Patent attributes
A drive mechanism has an engaging member that abuts on a first engageable part and moves to a first axial center direction position and an engaging member that abuts on a second engageable part and moves to the first axial center direction position, when a first unit is mounted on a second unit. When an operating member is located at a second position, in a case where the right and left engaging members are moved to the first axial center direction positions, the operating member is moved from the second position to the first position. In a case where at least one of the right and left engaging members is not moved to the first axial center direction position, the operating member is not moved from the second position to the first position.
