Sheet storage apparatus and image forming apparatus

A sheet storage apparatus comprising:

• a storage apparatus body;
• a sheet stacking portion, on which a sheet is stacked, configured to be movable upward and downward with respect to a bottom portion of the storage apparatus body;
• a side end regulation member supported movably on the bottom portion in a width direction orthogonal to a sheet feed direction, and abutting against an end portion in the width direction orthogonal to a sheet feed direction of the sheet stacked on the sheet stacking portion;
• a rear end regulation member supported movably on the bottom portion in a sheet feed direction and a direction opposite to the sheet feed direction, and comprising a main regulating surface abutting against an upstream end in the sheet feed direction of the sheet stacked on the sheet stacking portion;
• and
• a rear end regulation attachment detachably attached to the rear end regulation member and comprising a subsidiary regulating surface, the subsidiary regulating surface arranged downstream, in the sheet feed direction, of the main regulating surface and configured to regulate the upstream end of the sheet,
• wherein the sheet stacking portion has a side end cutout portion for allowing movement of the side end regulation member and a rear end cutout portion for allowing movement of the rear end regulation member, and
• wherein the rear end regulation attachment is attached to the rear end regulation member in a condition in which the rear end regulation attachment slidably contacts with the bottom portion of the storage apparatus body through the side end cutout portion.

A sheet storage apparatus comprising:

• a storage apparatus body;
• a sheet stacking portion, on which a sheet is stacked, configured to be movable upward and downward with respect to a bottom portion of the storage apparatus body;
• a rear end regulation member supported movably on the bottom portion in a sheet feed direction and a direction opposite to the sheet feed direction, the rear end regulation member being configured to regulate a position of an upstream end, in the sheet feed direction, of the sheet stacked on the sheet stacking portion;
• a side end regulation member supported movably on the bottom portion in a width direction orthogonal to a sheet feed direction, the side end regulation member being configured to regulate an end position in the width direction orthogonal to a sheet feed direction of the sheet stacked on the sheet stacking portion;
• and
• a rear end regulation attachment detachably attached to the rear end regulation member and comprising a regulating portion configured to regulate the upstream end of the sheet on a position downstream, in the sheet feed direction, of a regulating position of the rear end regulation member in a state where the rear end regulation attachment is attached to the rear end regulation member,
• wherein, when viewed from above, in a state where the rear end regulation member with the rear end regulation attachment on is positioned at the most downstream position in the sheet feed direction, the regulating portion of the rear end regulation attachment is located at a position overlapping a space in which the side end regulation member is movable in the width direction orthogonal to a sheet feed direction in a state where the rear end regulation attachment is detached from the rear end regulation member.