A manual lever drive for an adjusting device on a seat for converting a lifting movement into a discontinuous rotational movement has a support arm and a step-by step mechanism having an output member and an input member. The output member is configured to be coupled with a rotatingly moveable control member of the adjusting device. A transmission member is connected to the input member for torque transmission onto the input member. A manual lever is connected to the support arm so as to pivot about a first axis of rotation. The manual lever is configured to actuate the transmission member. The transmission member is arranged on the input member providing a second axis of rotation. A pivot angle of the manual lever imparts to the transmission member a pivot movement increasing a corresponding pivot angle of the second axis of rotation.