A mechanical latching unit for a main drive unit includes a rolling mechanical switch within a housing, with a main roller, a counter roller, a carriage and a carriage trip/locking lever, with a first joint created between the main roller and the first end of the carriage, where by the load of the traction link of the main drive unit carried out to the main roller distributes a primary force component carried out to the counter roller and a secondary force component carried out in a direction to a second end of the carriage, where by the mechanical latching unit includes a force reduction mechanism having at least two force reduction stages, a carrier reset spring fastened to the housing which resets the carriage back to a neutral respectively blocking position, and a lever reset spring which resets the carriage trip/locking lever back to a neutral respectively blocking position.