Assist mechanism and image forming apparatus

An assist mechanism for aiding movement of a retractable unit, reciprocally moving between an open and a closed position, of a device body, comprising:

• a pressing device configured to press the retractable unit toward the open position in which the retractable unit is extended;
• a stopper mechanism configured to control and release retraction of the retractable unit to the closed position in which the retractable unit is retracted, the stopper mechanism including a stopper and a blocking member configured to contact the stopper;
• an engagement member provided in the retractable unit;
• a catch portion configured to engage the engagement member;
• an assist member configured to assist retraction of the retractable unit to the closed position by a force configured to pull the retractable unit toward the closed position when the retractable unit is set in the device body and the engagement member engages the catch portion;
• a release member configured to release the force pulling the retractable unit when the retractable unit is moved to the closed position;
• a first swingable member pressed to the closed position;
• and
• a second swingable member supported by the first swingable member,
• wherein, the catch portion includes a clearance configured to maintain a separation between the engagement member and a catch surface facing a pulling direction when engaged with the engagement member,
• the assist member is configured to contact the release member, the engagement member is configured to engage the catch portion, and the blocking member is configured to contact the stopper in a state in which the engagement member is spaced from the catch surface, and
• when the retractable unit is moved to the closed position, the release member contacts the second swingable member to cause the second swingable member to swing in a direction opposite to the closed position relative to the first swingable member.