limiting unit and the frame on the rear of the apparatus main body when the locking mechanism locks the sheet accommodating unit in the locking position,

wherein after the insertion position of the sheet accommodating unit is limited by the single insertion position limiting unit while insertion of the sheet accommodating unit, the sheet accommodating unit is moved to the locking position by the elastic force of the spring,

wherein, in response to the sheet accommodating unit being inserted with an excessive force, the sheet accommodating unit rotates slightly about the single insertion position limiting unit, thus preventing damage to the side edge regulating unit and/or the trailing edge regulating unit.

5. The image forming apparatus according to claim 4 , wherein the leading edge regulating unit is a part of a box-shaped casing of the sheet accommodating unit.

6. An image forming apparatus including an image forming unit configured to form an image on a sheet fed from a sheet feeding device, the image forming apparatus comprising:

a sheet accommodating unit that accommodates sheets, and supported by an apparatus main body in an insertable and withdrawable manner in a direction orthogonal to a feeding direction of the sheets;

a leading edge regulating unit provided fixedly to the sheet accommodating unit, configured to regulate a position downstream of the sheets to be accommodated in the feeding direction thereof;

a trailing edge regulating unit provided in the sheet accommodating unit, configured to regulate a position upstream of the sheets to be accommodated in the feeding direction;

a side edge regulating unit provided in the sheet accommodating unit, configured to regulate a position of the sheets to be accommodated in a direction orthogonal to the feeding direction thereof;

a locking mechanism to lock the sheet accommodating unit in a locking position in the apparatus main body including a spring which push out the sheet accommodating unit, a hook portion and protrusion portion which is engaged with the hook portion to lock the sheet accommodating unit in the apparatus main body against an elastic force of the spring;

an insertion position limiting unit provided on a rear of the sheet accommodating unit in an inserting direction of the sheet accommodating unit and upstream from a center of gravity of the sheet accommodating unit in the sheet feeding direction, configured to be able to contact a frame on a rear of the apparatus main body in an inserting direction of the sheet accommodating unit to limit an insertion position of the sheet accommodating unit; and

an auxiliary insertion position limiting unit provided on the rear of the sheet accommodating unit in the inserting direction and downstream from the center of gravity of the sheet accommodating unit in the sheet feeding direction configured to be able to contact the frame on the rear of the apparatus main body in the inserting direction to limit the insertion position of the sheet accommodating unit and a leading edge portion of the auxiliary insertion position limiting unit in the inserting direction of the sheet accommodating unit is positioned upstream from a leading edge portion of the insertion position limiting unit in the inserting direction,

wherein after the insertion position of the sheet accommodating unit is limited by the insertion position limiting unit while insertion of the sheet accommodating unit, the sheet accommodating unit is moved to the locking position by the elastic force of the spring,

wherein, in response to the sheet accommodating unit being inserted with an excessive force, the sheet accommodating unit rotates slightly about the insertion position limiting unit, thus preventing damage to the side edge regulating unit and/or the trailing edge regulating unit.