Sheet cutting apparatus, sheet finisher provided therewith and image forming system equipped therewith

A sheet cutting apparatus comprising:

• (a) a cutting blade having a cutting edge structured to cut an edge of a sheet bundle conveyed to a cutting position of the sheet bundle;
• (b) a cutting blade moving section structured to move obliquely the cutting blade with respect to a sheet surface of the sheet bundle;
• (c) a fixed supporting table structured to support the sheet bundle in a vicinity of the cutting position;
• (d) a blade receiving member having a flat surface structured to press an upstream side of the sheet bundle with respect to the cutting position in a conveying direction of the sheet bundle to the cutting position between the fixed supporting table and the blade receiving member, the blade receiving member receives and contacts the cutting edge of the cutting blade in the vicinity of the cutting position, the flat surface of the blade receiving member which comes in contact with the sheet bundle being integrally formed and made of a same material, and the blade receiving member structured to be slidable in the conveying direction of the sheet bundle so that a receiving position of the blade receiving member to receive the cutting blade can be changed and a center position of a load application action of the blade receiving member is kept constant when the blade receiving member is slid, wherein the cutting blade cuts a downstream side of the sheet bundle with respect to the cutting position;
• and
• (e) a blade receiving member moving section provided with the blade receiving member structured to lower the blade receiving member so as to press the sheet bundle between the fixed supporting table and the blade receiving member when the cutting blade moves upward and cuts the edge of the sheet bundle, and raises the blade receiving member so as to be separated from the fixed supporting table when the cutting blade moves downward,
• wherein the center position of the load application action of the blade receiving member by the blade receiving member moving section, is set to the upstream side of the cutting position in the conveying direction of the sheet bundle, and in the vicinity of the sheet cutting position.