Sheet conveyance apparatus and image forming apparatus

A sheet conveyance apparatus comprising:

• a first conveyance unit configured to convey a sheet in a first conveyance direction and a second conveyance direction opposite to the first conveyance direction, the first conveyance unit being configured to convey the sheet in the second conveyance direction after conveying the sheet in the first conveyance direction;
• a second conveyance unit configured to convey the sheet in the second conveyance direction;
• a drive source configured to drive the first conveyance unit;
• and
• a drive transmission unit configured to enter a first transmission state of transmitting drive force of the drive source in such a manner that the first conveyance unit conveys the sheet in the first conveyance direction, a second transmission state of transmitting the drive force in such a manner that the first conveyance unit conveys the sheet in the second conveyance direction, and a non-transmission state in which the drive force is not transmitted to the first conveyance unit,
• wherein, when the first conveyance unit conveys the sheet in the second conveyance direction and the second conveyance unit does not convey the sheet, the drive transmission unit enters the second transmission state in such a manner that the first conveyance unit conveys the sheet at a first conveyance speed with the drive force,
• wherein the second conveyance unit conveys the sheet at a second conveyance speed higher than the first conveyance speed, and
• wherein, from a contact state in which the sheet conveyed in the second conveyance direction is in contact with both the first conveyance unit and the second conveyance unit is caused until the contact state is released, the drive transmission unit is kept in the non-transmission state in such a manner that the first conveyance unit is allowed to be rotated by the sheet conveyed at the second conveyance speed.