Friction transport device and paper sheet transport device

Abstract

A friction transport device includes a drive-side unit that transmits a transport driving force to one surface of a paper sheet transported along a transport path; a drive motor that supplies a driving force to the drive-side unit; a driven roller that is arranged to oppose the drive-side unit and that followingly rotates in contact with the other surface of the paper sheet; and a transport grip adjustment mechanism. The drive-side unit includes a drive roller that rotates on a shaft part orthogonal to a normal paper sheet transport direction, a rocking arm that includes the shaft part at one portion thereof and that has another portion thereof pivotally supported by a rocking shaft so as to change a transport grip by rocking the drive roller to change a distance from the driven roller, and an elastic biasing member that elastically biases the drive roller toward the driven roller via the rocking arm. The transport grip adjustment mechanism is configured to cause the drive roller to retreat in a direction away from the driven roller against a biasing force from the elastic biasing member to decrease the transport grip when transport load applied to the drive roller from the paper sheet transported on the transport path by the drive roller forwardly rotating changes beyond a predetermined value.