Abstract: A lever operated rotary drive mechanism, the mechanism including a mounting frame carrying a rotary output member adapted for driving engagement with a rotary drive input, such as a shaft, an operating lever pivotally mounted on the mounting frame for pivotal angular displacement relative to the frame, biasing means for biasing the lever to a rest angular position, the lever being movable within a first angular displacement region located on one side of said rest position and movable within a second angular displacement region located on the opposite side of said rest position and a drive transmission which drivingly connects the lever to the output member to cause rotation of the output member in one rotary direction only on displacement of the lever within said first angular displacement region and to cause rotation of the output member in the opposite rotary direction only on displacement of the lever within said second angular displacement region.