Actuating device for parts of motor vehicles movable by electric motors

摘要

A description is given of an actuating device for parts of motor vehicles movable by electric motors, which comprises a desired value transmitter and a digital actual value transmitter with incremental detection of the actual value as well as a microprocessor for the control of the electric motor. The actuating device is characterised in that, additionally to the actual value transmitter delivering incremental counting pulses, an absolute value transmitter is provided which is connected to the incremental actual value transmitter via gearbox elements and, over the whole displacement distance of the part to be moved, emits only one signal or one pair of signals which is assigned to a specific position of the movable part. This position can be, for example, the closed position of a sliding roof or of a window pane. The emission of the absolute signal at a specific position of the parts to be displaced corrects any errors arising in counting the incremental pulses and effects the calibration of the actuating device at each passage of the parts to be moved through the closed position (Fig. 1).