BETAETIGUNGSVORRICHTUNG ZUR FERNBETAETIGUNG DER LAGEREGELUNG EINES HYDRAULISCHEN KRAFTHEBERS

An actuating device for the mechanical remote influencing of a control means, especially a valve, for the position regulation of the hydraulic power lift (14) of a motor vehicle, for example an agricultural tractor (10), contains a rotatably mounted manual actuator (34) connected fixedly in terms of rotation to a driving gearwheel (36). The rotational movement of the manual actuator (36) can be converted into a longitudinal movement of a displaceably guided rack (42) connected to the valve by means of a transmission mechanism (44). In order to limit the stroke for each actuation of the manual actuator (34) and achieve an improved response behaviour, a reduction gear is inserted between the driving gearwheel (36) and rack (42). The reduction ratio of the reduction gear can assume a value of between 1:3 and 1:7. The reduction gear can be designed as a spur gear, in which a transmission gearwheel (38, 80) is interposed between a driving gearwheel (36), connected fixedly in terms of rotation to the manual actuator (34), and the rack (42). The reduction gear can also be designed as a planetary gear, in which the driving gearwheel (36) connected fixedly in terms of rotation to the manual actuator (34) is the sun wheel which drives at least one intermediate gearwheel (90, 92) mounted rotatably on the housing (32) of the actuating device and engaging into the internal toothing of a planet gearwheel (94), and the planet gearwheel (94) is in engagement with the rack (42) by means of an external toothing.