Overlapped transfer-preventing mechanism

An overlapped transfer-preventing mechanism provided in an image-forming apparatus, in which a paper-carrying plate with the papers carried thereon is moved between an upper paper-supplying position and a lower non-paper-supplying position, comprising an upper rotably driven separating roll and a lower separating roll offset from said upper separating roll and supported so that an interval between both separating rolls may be regulated by the up or down position of the lower separating roll, a pivot integrated with the lower separating roll being provided with a gear, a ratchet movable up and down engaging said gear, and a cam mounted on a pivot integrated with a raising member which is adopted to raise said paper-carrying plate up to said upper paper-supplying position during a raising operation of said raising member, the cam being interlocked with said ratchet through an interlocking member to rotate the lower separating roll in the direction opposite to a paper-supplying direction by the raising operation of said raising member regardless of the up and down position of the lower separating roll.